Reza Aghayari

   Nowadays nonlinear analysis methods are employed for the seismic evaluation and strengthening of various structural systems. Detailed investigation of the actual performance of buildings during earthquakes and the development of economically optimized designs clearly demonstrate the necessity of performing nonlinear analyses. In performance-based seismic design, structures are designed to achieve different expected performance levels corresponding to different seismic hazard levels. One of the most important steps in performance-based seismic design is the determination and calculation of the performance point. To evaluate the structural performance, nonlinear analyses can be utilized, which are generally >Accordingly, various approximate methods for determining the structural performance have been proposed in seismic codes and guidelines. Among these methods are the Displacement Coefficient Method, the Capacity Spectrum Method, and the Improved Capacity Spectrum Method (N2 method). The objective of this study is to evaluate the accuracy of these methods in estimating the performance point. For this purpose, several reinforced concrete building frames are modeled, and their performance points are calculated using the aforementioned methods. To assess the accuracy of the results obtained from these methods, nonlinear time history analyses are performed on the same frames. The results of the nonlinear time history analyses are considered as reference (exact) results and are used as a basis for evaluating the level of approximation and accuracy of the Displacement Coefficient Method, the Capacity Spectrum Method, and the Improved Capacity Spectrum (N2) Method.          Keywords: Performance Point, Nonlinear Static Analysis, Capacity Spectrum, N2 Method

   This research is conducted in two main stages. First, the behavior of a prismatic fuse-type damper is investigated and analyzed, and then its effect on the seismic performance of reinforced concrete structural frames under cyclic loading is evaluated. In many structures, especially in regions with high seismic hazard, controlling seismic response through energy dissipation systems such as dampers plays a crucial role. Prismatic fuse-type dampers, due to their high energy dissipation capacity and adequate deformability, are considered an effective solution for reducing the seismic vulnerability of structures. In this study, which is based on the use of two numerical analysis software packages, the damper is first modeled independently in Abaqus, and its load–displacement relationship is obtained. Subsequently, structural frames are modeled in SAP2000, and the damper behavior is introduced into the frame models in the form of a link element. The research methodology includes nonlinear numerical analysis of both the damper and the structural frames, which are performed separately using the aforementioned software. Finally, the performance of the frames equipped with dampers is investigated under cyclic loading to evaluate the effect of the damper on structural displacements and stiffness. The results of this study are expected to contribute to the improvement of design approaches for structures equipped with fuse-type dampers and to assist in selecting optimal materials for structural frames.

   Beams made of steel and concrete are called composite beams. steel beams have advantages and limitations. Some limitations of iron can be overcome with concrete, And such a thing has been done in the composite beam. The composite beam uses concrete to provide strength, proper mass, corrosion, and fire resistance and uses steel to provide ductility and tensile strength. Therefore, the importance of this research is to know more about the effective parameters in the bending behavior of prefabricated composite beams. On the other hand, considering that, for economic and technical reasons, the use of composite elements such as composite beams in prefabricated structures is expanding day by day, the need to know the bending behavior of prefabricated concrete-steel composite beams is felt more and more. Therefore, the main goal of this research is to numerically investigate the bending behavior of prefabricated concrete-steel composite beams. For this purpose, after validating the numerical modeling, the effect of various parameters on the bending behavior of prefabricated concrete-steel composite beams has been investigated.

Derivation of Trilinear Spring Models for Typical Regular and Irregular Multi-Story Reinforced Concrete Structures

In the seismic design of steel structures, the use of efficient lateral load-bearing systems capable of dissipating energy and controlling displacements is of great importance. Steel shear walls are widely used, but the main challenge with thin plates is the phenomenon of out-of-plane buckling, which can occur before full yielding and reduce the system's load-bearing capacity. This research aims to evaluate the potential of using aluminum shear walls as a ductile alternative by numerically and parametrically investigating the seismic performance of steel frames strengthened with this system. The present study was conducted using the Finite Element Method in ABAQUS software. To ensure the accuracy of the modeling, a numerical model was first developed and validated against the results of a reputable experimental study on a steel shear wall, achieving a suitable agreement between the force-displacement curves. In the main phase of the research, a comprehensive parametric study was performed on a single-story, single-bay steel frame strengthened with an aluminum shear wall. The primary variables included the aluminum panel thickness (at three levels: 1, 2, and 3 mm) and the ratio of the wall width to the bay span (at ten levels from 0.1 to 1.0), forming a total of 30 models. All models were analyzed under quasi-static cyclic loading, and indicators such as strength, stiffness, and energy absorption were extracted. Finally, the effect of adding a cross-shaped stiffener to one of the models was also evaluated. The results showed that adding an aluminum shear wall significantly improves the seismic performance of the frame. In the optimal case (F-1-3), the ultimate strength increased by 2.41 times, the initial stiffness by 12.42 times, and the energy absorption capacity by 5.81 times compared to the bare frame. It was found that increasing both the thickness and width of the wall directly leads to the enhancement of all performance indicators and, by controlling buckling, shifts the structural behavior towards the formation of a uniform and stable diagonal tension field. Furthermore, the addition of a stiffener, with a 42% increase in ultimate strength, proved its effectiveness as a viable strategy for optimization and further increasing the system's load-bearing capacity.   

در اين تحقيق رفتار لرزه‌اي ساختمان بتني با تعداد طبقات مختلف با 3 سيستم باربر قاب خمشي بتني بدون ميراگر، قاب با مهاربند شورون و قاب با ميراگر   TADASمورد بررسي قرار گرفت. سازه‌هاي 5، 8، 12 و 15 طبقه مدل‌سازي و تحليل شد. مقادير برش پايه و جابه‌جايي نسبي در فاز خطي و جابه‌جايي نسبي در فاز غيرخطي بدست آمد. سپس ضريب بزرگنمايي ديناميكي محاسبه شد.   نتايج نشان داد كه براي سازه‌هاي با سيستم باربر قاب خمشي بدون ميراگر مقدار ضريب بزرگنمايي Cd   در سازه 5 طبقه برابر 9.157 در سازه 8 طبقه برابر 18.029 در سازه 12 طبقه برابر 26.522 و در سازه 15 طبقه برابر 48.606 بدست آمد. براي سازه‌هاي با سيستم باربر مهاربند شورون مقدار ضريب بزرگنمايي Cd   در سازه 5 طبقه برابر 9.35 در سازه 8 طبقه برابر 22.65 در سازه 12 طبقه برابر 21.34 و در سازه 15 طبقه برابر 57.582 بدست آمد.   براي سازه‌هاي با سيستم باربر   ميراگر مقدار ضريب بزرگنمايي Cd   در سازه 5 طبقه برابر 10.176 در سازه 8 طبقه برابر 21.96 در سازه 12 طبقه برابر 22.90 و در سازه 15 طبقه برابر 54.510 بدست آمد. براي سازه با ميراگر حداكثر ضريب بزرگنمايي ديناميكي در سازه 15 طبقه و برابر 54.510 بدست آمد. در مقايسه ضريب بزرگنمايي ديناميكي Cd براي سازه‌هاي با سيستم باربر مختلف و تعداد طبقات 15 طبقه نتايج نشان مي‌دهد كه براي قاب خمشي برابر 48.606 براي مهاربند برابر 57.582 و براي ميراگر برابر 54.510 بدست آمد.   در مقايسه ضريب بزرگنمايي ديناميكي Cd براي سازه‌هاي با سيستم باربر مختلف و تعداد طبقات 12 طبقه نتايج نشان مي‌دهد كه براي قاب خمشي برابر 26.522 براي مهاربند برابر 21.34 و براي ميراگر برابر 22.90 بدست آمد. در مقايسه ضريب بزرگنمايي ديناميكي Cd براي سازه‌هاي با سيستم باربر مختلف و تعداد طبقات 8 طبقه نتايج نشان مي‌دهد كه براي قاب خمشي برابر 18.029 براي مهاربند برابر 22.65و براي ميراگر برابر 21.96 بدست آمد.   به‌عنوان نتيجه گيري كلي مقدار ضريب بزرگنمايي ديناميكي Cd با توجه به نوع سيستم باربر و طبقات متغير است. براي سازه با ميراگر در تعداد طبقات 5 طبقه اين ضريب از قاب خمشي و مهاربند بيشتر بدست آمد. براي سازه‌هاي 8 طبقه ضريب بزرگنمايي ديناميكي در سيستم باربر مهاربند بيشترين مقدار بدست آمد. براي سازه‌هاي 12 طبقه ضريب Cd براي سازه با سيستم باربر قاب خمشي بيشترين مقدار بدست آمد. براي سازه 15 طبقه ضريب Cd براي سيستم باربر مهاربند بيشترين مقدار بدست آمد. كليد واژگان: ضريب بزرگنمايي ديناميكي، قاب‌هاي خمشي، مهاربند شورون، ميراگر TADAS   

  Humans use lateral bracing systems in structures to deal with the lateral force that is applied to structures through earthquakes. In metal structures, braces are used to deal with this force, which behave in tension and compression. Brace systems are classified into different types, such as divergent and convergent brace frames and knee element braces. Convergent brace systems are more rigid than reduced section frames and bending frames, but less ductile. In order to increase the ductility of frames, the divergent brace system was invented by Mr. Popov in 1987. In this system, a member that was located as a connecting beam along the main beam element of the frame was responsible for energy dissipation. After the earthquake, if the beam element was continuous, the entire element would have to be replaced. However, if the connecting beam was guided and flanged to the main beam, it would be repairable and replaceable. In this case, the roof of the floor would have to be destroyed. After this, researchers searched for a system through research and laboratory studies. In 1986, a system called the Knee Brace Frame (KBF) was developed by Mr. Ochoa, which eliminated the shortcomings of previous systems. This system has reduced the cross-section and the bending frame has more stiffness and energy dissipation compared to divergent systems. In this study, the hysteresis curve of the knee brace frame (KBF) was first extracted through finite element software (ABACUS) and compared with the experimental model for verification. Then, by doubling the column length and considering it for the beam length, this rectangular sample was examined and analyzed in three models in ABACUS. In the KBF1 model, the beam length is 5.6 meters and the column height is 2.8 meters. The knee brace length is 0.55 meters. The diagonal brace X is passed through the beam and column X at the connection node, and the diagonal brace is perpendicular to the knee brace, but the knee brace length is not divided into two equal parts. In the KBF model, the beam length 5.6 meters and the column height is 2.85 meters, the length of the knee brace is 0.55 meters. And the diagonal brace is again perpendicular to the knee brace, but the X of the brace does not pass through the X of the beam and column at the connection node and divides the knee brace into two equal parts. Continuing in the KBF3 model, where the beam length is 5.6 meters and the column height is 2.85 meters, the length of the knee brace is 0.55 meters, the X of the diagonal brace passes through the X of the beam and column at the connection node and the diagonal brace is not perpendicular to the knee element, but the length of the knee brace is divided into two equal parts. Continuing in the form of a square model, which considers the height of the beam and column as 2.8 meters and the length of the knee brace as 0.22 meters, and the X of the diagonal brace passes through the X of the beam and column connection node and the diagonal brace is perpendicular to the knee element and divides the length of the knee element into two equal parts, but makes the length of the knee element much shorter, as much as twice the length. The knee element length in KBF1 mode is considered to be 22 cm, which means that the square model shows better stiffness, energy dissipation, and lateral load-bearing capacity than the other models. In this study, the behavior of steel materials and welds is controlled by failure criteria in different parts of the connection and the failure mechanism.

Concrete, as the most widely used construction material, is constantly exposed to aggressive environmental factors that reduce its durability and mechanical performance. Among these factors, sulfate attack and calcium leaching are considered the most critical deterioration mechanisms, simultaneously inducing chemical and mechanical weaknesses in concrete. This research was conducted to evaluate the mechanical behavior and durability of concrete under the combined effect of magnesium sulfate and ammonium nitrate solutions. For this purpose, standard concrete specimens were exposed to the aggressive environment for two durations (0 and 30 days) and subsequently assessed through mechanical, physical, and microstructural tests. The mechanical tests revealed that compressive strength decreased by 37.7%, from 28.95 MPa to 18.04 MPa, within 30 days. Moreover, tensile strength and fracture parameters, including fracture energy and fracture toughness, exhibited significant reductions in both notch geometries (0.1 and 0.5), indicating increased brittleness of the cementitious matrix. Physical tests further showed longitudinal and volumetric expansions caused by the formation of expansive phases such as ettringite and gypsum, which accelerated deterioration through microcracking. In contrast, weight change was minimal, suggesting that the dominant processes were related to structural and chemical alterations rather than mass gain. Microstructural analyses using SEM and EDS confirmed a notable reduction in calcium content and a decline in the Ca/Si ratio in 30-day specimens. These findings indicated the weakening of the C–S–H phase and increased porosity, which were directly correlated with strength loss and higher brittleness. Overall, the results demonstrate that the combined sulfate–nitrate environment can cause severe deterioration of the mechanical properties and durability of concrete even within a short exposure period of one month. From a practical perspective, these outcomes highlight the necessity of employing low-permeability mix designs, pozzolanic materials, and protective coatings in similar structures. Furthermore, the experimental data can serve as a basis for developing standards and design strategies aimed at extending the service life and reducing the maintenance costs of concrete structures.

  dar jameh kononi ranandegi baraye kar, zandegi ejtemaei, tafarih, tahsil, faalitenpehei egtesadi ve sayer jonbacpanteoja manpam est. ema tasadef vasail naghliyeh motori yeki az moteghirehaye mokharb, maloolit ve morg mohsub mi shod. bar asas motaleat enjam shodeh, chehar amel esli mosar dar vaghu havades ranandegi vojud dard keh shamel moteghirehaye ensani, jadeh, vasileh naghliyeh ve mohit mi bashod. tahlil tasadef jadegyi dar iran neshan midehad keh moteomtarin amel dar vaghu tasadefat ranandegi dar iran, amel ensani est. benabrain, yeki az moteghirehaye ravaneshenakhti mw?sar dar khatrat ranandegi, masoulitpaziri ranandegan est. npamchenin nezameh bavarehya ra mitavan yeki az moteghirehaye moteomi danst keh ertabat mosteghimi ba no raftar ranandegi dard. benabrain, tamrakz in pajoosh bar farayand masoulit paziri bar asas nezam etegadi dar bin ranandegan est. zira zehor khatrat ranandegi bah delil afzayesh raftarehaye ghiraadi ro bah afzayesh est. motaleh hazar bah rosh tosifi npambastegi bud. azmodninpehei pajoosh 3?0? nafar az ranandegan shehar ravansar bodand keh ba rosh nemonehgiri dar dasteres entekhab shodand. shiveh tajziyeh vatahlil dadegeya dar do bakhsh tosif dadegeya ve estanbat dadegeya bud. netaij neshan dad masoulitpaziri ve nezam bavarehya bar kanpash tasadefat ranandegi mosar est. dar tabiyn netaij bah dast amodeh bayad goft keh sistam masoulit paziri ve bavar naqsh mahvari dar kanpash tasadefat jadegyi dard. ba dark tasir in avamel mitavan esteratzhinpehei mw?sari baraye ertaghaye imni jadegeya ijad kard.

Seismic isolation is one of the most effective technologies available in reducing the seismic response of many structures. Elastomeric isolators reinforced with steel plates are considered one of the conventional types of seismic isolators that have good isolation performance in large and heavy structures. The use of these isolators in lightweight structures lacks technical justification due to the inability to achieve appropriate isolation periods. The aim of the present study is to investigate the behavior of a new type of elastomeric isolators with effective application in lightweight structures. The isolators under study are fiber-reinforced elastomeric isolators with a circular cross-section with holes that are used as supports. Due to the elimination of the end steel plates and the smaller volume of materials used in the construction of the isolator, the total cost is reduced. The presence of a central hole in the isolator leads to a decrease in the effective horizontal stiffness of the isolator and, as a result, an increase in its seismic isolation efficiency. So that these isolators, which have both high technical potential and low economic cost, can be used to isolate light structures and heavy industrial equipment. In this study, using the finite element software Abaqus, these types of isolators have been designed and analyzed with the aim of isolating light structures for effective vertical forces of 150, 250 and 350 kN. Under each of the mentioned vertical loads, three different types of isolators with the same external diameters and different internal diameters have been designed. The internal diameter (hollow diameter) is considered as a variable and the force-displacement curves of the isolators in the vertical and lateral directions have been determined by finite element analysis and the reduction in their vertical and horizontal stiffnesses compared to the corresponding solid circular isolator has been obtained. In the following, two analytical equations for calculating the vertical and horizontal stiffnesses of circular isolators with holes, considering their supporting boundary conditions, have been obtained through regression with an error of less than 10%. These relationships can be used for the initial design of supported circular hollow fiber reinforced elastomeric isolators.   

Earthquakes are one of the damaging factors that threaten the stability of technical buildings and vital arteries in many parts of the country. Therefore, seismic improvement of structures and technical equipment in vital arteries is necessary for the sustainable development of the country. Ground-mounted power transformers located in power distribution substations in urban areas are an example of technical equipment vulnerable to earthquakes. Due to the significant mass of these equipment, a significant inertial force is exerted on them during an earthquake, which can cause the equipment to slip or overturn and disrupt its performance by causing damage. One of these effective methods of seismic improvement of the described equipment is to reduce the accelerations affecting them during an earthquake using seismic isolation technology. The purpose of the present study is to study the feasibility of isolating heavy technical equipment with limited dimensions using only one elastomeric isolator reinforced with supporting ring fibers. To achieve the research objectives, ring isolators with different dimensions were designed for a selected transformer weighing 5000kg using the finite element software Abaqus. The outer and inner diameters of the isolator were changed as design variable parameters to study their effect on the lateral behavior of the isolators. In the present study, the range of changes in the outer diameter was from 1000mm to 2000mm and the range of the ratio of the inner diameter to the outer diameter in the studied isolators was 0.7 and 0.9. The results of numerical analyses show that with increasing the inner diameter of the isolator, the effective lateral stiffness and its lateral displacement capacity decrease. The achievable separation period in the isolated transformer can be increased by 1.5s and the maximum ground acceleration effective on the equipment can be reduced by 45%. Another part of this research is to develop analytical relations to estimate the vertical and lateral stiffnesses of ring isolators. The analytical relations presented in this study can be used in the initial design of the isolators. The results of this feasibility study show that fiber-reinforced elastomeric ring isolators have good potential for application in seismic isolation of technical equipment. However, for the practical application of these isolators in technical equipment, it is necessary to conduct laboratory studies and investigate the effect of various parameters on their behavior.   

   Abstract The use of supplemental dampers is considered one of the innovative methods for seismic retrofitting of structures. Among the various types of dampers, buckling-restrained braces (BRBs) are more commonly utilized across the country. This study investigates the impact of BRBs installed on scissor-like bases on the structural performance of a three-story frame. The primary objective is to evaluate the influence of design parameters such as the length and installation angle of the BRBs on controlling structural vibrations. The studied frame, used in the SAC project and well-documented in the literature, serves as the basis for this research. Nonlinear time history analyses are employed to assess the seismic behavior of the structure, including base shear, column moments, maximum roof displacements, and energy curves, both with and without BRBs. The study aims to evaluate the effectiveness of different BRB configurations in reducing seismic responses. The structural modeling and BRB integration were conducted using the SAP2000 software. Force-displacement hysteresis curves of the BRBs were also extracted and analyzed to identify the optimal length and installation angle. The BRBs used in this research, referred to as Chevron Base BRB 3, feature two dampers installed on scissor-like bases resembling a figure-eight configuration. The optimal installation angle for Chevron-based BRBs was found to be 45 degrees, while the ideal BRB length was determined to be 2.5 meters. The findings of this study are specific to the analyzed frame and may not necessarily be generalized to other frames or structural systems. Keywords:

  Humans use lateral restraint systems in structures to deal with the lateral force that enters the structures through earthquakes, and braces are used in metal structures to deal with this force, which behave in a tensile and compressive manner. Braces are classified in different types, such as divergent and convergent bracing frames and knee element bracing systems. Convergent bracing systems have a reduced cross-section compared to frames and the bending frame is more rigid but less malleable, in order to increase malleability. Frames In 1987, the diverging brace system was invented by Mr. Popov. In this system, the member that was located as a connecting beam along the length of the main beam element of the frame was responsible for energy consumption. After the earthquake, if the beam element was continuous, the entire element should be replaced and replaced. If the connecting beam was guided and installed in the main beam with a flange connection, it could be repaired and replaced, otherwise the roof of the floor would have to be destroyed. In 1986, a system by Mr. Ochoa called the knee brace frame(KBF)which fixed the shortcomings of the previous systems. Compared to the divergent and segmental systems, this system has reduced stiffness and more energy consumption of the bending frame. In this study, first, through the finite element software (Abaqus), the hysteresis curve of the bending frame was calculated. With the knee brace, we extracted and compared it with a laboratory model for validation. In the following, we checked the same bending frame by removing the knee element, and then by increasing the length of the knee element and changing the knee connection from bending to joint, which in the first case, considering The bending frame means the connection of the beam to the welded support column and the support bracket (welded) and the increase in the length of the knee element, the stiffness and the energy consumption and the lateral load are increased. In the following, all these models are changed from the connection of the beam to the support column in the previous state to a joint (welded joint). We have changed and considered the bracing to be of the welded type, which reduces the hardness, energy consumption, and side load a little, which in the following is in a similar model, such as the verification sample of the connection of the beam to the hinged column (welded) and considering the brace to be of the hinged type (pin) Considering that the hardness and energy consumption have decreased, but the resistance limit has slightly decreased with s Shear and bending mode in the link beam is dealt with in EBF frames, and if there is an architectural need and creating an opening in the frames, KBMF frame can be used with the failure of the link beam shear mode because it has Translated from Persian to English - www.onlinedoctranslator.com better stiffness and energy consumption. In this study, the behavior of steel and welding materials has been controlled by failure criteria in different parts of the connection and rupture mechanism

  يكي از سيستم هاي

  سيستم مهاربندي كمانش تاب با استفاده قابليت استهلاك

connections experienced brittle failure. Therefore, in order to prevent the brittlefailure of connections and to protect the main structural members from damagedue to seismic forces, slotted steel dampers were used at the beam-to-columnjunction. The analyzes carried out in the finite element software showed that in thecase of using slotted dampers with a conventional slot shape, the stressconcentration is only created at the end points of the strips and the middle parts donot play a role in energy consumption. In order to solve this problem, in this study,semi-elliptical gaps were used in the slotted damper. Then, the influence of thewidth of the damper strips on the seismic performance of beam-to-columnconnections was investigated. The results of the analysis showed that the use ofthe proposed slotted damper improves the seismic performance of the connection.Also, by reducing the distance between the slits, the participation rate of the middleparts of the slitted damper strips in energy absorption increases. In the next step,the effect of the distribution of the height of the slits on the behavior of the slotteddamper in beam-to-column connections was investigated. The results ofexamination of the samples in the finite element software showed that thedistribution of the height of the slits in the slotted damper with the shape of a halfelliptical slit with a slope of 2 degrees in such a way that the lowest slit height isin the corner and the highest slit height is in the middle, has the highest energyabsorption and ultimate resistance.Key words: earthquake, slit damper, semi-elliptical slot, strip width, slit heightdistribution   

Abstract: The present research presents the loading protocol for the conventional bending frame steel structure under the accelerometers of the Sarpol-e-zahab earthquake, Kermanshah. The impact of various loading protocols in the ATC-24, SAC, and Fang regulations and their comparison with the 1396 earthquake accelerometer of Sarpol-e-zahab, Kermanshah province, by applying it to steel bending frame structures has been investigated to provide a loading protocol. In this research, numerical modeling is used. The moment-resistance frame was designed according to Iranian codes, and then it was analyzed under the Sarpol-e-zahab earthquake record using the dynamic method. Then, the cyclic loading protocols were applied. The results from applying the earthquake record and the cyclic protocol will be compared, and the accuracy of the proposed protocol will be evaluated. In this research, low-rise (3-story), medium-rise (7-story), and high-rise (12-story) residential structures located in Sarpol-e-zahab city with II soil type are considered. By comparing the results of nonlinear analysis, it has been observed that using the SAC loading protocol gives the best result in low-rise structures. The ATC-24 loading protocol has obtained a more suitable result in the medium-rise structures. The slightest difference was related to the ATC-24 loading protocol. In the investigated 3-story structure, it was observed that under the ATC 24 loading protocol, there is a 20% difference in the results compared to the results of the Sarpol-e-zahab earthquake record. It can also be seen that under the Fang loading protocol, there is a 27% difference in the results compared to the results of the Sarpol-e-zahab earthquake record. In the 7-story structure, it was observed that under the ATC-24 loading protocol, there is an 8% difference compared to the results of the Sarpol-e-zahab earthquake record. It can also be seen that under the Fang loading protocol, there is a 15% difference in the results compared to the results of the Sarpol-e-zahab earthquake record. In the 12-story structure under the the ATC-24 loading protocol, there is a 22% difference in the results compared to the results of nonlinear time history analysis under the effect of the Sarpol-e-zahab earthquake record. It can be seen that under the Fang loading protocol, there is a 25% difference in the results compared to the results of the Sarpol-e-zahab earthquake record. As a general conclusion, as the height and number of stories in the frame increase, the accuracy of the results of using the proposed protocols will decrease compared to the natural earthquake record.   

   One of the relatively accurate methods for determining the seismic response of structures is the use of inelastic dynamic time history analysis. Due to the time-consuming nature of this type of analysis, the large amount of calculations and the need for seismic engineering knowledge, the inelastic static analysis method (Pushover) has been the focus of civil engineers. In general, this analysis method can be >In this thesis, in order to examine the rules of regulations in the discussion of higher modes, three buildings with a special RC-Moment resisting frame system and with the number of floors from 15 to 21, which have an irregular plan, were selected and modeled for analysis and design in the environment of the ETABS program. Linear static and spectral dynamic analyzes were performed on the structures. Then, based on the criteria of Article 9 of the National Regulations of Iran and Iranian Standard 2800, they were designed for the area with high seismic risk and soil type 3. After the design, the structures were inelastically modeled in the SeismoStruct program environment, and inelastic dynamic analysis was performed under three pairs of record’s far from the fault and three pairs of record’s near the fault, which were scaled according to the 2800 standard criteria. Inelastic static analysis (Pushover) was also performed under three lateral load patterns of the first mode, triangular and spectral. The structural displacement responses were extracted and used to check the criteria. By examining and controlling the inter-story drift ratio of structures, it was observed that the first mode lateral load pattern, in estimating the maximum ratio of inter-story displacement of structures, has better accuracy than other lateral load patterns and is closer to the results of inelastic dynamic analysis, although there are differences. This model estimates the need to displacement structures in upper floors more than other models. In the lower floors of structures, the triangular lateral load pattern estimates the need for displacement more than other patterns. Regarding the distribution pattern of inter-story displacement ratio, it seems that the main problem and the biggest difference is in the lower floors of the structures. However, it is concluded that the criteria of standard 2800 are justified in the discussion of pushover analysis and the effect of higher modes, and it is better to use inelastic dynamic analysis if the effect of higher modes dominates the structure.

  ased on the studies and investigations carried out and with the aim of designing and producing an effective and practical structural damper in the consumption of earthquake energy and high ability to protect the structure against damage caused by earthquakes with the ability to install and replace easily and also cost-effectively. From an economic point of view, after examining many mechanisms and presenting various initial ideas, a damper with an energy consuming mechanism based on cyclic bending of cheap steel rods was designed and built. In such a way that these inexpensive rods, after bearing the cyclic load and deformation of the plastic, and after losing their ability to absorb energy due to the deformation of the plastic, can be easily replaced with a new rod. So, our damper will be serviceable again.

The bending frame is one of the favorite lateral load systems of structural designers due to high redundancy. This type of lateral bearing system shows good ductility and energy dissipation. In recent years, progressive damage in various structures has caused irreparable financial and human losses, and the increase in such damage in the structure has led structural engineers to know and deal with such damage. after the 1994 Northridge and 1995 Kobe earthquakes, several studies were conducted on the seismic performance of beam-to-column connections and two general approaches to improve the seismic performance of connections emerged. Strengthening the connection of the beam to the column and weakening the cross section of the beam. By weakening the cross section of the beam, a part of the cross section of the beam near the connection to the column is reduced, and the potential for the formation of a plastic hinge is placed in that place. Weakening the beam cross-section is more economical than strengthening the connection and prevents failures such as weld failure at the beam-to-column connection, which was seen abundantly in the Northridge earthquake. this study ; for improve the performance of steel bending frames with RBS connections after the sudden removal of the column in During progressive failure, A new model has been presented by using a curved steel piece under the title of quarter-circle element. Validation of the laboratory sample has been done in Abaqus 2022 software, and in order to see the effectiveness of the proposed model, we will do parametric studies on the influence of the outer radius, thickness and width of the quarter-circle element. The results of the studies indicate that the proposed model has a positive effect on the strength and ductility of the connection and does not prevent the formation of a plastic hinge in the place of the reduced section of the beam.   

   Abstract In this study, the performance of Solar Chimney   integrated with phase change material and the phase change process of these materials were simulated and analyzed using computational fluid dynamics technique and software   Ansys Fluent software through the two-dimensional geometry. In order to speed up the melting process of the phase change material for a uniform heat flux of 700w/m^2, the inlet and outlet vents of the chimney were closed. The schematic of the system and the dimensions of the geometry were considered similar to reference [26]. Comparison of the results of the present work with the mentioned reference shows that the performed simulations are capable of predicting the performance of solar chimney systems equipped with phase change materials. The results of the simulation showed that by increasing the conductive heat transfer coefficient by 2 and 3 times, the melting time decreases by 9 and 15%, respectively, and by increasing the thickness of the phase change material layer by 1.5 and 2 times, the melting time It becomes 1.62 and 2.3 times respectively. Also, by dividing the thickness of phase changing material layer into two or three equal layers with the same type of material , there was no change in the overall melting time. Finally, by dividing the thickness of the PCM layer into two equal parts and Changing the range of phase change temperature of the nearest layer   to the absorber from (311-316 K) to (307-311 K), the total melting time did not change But the system saves energy in this mode at a faster rate than the single-layer PCM mode.

One of the systems Resistant to side loads, brace is Wind braces or braces are tensile and compressive members that are used for Coping with lateral forces is considered and in metal structures for force transmission. Earthquake is used for construction. Various types of belts Convergent - divergent - and the brace is divided by the knee element. In 1986, a new system called the knee brace frame (KBF) was introduced by Achua, which no longer solves the problem of beam replacement. It did not have the connection like the divergent frame. This system has higher hardness and better plasticity than the divergent frame and the bending frame. showed In this review, first, using the Abaqus curve software We extract the hysteresis from the frame with the knee brace and with the laboratory model We will compare for verification. In the following, the behavior of the KBF frame with different lengths of the knee member will be investigated, which is shown that the short knee member is submitted with shear mode and has more difficulty and the member The long knee is delivered in flexion mode and has less difficulty. short knee joint It consumes more energy than a long knee member, in general, in the knee members, a decrease in the length of the member causes Difficulty increases. Next, we place two other supports in the middle of the knee member, these supports They are not connected to the knee element and there is a small distance. In low to medium member drifts A knee does not hit the surrounding supports, but when the frame moves more, it causes the movement of the member. The knee increases and as a result hits the surrounding supports. Now instead Two supports, four supports cover the knee element, thus preventing that Deformation of the knee member exceeds a value and controls the displacements of the frame And the stiffness of the frame increases, which shows the positive effect of additional supports In the following, we show the increase in stiffness of the KBF frame with the hysteresis curve and compare it with the original sample. To This system is called KBF frame with variable stiffness Finally, to change the free distance of the support We will deal with the knee element and the change during the impact of the support  

   استفاده از مقاطع توخالي در اعضاي باربر سازه، مزيت كاهش وزن مخصوص را دارند؛ كه به سبب وزن كمتر، عملكرد بهتري را در مقابله با زلزله از خود نشان مي­دهند. الياف موادي ايده­آل براي استفاده در بتن و ملات­ها مي­باشند و استفاده از الياف در بتن سبب افزايش مقاومت در برابر آتش، سختي، افزايش مقاومت فشاري، خمشي و كششي و دوام مي­شود.پوشش­هاي FRP سبب افزايش ظرفيت باربري ستونها مي­شوند؛ و در سازه­هاي فرسوده واقع در مناطق لرزه­اي، به منظور بهبود شكل­پذيري و به تعويق انداختن شكست ناگهاني، كاربرد دارند. در اين پايان­نامه به بررسي و مقايسه مقاومت شعاعي و مقاومت در برابر حرارت بالا نمونه­هاي استوانه­اي توخالي بتني پرداخته مي­شود؛ بدين صورت كه نمونه هاي بتني، بتن اليافي و بتن با پوشش FRP به صورت استوانه­اي توخالي جدار نازك ساخته خواهد شد و سپس مقاومت شعاعي و مقاومت در برابر حرارت بالا نمونه ها اندازه­گيري و با يكديگر مقايسه مي­شوند.

   The prevalence of frequent earthquakes throughout the world and the extensive human and financial damage caused by this phenomenon have prompted many researchers to explore ways to reduce this damage. Numerous systems have been employed to mitigate the aforementioned damage, among which seismic isolators can be considered one of the most important. Fiber-reinforced circular isolators represent a novel type of seismic isolator composed of alternating layers of elastomers and fiber fabrics. Utilized in an unbonded (non-connected) application, these isolators were placed above the foundation and below the superstructure, successfully isolating the superstructure from ground motions during an earthquake event. In an unbonded application, shear forces are transferred to the isolator through friction between the isolator’s contact surfaces and its contact supports. When the isolator is subjected to a lateral force, it undergoes a pseudo-rolling deformation, resulting in a nonlinear force-displacement curve. Consequently, the existing analytical relationships for traditional elastomeric isolators cannot be generalized to this type of isolator. In the isolator design process, determining the lateral stiffness under the influence of lateral forces is of particular importance. In the literature, only one analytical relationship has been proposed for this type of isolator, which, according to the investigations conducted in this thesis, does not provide a suitable approximation of the lateral stiffness in many cases. In this dissertation, not only has the existing relationship been modified, but also novel analytical correlations, which have been calibrated utilizing the outcomes of finite element simulations of fiber-reinforced circular isolators for the purpose of generating their lateral force-displacement diagrams. To verify the accuracy of the suggested associations, the force-displacement curves were assessed by comparing them with the hysteresis loops obtained from four experimental laboratory specimens. The equations introduced in this study can effectively approximate the lateral stiffness derived from laboratory experiments on isolators, exhibiting an average accuracy of 20% for shear strains of up to 0.5, and improving to an average accuracy of less than 10% for greater strains. Consequently, these correlations have sufficient precision for utilization in the initial design stages of unconnected fiber-reinforced circular isolators.

  In the real world, shocksfrom low heights to bridges to heavy shocks on protective structures such astrenches , and even the protective structure of nuclear power plants have beenthe focus of many researchers. The impulse loads discussed in the present studyare an important >One of the basicchallenges for structural engineers is the effect of impact load on structuralelements. For this purpose, processing researches were conducted on reinforcedconcrete beams under the effect of impact, but none of them investigated theeffect of various factors such as the type of ECC concrete and the CFRP coatingthat was used for shear strengthening, bending strengthening and shear-bendingstrengthening had not been studied. Therefore, in this research, the main goalof the numerical evaluation of the factors affecting the dynamic performance ofreinforced concrete beams under the effect of impact load has been selected. Toachieve this goal, in the first step, verification has been done, and in thesecond step, the details of the reinforced concrete beam have been determinedbased on valid international regulations. In the third step, 12 numericalmodels are analyzed and then the maximum displacement of the middle of thebeam, permanent deformation, reaction force and their stress distribution arediscussed and investigated.The results of thisresearch show the positive effect of ECC concrete on the behavior of reinforcedconcrete beams. Also, in samples without CFRP coating, comparing the samplewith 100% ECC concrete (Sample E) with the sample with 50% ECC concrete in thetensile part (Sample NE), it can be concluded that the NE sample behavedbetter. Because their maximum displacement was not much different, but sample Eshowed more support reaction force and also permanent shape change and morestress was observed in it.In samples with 50% ECCconcrete, the use of CFRP coating has reduced the permanent displacements ofthe reinforced concrete beam. Also, simultaneous bending and shearstrengthening has had a greater effect in reducing permanent displacements ofnumerical samples.

Connections in precaststructures are of great importance and their design requires great precision totransfer lateral loads such as earthquakes and wind. On the other hand, everyyear, a large number of buildings catch fire and cause a lot of financial andhuman losses. In other words, fire in buildings is one of the serious threatsto the life and financial security of society. Therefore, the necessity ofresearch related to connections in precast structures and the importance ofstudying their behavior after fire is felt more than ever.The resistance ofstructural members against fire is one of the important parameters for having asafe building. Buildings of medium importance and high importance should bestable for at least 90 minutes in fire. Based on this, many researchers havestudied the behavior of beam-to-column connections after fire, but none of themhave investigated the behavior of precast concrete beam-to-column connectionswith metal-yielding dampers under the effect of fire with different diversions.Have not given so, this research is an attempt to fill this scientific gap,that if we have a metal-yielding damper in the connection of the prefabricatedbeam to the column, what is the effect of fire duration on its post-firebehavior?Therefore, in thisresearch, the first goal is to propose a new beam-to-column connection with ametal-yield damper in precast structures, and the second goal is to provide amethod to protect it against fire. The third goal, which is the main goal ofthis research, is to investigate the effect of duration of exposure to fire onits behavior.For this purpose, firstthe new articles were studied and then validation was done in ABAQUS software,and in the next step, several precast beam-to-column connections withmetal-yield dampers were analyzed, and one of them, which had better hysteresisbehavior, was selected to continue this research. In the next step, accordingto past studies, the use of concrete cover was used to protect the connectionin fire conditions. In the next step, after performing the heat transferanalysis, the mechanical analysis was performed. Finally, resistance afterfire, stiffness after fire, heat distribution were discussed in numericalmodels.The results of hysteresisanalysis of beam-to-column connection in pre-fire conditions show that theproposed beam-to-column connection has good seismic behavior. Also, afterthermal analysis and based on TEMP contour, in numerical models with 10 cmthick concrete cover, increasing the duration of the fire from 60 to 120minutes has caused more fire heat to reach the beam-to-column connection, asthe temperature of the coldest connection point of the beam to the column is about237 degrees Celsius in the 60 minute diversion, and in the 120 minutediversion, the temperature of the coldest connection point of the beam to thecolumn is about 394 degrees Celsius.Also, this research showsthat placing the beam-to-column connection exposed to fire with deflection of60, 90, and 120 minutes, on average, reduces the bending moment by 40, 50, and60 percent, respectively, and reduces the bending stiffness, respectively, byThe value is 39, 47 and 65 percent.  

One of the types of steelshear wall is the composite shear wall, which consists of a steel sheet and a layerof reinforced concrete. This type of shear wall is used in high and mediumheight steel structures to improve the performance of the structure and controlvibrations during earthquakes. On the other hand, one of the serious threats insteel pasture structures is fire. Therefore, the necessity of investigating thebehavior after fire in steel structures with shear walls is felt more thanever.After studying theprevious researches, the scientific gaps and scientific challenges wereidentified and based on that, the purpose of the research was determined. Themain goal of this research is to investigate the seismic behavior of thecomposite shear wall with reinforced concrete cover at different temperaturesin the first step and to compare its behavior with the shear wall withoutreinforced concrete cover in the second step. For this purpose, three types ofsteel frame, including steel frame without shear wall (reference specimen),frame with steel shear wall without reinforced concrete cover and frame withsteel shear wall covered with reinforced concrete were studied in the conditionsbefore and after the fire.   Thetemperatures selected in this research are 25, 350, and 700 degrees Celsius,and the numerical models are subjected to cyclic loading, and the seismicbehavior, including the ultimate strength, energy dissipated, is compared andinvestigated. Also, the thermal stress caused by the fire is also evaluated.The results of thisresearch show that at all temperatures, the composite steel shear wall hasbetter seismic behavior than the steel shear wall, so that at 25 degreesCelsius, the ultimate strength of the frame with steel shear wall and the framewith composite shear wall It is 12.8 and 24.6 times of the reference sample(steel frame without steel shear wall), respectively. As a result oftemperature increase from 25 to 700 degrees Celsius, in the frame with steelshear wall, the ultimate strength has decreased from 483 to 11 tons, while inthe frame with composite shear wall it has decreased from 925 to 124 tons.Also, the presence of reinforced concrete cover on the steel sheet at alltemperatures has increased the cumulative dissipated energy. In other words,the presence of reinforced concrete coating on the steel sheet has protectedthe frame with shear wall against fire.  

Cracking in concrete is alimiting factor for the inelastic performance of the structure, so byconfinement the concrete, its strength can be increased. Due to the highcompressive strength of high performance concretes, it is one of the well-knownmethods in increasing the strength of structures that has always beenconsidered by researchers and designers. Due to the need to respond to somedesign issues and the lack of uniform design criteria in the regulations, inthis research, an attempt has been made to test high performance concrete(UHPC) and by incorporating confinement conditions, compressive strength andstress diagrams. The aim of this thesiswas to experimental investigation the compressive behavior of ultra-highperformance concrete confined with FRP. For this purpose in this research, atfirst, reliable sources and new articles have been studied and reviewed. In thenext step, based on reliable sources, the mixing plan for normal concrete andhigh performance concrete (UHPC) is prepared. In the final step, 20 cylindricalsamples with different confinement conditions were subjected to compressiveloading and their stress-strain diagrams were evaluated.The results of thisthesis shown that, the ultimate strength of the third pattern was higher in thesample with NC concrete. Therefore, that in samples N25L1P3 and N50L1P3,respectively, the ultimate strength was 14% and 59% higher than the referencesample (N). While the second pattern has the lowest ultimate strength.5- The ultimate strengthof the third pattern was higher in the sample with UHPC concrete. So that inU25L1P3 and U50L1P3 samples, the ultimate strength was 394% and 433% higher thanthe reference sample (N).Also, increasing thepercentage of confinement in samples has increased the dissipated energy. Thelowest dissipated energy is related to the reference sample (N) and is equal to3.77 Kn.m, and the highest dissipated energy is related to the N100L1 sampleand is equal to 24.88 Kn.M. In addition, among the samples with UHPC concrete,the lowest dissipated energy corresponds to sample U and is equal to 10.28Kn.m, and the highest amount of dissipated energy is related to sample U100L1and is equal to 44.42 Kn.m.  

   با وجود ظهور تكنولوژي هاي نوين ساختماني، نوع و تركيب ديوار همواره محل بحث مشاوران و فعالان صنعت ساختمان مي باشد. مؤلفه هايي مانند مقاومت در برابر فشار باد، تاثير وزن ديوار بر اسكلت و رفتار آن در زمان وقوع زلزله و به تبع آن كاهش تلفات انساني، مقاومت در برابر حريق، ميزان جذب صوت، ميزان عايق حرارتي، سرعت اجرا و... همواره از چالش هاي ساختمان سازي بوده است. در اين تحقيق(آزمايش) هدف اين بود با توليد فايبر سمنت برد به روش پرسي ضمن كوتاه كردن خط توليد و همچنين آسان كردن روش توليد، هزينه توليد را با حفظ مشخصات نسبت به روش   هات چك   به ميزان قابل توجهي كاهش داد همچنين در اين   پژوهش صحت سنجي استفاده از شيشه   و مو به عنوان الياف و جك هاي 30 و 10 تني جهت پرس كردن در توليد صفحات سيماني مورد بررسي قرار گرفت. جهت ساخت نمونه هاي مختلف   فايبرسمنت برد، از سه مصالح ماسه، پودر سنگ و پوكه معدني بصورت جدا همراه با سيمان، آب ، الياف مو و شيشه استفاده شد كه نتيجه كلي بدين صورت بود كه استفاده از مو به عنوان الياف باعث كاهش مقاومت خمشي صفحات سيماني مي شود و الياف شيشه مقاومت خمشي صفحات   سيماني   را افزايش مي دهد. نتايج آزمون   تعيين مقاومت خمشي بر روي آزمونه ها، نشان مي دهد كه صفحات ساخته شده با تركيب سيمان، پوكه معدني رد شده از الك 14 والياف شيشه   ساخته شده با دستگاه پرس 30 تني الزامات استاندارد   EN 12467   را در رده مقاومتي 2 (مقاومت خمشي 8.26 مگا پاسكال در شرايط خشك) و صفحات ساخته شده با سيمان، پودر سنگ رد شده از الك 30 و الياف شيشه ساخته شده با دستگاه پرس 30 تني الزامات استاندارد EN 12467   را در رده مقاومتي 3( مقاومت خمشي 10.3 مگاپاسكال در شرايط خشك ) برآورده مي كنند.               

  Iran's Standard No. 2800 provides a code for the design of structures against earthquake loads. Due to the fact that mostly, far-field records have been used to prepare the seismic design spectra, in order to consider the destructive effects of near-field earthquakes in the 4th edition of St.2800, the incremental spectral correction coefficient (N) was introduced. In this paper, the accuracy and estimation of the value of this coefficient for 5 structures of special reinforced concrete moment-resisting frame with the number of floors from 3 to 15, are evaluated. Due to the fact that the increase in seismic requirements under the pulses of near-fault earthquakes is not the same for all seismic response parameters, so different correction coefficients can be used to estimate displacement response quantities and force quantities. For this purpose, first, the structures are statically analyzed according to the criteria of Iranian Standard 2800 and are designed according to the criteria of Article 9 of the National Regulations of Iran. Then the dimensions of beams, columns and rebars required by the structures are determined. After that the response spectrum of single-degree of freedom system to a set of records (including 7 far-field records, and 22 near-field records) is calculated, then using incremental dynamic analysis, the seismic response of structures at different seismic intensities is calculated. By calculating the response ratio of structures under near-field records to far-field records, the value of the N-coefficient is calculated. Based on the results, the value of the N-coefficient of the standard spectrum of St.2800 is suitable for estimating the base shear demand of structures, but this coefficient is not accurate enough to estimate the need for lateral drift of structures. In general, the coefficients obtained from elastic and inelastic analyzes for the need for displacement in reinforced concrete flexural frame structures are higher than the values provided by the St.2800. This difference has reached 58% in some structures. It was also observed that there is no regular relationship between the 1st natural period of the structures and the magnitude of the spectral correction coefficient and the magnitude of the spectrum correction decreases with increasing seismic intensity.

  Usually, most of the destructive earthquakes that occurred in Iran and left many casualties and damage were near earthquakes. Earthquakes such as Manjil 1369, Bam 1382 and Sarpol-e Zahab 1396 are examples of these near-field earthquakes that occurred in Iran. Determining the performance and evaluating the structure and its components is important to determine the seismic capacity and requirements. Due to the fact that most instruments enter the nonlinear area during moderate and severe earthquakes, so estimating the exact capacity of the structure requires the use of more efficient methods in the science of structural analysis. In the analysis and design of structures according to the type and manner of application of loads on the structure and the philosophy of seismic design and the occurrence of nonlinear behavior under the forces on the structure due to earthquakes, in order to determine the exact behavior of the structure is necessary. Different nonlinear dynamic analyzes are used. Dampers are considered as the best method to control and improve the behavior of structures as well as to improve the performance of structures. The main purpose of the thesis is to investigate the seismic performance of flexural frames of reinforced concrete equipped with rotary friction dampers. The results showed that the coefficient of increasing resistance for medium flexural frames equipped with dampers was obtained according to the overlay analysis of 2.63 and based on nonlinear dynamic analysis of 2.90. The obtained ductility coefficient for flexural frames with medium ductility equipped with dampers according to the cover analysis is 2.52 and based on nonlinear dynamic analysis is 3.15. The behavior coefficient for medium bending frames equipped with dampers was 6.56 according to the cover analysis and 8.83 according to the nonlinear dynamic analysis. The coefficient of increasing resistance decreases with increasing number of classes, while the coefficient of behavioral ductility has the opposite. The damper improves the three factors of increasing strength, ductility and modifying the response (coefficient of behavior) according to nonlinear dynamic analysis, while the other analysis of the ductility factor for short structures shows the opposite.

   Abstract Like other steel systems, steel moment frame system is used for various reasons such as high manufacturing speed, high strength, ductility, etc. The significant advantage of this system is the architectural considerations that make it possible to open the openings. This system analysis and design process assumes that the connections have a complete rigid behavior, while this assumption may not be accurate, and the connections’ rigid behavior assumption will cause errors in the analysis and design results.    This paper examines the effect of semi-rigid connections on the behavior of steel moment frames to determine the structure behavior factor. Hence, we analyzed and designed rigid steel moment frames, with different openings and floors, following 2800 regulations and topic 10 of the National Building Regulations. Then, we conducted pushover analysis on the frames and plotted the capacity curve of the frames, once assuming the rigid connection and then considering the nonlinear behavior of the connection. We used two springs with zero length at the end of the beams with the anchor-connection curve to model the connection behavior. The results show that for frames, assuming a rigid connection, the calculated behavior factor is close to 5, which is the recommended value for this structural system in Regulation 2800. In semi-rigid structures, the values ??of the behavior factor are in the range of the behavior factor of the rigid structure.    Keywords: Rigid Connections, Semi-Rigid Connections, Steel Moment Frames, Nonlinear Static Analysis, Extensive and Concentrated plasticity

   Deep beams as the most important bending-shear member are widely used in a variety of structural and non-structural structures. The cross-sectional height of these beams is higher than that of ordinary beams, so that according to the American Concrete Code, in deep beams, the cross-sectional height is greater than four times the length of the span. Analysis and design methods in deep reinforced concrete beams differ from ordinary beams due to their unique properties. Closing method is one of the most common methods in the analysis and design of deep beams. In this research, the mentioned method as one of the main topics was reviewed and some examples of existing experimental models were analyzed and evaluated. In order to study the details of the mentioned model, 432 laboratory samples with simple support and concrete efficiency coefficient were collected and examined from the laboratory researches carried out in recent years, considering the effect of reinforcing reinforcements where the total shear force applied to the beam is borne by two independent supports. The most important purpose of this study is to provide a formula for predicting shear strength by considering all effective factors. To achieve the project goal, numerical studies based on artificial intelligence were performed. Artificial intelligence is a computational method that tries to mimic human cognitive ability in a very simple way to solve engineering problems that have disregarded common computational techniques. Next, according to the experimental results, a new fastening model that included a wide range of deep beams with different arrangements of shear reinforcement, concrete strength and effective shear-height ratio was investigated. In this study, the shear capacity of deep beam specimens that have been tested by different people so far was calculated and the results were compared with the actual values ??and results of several other existing bonding methods. The results of the comparison indicate the satisfactory accuracy and efficiency of the proposed model. The proposed method is able to predict the shear strength of simple deep beams with acceptable accuracy.

Earthquakes and that associated effects occur every year in different areas of the world and a lot of damage to all sectors and national infrastructure, including various industries and facilities that this issue leads to the loss of Financial and spiritual valuable capital at the macro level. One of the most important parts that affected by earthquakes has high vulnerability is the power distribution network. The electricity distribution network is one of the most important and basic industries in people's lives, and this issue important has more manifestation, especially when the earthquake occurs. The purpose of this study is the assessment of the vulnerability of electric distribution network againstsite frequency resonance in Kangavar city, which this work is based on frequency microzonation done in Kangavar city in previous research and modeling components and electricity distribution equipment used in Kangavar city with Abaqus software and analyze and drawing the seismic risk maps of the electricity distribution network. For this research, the modeled components and equipment include 9m distribution reinforced concrete poles with a nominal strength of 200 and 400 kg force and 12m with a nominal strength of 200 and 400 force which 9m pole with a nominal strength of 200 kg force according to the role its passage and branch is without transformer equipment and 9m pole with anominal strength of 400 kg force is modeled in the forms of single pole without transformer equipment, single pole with 200 kVA transformer, double pole without transformer and double pole with 250 kVA transformer and regarding 12mpoles with nominal strength 200 kg force, the modeling is in the forms of single-pole without transformer equipment, single pole with 50 kVA transformer, double pole without transformer and double pole with 50 kVA transformer, and 12m pole with nominal strength of 400 kg force is in the forms of single-pole without transformer equipment, double pole without transformer and double pole with 350 kVA transformer. The results separately include the first to third deformation modes of each component and accompanying equipment. The output of thesemodes is in the form of frequency, which is extracted from Abacus software as the normal frequency of equipment. The frequency in a single 9m distribution reinforced concrete pole with a nominal strength of 200 kg force without accompanying equipment in all three movement modes is in the range of 1.4 - 7.2 Hz, in a single 9m distribution reinforced concrete pole with a nominal strength of 400 kg force without accompanying equipment is in the range of 1.5-9.2 Hz, in a single 12m distribution reinforced concrete pole with a nominal strength of 200 kg force without accompanying equipment is in the range of 1.0– 5.0 Hz, and in a single 12m distribution reinforced concrete pole with anominal strength of 400 kg force without accompanying equipment is in the range of 1.2 – 6.8 Hz. These frequencies decrease with the increase of weight of components and accompanying equipment. By comparing these values of equipment frequency with the natural frequency of the ground that has been measured in previous research, the vulnerability is investigated. The result of the research is shown, in the form of tables and risk maps. The result of this study shows that the amount of risk of the main components and equipment of electricity distribution due to site frequency resonance in Kangavar city is different. The results indicate that the eastern and southern areas of Kangavarare more at risk

استفاده از دانه هاي لاستيك توليد شده از تايرهاي ضايعاتي و نيز پودر شيشه حاصل از بازيافت شيشه ضايعاتي به عنوان جايگزين بخشي از مصالح (سنگدانه يا سيمان) در توليد بتن يك راه پايدار براي كاهش آلودگي محيط زيست همچنين كاهش مصرف منابع طبيعي و آلودگي هاي ناشي از توليد آن مي باشد. همچنين با توجه به افزايش توليد لاستيك   وشيشه به علت افزايش تقاضا و مشكلات عديده در راه بازيافت اين مواد، توجه به اين امر لازم و ضروري مي باشد. در اين تحقيق سعي مي شود از خرده لاستيك دانه بندي شده به عنوان بخشي از سنگدانه ريز، جايگزين شده و ميزان بهينه اين مصالح در بتن به جاي جمع آوري و يا سوزاندن آنها، تعيين شود. همچنين تاثير استفاده از پودر شيشه نيز به عنوان يكي ديگر از مواد بازيافتي در بتن مورد بررسي قرار گرفت . بعلاوه، تلاش شد كه با بهره گيري از ماده شبه سيماني متاكائولين، ميزان كارايي آن ارزيابي شده و همچنين مصرف سيمان كاهش يابد. هدف اصلي تحقيق ساخت بتني مناسب از نظر زيست محيطي و همچنين تامين­كننده الزامات آئين نامه­اي بود. براي اين منظور پارامترهاي مربوط به خصوصيات مكانيكي ازقبيل مقاومت فشاري، كششي، خمشي، تعيين منحني هاي تنش – كرنش و جذب آب در بازه زماني نيم، يك و 24 ساعته ارزيابي شد. كاهش در وزن، مقاومت فشاري 7 و 28 روزه نمونه هاي حاوي خرده لاستيك مشاهده شد. كاهش وزن در نمونه هاي 7 و 28 روزه به ترتيب به طور ميانگين 16/2 و 02/6 درصد مي باشد. با اين حال ميزان افزايش مقاومت فشاري 28 روزه نسبت به 7 روزه در نمونه هاي حاوي متاكائولين نمود بيشتري داشت. خرده لاستيك موجب كاهش مقاومت كششي و خمشي نمونه ها نيز شد. تاثير متاكائولين به تنهايي در بهبود خصوصيات مكانيكي بتن حاوي خرده لاستيك، بيشتر از پودر شيشه بود و مي توان انتظار داشت تاثير مثبت متاكائولين در سنين بالاتر در افزايش مقاومت فشاري چشمگير باشد.   

   One of the most important issues in the field of earthquake engineering is finding ways to reduce the seismic force on the members of the building structures. With the advancement of research in this field, control systems were introduced as one of the effective ways to reduce vibrations and protect structural members against earthquakes. Passive control systems do not require an external energy source for their operation and the control force is generated by the movement of the structure. For this reason, they are mostly used. The most important feature in this type of dampers to control the seismic force is the slip load of the damper. Finding an optimal value for this load greatly improves the results of the structural response. Various methods have been proposed by previous researchers to obtain the optimal slip force of friction dampers at the height of the structure. The main purpose of this study is to investigate the methods of sliding load distribution in building floors with friction dampers. For this purpose, 3 reinforced concrete structures with the same specifications and friction dampers are designed and the slip load in their floor dampers is distributed in four common ways and with appropriate accuracy. The studies show that the optimal slip load is achieved when the displacement, acceleration and base shear responses of the structure are in the desired state. It was also found that among the existing methods, nonlinear time history analysis method is the most appropriate method to determine the optimal slip load of dampers in most structures with different heights.

   Bitumen as an adhesive in asphalt mixtures has many weaknesses in its structure, and although it forms a small amount of asphalt mixtures, it has a decisive effect on its properties. Weakness in the bitumen structure can accelerate the occurrence of various failures, including rutting in the passage of the wheels, asphalt bleeding and cracking. Thermal cracks are the main cause of pavement failure in cold regions, which leads to several problems, including reduced safety of road users and reduced service life of roads. Therefore, the need to modify the chemical properties of bitumen adhesives and the use of modifiers in these areas can be justified.FractureMechanics Quantitatively describe the failure process in a crack-containing specimen and its growth process, and generally examine the germination and crack growth in brittle materials. Research shows that the cause of these fractures is defects such as fine cracks, the presence of which causes structural failure at stresses less than the stresses designed for the material.Inthis study, the effect of two modifiers, GO and LDPE, on the fracture toughness of hot mix asphalt in mode II loading has been investigated by performing three-point bending test at temperatures of 0 and -10 ° C. Resistance and Marshall modulus experiments were performed on the optimal percentage of additives in the three-point bending test and the control sample, and the results of these two experiments were used for economic and environmental analysisBased on the obtained results, the use of GO and LDPE at both temperatures and for all percentages used, improves K??C   compared to the control sample. The economic analysis shows that LDPE is economical and GO is uneconomical. Reduction of emissions of environmental pollutants was also calculate for different stages of asphalt mixture production

  Concrete is one of the most widely used and widely used building materials, which has been especially welcomed in the construction industry due to its easy access and low cost components. One of the most important parts of concrete construction and operation is its processing part, which is necessary to achieve the desired strength, and especially in our country, little attention is paid to it. Lack of proper processing can reduce the mechanical and durability properties of concrete and cause damage to the concrete structure. On the other hand, concrete can be exposed to damage for various reasons, sometimes we need to repair these defects, which can be much more difficult to process the repaired parts, in the presence of materials in Inside the concrete that performs this action, the concrete can achieve the required strength without external processing. Polymeric superabsorbents are a group of materials that can absorb several times their own weight of water and over time this water is removed from their structure, so their type of performance affects the structure of concrete. Concrete samples constitute the statistical population of the research and their construction is in accordance with the standards of Concrete Laboratory (ASTM). In this study, concrete was evaluated by adding two types of polymer superabsorbents in the amounts of 0.6,0.3 and 0.9 and one type of powder polymer in the amounts of 1 and 2 wt% of cement in the ratio of water to fixed cement 0.38. Our evaluation tools in this research are concrete laboratory devices such as concrete compressive strength measuring device, concrete slump cone, etc. We found that the polymer superabsorbents used in this study reduce the flow of concrete. Permeability of concrete is one of the parameters for evaluating its durability, which is reduced by adding polymer superabsorbents, which increases its durability. Polymeric superabsorbents reduce the compressive strength of concrete, which is partially compensated by the addition of ethylene vinyl acetate. At 0.3% by weight of cement, they increase the compressive strength compared to the control sample without processing. They increased the energy absorption compared to the control sample without processing. At 0.6% and 0.9% by weight of cement, the modulus of elasticity decreased. Were observed in concrete, and the addition of ethylene vinyl acetate exacerbates this reduction.

  Concrete is the most widely used material in the world after water. Today, concrete is used much more in structures and construction projects than in the past, so that billions of tons of concrete are used annually in the construction of structures. Due to the rapid advancement of technology in order to save energy, the time and cost of construction projects, new methods and materials have replaced the old methods and materials. One of the newest and most unique concrete products is the concrete canvas, first proposed in 2005 by Berwin and Crawford. Concrete canvas is a composite with cement properties, which can be used in less than 24 hours to achieve a desirable concrete surface with low thickness, waterproof, fire resistant, etc. . In this study, in order to introduce this product, an attempt has been made to investigate the tensile behavior of concrete canvas according to different geometric patterns of 3D fabric, so that to increase the tensile strength in the warp and weft of concrete blanket fabrics. The results obtained were that the larger the number of layers, the smaller the diameter of the hole in the top layer of the fabric and the higher the density of the spacer yarns, the tensile strength of the concrete canvas. It is higher and also the rate of increase of resistance in the direction of weaving is more than the direction of the warp.

   Abstract In resent years, FRP composites have broadly and successfully been used to improve seismic behavior of the structures. Great resistance of these materials against erosion together with the high ratio of strength to weight in these materials are the reasons why strengthening the structure by using these materials do not impose extra weight to the structure, unlike the traditional methods in which shotcrete or ferrocement are used. Beam-column connections in reinforced concrete moment frames are critical points in performance of reinforced concrete moment frame during the earthquake. Many studies have done on reinforcement of beam-column connections in reinforced concrete frames using FRP materials. Most of these studies are done in micro scale on shear strength and ductility of connection, and some solution are provided for its improvement, and little studies have done on seismic parameters such as behavior factor of reinforced concrete frame, the amount of energy absorption, and loading and displacement capacity of the frame reinforced with FRP in connection point in macro scale. In this thesis to numerically investigate the behavior of beam-column connection in reinforced concrete buildings in macro scale using finite element theorem, and some solutions are recommended for reinforcing and improving their seismic performance using FRP composites. In contrast of experimental samples which have many constrains for observing and obtaining results, in finite element modeling, these constrains are fewer, and it is easier to model a sample nearer to reality.   

  رفتار ديناميكى قابهاى پيش ساخته بتن مسلح همراه با ديوارهاى برشى داراى ميراگرهاى فولادى جذب انرژي

  In the polymer modified concrete, polymer is added to the concrete as the main component to enhance adhesion, ductility and durability. The joint performance of 3D polymer film in conjunction with the materials produced by cement hydration, improves some concrete properties. In this research, experimental studies to investigate the effect of three polymer of methyl methacrylate (MMA), pure acrylic (PA) and styrene butadiene rubber (SBR) with 3, 5, 8 and 10 percent cement replacement on polymer modified concrete containing 5% micro silica was made. The reduction of compressive and tensile strength causes the use of micro silica. To investigate the physical and mechanical properties of concrete, the specimens were tested to slump tests, air ratio of fresh concrete, compressive strength, tensile strength and water absorption.   Also, by drawing stress-strain diagram of all specimens, energy absorption capacity, modulus of elasticity, strain and ductility coefficient were also investigated. The results showed that by adding these three polymer to the concrete, in all specimens, reduced the compressive strength, tensile strength, water absorption, elasticity modulus. The air ratio, the ratio of tensile strength to compressive, energy absorption capacity, strain and ductility coefficient increased. The slump values also increased with the addition of styrene butadiene rubber (SBR) and decreased with the addition of methyl methacrylate (MMA) and pure acrylic (PA).

  Abstract: Due to increased energy consumption and environmental protection, Warm Mix Asphalt is used to produce asphalt mixtures. By reducing the temperature in the production of WMA, in addition to reducing environmental pollution and saving energy, better conditions in the workplace for workers are provided in terms of lower temperatures and less toxic emissions. In this study, we tried to measure the performance of WMA performance against moisture susceptibility, which is one of the weaknesses of this technology. Also, resistance to fatigue cracks, which is one of the most important parameters of asphalt quality measurement, is measured by bituminous refining with the help of synthetic zeolite and Nano Clay. In this study, Marshall samples were made by modified bitumen. For moisture susceptibility test by modified Lathnem method. Then, based on the acceptable percentages of the results of the moisture susceptibility test, fatigue tests were performed to evaluate the fatigue performance of asphalt mixtures. The best performance of the moisture susceptibility of the asphalt mixtures tested in this study is related to a mixture containing 5% zeolite and 7% Nano Clay by %87 of TSR which had a high increase compared to samples with no Nano Clay. Repetitive loading beam tests are the most common method for evaluating fatigue behavior of asphalt mixtures. The maximum tensile stresses and the number of loading cycles with controlled stress in the stress ratios equal to 0.2 and 0.5 of maximum tensile stresses for asphalt mixtures without additive and with different additive percentages were measured by Four-point fatigue test. Fatigue test results showed that the addition Nano Clay increases the fatigue of asphalt mixtures. The results show that the addition of Nano Clay to (3%) increases the fatigue of asphalti mixtures in all stresses ratio of the test. Keyword: Warm Mix Asphalt, Moisture Susceptibility, Fatigue, Synethic Zeolite, Nano Fe2O3.

  Every year earthquakes occur around the world. In the province of Kermanshah, during the history has occurred a lot of earthquakes. Earthquakes including 4 earthquakes in 2013 with magnitude 5.2,5.7,5,4 and 5.3 in Qasr Shirin, 2 earthquakes with magnitude 7.3 and 5.3 in 2017 in Ezgele, 10 earthquakes with magnitude 5.6 and 6 in Taze Abad, 5.1,5.1,5.3,5.2 In Sumar and earthquakes of 6.4 , 5,5.1 and 5.2 R in Qasr shirin in 2018, there are important recent earthquakes in Kermanshah province .This subject show the importance of determining the seismic vulnerability of Kermanshah Province to help urban planners to rehabilitation, urban development, also Crisis Management during an earthquake. In this regard, this study analyzes the physical seismic vulnerability of Kermanshah city with the combination of three methods of Analytical Hierarchy process (AHP), fuzzy logic and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The purpose of this study was to determine the regions of Kermanshah which have high vulnerability and more critical conditions than other areas during an earthquake. The proposed method has a parametric approach and, in addition to considering uncertainties due to incomplete or inaccurate information, provides an independent approach to the study area. In each study, which uses several criteria for determining the results, the significance of each of these parameters and criteria must be determined. Determining the importance of each criterion in the analysis process is done using the AHP method. In most studies, especially studies that determine the vulnerability of the regions, there may be incomplete or inaccurate data. These uncertainties can be considered using fuzzy logic techniques. Finally, using the Topsis method, can determine the ultimate vulnerability of each unit. The results estimate the vulnerability of the city of Kermanshah in most areas within a high vulnerability. Only in parts of the city that is new build to other area , there is little damage. In these areas, in addition to the proper conditions of the construction parameters, the conditions of seismic hazard parameters such as litology are appropriate, which indicates that it is suitable for the expansion of the city.

بررسي عملكرد ميراگرهاي جرمي تنظيم شونده ويسكوالاستيك 

مقاوم سازي قاب بتني خمشي با استفاده از ميراگر اصطكاكي

بررسي تجربي آزمايشگاهي مقاوم سازي دال هاي تخت بتن مسلح در برابر برش پانچ

بررسي آزمايشگاهي بتن ساخته شده از مصالح بازيافتي پلي اتيلن سنگين به عنوان سنگدانه

  Pipelines are one of the most important engineering structures and systems. These systems are very significant from the economic and strategic point of views, and are widely used all over the world. Therefore, they must be investigated more accurately. Since the length of the pipelines is very long and may exceed several hundred kilometers, a more precise study of the flow patterns such as velocity, pressure, friction as well as feasible deformation may lead to a more economical and accurate design of mentioned systems. Although investigation of the related equations is complicated, costly, and time consuming, these difficulties may be overcome using engineering software. In this article, a robust analytical software of fluid mechanics Ansis Fluent 15 is employed to verify validity and accuracy of turbulence models k-omega, k-epsilon, and Reynolds stress. The results obtained in this study have good agreement with those reported in the literature.

  Today, despite significant advances in construction, many of the existing structures against earthquakes do not function properly. The inappropriate seismic behavior of these structures can lead to many fatal and financial damages. In order to prevent such damages, an appropriate and economical solution is to retrofit existing buildings.Considering the damage caused by earthquake in prone to earthquake, it has been observed that joints are one of the most important and vulnerable areas in concrete structures. Therefore, due to the importance of joints in the proper seismic performance of the structure, the behavior of concrete joints and their retrofitting methods against earthquakes has been investigated.In this study, the reinforcement of the external connections of the beam to the reinforced concrete column was investigated using FRP sheets and steel jacket. In this regard, for different makeup of FRP and steel jackets and for three concrete grades 25, 30, 35 Mpa, various parameters such as strength, hardness, energy absorption and ductility were calculated and evaluated.

  In this study, frames with concrete-filled steel tubular (CFST)   columns with sandwich panels were used. The CFST columns, due to the many benefits that it has, are propagation every year. The advantages of steel and concrete are well-known, concrete with good compressive strength, reasonable price for other materials and considerable resistance to fire burning, and steel is a material with high ductility and high strength. The combination of these two materials is a composite material with good properties. In CFST columns, the existence of a steel tube makes it more confinement to the concrete inside it, as well as the existence of concrete inside the steel, preventing the local buckling of the steel and thus increasing the load capacity of the column. Sandwich panel as an effective member is widely used in industrial buildings and structures. The sandwich panel has a good flexible and relatively low weight, with a central core and outer layers attached to the sides of the core. In this study, numerical models have been used to investigate the effect of different parameters on stiffe   , ultimate strength and energy dissipation of the CFST frame with the sandwich panels intermediate. In order to verify the numerical modeling, several experimental tests Wang-2017 (reference 3) were modeled using ABAQUS fainant element   software and the acceptable acceptance of the results of the analyzes confirmed the validity of the modeling. . The results showed that the use of the sandwich panel intermediate reinforced the ultimate strength, structural stiffness and energy dissipation considerably

  The lightweight steel frame (LSF) structure, is a building system used primarily for short-term and intermediate-level buildings. Due to its plenty of advantages compared to other existing systems in construction, the use of this system is increasing. In this structure, cold formed steel sheets (CFS) are used to make thin-walled steel sections. These sections are galvanized steel sheets, which are formed using cold forming. In this system, CFS beams and columns are used as barrier members. The beams used in this system are often made up of 0.5 to 3 mm, which, Because of their low thickness, they are prone to buckling. This geometric feature affects their load-bearing capacity and makes it impossible to can not to use the load bearing capacity of the sections well. Therefore, using the method that increases the resistance buckling of beam, it can be used the load-bearing capacity more efficiently.An ideal method for achieving this goal is to create a bracing for the CFS beams by casting concrete around the web. the concrete can provide bracing for beam and improve the buckling resistanae of it. For this purpose, the ultra-lightweight-concrete encased cold-formed steel beams have been investigated. This concrete has a slight compressive strength and is often used as an insulating or filler material, but it has now been found to be structural performance.In this study, using finite element analysis, polystyrene aggregate concrete (PAC) encased CFS beams under four-point bending loading have been investigated. For this purpose, 2C and 2U cross-section beams with different geometric dimensions were modeled and investigated. The results showed that, using of PAC can provide full bracing for the steel beams and increase their ultimate strength capacity level by 43%. In addition, due to the lightness of this concrete, A slight load is added to the weight of the structure and the advantage of the lightness of the LSF structures is maintained.

  Unbonded fibre-reinforced elastomeric isolator (U-FREI) is a relatively new seismic base isolator in which fiber layers are used as reinforcement to replace steel shims as are normally used in conventional isolators. Further, the top and bottom end steel connector plates of conventional isolators are also removed. In general, the horizontal response of U-FREI is nonlinear because of reduction in contact area due to rollover deformation and reduction in shear modulus of isolator under large deformation. Thus, evaluation of horizontal stiffness of U-FREI is a challenging problem. The unbonded application leads to rollover deformation that results in advantages such as decreasing the demand tension stress between internal layers and increasing efficiency of the bearing as a seismic isolator. Most of the previous finite element analysis studies on FREIs only have addressed the simulation of the monotonic behavior of this type of isolators. In this thesis, the main objective is to simulate the laterl load-displacement hysteresis loops of U-FREIs. The combination of an effective hyperelastic behavioral model in large deformations with viscoelastic behavior, the hyper-viscoelastic model will be produced that has the ability to consider the time dependency in the finite element analysis of isolator. The hyperelastic parameters are evaluated by curve fitting of theoretical curve to three uniaxial tension test of elastomer dumble-shaped specimens. The viscoelastic behavior is simulated using the Prony Series, and its parameters are determined by using the Nelder-Mead simplex method optimization algorithm, and the cyclic experimental results. The results show that the use of viscoelastic material model in conjunction to hyper-elastic material model leads to the effective simulation of horizontal stiffness and hysteresis load-displacement loops of FREIs. As another component of this thesis, The lateral response of isolator under various vertical compression stresses is studied using the finite element model that is developed in this study. Results show that both the effective horizontal stiffness, and equivalent viscous damping are increased by increasing vertical compression stress.

Many systems have been used for this purpose including seismic base-isolators which are among the most important ones. In this method, structures move isolated from the ground by placing a flexible lateral structure between the structure and the foundation. Isolators have several types, the most common of which are Steel Reinforced Elastomeric Bearings (SREBs). These isolators are made of intermittent and bonded  elastomer layers and reinforced steel plates. Such isolators currently lack required economic justification for many conventional structures due to high expenses. In the last fifteen years, new elastomeric isolators have been developed called Fiber Reinforced Elastomeric Bearing (FREBs). In these isolators fiber reinforced layers are used, instead of heavy metal plates, to control the lateral strains of the elastomeric layers and to provide the necessary hardness along the vertical axis. In terms of bonding to the bearing, the isolators are categorized into three groups of "bonded", "partially bonded" and "unbonded". In unbonded mode, isolators lack the upper and lower steel plates, which reduce the expense and weights of isolators. In unbonded mode, no mechanical connection is made between bearing surfaces. In this situation, shear force is transmitted through friction at contact surface of the isolator with the bearing. These detachers undergo a unique deformation under rollover lateral displacement, which leads to the contact of the initial vertical surface of isolator with the upper and lower bearing of the isolator.   Following a rollover deformation, the effective lateral hardness of the isolator has been reduced further, which means increasing the vibration isolation period and, in fact, increasing the seismic isolation efficiency. In this research, the finite element analysis has been used to model the behavior of force- one-way lateral deformation of Fiber Reinforced Elastomeric Bearing (FREBs) isolators. The modeling of these isolators is conducted in 3D format using MCS MARC finite element software. Providing a 3D model of Fiber Reinforced Elastomeric Bearing isolator with material specifications and geometric dimensional scaled with real dimensions in finite element analysis allows us to avoid some costly and time-consuming laboratory studies. The focus of this thesis is on the modeling of three-dimensional finite elemental behavior of the Fiber Reinforced Elastomeric Bearing circular isolators. Research literature in this area has nothing to say. In the analysis, the effect of the geometry of the rubber layers on horizontal and vertical responses of elastomeric isolators was studied. The effect of thickness is investigated by (

...

تحليل تكيه گاه بتن آرمه اي ميراگرهاي ويسكوالاستيك متصل به ديافراگم طبقات

  lt  gt;بررسي رفتار تيرهاي عميق بتن مسلح تحت بار گسترده با استفاده از مباني strut-and-tie</P>

  Historic bridge bridges are of great artistic value for humanity, and their historical architecture reflects the cultural identity of peoples of that time. Over the centuries, these structures are still stable and serviceable at risk for natural hazards such as earthquakes, floods, fires, wars and the growing population of the world. The bridge studied in this study is the old bridge. This bridge is one of the national Iranian and archeological works of Kermanshah Province which is located on the eastern border of Kermanshah, located on the Gharasso River, as a way of communicating the villages of Faramans Drood in entering Kermanshah. The bridge was constructed in the Sassanid period and was rebuilt in the current Safavid period, with six spans, about 188 meters in length, 9 meters in height, and 8.6 meters in height, including the crown of the bridge. The foundations of this bridge are hexagonal, the inner part of which is made up of lime sandstone and lime sandstone, and is surrounded by rectangular cubic stone blocks. At the front of the stands, opposite to the flow of the droplets of the triangle is a shape.

<  gt;ارزيابي تاثير مقاوم سازي اتصالات تير -ستون با ورق FRP در پارامترهاي رفتار ديناميكي قابهاي بتن مسلح</P>

Progressive collapse is a phenomenon that a local damage results in failure of adjacent elements and finally results in global collapse of the structure or a large part of it. The main feature of this phenomenon is that global collapse is not proportional to initial failure. This type of failure, the first time in 1991 and during the 22-story building collapse Ronan Point in London, it attracted attention of engineers. It is clear that the phenomenon of progressive collapse, because of that occurs in a very short period and the imposition of non-linear transformations to elements before the rupture, has a nonlinear dynamic nature. Since 1990, numerous studies on the use of buckling restrained braces on improving the performance of Steel and Reinforced concrete frames has been done, but so far the effect of this type of braces on the progressive collapse of the reinforced concrete frames has not reviewed. In this thesis, a regular reinforced concrete structure designed in accordance with standard 2800 first edition and then the building has been under nonlinear static analysis. Because of the structure has not played to the level of performance, in accordance with the fourth edition of the standard 2800 and publication 360 Edition 1392 using braces Buckling Restrained, Chevron, V-shaped has been retrofitted. As well as a reinforced concrete structure in accordance with the Fourth Edition 2800 has been designed and in the end, the effect of progressive collapse in the outer frame of these structures, according to an alternative load path, using nonlinear dynamic analysis in OpenSees software has been investigated. The results show that the use of braces, not only improves the performance of the structure under lateral loads are reduced but the probability of occurrence of the phenomenon of progressive collapse in retrofitted reinforced concrete frames are reduced too and as well as the Buckling Restrained braces have better performance than the V-shaped braces and Chevron in the phenomenon of progressive collapse.

  Progressive collapse is the event that if occurred may be caused to irreparable disaster. Nowadays, different methods are suggested to resistance against progressive collapse that these methods are divided into the direct and indirect method. In indirect method due to approximation in the calculation, isn’t properly for this study. In direct methods, alternate path method is the excellent and complete method to evaluation the structure against progressive collapse. In alternate path method, a column is removed suddenly from the structure. By this method, standards are carried out independent of extreme loads like blast, earthquake, fire and construction or design error. In this study, to the evaluation of reinforced concrete structures against progressive collapse, alternate path method is used. In this research, a six-story reinforced concrete building with intermediate moment frame in both directions is considered. The dimensions of beam and columns and the number of bars are determined by ETABS2000. In this building, one-way joist running is used to floor systems. After building design, two external frames of the building is modeled in open system program OpenSees. Frames modeled in three manners. In a first manner, frame modeled without infill wall, then in a second manner, frame with infill wall without opening and finally in a third manner, with infill wall by considering 30% opening. In this thesis, six scenarios are considered for each frame that with considering of two frames and three manners of infill wall, 36 scenarios are performed. In this thesis, the nonlinear dynamic analysis is used to capture the real behavior of frames after sudden column removal. Push down analysis is performed for evaluation of the capacity of the frames after column removal. In push down analysis, the gravity loads are applied increasingly to frame until the frame is collapsed. In this study, it is obvious that in a higher level of frames, the potential of damage is increased. Using of one way joist running is concluded to increase potential collapse in bays that loads of floor system is carried to them. In addition to above mentioned, it can be said that infill walls can more considerable role in stiffness and resistant of frames. This effect is more be seen when the length of bays is increased or the infill wall hasn’t opened. Opening in infill wall can reduce considerable of frame strength; this reduction of strength can be limited to equal or less than of frame without infill wall.

  AbstractSoil-structure interaction effects of soil under the foundation of flexibility, relative vibrations between the foundation and the free surface arises. The inclusion of this effect and inertial forces can be a real shift system -Py-soil structures under seismic movements set free surface.Over the past three decades extensive research to characterize the soil-structure interaction effects engineering have been conducted. The results of this research in many earthquake regulations such as NEHRP, UBC, ATC,… come.Many construction requires the deep and wide excavation that the construction and operation may take several years. deep and wide excavation in an urban environment where the drilling location is surrounded by many building, it is important that the impact on the environment the vital challenge is investigation interaction between excavation and building during earthquake.Earthquake regulations have not studied this work. The aim of this thesis is investigation effect of adjust deep excavation on structural performance during earthquakeThe result for study Kermanshah hamyari building that adjust urban train excavation shown Increasing amounts of displacement, Increasing the period of the structure, Reducing the base shear.As a result excavation investigates adjacent structures is very necessary in the analysis.Key words: soil-structure interaction, deep excavation, base shear, period of first mode  

  Investigation that how Earthquakes Can effect on our structures made by human is very important for economical and safe design of the structures. By the previous research on the behavior of the structures it is obvious that a shear force acts at the base of structures during earthquake. Estimating a Reliable valu for base shear are very important to reduce structural damages caused be wind or earthquake. For the first time after the 1908 italy Earthquake engineers set it as 10% 0f structural weight. They changed it to 12.5% of structural weight in form of base shear.  By considering this provision structural performance was improved in later hazards and make structures after during.But structures show different behaviours against same earthquake.  Today millions of people live in structures made by Reinforced Concrete Coupled Shear Wall Systems. And some of most important structure like nuclear power plan, high rise tower and etc, are made in this way too. A coupled shear wall is a structural system made from to combined RC shear wall connecting by a beam named as coupling beam.  In this system thickness of concrete slab and shear wall are equal usually, for more rapid construction.  In many design Code such as the code and ASCE200 and UBC 1997 and regulation in turkey effect of earthquake force reduction factor in considered using ioss of the strength and ductility.  However, in none of the regulation , there is no way for calculating the behavior coefficient for those building that don’t have coloumn or girder and consisting ceiling and slab( tunnel form structure).vertical and lateral loads in tunnel form system are to lerated by the system.  In most cases, to access , and architectural elements or through ducts in the walls of the facility is a porter opening occurred in the structures of these systems proved to scientist.  The behaviour of such systems is entirely dependent on the geometry of the structure and behaviour of structures with different opening.  First a brief description on construction methods of this system was performed. Then some non-linear dynamic analysis on some models were performed by ABAQUS ver 6.14.3.  After that some smaller models made of walls and slabs modeled here in ABAQUS. For the sensitivity case study of the opening ratio on the behaviour of them were constand and only the opening ratio of the plan were different.  At final, after doing analyses curves were presented for the realative change of the behaviour.

  AbstractDue to the significant load carrying capacity of masonry wall, they were comprised the main construction materials in the past year. First, this materials were obtained by the hardening of mud on side of the grill and cooking ovens. Todays bricks were built based on this issue. At that time, it was used only because of its strength and availability, but with the passage of time and observing the behavior and performance of these materials in earthquakes and wind, the need to understand the exact behavior of these materials were felt more than ever.,Wood has been used since the beginning of history and due to its good tensile strength and economical and easy process there in its manufacturing and also help to protect the environment because of carbon dioxide that its stored in, is taken into consideration. Another advantage of wood are cheap cost and availability in the Cities and villages are underdeveloped.Masonry structure with timber framed is a structural system with high diversity and complexity. Limited analytical and experimental research has been done to detect seismic response on this structure. From the Bronze Age, this system was common in seismic areas. According to the behavior of masonry structures, the fundamental weakness of them against the earthquake, not lack of strength, But it is the lack of stiffness or plasticity. This weakness can be alleviated by reinforcement. Despite of the high shear strength of masonry structures, due to brittle behavior of materials, the improvement of performance of these structures for increasing in capacity and ductility is very important and the use of reinforcement elements such a member in order to eliminate disadvantages of these structures had historically been considered.

  Due to the development of appropriate methods for seismic retrofit and rehabilitation of buildings against seismic loads due to the vulnerability of masonry buildings that include a large number of buildings in the country is an important. One of the methods of retrofit and rehabilitation for unreinforced wall is use of steel bars with concrete coverage in one or both sides of wall. This steel gride is connected to the wall with steel nails. Implementing of such method increases the lateral loading capacity of wall, but also caused more cohesion of wall in integrity manner. In recent years, engineers implemented this method as an efficient and economical way for the most rehabilitation plans of the countries present masonry buildings. But since the lack of experimental information over these walls seismic performance and actions, which their designing generally based on the standards of concrete instructions or engineering judgment. According to the studies that have not been performed about the effect of steel nails in the reinforced wall. In this thsis first a pull-out test was carried out to place the steel rebar embedded in brick-mortar sample under tensile load. As the result of this test, bond strength, maximum tolerable tensile and displacement corresponding to the tensile load and load-displacement curve are obtained. Then, the experimental model was numerically simulated to obtain sliding, displacement, plastic strain, and the stress of the steel rebar and the brick-mortar sample. Second by using ANSYS17 software is investigated the effect arrengement of this steel nail on seismic performance of masonry walls with 10cm, 20cm, 30cm thickness in full-scale and small scale. The load – displacement diagram to one side wall on both sides of reinforced concrete with an experimental model has compared then the load – displacement diagram, displacement contour, and plastic strain for two side and one side reinforced wall in two forms with steel nails and without steel nails has compared. Finally, the steel nails force diagram is shown.

  umerical Study Of the Effect of Local Change of Channel Width On Flow Pattern In Open-Channel Junction