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Open Access Article
1 - Vibrations and Damping Analysis of Composite Sandwich Panels with Reinforced Kevlar Fibers
Abdolhossein Fereidoon Ali Hazrati NiyariThe purpose of this paper is the damping analysis of composite sandwich panels using the Ritz method. Damping is a useful parameter for controlling vibration in moving structures. Due to their high ratio of stiffness and strength to weight, composite sandwich structures MoreThe purpose of this paper is the damping analysis of composite sandwich panels using the Ritz method. Damping is a useful parameter for controlling vibration in moving structures. Due to their high ratio of stiffness and strength to weight, composite sandwich structures have proven their usefulness in a large number of applications in various technical fields, especially in automotive industry and mechanical engineering. In this study, all theoretical calculations were performed using MATLAB software, and damping was evaluated by using the commercial software ABAQUS. The results indicated a good match between the finite element modeling and the theoretical approach. Manuscript profile -
Open Access Article
2 - The effect of far and near field earthquakes on the collapse capacity of performance base optimization RC moment frames
ashkan khodabandehlou siamak saboonchiPerformance-based design is a new approach to the topics of seismic design of structures, which is based on changing the location of the structure, unlike the traditional methods of force-based design. The use of this approach in the process of structures design leads t MorePerformance-based design is a new approach to the topics of seismic design of structures, which is based on changing the location of the structure, unlike the traditional methods of force-based design. The use of this approach in the process of structures design leads to the achievement of structures with proper performance and an acceptable level of reliability. The main goal of this research is to investigate the impact of near and far field earthquakes on the collapse capacity and fragility of performance base optimization RC moment frames using the center of mass meta-heuristic algorithm. Push over analysis has been used in the optimization process to control the responses of the studied frames at performance levels and incremental dynamic analysis has been used to evaluate the fragility of the obtained optimal frames. According to the obtained results for the collapse margin ratio and the adjusted collapse margin ratio for the 3, 6, and 12-story frames, we can see that the collapse margin ratio and therefore the seismic safety under far field earthquakes 7%, 16% and 8%, higher than from collapse margin ratio and seismic safety under near field earthquakes respectively. In other words, the optimal frames in this study against near-field earthquakes have low seismic safety and more fragility than far field earthquakes. Manuscript profile -
Open Access Article
3 - Seismic Performance Investigation of Buckling Restrained Braces with Parallel Yielding Double Core
Kourosh Mehdizadeh Abbasali Sadeghi Seyede Vahide HashemiThe buildings equipped with buckling restrained brace (BRB) are earthquake resistant structures that have two properties of high lateral stiffness and ability to absorb and dissipate energy at the same time In this study, a parallel double core mechanism with the same c MoreThe buildings equipped with buckling restrained brace (BRB) are earthquake resistant structures that have two properties of high lateral stiffness and ability to absorb and dissipate energy at the same time In this study, a parallel double core mechanism with the same core length and with different yielding stress was used to investigate the seismic performance of buckling restrained brace of single core and double core. Therefore, in this research, three 3-dimensional 3, 6 and 9-story buildings equipped with concentric buckling restrained braces were designed according to AISC-LRFD Code along with the controlling of the seismic criteria based on standard 2800 version 4th in ETABS 2017 software. Then, the two dimensional perimeter frames equipped with buckling restrained brace were modeled in SeismoStruct 2018 software in two states of single core and double core. In order to investigate the behavior of these structures, the adaptive pushover nonlinear static analysis and time history nonlinear dynamic analysis were performed under three far fault earthquakes. The results presented that the use of a parallel yielding double core increased the elastic stiffness of the structures but does not cause a noticeable change in the lateral strength of the prototypes. Also under applied earthquakes, the hysteresis curves were obtained and these figures showed that the use of a parallel double core increased the earthquake energy dissipation. In general, the use of the double core buckling restrained brace reduced seismic responses such as roof displacement, roof acceleration, drift and base shear by approximately 20%. Manuscript profile -
Open Access Article
4 - Investigation of the Response Modification Factor of Frames Equipped with Eccentric Buckling Restrained Braces based on Performance Levels
Vahid Saberi hamid saberi Abbasali Sadeghi Seyede Vahide HashemiStructural response modification factor refers to a coefficient that indicates the energy absorption capacity of the structure in the inelastic region. By using it, the shear force of the structural design is reduced by several times. In this research, the response modi MoreStructural response modification factor refers to a coefficient that indicates the energy absorption capacity of the structure in the inelastic region. By using it, the shear force of the structural design is reduced by several times. In this research, the response modification factor of frames equipped with eccentric buckling restrained braces were investigated based on performance levels under the records far from the fault. In this research, three 3, 6, and 10-story frames with eccentric buckling restrained braces were designed using ETABS software and then SeismoStruct software was applied in order to perform nonlinear static pushover analysis and incremental dynamic analysis (IDA). In IDA analysis, the intensity parameter corresponding to (PGA) and the damage index corresponding to the maximum relative displacement of the floors (MIDR) were considered and the two performance levels of life safety (LS) and collapse prevention (CP) were investigated. The results presented that the collapse prevention performance limit was about 30 to 35 percent higher than response modification factor corresponding to the life safety performance limit, which means that the response modification factor of safety life limit can be increased by 30 percent in order to be used for structural design at the functional level of collapse prevention. Manuscript profile -
Open Access Article
5 - Investigation of Fragility Curve of Mid-rise Sreel Moment Frame with Reduce Beam Section
mohammad asadi mehdi rahimi asl ali bakhshi In this study to determine the reduce beam section effect, on intermediate moment frame system behavior and its results, are discussed. For this purpose, non-linear static analysis is used. Generally, two types of structures ha More In this study to determine the reduce beam section effect, on intermediate moment frame system behavior and its results, are discussed. For this purpose, non-linear static analysis is used. Generally, two types of structures have been selected in this study, the first 5, 10 and 15-story moment frame and the second with a cross section reduction in beam structures. Since this research has been done using software OpenSEES also to modeling reduce beam section, we used Krawinkler-Ibarra rotational spring model with concentrate plasticity on beams. After verification of RBS for a cantilever beam, this model has been extended to multi degree of freedom buildings. Finally different models have been subjected to incremental dynamic analysis and the results of analyzing the flexural structures of the frame and RBS structures have been used to calculate and extract the fracture curves of the structures and compare them. With respect to the fracture curve graphs of intermediate structures, the probability of colliding the IMF model with the RBS is higher. Manuscript profile -
Open Access Article
6 - The Investigation Effect of Viscous Damper on the Floor level on Seismic Response at Reinforced Concrete Tall buildings with Internal Resistant Core the Tube in Tube System
sajjad Alizadeh ashkan khodabandelouApplication of dampers as means of attenuation of earthquake energy is one of the most significant approaches and viscose damper is the most popular one. The aim of this paper was to investigate the effect of viscose dampers on decreasing the vulnerability of tall struc MoreApplication of dampers as means of attenuation of earthquake energy is one of the most significant approaches and viscose damper is the most popular one. The aim of this paper was to investigate the effect of viscose dampers on decreasing the vulnerability of tall structures at earthquake and selection of the optimal arrangement of dampers in these structures. so, two types of concrete special moment frames with central cores with 26 floors were designed with SAP2000 software. Then, they were applied to five earthquake records and their vulnerabilities were investigated according to non-linear timehistory dynamic analysis. Then, dampers were erected into the structure and modeled. To do so, the dampers were horizontally positioned in the structure and the models were evaluated again using non-linear timehistory dynamic analysis. The results obtained by investigating three parameters of maximum Floor displacement, base shear, and structure Acceleration verified signified decrease in all three parameters. In such a way that the displacement of the structure, between 10 to 25 percent,the base shear 15 percent, as well as the acceleration of the input to the structure, to about 17 to 20 percentage reduction. Manuscript profile -
Open Access Article
7 - Effects of Bracing Arrangement along the Building Height on Collapse Fragility Curve of Steel Braced Frame Systems
Ali Seyedkazemi Seyed Reza Hashemi ShahandashtiThe steel braced frame system is one of the lateral load resisting systems which is used extensively for low- to mid-rise buildings. In this structural system, the braces can be arranged in different forms along the building height due to different reasons such as archi MoreThe steel braced frame system is one of the lateral load resisting systems which is used extensively for low- to mid-rise buildings. In this structural system, the braces can be arranged in different forms along the building height due to different reasons such as architectural and structural limitations or design considerations. The bracing arrangement affects the seismic performance of the structural system and each of the elements. In this study, the impact of bracing arrangement along the building height on ultimate failure capacity and collapse fragility curves of steel CBFs is investigated. For this purpose, 4 and 8-story steel CBF buildings with 6 different arrangements of braces were selected and modeled in PERFORM-3D software. The models were then analyzed using the incremental dynamic analysis (IDA) method. Afterwards, the collapse capacity of the models and the uncertainty index were calculated, and the collapse fragility curves were generated. The results show that, by modifying the arrangement of braces without significant changes in lateral stiffness and fundamental period of structure, it is possible to increase the collapse spectral acceleration and decrease the probability of collapse at the maximum considered earthquake intensity. Manuscript profile -
Open Access Article
8 - Effect of Tuned Mass Damper with Various Mass Fractions on the Seismic Performance of Isolated Reinforced Concrete Structures
mehdi kouhdaraghDampers and isolators are energy dissipating devices to control and reduce the seismic responses of structures under strong earthquakes. One of the most widely used of these devices is a special type of damper called TMD mass dampers and LRB lead core separators. Tuned MoreDampers and isolators are energy dissipating devices to control and reduce the seismic responses of structures under strong earthquakes. One of the most widely used of these devices is a special type of damper called TMD mass dampers and LRB lead core separators. Tuned Mass dampers (TMD) and Lead Rubber Bearings (LRB) are of the most widely used types of these devices. The scientific study of the seismic characteristics and nonlinear behavior of structural systems equipped with this type of dampers and isolators can significantly help to understand the behavior of these systems against the lateral forces imposed by strong earthquakes. In this research, a 12-story concrete structure with mass damper with various mass fractions, without isolator and with lead core isolator is designed. Then, applying time history analysis in SAP2000 software in isolated states without damper and with damper with different mass fractions, the responses of the structures against the mentioned earthquakes are obtained. The results of the analysis presented that the presence of mass damper is very effective due to the increased displacement in the isolated level. This effect is increased by increasing the mass fraction of the damper. The seismic isolator, on the other hand, can reduce the relative displacements of stories by 20 to 30% on average. The mass damper controls the large displacements of the isolator. The results in the studied structure revealed that in order to utilize the maximum capabilities of the isolator, it should be combined with mass damper. Manuscript profile -
Open Access Article
9 - Investigating the effects of using a rocking motion system on the bending seismic Behavior of special steel frames
Ali Parvari S.Behnam BeheshtiToday, the need to design and implement structures with less vulnerability and damage, and easier repair after an earthquake is essential. Traditional seismically resistant lateral systems can cause serious damage to the structural system and the relative displacements MoreToday, the need to design and implement structures with less vulnerability and damage, and easier repair after an earthquake is essential. Traditional seismically resistant lateral systems can cause serious damage to the structural system and the relative displacements remaining in the structure make it very difficult and uneconomical to repair the structure after an earthquake. The utilize of rocking motion in the structure causes the destruction of destructive seismic effects including energy dissipation and improves the seismic behaviour. In this research, in order to investigate the effects of the rocking motion system on the seismic response of short and tall regular steel buildings, a five- and ten-story steel frames with special moment frame lateral bearing system according to the fourth edition of Standard 2800 and the latest editions of the sixth and tenth national building regulations are designed by Perform3D software. Seven earthquake records were selected and then these records were based on ASCE regulations scaled according to the spectrum of the 2800. By using nonlinear time history analysis, the seismic response of the studied building has been investigated in conditions with and without using a rocking motion system. The results of studies such as base shear, Relative displacement of floors, energy dissipation and lateral and vertical accelerations of the roof indicate that the use of rocking motion system in short and tall steel buildings can significantly improve the seismic response of the structure. Manuscript profile -
Open Access Article
10 - Evaluating the seismic performance of steel-sma hybrid Bracing structures
mohammad hooshmand behzad rafezi jafar khalileAlafiIn this study the seismic performance of hybrid braces composed of steel and shaped- memory alloys (SMA). is investigated Six types of hybrid braces were used, constituted by SMA content of 0, 20, 40, 60, 80, and 100%. A nonlinear dynamic analysis was performed under El MoreIn this study the seismic performance of hybrid braces composed of steel and shaped- memory alloys (SMA). is investigated Six types of hybrid braces were used, constituted by SMA content of 0, 20, 40, 60, 80, and 100%. A nonlinear dynamic analysis was performed under El Centro earthquake records, with the maximum acceleration of 0.6g and 0.9g. Our results showed that the seismic performance, i.e., the amount of energy absorption and residual strain, of steel–SMA hybrid braces depends on the SMA content. The optimal value of SMA content was 20%, as, at this concentration, a hybrid brace can be designed with good seismic performance at a justifiable fabrication cost. Manuscript profile -
Open Access Article
11 - Investigating Coefficient of Steel Frame Behavior Under the Influence of Structural Geometry
Babak Hosamzadeh mohammad reza hashemiThe analysis and design of structures based solely on the elastic behavior of the members and the lack of attention to the plastic behavior in tolerating of the lateral forces leads to noneconomic design. All the regulations in the world, a special coefficient, called t MoreThe analysis and design of structures based solely on the elastic behavior of the members and the lack of attention to the plastic behavior in tolerating of the lateral forces leads to noneconomic design. All the regulations in the world, a special coefficient, called the building's coefficient of behavior, which is calculated to reduce the earthquake forces is considered and allows the designer to analyze the elastic structure under reduced forces and design based on its results. The magnitude of this coefficient in the earthquake regulations is based primarily on the observations of the performance of various building systems in past strong earthquakes and based on engineering judgments. Accordingly, many researchers have expressed concern about the lack of reasonable coefficient of behavior, based on research studies and computational backing in earthquake regulations, and emphasized on the correction of these coefficients based on scientific studies. By studying the results of dynamic analysis on the studied structures in two types with behavior factor 6 and behavior 7, it was shown that increasing the coefficient of behavior can play a very important role in the Seismic response. The coefficient of behavior in the building does not have a significant effect on the horizontal displacement of the structure. Because in the buildings of one and four story, according to the 2800, the effect of twisting is not considered, and because of this, the coefficient of behavior in the buildings of one and four floors does not have much effect on the earthquake force. Manuscript profile -
Open Access Article
12 - Comparison of the Seismic Performance of Braced Steel Frames with Suspended Zipper Element and CBF with the possibility of Rocking Motion
Ali Parvari Behnam FallahZipper bracing system is one of these types of braces. The zipper bracing members transfer the unbalanced tensile forces created in a floor to its upper floor, and this process continues until there is an increase in lateral load and causes the braces of the higher floo MoreZipper bracing system is one of these types of braces. The zipper bracing members transfer the unbalanced tensile forces created in a floor to its upper floor, and this process continues until there is an increase in lateral load and causes the braces of the higher floors to buckle. In this article, the dynamic behavior of the braced structure with zipper under the influence of earthquake records with rocking component and without rocking movement has been studied. SAP2000 software was used for modeling. Seven accelerometer pairs have been utilized for nonlinear dynamic analysis. The studied frames are 6-, 9- and 12- floors with a floor height of 3 meters. In all the studied models, the joint in the bracing part has been damaged. In this part, most of the damages have been at the level of continuous usability, and in the 9- and 12-story structures, the damage is a little wider and at the level of life safety performance. In the structures where rocking movement has been applied in the foundation part, it has caused the movement and shearing of the foundation of the structure to be reduced by 20 to 35 percent because it absorbs some of the earthquake force. Examining the results related to the displacement of the roof of the structure, it has been observed that the displacement of the roof in the structure with CBF bracing was about 10 to 25% less than the structure with zipper bracing. Manuscript profile -
Open Access Article
13 - Evaluation and Comparison of Response Modification Factor of the Base-Isolated Steel Moment Frames by Incremental Dynamic Analysis versus Pushover Method
Hamid Reza Sadrarhami Farshid FathiThe Response Modification Factor (R), which represents the non-elastic performance of structures during severe earthquakes is widely utilized in Codes to determine the seismic demand and to design the structures. The closer the calculated value of R is to the reality, t MoreThe Response Modification Factor (R), which represents the non-elastic performance of structures during severe earthquakes is widely utilized in Codes to determine the seismic demand and to design the structures. The closer the calculated value of R is to the reality, the more accurate the determination of the required resistance of the structure will be. The common analytical method for calculating the Response Modification Factor of ordinary buildings is the non-linear static analysis (Pushover) method. But the use of this method for buildings with base-isolation is doubtful. Incremental nonlinear dynamic analysis (IDA) is one of the new methods with wide application, which can be a suitable alternative for calculating the R of buildings with isolated bases. In the present research, the Response Modification Factor of the steel moment frame structure equipped with base isolation has been calculated and compared for 5-, 8-, and 12-steel story models by using two methods: the incremental nonlinear dynamic analysis (IDA) versus the Pushover analysis (conventional method). The results indicate that the incremental nonlinear dynamic analysis method is more accurate than the pushover analysis, due to the direct use of earthquake records, as well as considering all the dynamic characteristics of the structure, especially the dynamic characteristics of its base isolator. So that, the Response Modification Factor obtained from the IDA analysis compared to the pushover analysis, exhibits an increase of 2.8% in the 5-story, 16.61% in the 8-story, and 8.84% in the 12-story structures. The Response Modification Factors obtained from the above-mentioned analyzes have been compared with the values recommended in the FEMA P695 Code. Manuscript profile -
Open Access Article
14 - Improvement of Loose Clayey Soil Layers Under Shallow Foundation with Using Geogrid
ramin vafaeipoor sadaf mahmoudi azarGeogrid as reinforcement in the present, can solve the problems with the construction of heavy structures and embankments on weak soils without need for piling or excavation operations. This is done by placing geogrid on weak soils Between them at appropriate distance MoreGeogrid as reinforcement in the present, can solve the problems with the construction of heavy structures and embankments on weak soils without need for piling or excavation operations. This is done by placing geogrid on weak soils Between them at appropriate distances then cut the failure surfaces This article is about geotechnical information of weak soil of Fereshteh street in Tabriz city. in the present study, two sides geogrid is widely used and parallel under foundation with burst zero, one, two, three and four meters. In the PLAXIS modeling software, model has been designed for statically and dynamically or seismic analysis and their behavior has been compared. according to the results by Construction of two layers of geogrid vertical settlement for this soil has been 4.30 centimeters in thirty days. Which has the lowest amount compared to other layers in this case this can help in preventing long-term soils settlement. This result can be used for the lands which there is no limit on the adjacent Residential structures to a radius of three meters. Manuscript profile -
Open Access Article
15 - The Effect of Non-parallel System Irregularity on Seismic Performance of Braced Steel Frame Buildings
Ali Seyedkazemi Elmira AbbasnezhadA number of buildings have irregular non-parallel systems due to ground conditions and architectural design, which fall into the category of irregularities in the plan. However, the building codes do not specify a limit as the deviation value of the vertical lateral loa MoreA number of buildings have irregular non-parallel systems due to ground conditions and architectural design, which fall into the category of irregularities in the plan. However, the building codes do not specify a limit as the deviation value of the vertical lateral load bearing components from the major orthogonal axes of the building for this type of irregularities. The building frame system with bracing, on the other hand, is one of the most common systems for low- to mid-rise structures. In this research,the effect of non-parallel system irregularity on the seismic performance of steel building frame with special convergent bracing was investigated. Steel structures with 3, 6, and 9 stories were selected in this study, and in addition to the regular structural models, irregularity of non-parallel systems with different angles to the orthogonal axes from 1 to 5 degrees (i.e., 0.5 m to 2 m deviations for span length) were considered. First, the structures were designed according to the Iranian Earthquake Design Code and the Iranian Steel Structure Design Code. In order to evaluate the effect of irregularity on the seismic performance of the studied buildings, nonlinear static and dynamic analyses of time history for selected models were performed using Perform 3D software and the seismic performance indices of the structures were examined. The results indicate that with increasing irregularity; stiffness, strength, ductility and energy dissipation capacity of the structure decreases while the relative inter-story drift increases Manuscript profile -
Open Access Article
16 - Investigation of seismic Fragility and collapse capacity of RC Moment Frames Considering the increase of stiffness of the column relative to the beam under far and near field earthquakes
siamak saboonchi ashkan khodabandehlouIn the present research, the seismic fragility and collapse capacity of concrete moment frames have been investigated by considering different ratios for the weak beam-strong column rule in the optimization process in the performance-based design framework. In order to MoreIn the present research, the seismic fragility and collapse capacity of concrete moment frames have been investigated by considering different ratios for the weak beam-strong column rule in the optimization process in the performance-based design framework. In order to implement performance-based optimization, the center of mass metaheuristic algorithm has been applied in this research. The philosophy of design approach based on performance and even traditional design methods allows the structure to suffer damage facing strong and relatively strong earthquakes. Therefore, in order to estimate the level of safety of the structure against earthquakes, it seems necessary to use quantitative indicators of seismic safety and the collapse capacity of the structure. In order to predict the collapse capacity of each optimal structure, using incremental dynamic analysis, the modified collapse safety margin ratio under far and near fault earthquakes has been calculated. Two examples, 3-span three and six floor frames have been studied in this research, which are designed in the performance-based optimization framework and considering the coefficients of 0.8, 1.2 and 1.6 to control the weak beam-strong column rule in the optimization process. The results indicate that increasing the rigidity of the column compared to the beam in this research actually affects the ductility of the structure, and by choosing structures with greater rigidity of the column compared to the beam, it leads to an increase in the collapse capacity and a decrease in the fragility of the structure. Manuscript profile -
Open Access Article
17 - Seismic Performance of X-Type Braced Steel Frame with Rubber and Lead Rings in Bolt Connections
omid esmaeili saeid esmaeiliIn structures with brace, one major problem is the great hardness of the bracings frames which are efficient to improve the seismic performance and to reduce the size of the hardness. A highly stiff braced frame cannot adequately dissipate the energy exerted by earthqua MoreIn structures with brace, one major problem is the great hardness of the bracings frames which are efficient to improve the seismic performance and to reduce the size of the hardness. A highly stiff braced frame cannot adequately dissipate the energy exerted by earthquake, so it causes the structure to absorb a large portion of this energy. As a result, designers always look for viable strategies that allow the steel structure to move along earthquake motions and dissipate this energy. This paper sought to evaluate one of such strategies, which is the use o Manuscript profile -
Open Access Article
18 - Nonlinear Behavior of a Reinforced Concrete (RC) Building Strengthened with CFRP Under Progressive Collapse Based on Alternate Path Method
ali delfani armin aziminejhad abdolreza sarvghadmoghaddamThe spread of an initial local failure from element to element, eventually resulting in the collapse of an entire structure or a disproportionately large part of it is defined as progressive collapse. Occurrence of events such as blast, firing, vehicle collision and err MoreThe spread of an initial local failure from element to element, eventually resulting in the collapse of an entire structure or a disproportionately large part of it is defined as progressive collapse. Occurrence of events such as blast, firing, vehicle collision and error in design calculations or construction could cause local damages to structures. Although prospect of progressive collapse is not considered in ordinary buildings, such incident could result in significant human casualties, economic losses, and security threats in buildings which fall into very high importance categories. In this paper progressive collapse analysis is briefly presented and then nonlinear behavior of a seven-story reinforced concrete building with special resisting moment frame designed against seismic loads is evaluated under progressive collapse in accordance with Unified Facilities Criteria, UFC4-023-03 code, based on alternate path method using SAP software. It is observed that the structure is unable to meet the requirements presented in the UFC. Thus, weak beams were strengthened in flexure by carbon reinforced polymer (CFRP) fabrics. Results of the analysis indicate that the adopted method greatly enhances continuity and strength in beams adjacent to the lost column and hence in plastic hinge development, remaining the damage to be local. Manuscript profile -
Open Access Article
19 - Improve seismic performance of Concrete Moment Frame Structures using TLD damper
Ali Sarmad Mehrdad MovahedniaIn this paper, the effect of using a (TLD) damper on the seismic behavior of the Concrete Moment Frame Structures is investigated. Modeling ANSYS software is done. Modeling with structural elements including beams and columns in a concrete framing frame of Beam 189 and MoreIn this paper, the effect of using a (TLD) damper on the seismic behavior of the Concrete Moment Frame Structures is investigated. Modeling ANSYS software is done. Modeling with structural elements including beams and columns in a concrete framing frame of Beam 189 and a nonlinear dynamic analysis was used. The seismic behavior of the structures was investigated under the earthquakes of Kobe, Chichi and Tabas. The TLD Damper in the 5, 10 and 15 buildings were compared and compared. The effect of different damper positions on different structures of the structures was investigated. The effect of different damper positions on different structures of the structures was investigated. Using of a damper can cause plastic joint failure in the joints. It was also found that depression position is an effective parameter on the seismic behavior of the studied structures. For the 15th floor structure, the use of a damper on the fifth floor of the structure reduces the roof structure displacement by 10.5, in the fifth floor, 17 percent, and 53 percent in the fifth floor. In the structure of the ten floors of the dam, it reduces the displacement of the roof structure by 50%. In the 10-story structure, the dampers in the 5-day delay reduce the roof's displacement by 33%. In the five-story structure, the use of a barrier on the 5th floor decreases the roof by 64%, and the position of the damper on the third floor leads to a 26% decrease in the structure's roof. Manuscript profile -
Open Access Article
20 - Evaluation of the Peak Ground Acceleration on Seismic Characteristic of Critical Slice Surface on Embankment dams
Mehdi ShirdelAbstract: Usually, safety of slip surfaces in embankment dams have been evaluated with 2 methods: peak ground acceleration increasing method and stuff resistance decreasing method are 2 main methods for evaluation of critical bound. In this research, peak ground accele MoreAbstract: Usually, safety of slip surfaces in embankment dams have been evaluated with 2 methods: peak ground acceleration increasing method and stuff resistance decreasing method are 2 main methods for evaluation of critical bound. In this research, peak ground acceleration increasing method has been used to evaluate stability safety of slip surfaces. In this method, peak ground acceleration has been increased to receiving critical bounds for parameters in time domain (for example permanent deformation, equal dynamic factor of safety, and minimum dynamic factor of safety). To evaluate the effect of this parameter, Masjed Soleiman dam has been selected for a case study. 10 Finite Element model of Masjed Soleiman dam has been constructed considering the Mohr-Coulomb failure criterion for the body of the dam. The 2 earthquake records have been applied horizontally to the bedrock as the input for dynamic analysis without any change in frequency content. Results show that, in critical sliding surface on downstream, with increasing of peak ground acceleration, equal dynamic factor of safety decreased but changing of minimum dynamic factor of safety and permanent deformation have meaningful process. Manuscript profile -
Open Access Article
21 - The effect of far- and near-field earthquakes on the collapse capacity of performance based optimization of RC moment frames
siamak saboonchi ashkan khodabandehlouPerformance-based design is a new approach to topics of the seismic design of structures, which unlike the traditional methods of force-based design, is based on changing the location of the structure. The use of this approach in the process of structure design results MorePerformance-based design is a new approach to topics of the seismic design of structures, which unlike the traditional methods of force-based design, is based on changing the location of the structure. The use of this approach in the process of structure design results in the access to structures with proper performance and an acceptable level of reliability. The main goal of this contribution is to investigate the impact of near- and far- field earthquakes on the collapse capacity and fragility of performance based optimization of RC moment frames using the center of mass meta-heuristic algorithm. Push over analysis has been utilized in the optimization process to control the responses of the studied frames at functional levels and incremental dynamic analysis has been used to evaluate the fragility of the obtained optimal frames. According to the results for the collapse margin ratio and the adjusted collapse margin ratio for the 3-, 6-, and 12-story frames, it is indicated that the collapse margin ratio and therefore the seismic safety under far-field earthquakes are 7%, 16%, and 8% higher than those of the near-field earthquakes, respectively. In other words, the optimized frames in this study against near-field earthquakes have low seismic safety and more fragility than far-field earthquakes. Manuscript profile -
Open Access Article
22 - Optimizing the design of the earth dam body by performing quasi-static and dynamic analyzes using Plaxis software (Case study: Droodzen Dam)
Masoud Mesbahi Majid Abbasizadeh Mohammadreza NikmaneshOne of the effective and very important factors in the stability of earth dams is the shear resistance of earth materials in the body and foundation of the dam, and damages caused by the sliding of earth slopes can cause irreparable damage to an earth dam. Considering t MoreOne of the effective and very important factors in the stability of earth dams is the shear resistance of earth materials in the body and foundation of the dam, and damages caused by the sliding of earth slopes can cause irreparable damage to an earth dam. Considering the importance of earth slopes, the effect of static forces and earthquakes on its stability is extremely important. In this research, the optimization of the design of the Droodzen earth dam body is done by performing quasi-static and dynamic analyzes using Plaxis software. Based on the obtained results, geocell reinforcements increase the safety factor of dam stability and reduce the lateral deformation of the slope due to tensile strength and bending anchor. Also, by increasing the depth of the geocell placement, the tensile strength and bending moment of reinforcing increases, and by reducing the length of the geocell cover, the shear resistance of the top and bottom joint of the geocell decreases. Finally, we should mention that soil compaction leads to a significant increase in tensile force and bending moment along the length of the geocell layer. Manuscript profile -
Open Access Article
23 - Dynamic Analysis of Earthquake-Damaged Concrete Dam by Reservoir Modeling and Consideration of Dam Interaction with Reservoir
Reza Hajisharafi Shadi kuchackdezfuli -
Open Access Article
24 - تحلیل استاتیکی، دینامیکی و ارتعاش آزاد ورق متخلخل مدرج تابعی با استفاده از تئوری تغییر شکل برشی مرتبه اول ورق
کامران عاصمی سعید خبری مسعود باباییدر این پژوهش، پاسخ استاتیکیT دینامیکی و ارتعاش آزاد ورق متخلخل اشباع مدرج تابعی مورد بررسی قرار گرفته است. دو نوع توزیع شامل توزیع غیرخطی نامتقارن تخلخل و توزیع غیرخطی متقارن تخلخل در راستای ضخامت ورق در نظر گرفتهشده است. برای تحلیل، از تئوری تغییر شکل برشی مرتبه اول و Moreدر این پژوهش، پاسخ استاتیکیT دینامیکی و ارتعاش آزاد ورق متخلخل اشباع مدرج تابعی مورد بررسی قرار گرفته است. دو نوع توزیع شامل توزیع غیرخطی نامتقارن تخلخل و توزیع غیرخطی متقارن تخلخل در راستای ضخامت ورق در نظر گرفتهشده است. برای تحلیل، از تئوری تغییر شکل برشی مرتبه اول ورق استفاده شده است. برای بیان معادلات حرکت از معادله لاگرانژ و برای حل روابط حاکم بر مسئله در حوزه زمان و مکان از روش عددی اجزا محدود و روش انتگرالگیری مستقیم نیومارک استفاده شده و سپس تأثیر پارامترهای مختلف از جمله، ضریب تخلخل و ضریب اسکمپتون و دو نوع توزیع مختلف تخلخل، نسبت طول به ضخامت و شرایط مرزی مختلف بر توزیع خیز استاتیکی و گذرا و همچنین فرکانسهای طبیعی ورق متخلخل اشباع مدرج تابعی مورد بررسی قرارگرفته است. نتایج نشان میدهند که افزایش ضریب اسکمپتون همواره سبب کاهش خواهد شد، درحالیکه افزایش ضریب تخلخل باعث افزایش جابهجایی خواهد شد. Manuscript profile -
Open Access Article
25 - تحلیل استاتیکی و دینامیکی شاسی و سازه اتوبوس O-457
ابوالفضل محبوبی شاد محسن اصفهانیاندر این مقاله شاسی و بدنه اتوبوس457–O به روش اجزاء­محدود مورد تحلیل استاتیکی و دینامیکی قرار گرفته است. این فرایند با مدل­سازی سه­بعدی سیستم تعلیق، شاسی و بدنه اتوبوس آغاز شده است. در ابتدا تحلیل استاتیکی انجام شده تا از مقاومت شاسی در حالت معمولی اطمین Moreدر این مقاله شاسی و بدنه اتوبوس457–O به روش اجزاء­محدود مورد تحلیل استاتیکی و دینامیکی قرار گرفته است. این فرایند با مدل­سازی سه­بعدی سیستم تعلیق، شاسی و بدنه اتوبوس آغاز شده است. در ابتدا تحلیل استاتیکی انجام شده تا از مقاومت شاسی در حالت معمولی اطمینان حاصل شود. سپس، تحلیل دینامیکی بر روی سازه و شاسی انجام شده که در این تحلیل آنالیز مودال و گذرای سازه و شاسی بررسی شده است. در تحلیل گذرا پیچش و خمش ناشی از تحریک­های وارده از طرف جاده به سازه و شاسی با استفاده از مدل المان­محدودی که مشخص­کننده کل سازه وسیله نقلیه می­باشد، بررسی گردیده و از استحکام کافی سازه و شاسی در این حالت نیز اطمینان حاصل شده است. Manuscript profile -
Open Access Article
26 - مدلسازی و تحلیل مودال برای نوسانات تیر IPMCو شبیهسازی به عنوان عملگر
آرش رجایی علی مختاریان مصطفی پیرمرادیانهدف این مقاله تحلیل مودال تیر از جنس پلیمر-یونی فلزی است، سپس سیستم را به یک مود با پارامترهای منحصربه­فرد خود خلاصه کرده تا در شبیه سازی عملگر به ما کمک کند. در این مقاله ابتدا با استفاده از تحلیل ریاضی و فرم بسته تابع تبدیل سیستم تیر یکسر گیردار، پاسخ دینامیکی آن Moreهدف این مقاله تحلیل مودال تیر از جنس پلیمر-یونی فلزی است، سپس سیستم را به یک مود با پارامترهای منحصربه­فرد خود خلاصه کرده تا در شبیه سازی عملگر به ما کمک کند. در این مقاله ابتدا با استفاده از تحلیل ریاضی و فرم بسته تابع تبدیل سیستم تیر یکسر گیردار، پاسخ دینامیکی آن را به نیروهای ورودی مختلف (متمرکز و پیوسته) محاسبه کرده و برای انواع مختلف سیستم، نقاط تشدید و ضد­تشدید را در تحلیل فرکانسی پیدا می­شود، سپس با استفاده از آنالیز مودال در سیستم، کل پاسخ آن­را در مود پایه خلاصه کرده و پارامترهای فرکانس طبیعی نامیرا و ضریب میرایی در این مود برای سیستم معرفی می­شود، سپس تیر یکسر­گیردار کامپوزیتی را به عنوان یک عملگر در نظر گرفته می­شود که با ولتاژ ورودی، تغییر مکان و نیرو در سر آزاد خود ایجاد می­کند که با بررسی پاسخ­ها به ورودی­ها، رفتار سیستم تحلیل می­شود Manuscript profile
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