List of Articles Nonlinear static analysis

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  1 - Seismic Vulnerability assessment of concrete railway bridge using nonlinear analyses
  Araliya Mosleh Hamed Hamidi Ahmad Nicknam José Jara Humberto Varum
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  2 - Evaluation of Nonlinear Seismic Behavior of Reinforced Concrete moment Frames with Special Ductility with and without Viscous Dampers on the Floors Level
  ashkan khodabandehlou siamak barmaki
  10.30495/civil.2023.1974310.1311
  The main goal of this research is to evaluate the nonlinear seismic behavior of special RC moment with and without viscous dampers at the floor level. In this research, 2 high-rise three-dimensional RC building frames of 12 and 16 stories, each frame with 8 models, 4 mo More

  The main goal of this research is to evaluate the nonlinear seismic behavior of special RC moment with and without viscous dampers at the floor level. In this research, 2 high-rise three-dimensional RC building frames of 12 and 16 stories, each frame with 8 models, 4 models with and 4 models without viscous damper at the floor level, located in the area with High seismicity on type 3 soil is considered. In order to seismic analysis of frames with and without viscous dampers, nonlinear static analysis method was used according to the second appendix of Iran earthquake regulations, fourth edition. The initial dimensions of the structural elements of the studied frames and the thickness of the roof slabs have been determined in ETABS-V15 and SAFE2014 software, respectively, and finally, modeling, gravity and lateral loading, and nonlinear static analysis of the studied frames have been performed in the SAP2000-V19 software. The results show that the change in the sections of beams and columns from square to rectangle in frames with and without viscous damper causes an increase in the relative lateral displacement of the floors, as well as an increase in the number of openings along the Y axis (model 1 compared to 3), and an increase in the length of the opening along the Y axis (model 1 Compared to 4), in frames with and without viscous damper, it reduces the absolute lateral displacement of floors. Manuscript profile
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  3 - Seismic Performance Investigation of Buckling Restrained Braces with Parallel Yielding Double Core
  Kourosh Mehdizadeh Abbasali Sadeghi Seyede Vahide Hashemi
  The 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 More

  The 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
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  4 - Strengthening Reinforced Concrete Frames by Using Steel Mega Bracing System
  Mohammad amin ُSharifi Abdolrahim Jalali
  The present study investigates the seismic performance of reinforced concrete moment frame system retrofitted with different steel bracing systems. Two types of structural combinations including concentric steel bracing system and steel mega bracing system were used in More

  The present study investigates the seismic performance of reinforced concrete moment frame system retrofitted with different steel bracing systems. Two types of structural combinations including concentric steel bracing system and steel mega bracing system were used in two types of structures with different numbers of stories. These two structures which are designed by 5 and 10 story reinforced concrete moment frame system have poor lateral stiffness. They were considered to compensate for the limitations of drift regulations in areas with high seismic risk and life safety performance level. Then, these frames are improved by concentric steel bracing system and mega bracing system. In this study, the nonlinear static (pushover) analysis was used to evaluate the performance of the structure under the influence of ground motions. Also chord rotation, story drift and base shear were used to compare the response of the improved structure. It was shown that the steel mega bracing system and the concentric steel bracing system are respectively the best types of steel bracing systems for upgrading and retrofitting the structures in terms of drift control regulations, the amount of base shear, the number of plastic hinges, the number of collapse elements and the economic issues. Manuscript profile
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  5 - Investigating the effect of infill walls in creating short columns in concrete frames (a case study
  Mohammad Reza Tabeshpour soudabeh taheri
  10.30495/civil.2023.702324
  Owing to the common use of infill walls in conventional buildings, it is a practical and important topic to investigate the effect of infill walls on the behavior of structures during earthquakes. One of the disadvantages of infilled frames is the presence of large wind More

  Owing to the common use of infill walls in conventional buildings, it is a practical and important topic to investigate the effect of infill walls on the behavior of structures during earthquakes. One of the disadvantages of infilled frames is the presence of large window openings in some of the reinforced concrete frame buildings, which results in the short column phenomenon. The part of the column that is adjacent to the wall is almost integrated with the wall and leads to a reduction in the height of the column. Therefore, the lateral stiffness increases considerably. With increasing stiffness, the lateral force applied to the column also increases. In this study, a 4-story, 3-span reinforced concrete model with a different arrangement of infill walls in the stories and considering short walls on the ground floor, the short column phenomenon has been investigated in ETABS software. Also, the seismic capacity of the structure has been calculated by valid methods based on the capacity spectrum method proposed by ATC40. The results indicate that with increasing stiffness, the maximum shear force applied to the column due to the presence of the infill wall under the designed earthquake load will increase by about 50% compared to the frame without the infill wall. Furthermore, the amount of stiffness difference in the frame with and without infill wall in the analyzed models is about 70%, which can prevent irreparable damage by predicting this event and proper design. Manuscript profile
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  6 - Comparing the Performance of Short Link Beam in Buckling Unrestrained and Restrained Eccentric Braced Frames under non-linear Static and Dynamic Analysis
  Arash Hossein Shahi aboozar saleh
  According to the fact that our country is located in one of the seismic zones of the world, the possibility of strong earthquakes in different regions is inevitable. Over the past years, researchers have proposed different systems for absorbing and dissipating earthquak More

  According to the fact that our country is located in one of the seismic zones of the world, the possibility of strong earthquakes in different regions is inevitable. Over the past years, researchers have proposed different systems for absorbing and dissipating earthquake energy in structures, which, in this regard, unrestrained buckling braces have been focused by engineers. The purpose of this research is to examine the behavior of short link beam in steel frames with buckling and non-buckling braces. For this purpose, three structures, 3, 6 and 9 stories with buckling and non-buckling braces are designed according to valid regulations and all seismic rules have also been controlled. Then, their lateral two-dimensional frame is modeled with eccentric braces on the SeismoStruct 2016 software. In order to investigate the behavior of the link beam, nonlinear static and time history analysis have been used for three far-field earthquakes and type 2 soil. In the following, the results of the shear force and the bending moment of the link beam and the nonlinear static analysis curves of the frames in two models with buckling and non-buckling braces are compared. The results of nonlinear static analysis show that the moment and shear in the non-buckling link beam can be up to 38 and 50 percent more than the frame with buckling braces, respectively. Non-linear time history analysis shows a higher growth of link beam forces in a frame with non-buckling braces than nonlinear static analysis. Manuscript profile
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  7 - 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 Fathi
  10.30495/civil.2023.701146
  The 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 More

  The 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
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  8 - The Effect of Non-parallel System Irregularity on Seismic Performance of Braced Steel Frame Buildings
  Ali Seyedkazemi Elmira Abbasnezhad
  10.30495/civil.2022.689389
  A 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 More

  A 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
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  9 - The Effect of Viscous Dampers in Seismic Retrofitting of Steel Buildings
  Mehdi Vakilzadeh Kambiz Mazaheri Mohaddeseh Bakhtiyari Azad
  The target of seismic improvement of a building is to strengthen the structural and non-structural members in order to reduce the earthquake damage. Dampers dissipate the structure’s energy.By using these types ofequipment,the damage to the structure is dramatical More

  The target of seismic improvement of a building is to strengthen the structural and non-structural members in order to reduce the earthquake damage. Dampers dissipate the structure’s energy.By using these types ofequipment,the damage to the structure is dramatically reduced. In this article steel frames with three, six and ten stories with and withoutdampers aremodeled in SAP software.They are evaluated by using seismic retrofitting guidelinesand nonlinear static method. The results show that adding a viscous damper reduces seismic effect and damage performancelevel.In addition, using dampersin high-rise structures is more effective than shorter ones in reducing the effects of an earthquake. Manuscript profile
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  10 - Effect of yield-torsional damper on the vibrational Energy Absorption of the Structure
  alireza ansari saeed abbasi asghar rasouli
  10.30495/civil.2022.691517
  To improve the behavior of seismic system and increasing the capacity of structures, using of dampers is a suitable method for energy dissipation and reduction of seismic demand. The behavior of structures during earthquake has a direct relationship with the stiffness, More

  To improve the behavior of seismic system and increasing the capacity of structures, using of dampers is a suitable method for energy dissipation and reduction of seismic demand. The behavior of structures during earthquake has a direct relationship with the stiffness, ductility and hysteresis curves of the energy dissipation of the resistant system. Controlling and dissipating the energy input to the structure in order to reduce earthquake damage is a perfect way to meet the needs of structures. For this purpose, a system has been introduced that is utilized as a fuse during the earthquake due to its high ductility and prevents damage to the main elements of the structure. In this study, a specific type of yield damper with torsional behavior named yield-torsional damper or TFD is investigated and the energy absorption capacity of the structure is evaluated. It was observed that this system increases the power of structural energy absorption. For this purpose, the proposed system has been numerically examined nonlinearly in ABAQUS software. The results of this research indicate that the application of TFD dampers results in the structure to depreciate energy in the interface member and significantly reduces the contribution of other structural members in the energy absorption and puts the behavior of the structure at a better performance level. Manuscript profile
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  11 - Evaluation of Nonlinear Seismic Behavior of Reinforced Concrete Flexural Frames with Special Ductility with and without Viscous Dampers on the Floors Level
  siamak barmaki ashkan khodabandehlou
  10.30495/civil.2023.708011
  The main goal of this research is to evaluate the nonlinear seismic behavior of special RC moment with and without viscous dampers at the floor level. In this research, 2 high-rise three-dimensional RC building frames of 12 and 16 stories, each frame with 8 models, 4 mo More

  The main goal of this research is to evaluate the nonlinear seismic behavior of special RC moment with and without viscous dampers at the floor level. In this research, 2 high-rise three-dimensional RC building frames of 12 and 16 stories, each frame with 8 models, 4 models with and 4 models without viscous damper at the floor level, located in the area with High seismicity on type 3 soil is considered. In order to seismic analysis of frames with and without viscous dampers, nonlinear static analysis method was used according to the second appendix of Iran earthquake regulations, fourth edition. The initial dimensions of the structural elements of the studied frames and the thickness of the roof slabs have been determined in ETABS-V15 and SAFE2014 software, respectively, and finally, modeling, gravity and lateral loading, and nonlinear static analysis of the studied frames have been performed in the SAP2000-V19 software. The results show that the change in the sections of beams and columns from square to rectangle in frames with and without viscous damper causes an increase in the relative lateral displacement of the floors, as well as an increase in the number of openings along the Y axis (model 1 compared to 3), and an increase in the length of the opening along the Y axis (model 1 Compared to 4), in frames with and without viscous damper, it reduces the absolute lateral displacement of floors. Manuscript profile