List of Articles Hover

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  1 - Species diversity of hover flies (Diptera: Syrphidae) and determination of the dominant species in Garmsar region
  Azadeh Jabbari Ali Ahadiyat Rustem Hayat
  Hover flies (Diptera: Syrphidae) are considered as one of the most important natural enemies of aphids, and one of the most useful pollinators of plants. Their larvae are predators of aphids and they have an important role in ensuring biological balance. In this study, More

  Hover flies (Diptera: Syrphidae) are considered as one of the most important natural enemies of aphids, and one of the most useful pollinators of plants. Their larvae are predators of aphids and they have an important role in ensuring biological balance. In this study, which were performed in Garmsār region in 2010, these flies were collected and identified. The species diversity of these insects was measured by indexes of Shanon–Winer (H´), Brilloun (Ĥ), and Margalov (Dmg). In the faunistic studies, 16 species belonging to 10 genera and 2 sub-families, were identified, among them the species, Eupeodes lapponicus, is considered as the new record form Iran. The maximum diversity and abundance of hover flies in Garmsār were as Ĥ=1.125, H´=2.247, Dmg=22.878 at the first week of Khordād month (end of May). Also, Episyrphus balteatus is dominant speciesin Garmsar region. Manuscript profile
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  2 - Assessment of ASCE 41-06 Pushover Procedure in Performance Evaluation of Concrete Vertical Irregular Buildings
  Ehsan Danesh Dezfuli armin Aziminejadb
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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 - 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 Hashemi
  Structural 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 More

  Structural 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
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  5 - Experimental and seismic analysis performance of three-core buckling restrained braces
  ali chigoi mohhamad ali rahgozar mohsen izadinia
  10.30495/civil.2021.680324
  In this paper, in order to improve the seismic behavior of BRBs, buckling-restrained braces with three parallel cores with different yield stress have been suggested and introduced. The buckling restrained braces were made in one and three steel core with the same tensi More

  In this paper, in order to improve the seismic behavior of BRBs, buckling-restrained braces with three parallel cores with different yield stress have been suggested and introduced. The buckling restrained braces were made in one and three steel core with the same tensile and compressive capacity. These braces were subjected to cyclic tensile and compressive loads in the laboratory under the ATC-24 loading protocol. Hysteresis cyclic performances of each brace were obtained and examined. Then, the one and three core buckling braces were placed diagonally in a steel moment frame and their seismic performance and response modification factors were obtained using adaptive pushover analysis. The results indicated that the three core brace has 16.3% and 8.8% higher energy absorption and damping capacity. In addition, the damping in the three-core brace in drift 2.5% is 8.8% higher than the one core brace. Mean value of response modification factors for steel moment frame with one-core brace is 8.11 and steel moment frame with three-core brace is 9.14. In conclusion, the three-core brace has higher energy absorption and damping capacity and the ductility of the steel moment frame with the three core brace is higher than that of the frame with the one core brace, which presented the three-core brace has more acceptable seismic performance and is highly recommended for rehabilitation Manuscript profile
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  6 - Study on Behavior of Infilled Composite Steel Frame under Lateral Loading
  Hasan PoorMohammad seyedali tabatabayi
  Abstract In previous earthquakes, the effect of infill in the structures has shown the importance of modeling and evaluating their influences in analyzing and designing the structures. Different modeling methods have been presented up to now in this field. In this rese More

  Abstract In previous earthquakes, the effect of infill in the structures has shown the importance of modeling and evaluating their influences in analyzing and designing the structures. Different modeling methods have been presented up to now in this field. In this research, the effect of infill with various number of stories is investigated by pushover method. The results of this research reveal that the expected behavior of the structures with and without infill differs significantly. Also with increasing the number of stories, values of initial stiffness, periods, shear values and drift in buildings with infill vary basically in comparison with building without infill. 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 - Seismic behavior of knee brace compared with X and Chevron bracing in steel frame
  Mohamad haghayegh gafar Asgari mohammad sadeg rohani manesh
  In this paper, with the introduction of a new Knee Brace Frame the seismic behavior of steel frames braced with knee brace compared with X and Chevron brace frame are discussed. For this purpose, the braced steel structures, with the number of floors three, five and eig More

  In this paper, with the introduction of a new Knee Brace Frame the seismic behavior of steel frames braced with knee brace compared with X and Chevron brace frame are discussed. For this purpose, the braced steel structures, with the number of floors three, five and eight-story frame with four meters three-span by using pushover analysis are analysed. Considering that lateral displacement structures parameter is an effective parameter on failure of structural and non-structural members, The amount of lateral displacement of steel frames braced with different types of braces, and also given the importance of ductility coefficient such behavior braced steel frames are compared with each other. Studies have shown that, the Knee Brace Frame, ductility and stiffness conjoined provides. Manuscript profile
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  9 - 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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  10 - A Review of Partial Discharge Signals Occurrence in Polluted High Voltage Insulator
  Hosein Fadaeeasrami Faramarz Faghihi Hosein Mohammadnezhad
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  11 - Numerical solution of hovering propeller performance at various blade pitch angles and revolutions with different turbulence models
  Behrooz Shahriari Mohammad Reza Hashemi
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