mohammadreza adib ramezani

Evaluating the seismic vulnerability and collapse capacity of structural systems typically involves conducting Incremental Dynamic Analysis (IDA) and generating fragility curves, both of which are complex and time-consuming. To simplify the extraction of fragility curves at different performance levels, the SPO2FRAG software was developed by previous researchers. However, its accuracy in predicting the collapse capacity of systems with varying heights has not been thoroughly validated against detailed analyses using seismic records. This study evaluates the efficiency and accuracy of SPO2FRAG in steel plate shear wall systems (SPSWs) with 4, 8, 12, and 16 stories, all designed in accordance with relevant codes. The numerical models were validated against a well-documented experimental specimen to ensure reliability. Fragility curves at the collapse performance level were derived using two

(1) IDA with 22 pairs of far-field earthquake records, and (2) the SPO2FRAG software he results show that for 4- and 8-story buildings, SPO2FRAG provides conservative estimates of collapse capacity compared to the more precise IDA. However, its reliability decreases with building height, leading to significant overestimation in the 16-story structure. While SPO2FRAG is a quick and cost-effective tool for assessing low- to mid-rise SPSWs, more accurate methods like IDA are recommended for taller structures. This study highlights the limitations of SPO2FRAG in evaluating taller SPSWs and underscores the importance of using detailed analysis methods for critical infrastructure. Future research should focus on enhancing the predictive capabilities of simplified tools like SPO2FRAG for high-rise structures.

In recent decades, the coupled Steel plate shear wall system is considered as an efficient lateral force resisting system by engineers and researchers. Different parameters affect the nonlinear behaviour of Coupled Steel plate shear wall system. Other models are produced according to the base model. After verifying the nonlinear behaviour of this system by cross stiffeners on the Coupled Steel plate shear wall, an increase in the thickness of the stiffeners and the thickness of the Coupled Steel plate shear wall have been evaluated. In this study, the effect of the parameters on the initial stiffness, ultimate strength, and energy absorption by the samples have been compared with each other and the base model. The cross stiffeners on the Coupled Steel plate shear wall have also increased the sample's initial stiffness, ultimate strength, and energy absorption. However, the use of stiffeners does not significantly affect the energy absorption by the samples. Stiffeners increase the sample's initial stiffness, ultimate strength, and energy absorption, which has little effect on the energy absorption by the sample.

This research has investigated the improvement of the seismic behavior of repairable systems with a cradle mechanism in steel braced buildings with irregular mass in plan. A new method is used to find a suitable method in a building with a regular plan with asymmetric mass distribution, in order to reduce the adverse effects of the structure and to quickly repair the damage caused to the structure after a strong earthquake. In this method, by creating lifting conditions at the base of braced bay columns and by using energy-dissipating devices in this part, energy absorption and consumption are transferred to this part of the structure and prevent damage to other parts. Based on the results, the effect of taking into account the effects of vertical and horizontal earthquakes in different mass irregularities of structures in the seismic performance of low-rise structures was determined. Also, the irregularities in the numerical model of the structure have a significant effect on the IDA curves. As the height of the structure increases in the four failure modes, the mean probability of fragility of the structures occurs at a lower Sa, which means that the vulnerability of the structure increases. Also, with the increase in height, the slope of Sa reduction in four failure modes becomes milder, and the fragility curves for two IO performance levels and CP performance level have been obtained for all 6 structures. Considering the effect of irregularities, they are significantly effective in the structural failure of structures, so that considering the effect of these irregularities in mass distribution can lead to an increase in the probability of structural failure.

Seismic intensity measures (IMs) perform a pivotal role in probabilistic seismic demand modeling. Past studies investigated appropriate IMs for structures, including the vital component of the transportation system, the highway bridges. These studies were mainly focused on far-field earthquakes and did not consider the strong vertical component of ground motions in near-field earthquakes.  In order to evaluate the optimal IMs for the multi-span continuous concrete box girder bridges subjected to near-field earthquakes, ten sample bridges were modeled and then subjected to three-component records of 164  near-field earthquakes applying the OpenSees software framework. In the present research, 5 engineering demand parameters considering the most critical response parameters related to columns and deck were selected, along with 24  intensity measures considering the horizontal and vertical components of ground motions. Base on the optimality investigation method, parameters such as efficiency, practicality, proficiency, sufficiency, and relative sufficiency were considered. In total, 8200 nonlinear time-history analyses were conducted. The results presented that the peak ground velocity of the horizontal component (PGVH), velocity spectrum intensity of the horizontal components(VSIH), and Housner intensity of horizontal components (HIH) were the optimal intensity measures, and vertical component of ground motions in near-field earthquakes should be considered in optimality investigation.

Achieving customer satisfaction is a condition for the survival of organizations and as a strategic factor in gaining their competitive advantage. In this research, an attempt has been made to establish a relationship between the customer and logistics services, which has been made possible through the QFD technique. In this research, fuzzy logic has been used due to the use of customer and expert opinions on issues about which there is little or no difficulty in expressing opinions or there is no accurate information about the issue. In this research, the emphasis is on the first stage of QFD, which is called the quality house matrix. All stages of data analysis have been performed using the fuzzy QFD approach in which changes have been made to the logistics services. In general, the purpose of this study is to determine which of the logistics organizations to focus on in order to achieve maximum customer satisfaction and, consequently, maximum profit for the organization.

The aim of this study was to investigate the length of the gusset-plate hinge zone proposed by Iranian National Building Code (Part 10) for Special concentrically braced frames (SCBF). For this purpose, numerical studies were done on the seismic behavior of this frames using ABAQUS software. Numerical modelling procedure is validated using the reproduction of the results of an experimental study. A five story building with Special diagonal concentrically braced frames was modeled in ETABS software and a portal frame from the first story of the building was considered for investigation. The detailing of the frame was designed for tension and compression based on Iranian code. Seismic behavior of single and double tapered gusset plates with various connection angles and dimensions as well as various length of the hinge zones including -3t, -2t, -t, 0t, t, 2t and 3t were investigated using nonlinear cyclic deformation loading to the ATC-24 test protocol.Seismic behavior of the connections were studied based on ductility, number of cycles before failure, drift before failure and tension and compression strength.Evaluation of the failure limit of the models was carried out using the concept of equivalent plastic strain. Based on the results of the investigated models it can be said that: It is not recommended to use double gusset plates instead of single ones for SCBFs. Gusset plates with a 15 degree angle of inclination have higher ductility capacity and better seismic behavior than ones with a 25 degree angle of inclination. For single gusset plates with a 15 degree angle of inclination, the appropriate length of the hinge zone is -2t, which is not consistent with Iranian code. For single gusset plates with a 25 degree angle of inclination, the appropriate length of the hinge zone is 2t, which is consistent with the Iranian code.