Sharif Digital Repository

Researches carried out on the damages imparted to the building structures under severe earthquakes have shown the importance of asymmetry effects of the buildings on the level of these damages. In these cases, the structures enter into the nonlinear state of their behavior and the structural elements, as well as nonstructural ones undergo large deformations. Additional damping systems have been proposed in many studies to avoid enforcing such large forces on the structures. One example of these systems is viscous fluid damper. The effectiveness of this type of dampers in reduction of the forces has been shown in many previous works. In this research we look for a damping eccentricity which... 

The feasibility of passive energy dissipation devices such as viscous fluid dampers in controlling the torsional response of structures against seismic loadings has been explored by different researchers in recent years. In the majority of these studies, it is assumed that the structures are located on rigid bases. On the other hand, the effect of Soil-Structure Interaction (SSI) for the structures located on soft soil, on their dynamic parameters and structural responses can be prominent. In this study, the application of viscous fluid dampers in improving the torsional behavior of asymmetric concrete moment resisting frame buildings is investigated, taking into account the soil-structure... 

By investigating reports of severe and destructive earthquakes of the past years we have realized that shear-wall structures most of the times had better seismic performance and more reliability than moment resistance frames. Asymmetrical arrangement of shear walls due to architectural limitations caused distortions in the structure. On the other hand, seismic regulation don’t compliance existence of twisting moment in the structures. What was said are all the most important reasons for not employing asymmetric shear wall sets in the structures by designers. The purpose of this study is to compare the seismic behavior of symmetric moment frame structures with seismic behavior of symmetric... 

The dynamic response of the structural systems are influenced by various parameters such as the effect of higher and torsional modes, the change in frequency or inertial loads caused by the structural softening, frequency content of earthquake records, etc.. Therefore, any method that is only based on static procedure without considering the dynamic characteristics of the structural system may lead to erroneous output. The enhanced pushover procedures have been developed to minimize the inaccuracies of the nonlinear static analyses in predicting the real nonlinear response of structures while maintaining their simplicity. In this research the innovative methods are proposed individually for... 

Nowadays, many structural engineers use fillet welds in their designs because of their high strength and affordability. In these welds, eccentric loadings either out-of-plane or in-plane create complex condition in welds from stress point of view. To determine the capacity of such fillet welds different methods have been proposed over time. For instance, the method approved by AISC is the Elastic method. This method when combined with load factors, as required by the LRFD design method, yields very conservative designs for fillet welds. Therefore, in this project, we try to propose the plastic method for welds under eccentric loadings. This method is more economical than the elastic method...