34www.ijeas.org  Abstract-In this study, the seismic behaviour of the concrete shear wall considering the opening with different shapes and constant cross-section has been studied, and for this purpose, several shear walls are placed under the increasingly non-linear static analysis (Pushover). These case studies modelled in 3D Abaqus Software, and the results of the ductility coefficient, hardness, energy absorption, added resistance, the final shape, and the final resistance are compared to shear walls without opening.

Composite columns are one of the most used cross-sections in various buildings and bridges. In this research, the impact of different parameters such as the effect of the eccentricity of loads or the change in the horizontal distance of the loading profiles in buckling of the composite columns with double IPE cross-sections as well as the impact of different value of slenderness on buckling of composite box columns has been investigated. Based on the results, the steel member's yielding will be delayed by filling the steel sections with concrete. Also, an increase in the amount of composite column capacity is directly related to the associative ratio of composite concrete. In other words, increasing the ratio of the concrete surface leads to greater capacity which is caused by being filled with concrete.

The external post-tension technique is one of the best strengthening methods for reinforcement and improvement of the various steel structures and substructure components such as beams. In the present work, the load carrying capacity of the post-tensioned tapered steel beams with external shape memory alloy (SMA) tendons were studied. 3D nonlinear finite element method with ABAQUS software is used to determine the effects of the increase in the flexural strength, and the improvement of the load carrying capacity. The effect of the different parameters, such as geometrical characteristics and the post-tension force applied to the tendons were also studied in this research. The results revealed that the external posttension with SMA tendons in comparison with the steel tendons caused a significant improvement of the loading capacity. According to this, using SMA tendon for the reinforcement of the tapered beams resulted in a decrease in weight of these structures and as a consequence responded economic benefits in their application. This method can be used extensively for steel beams due to low executive costs and simplicity of the operation for post-tension.

In this study, the seismic behavior of the concrete shear wall considering the opening with different shapes and constant cross-section has been studied, and for this purpose, several shear walls are placed under the increasingly non-linear static analysis (Pushover). These case studies modeled in 3D Abaqus Software, and the results of the ductility coefficient, hardness, energy absorption, added resistance, the final shape, and the final resistance are compared to shear walls without opening.