Seismic performance evaluation of steel frames with viscous dampers using Endurance time method.

It is unavoidable to prevent serious damage to the structure and to reduce the casualties and damage caused to it. For this purpose, structural control systems can be used. The study used a viscous damper. The Endurance Time method (ET) is a simple method of analyzing history when the structure is exposed to a gradual accelerating function. The advantage of this method is that with only one analysis of the structure under the acceleration function of endurance time, the performance of the structure can be evaluated at different functional levels. In this study, the application of endurance time method in nonlinear seismic analysis of steel structures equipped with viscous dampers has been investigated. The parameter of engineering demand is the maximum drift of the floors, which is calculated in structures with and without viscose damper. Finally, using curves of endurance time, it was found that the use of viscous dampers reduced the maximum drift of the floors. Non-linear time history analysis (NTH) has also been used to validate the results of the (ET), which showed that the (ET) results are well matched to the nonlinear time history analysis. Finally, the results demonstrated that utilizing of ET method can be replaced in structural building which the viscous damper was utilized.