Improving the nonlinear seismic performance of steel moment-resisting frames with minimizing the ductility damage index

Abstract In this paper, the parameters optimization of a tuned mass damper (TMD) is presented to enhance seismic performance six-story steel structure based on ductility damage index. Herein, frame modeled nonlinearly in OpenSees software by concentrated plasticity model. Finally, most suitable algorithm selected among several algorithms convergence rate and objective function's values. process, water cycle has shown best results. Therefore, optimal TMD are calculated such way that index minimized under earthquake loads. For purpose, nonlinear dynamic analysis performed earthquakes loads using software. Also, optimum computed minimize linking Matlab The results show system obtained could appropriately decrease It can simultaneously increase structure's reduce displacement, stories damage, drift ratio.