Seismic performance assessment of steel frames equipped with a novel passive damper using a new damper performance index

Abstract

Seismic response of steel moment-resisting frames equipped with a novel passive damper called infilled-pipe damper (IPD) is investigated in this study. The IPD is a very economical and easily assembled structural control device with high energy absorption, invented recently by the authors. A simplified trilinear load–displacement model for IPD devices is suggested to be used in this study and further investigations. Next, criteria for IPD elements size selection are proposed for passive control of structures against earthquake loads. Steel frame structures of 5, 10, and 20 stories are designed without any IPD devices. Then, the frames are equipped with IPDs of different stiffness. The frames are subjected to seven earthquake excitations scaled to design basis earthquake and maximum considered earthquake levels. Several response parameters including energy segments and normalized energy ratios are considered, and the performance of the IPDs in reducing each response is evaluated. A new damper performance index, considering global structural damage, local destructive damage and nonstructural damage in a single relationship, is suggested in this study. The index can be employed for optimization purposes in structures equipped with different types of dampers. The results show that the IPD devices dissipate a considerable portion of the seismic input energy and reduce the structural and nonstructural damages. Copyright © 2014 John Wiley & Sons, Ltd.