SEISMIC FAILURE CONTROL OF BUILDINGS USING MR DAMPERS

This paper focus on the failure control of buildings subjected to earthquakes, and two damage indices, the local index and the global index, are also presented. The local damage index is defined as the equivalent strain of element, and the global damage index is assembled through the local one, in which the relevant absorbing energy is used as weighting factors. As a numerical example, the 9-story benchmark structure with magnetorheological (MR) dampers is analyzed under different earthquake excitations. Comparison with the uncontrolled structure indicates that the controlled one has a much smaller damage and longer failure path. The damage of columns on the first story is related to their location and earthquakes, and the side columns orthotropic to the larger component of the near field earthquake are the most damageable. An increasing dynamic analysis (IDA) is also conducted, results show that the damage of controlled structure increases linearly to the seismic intensity due to the capacity of control devices, and after the second peak acceleration of 7 times El Centro earthquake, the uncontrolled structure collapses quickly while the controlled structure can withstand it with only small damage, which demonstrates that MR dampers are one of the most effective devices to reduce the damage extent and lengthen the failure path of structures under strong earthquakes.