Seismic response reduction of irregular buildings using passive tuned mass dampers

This paper illustrates the practical considerations and vibration control effectiveness of passive tuned mass dampers (PTMDs) for irregular buildings, modelled as multi-storey torsionally coupled shear buildings, under bi-directional horizontal earthquake excitations. The PTMD is designed to control the mode which makes most contribution to the largest response of the building. Its optimum installation location and moving direction are determined from the controlled mode shape values. The optimal system parameters of PTMD are then calculated by minimizing the mean-square modal displacement response ratio of controlled mode between the building with and without PTMD under earthquake excitation from critical direction. As two PTMDs are used to reduce both translational responses, this study arranges the two mass dampers to achieve the largest vibration reduction. Numerical and statistical results from a long and a square five-storey torsionally coupled buildings subjected to five real earthquakes from different incident angles verify that the proposed optimal PTMDs are able to reduce the building responses effectively. (C) 1999 Elsevier Science Ltd. All rights reserved.