Frequency domain transfer function based multimodal design method for seismic mitigation of building structures

Abstract

Multiple tuned mass dampers (MTMD) are widely used to mitigate structural seismic response. With the emergence of more and more high-rise buildings, various MTMD design methods applicable to multi degree of freedom (MDOF) model have been developed. However, the existing MTMD design methods for MDOF models often involve complex optimization algorithms. In order to simplify the MTMD design while effectively reducing the seismic response of the structure, this paper proposes an explicit frequency domain transfer function, theoretically showing the mechanism of decomposing the seismic mitigation of MDOF model into simultaneous seismic mitigation of multiple modes, and developed a theoretical design method of MTMD, so that the dynamic parameters and position of each TMD can be directly obtained based on the developed explicit design formula. A benchmark model was used as an example to verify the seismic mitigation performance. It is shown that the developed multimodal control MTMD design method achieves 22.25% reduction rate of acceleration and 18.5% reduction rate of displacement with 3% mass ratio.