Probabilistic Design Optimization of TMDI System for Seismic Mitigation Subjected to Random Ground Motions

Abstract

The tuned mass damper Inerter (TMDI), consisting of mass blocks, springs, dampers and two-terminal inertial elements, is a passive control device on the basis of the tuned mass damper (TMD). A large number of studies on the design optimization and performance evaluation of the TMDI system have been conducted in recent year. But they are almost analyzed from the perspective of deterministic analysis. This is far from non-stationary and non-Gaussian processes that feature the characteristics of engineering excitations such as earthquake ground motions and typhoons. Aiming at such a challenge, the variance-based design optimization of TMDI system for seismic mitigation and probability density evolution analysis subjected to stochastic ground motions are performed in this study. First, based on the theoretical formula and the numerical optimization via genetic algorithm (GA), the design method of TMDI system with respect to the primary structure frequency ratio and the TMDI damping ratio subjected to Gaussian white noise is proposed. On this basis, the probability density evolution method and physically-motivated stochastic ground motion model are used. Combining with numerical examples, the optimal parameter design of structure-TMDI system and probability density evolution analysis under the action of stochastic ground motion are carried out. The seismic mitigation performance and structural reliability of structure-TMDI system with different cases of parameters are then explored. Numerical results reveal the technical advantages of TMDI system, i.e., high performance, mass reduction and stroke limitation in a probabilistic sense.