Experimental Investigations of Stochastic Control of Randomly Base-Excited Structures

A series of numerical simulations and experimental verifications on vibration control of structures subjected to earthquake excitations have been conducted. In most existing researches, only several ground motions at different levels are considered, and the efficacy of vibration suppression is usually denoted by the reduction of peak responses. In this paper, a complete shaking-table test on a controlled structured is carried out, in which the randomness inherent in the earthquake ground motions was considered. The representative time histories of ground accelerations, as the base excitation, are generated employing the stochastic ground motion model. The stochastic response analyses of the experimental structures with and without control are conducted, respectively, based on various criteria, including peak responses, RMS responses and PDFs of responses. Experimental results indicate that the seismic performance of the test structure with magnetorheological (MR) dampers is significantly improved compared with that of the uncontrolled structure. The investigation on PDFs of the stochastic responses with control system is very important to better understand the structural performance.