OPTIMAL BILINEAR MODELS OF SUPER HIGH DAMPING RUBBER BEARING FOR SEISMIC RESPONSE ANALYSES

Abstract

Bilinear hysteretic models are widely used for representing restoring forces of laminated rubber bearings. In this paper, the optimal bilinear model of a super high damping rubber bearing is proposed. At first, the bilinear model specified by the present design code is shown to be inaccurate especially in the large amplitude range. Then, optimal bilinear models under uni-axial and bi-axial seismic excitations are obtained with the aid of the multi-axial high order model and real-coded GA. Finally, equations for estimating the parameters of bilinear models are proposed, and they are found to be much more accurate than the present design code.