Improved nonlinear rotational constitutive law for predicting critical loads in elastomeric isolation bearings

Abstract

Abstract Predicting critical loads in elastomeric isolation bearings has important implications for the design of isolation systems. The key mechanism for predicting the critical loads is to precisely predict the nonlinear rotational properties of the bearings. However, most of the existing rotational constitutive laws of elastomeric bearings are divided into linear stage and nonlinear stage. The predicted critical loads from these piecewise models lead to inaccurate results compared to experimental observations. In this paper, the basic assumptions of previous researches are extended considering the nonlinear properties of bonded rubber layer. On the basis, an improved nonlinear rotational constitutive law is proposed. The improved model can provide a continuous prediction of critical loads throughout the horizontal displacements. The calculated critical loads are confirmed by comparison with existing test data.