| In base isolation、the devices are required to possess flexibility and high damping in order to extend the natural periods and reduce the displacement response of sturctures、 respectively. In current practice of the design of highway bridges in Japan、 bilinear model has been employed for seismic analysis of rubber bearing. However、 the mechanical behavior of rubber bearing is very complicated due to having the inherent viscoplastic property. In this regard、the current model cannot represent explicitly the inherent complex properties i.e.viscoplastic properties of rubber bearing. To address the complex behavior of rubber bearing and implement into the seismic analysis of bridge、a rheology model based on the experimental investigations has been proposed in this study. The scheme of the study comprises of parameter identification of the proposed model along with verification with experimental results.[*]The proposed model adequately presents the equilibrium response of rubber bearing with a slight overestimate in equivalent damping. Accordingly、 the present work has suggested for improving the nonlinear viscosity model by modifying the mathematical expression(Equation l(e)). In addition、the authors also feel the need to consider the temperature dependency of model parameters especially parameters relating viscosity in further study. |
