1. Huazhong University of Science & Technology, Wuhan 430074, China;
2. Earthquake Engineering Research & Test Center, Guangzhou University, Guangzhou 510405, China;
3. Disaster Prevention Research Institute, Kyoto University, Kyoto 611-0011, Japan;
4. Kyoto University, Kyoto 606-8501, Japan
Abstract：The high damping rubber bearing (HDRB) is widely used in the civil engineering practices. However, because the components of the HDRB are extremely complicated, especially damping materials are adopted, the stress-strain relationship of the HDRB exhibits significantly rate dependent. So far few constitutive models can capture the rate-dependent behavior accurately. In this paper, a rate-dependent constitutive model of HDRB is developed based on the improved hyperelastic Zener model based on the rubber material property of the HDRB. The model consists of two hyperelastic springs and a nonlinear dashpot, which can be utilized to characterize the rate-dependent property of HDRB. A novel strain energy function of the hyperelastic spring was proposed to describe the initial stiffness of high damping rubber material. Multi-step relaxation tests and cyclic shear tests at different strain rates were carried out to calibrate the model material parameters. Bearing tests were conducted to verify the proposed model, finally, dynamic responses of an isolated bridge equipped with the HDRBs under the earthquake excitations were obtained by using a new real-time substructuring test system based on the velocity-control loading concept. The accuracy of the proposed model in the nonlinear analysis for predicting the seismic responses of the isolated structure with HDRBs was verified by using the test results.
