Tests, model, and applications for coned-disc-spring vertical isolation bearings

Abstract

To study the mechanical performance and asymmetric hysteretic models of coned-disc-spring vertical isolation (CDSVI) bearings, their mechanical properties under reversed loading conditions were tested, and the characteristics of their load–displacement hysteretic curves were investigated. The test results indicate that the load–displacement hysteretic curves have asymmetric characteristics, and that the loading frequency has only a marginal influence on the mechanical properties of the bearings, whereas the preloading displacement and dynamic loading amplitude have a critical influence. Based on the test results, an origin-oriented hysteretic model (OO hysteretic model) was proposed for CDSVI bearings. The results indicate that the OO hysteretic model has asymmetric characteristics, and the frictional forces critically influence the restoring forces of the bearings. Furthermore, the experimental results were used to verify the OO hysteretic model. The results indicate that the OO hysteretic model can simulate the mechanical performance of the CDSVI bearings effectively, and the relative errors between the simulated and experimental results of both equivalent stiffnesses and equivalent damping ratios are within 5%. Finally, the nonlinear dynamic time-history analysis of a typical CDSVI-SDOF system was carried out to study the influences of the asymmetric hysteretic model on the calculated seismic responses of the structures. Numerical results show that CDSVI bearings can effectively reduce the earthquake responses of the structure.