Seismic performance test of a new composite seismic isolation bearing with sliding-rolling friction and research on the seismic isolation effect

Abstract To investigate the seismic isolation performance of the novel sliding-rolling friction composite isolation bearing, this study systematically examined the dynamic friction characteristics of four-roller and five-roller composite friction bearings through pressure-shear experiments under varying vertical pressures, horizontal velocities, and shim configurations. The experimental results demonstrate that the dynamic friction coefficient reaches a minimum value of 0.059 (with a mean value of 0.059) when the vertical pressure applied to the ball group accounts for 25%–50% of the total bearing load. Under working conditions of a 204 kN vertical pressure and a 5 mm s −1 motion speed, the dynamic friction coefficient first decreases and then increases with increasing roller quantity, achieving a minimum mean value of 0.044 in the five-roller configuration. On the basis of dynamic principles, the governing equations of this innovative bearing were formulated and solved numerically via MATLAB simulations. The dynamic response analysis reveals two critical thresholds: the dynamic friction coefficient should not fall below 0.02 to prevent excessive floor displacement amplification under seismic excitation, and the upper limit of the dynamic friction coefficient should not exceed 0.05 to effectively control floor acceleration responses. These findings provide essential theoretical guidelines for optimizing the dual-mechanism composite isolation system.