Lead rubber bearings (LRBs) are critical components of isolated bridges, and their performance dictates the seismic safety of the bridge. Cyclic shear deformation during earthquakes induces lead core heating, which subsequently degrades the bearing’s hysteretic energy dissipation, characteristic strength, and stiffness. Since ground motion duration significantly influences the cumulative number of hysteretic cycles, the impact of the heating effect on LRBs warrants further investigation. This study analyzes 22 types of circular LRBs compliant with Chinese standards, utilizing 66 equivalent single-bearing isolated structure models with varying periods for dynamic time-history analysis. The seismic responses under long- and short-duration ground motions were compared. The results indicate that long-duration ground motions significantly exacerbate lead core heating and strength degradation. Furthermore, they induce larger peak shear strains and higher energy dissipation demands compared to short-duration motions, particularly in long-period structures.
