Coupled Thermal and Mechanical Behavior of Lead–Rubber Bearings: Full‐Scale Testing and Numerical Modeling Methodology

Self‐heating effect of the lead core in lead–rubber bearings (LRBs) under cyclic loading causes degradation of mechanical properties of LRBs, which in turn affects their self‐heating effect. This study conducts full‐scale tests and proposes a numerical modeling methodology to investigate the coupled thermal and mechanical behavior of LRBs. The methodology integrates mechanical modeling, thermal modeling, temperature‐dependent material properties, and thermal‐mechanical modeling. Experimental results reveal significant mechanical degradation under high‐speed cyclic loading (0.25 Hz, 100% shear strain), with a temperature rise of 90°C in the lead core and a 22°C increase observed in adjacent rubber layers after 10 cycles. The numerical model demonstrates a good agreement with test data, accurately capturing force‐displacement loops and temperature within the lead core. Numerical results show that the thermal–mechanical behavior of LRBs is sensitive to loading frequency and shear strain: increasing the frequency from 0.25 Hz to 0.5 Hz amplifies energy dissipation rates by 38%, while a 50% increase in shear strain (100%–150%) increases peak temperatures by 27%. A case study under nonharmonic motion shows that conventional mechanical models overestimate energy dissipation by 37% compared to the coupled thermal–mechanical model. The proposed modeling methodology provides a usable tool for investigating the coupled thermal and mechanical behavior of LRBs under various seismic conditions.