An Improved Bouc–Wen Model for High‐Damping Rubber Bearings Incorporating Large‐Strain Behavior: Development, Validation, and Comparative Analysis

ABSTRACT High‐damping rubber bearings (HDRBs) are among the most widely used seismic isolators in bridge and building engineering. However, they exhibit significant nonlinear behavior, particularly under large‐strain deformation. Key nonlinearities include large‐strain hardening, degradation, temporary hardening, and initial hardening. Incorporating all these characteristics into a single macroscopic model is challenging. This study reviews the most relevant and accurate models for HDRBs and highlights their significant features. To address the limitations in existing models, an improved Bouc–Wen (IBW) model is proposed and implemented in OpenSees. Reversed loading cycles were conducted on HDRB specimens, and the widely adopted deformation history integral (DHI) model is also introduced for comparative analysis. The IBW model is validated by comparing it with DHI model and experimental results, with comparisons focused on the shape of hysteretic loops, equivalent stiffness, and damping ratios. Results demonstrate the applicability and accuracy of the proposed numerical element in modeling HDRBs under displacement‐controlled reversed loading. The IBW model proves more concise and effectively represents the primary nonlinearities of HDRBs. Overall, it outperforms the DHI model in scenarios involving large strains and initial loading cycles, while the DHI model shows slightly higher accuracy in low‐to‐moderate strain cycles. Future research should investigate strength degradation under prolonged loading and the dynamic response of both bearings and isolated superstructures under seismic loading.