Seismic isolation systems with adaptive behavior are critical for ensuring structural resilience across varying earthquake intensities. Variable curvature friction pendulum bearings (VC‐FPBs) offer a promising solution by providing displacement‐dependent stiffness and enhanced energy dissipation. This study investigates the size effect on the seismic performance of VC‐FPBs through experimental testing and finite element simulations. Five VC‐FPB specimens of different scales were subjected to cyclic quasistatic tests to evaluate their force–displacement responses, adaptive stiffness characteristics, and frictional behavior. Results revealed that smaller specimens failed to replicate the full‐scale adaptive stiffness behavior due to geometric limitations, stress distribution differences, and friction pad wear mechanisms. Modified small‐scale specimens with enhanced curvature profiles restored the intended stiffness softening behavior. Numerical models successfully captured the experimental trends, validating the influence of geometric scaling on mechanical performance. These findings highlight the necessity of thoughtful modifications in scaled VC‐FPB models to ensure accurate representation of full‐scale behaviors for seismic isolation applications.
Cao et al. (Thu,) studied this question.