Experimental and Analytical Study of a Novel Friction Pendulum Bearing With Uplift Restraint

ABSTRACT An innovative uplift‐restraint friction pendulum bearing (UR‐FPB) was proposed to enhance the applicability of seismic isolation technology. Departing from traditional FPB, the UR‐FPB integrates a friction set responsible for structural isolation and an anti‐uplift set enabling the bearing to withstand tension. Three theoretical constitutive models describing the friction set were first derived. Corresponding numerical finite element models were developed in Abaqus. A full‐scale UR‐FPB specimen utilizing various friction materials was fabricated. Subsequently, three experimental investigations were conducted to characterize the bearing's hysteretic response, fatigue behavior under sliding, and uplift resistance under tension. Experimental and numerical results demonstrate excellent agreement with the theoretical hysteresis characteristics, validating the bearing's effectiveness in providing isolation and preventing uplift. This validation encompasses sliding sequences, force–displacement relationships, and parameter effects. Observations from fatigue testing reveal damage modes in the friction plates, including significant out‐of‐plane warpage, local tearing or fracture, wear debris, and plastic deformation in length, width, and thickness. Notably, the bearing maintains stable hysteretic behavior, indicating that friction plate degradation has a limited influence on the friction coefficient at the polished slider interface. In the tensile test, the bearing achieves an ultimate tensile capacity of 300 kN, with failure occurring via predefined shear fracture within the anti‐uplift track. This result confirms the bearing's excellent uplift‐restraint capacity against external tension loads. The development of this novel UR‐FPB offers valuable insights for designing future uplift‐prevention systems in aseismic applications.