Performance evaluation and optimisation of fiber-reinforced elastomeric isolators with polyurethane cores under lateral cyclic loads

Polyurethane elastomer has been proposed as a substitute for lead cores in low-cost isolation bearings, particularly fiber-reinforced elastomeric isolators, to improve energy dissipation capacity. This paper investigated the lateral performance of carbon-fiber-reinforced elastomeric isolators with polyurethane cores (C-FRPEs) under lateral cyclic loading. Finite element (FE) models of C-FRPEs were established in ANSYS and validated against test results. Responses of the polyurethane cores during tests were analysed numerically, revealing a limited energy dissipation contribution. A multi-criteria optimisation (MCO) method was applied to identify the optimal polyurethane viscoelastic material from the literature and the optimal elastic modulus for polyurethane cores to optimise the lateral performance of C-FRPEs. Compared with test results, the optimal polyurethane viscoelastic material enhanced the energy dissipation of C-FRPEs by 355%, and increasing the elastic modulus of polyurethane cores further improved energy dissipation. Based on the optimal polyurethane material, a sensitivity analysis of C-FRPEs’ lateral performance to various parameters was conducted using the tornado diagram method. The lateral performance was highly sensitive to geometric parameters but less affected by polyurethane core layout parameters. Increasing the individual rubber layer thickness, number of reinforcement layers, and polyurethane core diameter could significantly improve the energy dissipation capacity of C-FRPEs.