Bending Stiffness of Fiber-Reinforced Circular Seismic Isolators

Abstract

The reinforcing elements of multilayer elastomeric isolation bearings, which are normally steel plates, are replaced by a fiber reinforcement. In contrast to the steel reinforcement which is assumed to be rigid, the fiber reinforcement is flexible in extension. This paper presents the theoretical approach to analyze the bending stiffness of the fiber-reinforced circular isolators. The elastomer is assumed to be incompressible and pressure dominant. The stiffness formula is derived. The influence of fiber flexibility on the mechanical properties of fiber-reinforced circular isolators under bending moment, such as the pressure in the elastomer, the stress in the reinforcement, and the bonding shear stress between the elstomer and the reinforcement, are presented.