Simplified Approximations for Critical Design Parameters of Rectangular Fiber-Reinforced Elastomeric Isolators

Analytical solutions for critical design properties of elastomeric bearings, such as the compression modulus, bending modulus, and maximum shear strain due to compression or rotation, including the compressibility of the elastomer, have been developed for most basic laminated elastomeric bearing geometries. Due to the introduction of extensible fiber reinforcement, these analytical solutions have been expanded to include the extensibility of the reinforcement as an additional design parameter. Extensible reinforcement can have a pronounced effect on these design properties, comparable to the compressibility of the elastomer. These analytical solutions have previously been used to derive simplified approximations appropriate for use in design codes and standards. Thus far, a rectangular bearing geometry, which is in fact the most common in bridge bearing applications, has been largely omitted from these derivations. Simplified approximations for the compression modulus, maximum shear strain due to compression, and bending modulus of a rectangular laminated bearing with extensible reinforcement are proposed and evaluated against the analytical solution, including the effects of compressibility of the elastomer and extensibility of the reinforcement.