Shear Behavior of Low-Damping Steel-Reinforced Elastomeric Bearings: Experimental Characterization and Simplified Nonlinear Finite Element Modeling Strategies

The shear response of steel-reinforced elastomeric bearings (SREBs) governs their performance in bridges and base-isolated buildings, yet the material and geometric nonlinearities involved are not captured by the simplified design rules of current standards. In this study, cyclic shear tests were performed on nine groups of rectangular low-damping SREBs with different dimensions and lower values of the shape factor to determine the apparent values of the shear modulus and shear stiffness. Uniaxial compression and tensile tests were also performed on rubber specimens to calibrate the appropriate built-in material models for the finite element (FE) simulations of shear tests. Geometric characteristics had a limited influence on the apparent values of the shear modulus, with rollover at the bearing edges as the main source of variation. FE plane-strain models reproduced the three-dimensional shear response with negligible loss of accuracy at substantially lower computational cost, rigid plates may replace the realistic elastic–plastic properties of steel without compromising accuracy, and moderate compressive preload had a negligible effect on shear response. Material models calibrated from compression tests reproduced the nonlinear and hysteretic behavior more accurately than those calibrated from tensile tests. A simplified modeling strategy combining plane-strain analysis, rigid reinforcement, and compression-calibrated built-in material models is recommended for the FE analysis of low-damping SREBs in shear.