Cross-platform implementation, verification and validation of advanced mathematical models of elastomeric seismic isolation bearings

Abstract

Stable inelastic response of seismic isolation bearings is key to the successful performance of base isolated nuclear structures, buildings and bridges. Since full-scale isolated nuclear structures (and buildings) cannot be tested for extreme earthquakes on simulators because their payload capacities are orders of magnitude smaller than weights of structures, confirmation of adequate performance must be provided by analysis of numerical models and testing of individual bearings. As the consequences of isolator failure are high, for example, core damage in a nuclear power plant and collapse for a building, the numerical models of the key nonlinear components, namely, the isolators, must be verified and validated (V + V). Herein, advanced models of elastomeric seismic isolation bearings are implemented as user elements in the open-source code OpenSees, and the commercial codes ABAQUS and LS-DYNA. These advanced models are verified and validated following ASME best practice to predict response under extreme loadings. Sources of error in the computational models are quantified, and where possible, eliminated. Those isolator characteristics crucial to robust estimates of performance are identified. Experiments are performed to obtain data for validation. The isolator models are validated using data from experiments and values of model parameters are recommended.