Similitude theory for scaled friction pendulum bearings for shaking table experiments

Abstract

Scaled models of friction pendulum bearings (FPBs), which require a similitude design based on a set of scaling laws, are typically employed in shaking table experiments to investigate the seismic behavior of the models. In this study, scaling laws for scaled FPBs are developed to determine the physical parameters of their models. Then, an equivalent method for the distribution of scaled FPBs in the model isolation layer is proposed for scaling cases in which fewer FPBs are arranged in the model than in the prototype. In addition to an accurate simulation of the global seismic response of the prototype isolation layer, the proposed equivalent method also aims to simulate the possible worst-case loading conditions of an individual FPB in a prototype. A model of an FPB-isolated space truss on top of four towers was scaled, manufactured and tested on a shaking table. A comparison of the seismic response of the global isolation layer and the individual FPB between the model and the prototype demonstrates the effectiveness of the developed theory.