Real-Time Hybrid Simulation Using Shake Tables and Dynamic Actuators

Abstract

The development and implementation of the real-time hybrid simulation (RTHS), a seismic response simulation method with a combination of numerical computation and physical specimens excited by shake tables and auxiliary actuators, are presented. The structure to be simulated is divided into one or more experimental and computational substructures. The loadings generated by the seismic excitations at the interfaces between the experimental and computational substructures, in terms of accelerations and forces, are imposed by shake tables and actuators in a step-by-step manner at a real-time rate. The measured displacement and velocity responses of the experimental substructure are fed back to determine the loading commands of the next time step. The unique aspect of the aforementioned hybrid simulation method is the versatile implementation of inertia forces and a force-based substructuring. The general formulation of RTHS enables this hybrid simulation method being executed as real-time pseudodynamic (PSD) testing, dynamic testing, and a combination of both, depending on the availability of the laboratory testing equipment and their capacity. The derivation of the general formulation and the corresponding testing system are presented in this paper. Numerical simulation and physical experiment were conducted on the RTHS of a three-story structural model. Simulation and experimental results verify the concept of the proposed general formulation of RTHS and the feasibility of the developed corresponding controller platform.