Evaluation of a real-time hybrid simulation system for performance evaluation of structures with rate dependent devices subjected to seismic loading

Real-time hybrid simulation is a viable experiment technique to evaluate the performance of structural systems subjected to earthquake loads. This paper presents details of the real-time hybrid simulation system developed at Lehigh University, including the hydraulic actuators, the IT control architecture, an integration algorithm and actuator delay compensation. An explicit integration algorithm provides a robust and accurate solution to the equations of motion while an adaptive inverse compensation method ensures the accurate application of the command displacements to experimental substructure(s) by servo-hydraulic actuators. Experiments of a steel moment resisting frame with magneto-rheological fluid dampers in passive-on mode were conducted using the real-time hybrid simulation system to evaluate the ability for the simulation method to evaluate the nonlinear seismic response of steel frame systems with dampers that are intended to enhance the response of the structure. The comparison with numerical simulation results demonstrates that the real-time hybrid simulation system produces accurate and reliable experimental results and therefore shows great potential for structural performance evaluation in earthquake engineering research.