Experimental Validation of a Generalized Procedure for MDOF Real-Time Hybrid Simulation

Real-time hybrid simulation (RTHS) has increasingly been recognized as a powerful methodology to evaluate structural components and systems under realistic operating conditions. The concept of RTHS combines the advantages of both numerical analysis and physical laboratory testing. Furthermore, the enforced real-time execution condition enables testing of rate-dependent components. One of the most important challenges in RTHS is to achieve synchronized boundary conditions between computational and physical substructures. The level of synchronization, i.e., actuators tracking performance, largely governs RTHS test stability and accuracy. The objective of this study is to propose and validate a generalized procedure for multiple-degree-of-freedom (MDOF) RTHS. A loop-shaping H∞ robust control design strategy is proposed to control the motion of the actuators. Validation experiments are performed successfully, including the challenges of multiple actuators dynamically coupled through a continuum steel moment resisting frame (MRF) specimen. The resulting framework is further utilized to evaluate the performance of a magnetorheological (MR) damper in its effectiveness to mitigate structural vibration when the structure is subjected to dynamic disturbances, e.g., earthquakes.