Evaluating actuator delay effects on real-time hybrid simulation involving degradation

Improving seismic performance of structures involves testing newly proposed designs\ud under such loadings. Real-Time hybrid simulation is a relatively new and viable method\ud for this purpose. This method integrates a physical model into a numerical model.\ud Displacement is imposed on the physical model using hydraulic actuators and the resulting\ud force is measured and used in calculating consecutive imposed displacements in real-time.\ud However, there is a response delay inherent in these actuators that needs to be addressed\ud when conducting real-tie testing. Damage in structures reduces their stiffness and strength\ud which effects the response of the structure to the same load pattern. This study investigates\ud how the actuator delay error changes with structural degradation. The results indicates the\ud stiffness degradation increases this error while strength degradation does not. A\ud probabilistic tool is provided for reliability analysis of real-time hybrid simulation results