A POST-CORRECTION METHOD FOR THE INFLUENCE OF TIME DELAY IN REAL-TIME HYBRID SIMULATION BASED ON THE ERROR PROPAGATION OF NUMERICAL INTEGRATION ALGORITHM

The time delay effect in a real-time hybrid simulation (RTHS) is basically compensated through the compensation of the displacement command calculated by the numerical substructure, then the compensated command is sent to the actuator to vanish the delay. In RTHS, the loading is generally small related to the capacity of the actuator to keep the performance of actuator in a relatively ideal range. This also limits the conduction of large-scale RTHS. Due to the large loading, higher requirements are put on the control system and actuator of RTHS. Moreover, the state-of-art time-delay compensation method cannot eliminate the effects of time delay completely. For the problems mentioned above, this study proposed a method that can reduce the influence of the time delay after an RTHS. This method is based on the error propagation of the dual explicit numerical integration algorithm. To illustrate the method proposed in this study; it analyzed the effect of time delay on the RTHS results and in some cases with a large time delay, the time delay may cause results to be almost completely "wrong"; it gave the theoretical derivation process of the method proposed; it performed simulation verification in four cases when the physical substructures are linear stiffness, linear damping, nonlinear stiffness and nonlinear damping, respectively. The results show that: the method proposed can restore test results according to the error propagation of the dual numerical integration algorithm, reduce the errors caused by the time delay. In the case that the effort of delay compensation is not satisfactory due to the limitation of the test equipment, the method can simultaneously correct the displacement, velocity and acceleration results after the test.