Study on Extrapolation-Newmark Optimal Compensation Strategy of Real-Time Hybrid Test System

Real-time hybrid test is an economical and efficient testing method to evaluate nonlinear structural performance. During the operation of real-time hybrid test, the time delay caused by the operating error of the actuator results in the worse stability and accuracy of the real-time hybrid test. To compensate for the delay of the actuator, the stability of the hybrid test system and the accuracy of the test are improved. In this paper, the advantages of the numerical integration algorithm and the linear acceleration extrapolation method are composed organically, and then a universal linear extrapolation-Newmark optimization compensation strategy is proposed to compensate for the time delay. Under the action of different seismic waves with and without the optimized compensation strategy, the self-developed DELTA-OpenSees real-time hybrid test system is used to comprehensively compare and analyze the real-time hybrid test of three-story frame structure with linear springs. The root mean square error and maximum error amplitude of the maximum error amplitude of the optimization results can reach 2.73% and 2.18%, respectively, which proves that the developed linear extrapolation-Newmark optimization compensation strategy can effectively improve the stability and accuracy of the real-time hybrid test system, and the optimization compensation strategy has good tracking performance and robustness.