ABSTRACT

In a real time hybrid simulation (RTHS), the actuator delay might deviate experimental results, or even destabilize the real-time test. Currently, research is very limited on stability of multiple-degree-of-freedom (MDOF) structures with multiple delays. Using the Lyapunov-Krasovskii (L-K) method, this study proposes stability criteria for MDOF systems with multiple time-varying/constant delays, and derives a more accurate result. Application of criteria shows that the stability of time-varying delay system is smaller than the corresponding constant delay system. With number of DOF and delay increasing, the criterion accuracy decreases slowly for constant delay system; meanwhile, the stability difference between constant- and time-varying- delay system increases gradually. Such difference is significant with small stiffness ratio of physical substructure.

摘要

在实时混合仿真 (RTHS) 中，执行器延迟可能会偏离实验结果，甚至会破坏实时测试的稳定性。目前，关于具有多个延迟的多自由度（MDOF）结构的稳定性的研究非常有限。本研究使用 Lyapunov-Krasovskii (LK) 方法，提出了具有多个时变/恒定延迟的 MDOF 系统的稳定性标准，并得出了更准确的结果。判据的应用表明时变时滞系统的稳定性小于相应的常时滞系统。随着自由度数和时延的增加，恒时延系统的判据精度下降缓慢；同时，恒时延系统和时变时延系统的稳定性差异逐渐增大。