A Linear Method to Evaluate Iteration Convergence of Offline Real‐Time Hybrid Testing Base on Impulse Response

ABSTRACT Real‐time hybrid testing (RTHT) is an effective method for obtaining the dynamic responses of large‐scale structures. Conventional RTHT typically employs the online RTHT method with real time interaction between substructures. However, achieving real time computation, real time loading, and real time data exchange poses significant challenges. In recent years, an offline RTHT method has been proposed, in which the loading of the experimental substructure and the computation of the numerical substructure are performed independently. This approach offers a new solution to address the real time issues in RTHT. Offline RTHT demonstrates significant advantages in terms of accuracy, stability, and experimental equipment costs compared to conventional online RTHT in specific scenarios, showing broad application prospects. Nevertheless, the development of offline RTHT is still incomplete, and there is currently no mature convergence evaluation method. Therefore, this paper proposes a method to evaluate convergence of offline RTHT based on impulse response. The time history iteration behavior of the offline RTHT is thoroughly analyzed based on the impulse response function. A series of indicators for evaluating convergence stability and convergence performance are proposed. These indicators are easily obtainable and possess clear physical significance, enabling the prediction of time history iteration behavior before formal testing and assisting in test design. Numerical simulations were conducted to investigate the effects of key parameters on the time history iteration and to validate the effectiveness of the proposed indicators.