Time History Iteration Method for Offline Real‐Time Hybrid Testing Involving Multiple Experimental Substructures

ABSTRACT Real‐time hybrid testing (RTHT) is an effective approach for obtaining the dynamic response of large and complex structures, but achieving real‐time performance is highly challenging. In recent years, an offline RTHT method has been proposed, where the loading of the experimental substructure and the computation of the numerical substructure are performed independently. Compared to conventional online RTHT, offline RTHT demonstrates significant advantages in terms of accuracy, stability, and cost. In the scenarios involving multiple experimental substructures, it can further reduce the cost of the testing system. However, the existing offline RTHT methods are primarily employed in single experimental substructure scenarios and have difficulties being applied in multiple experimental substructure scenarios. In this study, a Time History Iteration (THI) method and an Accelerated Time History Iteration (ATHI) method are proposed for application in offline RTHT involving multiple experimental substructures. System identification and virtual iteration are performed to accelerate the iteration process. The proposed methods are validated through offline RTHTs for a dual‐TMD wind resistance problem. The test results demonstrate that the proposed THI method enables the reuse of the same testing equipment and specimen in offline RTHT. Meanwhile, the proposed ATHI method significantly accelerates the convergence process while ensuring stability and accuracy. Summary Compared to conventional real‐time hybrid testing (RTHT), the offline RTHT method can reduce testing costs by lowering hardware and software requirements, particularly in experiments involving multiple experimental substructures. A Time History Iteration (THI) method is developed to enable the repeated use of testing equipment and specimens, thereby substantially decreasing the complexity and cost of the testing system. An Accelerated Time History Iteration (ATHI) method is developed to further reduce test cost by system identification and virtual iteration. The proposed methods are validated through offline RTHTs for a dual‐TMD wind resistance problem.