Preliminary feasibility studies of real-time substructuring control strategies

Dynamic substructuring is a hybrid testing strategy, which enables full-size, critical components of an entire engineering system to be physically tested, whilst the remaining parts are simulated numerically. Successful tests require a robust controller to compensate for unwanted dynamics introduced by supplemental actuators within the physical substructure and to achieve synchronized responses of the numerical and physical parts in real-time. The aim of this feasibility study tries to identify the relative strength and weakness of three types of substructuring control strategy in literature, including (i) emulated-system-based (ii) numerical-substructure-based, and (iii) output-based controllers. The first two controllers are synthesized via conventional dynamics-based approaches, while the third using forward-prediction and curve-fitting concepts is classified as a geometry-based strategy. A practical substructuring example using a shaking-table system is presented for control comparisons. In the presence of uncertainties with the actuators or specimens, simulation studies show that these controllers exhibit distinct robustness in different cases.