Discussion on the accuracy of methods for determining interface force between numerical and physical substructures in shaking table-based real-time hybrid simulation

Abstract

Real-time hybrid simulation (RTHS) is a developing experimental technology that combines the advantages of numerical simulation and physical test. In RTHS, the interface force is a key physical quantity coupling the dynamic response of physical substructure and numerical substructure. An inaccurate force determination method can distort RTHS results and may cause incorrect estimations of the dynamic performance of structures. This article aims to systematically discuss the impact of possible error in determining the interface force during shaking table-based RTHS. The errors caused by two typical force determination methods, (1) using force sensors and (2) using strain gauges, are comprehensively investigated. These two force determination methods are typically used for (1) performance evaluation of nonlinear damping systems and (2) investigation of soil–structure interaction effects. Virtual hybrid simulation numerical models (in which both physical and numerical substructures are simulated numerically) representing the interface force determination processes are established. The impacts of error on the RTHS results are evaluate quantitatively. The reported findings can assist in developing a deeper understanding of the causes of errors during RTHS and enhance the experimental designs. This, in turn, leads to more accurate and reliable results in RTHS testing.