Research on the methods of evaluating reaction force for dynamic sub-structure experiments using shaking table

Real-time dynamic substructure testing by using shaking table is a novel structure testing method in recent years.Because of the application of sub-structure technique,the real-time dynamic substructure testing overcomes the test model scale limitation,which is inevitable in traditional shaking-table test.Meanwhile,the loading rate dependent behavior of testing materials could be considered,since the tests are operated in real-time.In the proposed technique,the upper part of the object structure is the experimental substructure and the lower part is the numerical substructure.The force exerted on the interface of the two separated substructures is used as exchange platform to keep equivalence between the substructure and whole structure.So it is key to obtain the interface force conveniently and accurately.In this study,the authors make a comparative analysis of the four common methods used to get the interface force.The four methods can obtain interface force accurately by the analysis of the shaking table test results of a steel frame model structure.Applicable conditions and some suggestions about these methods are proposed at last.