Study on the Stabilities of RTH Tests Using the CDM Method considering Two Kinds of Systematic Errors

Abstract

Real-time hybrid (RTH) test is a promising test method to investigate seismic responses of structures and is essentially a time history analysis. Therefore, an in-depth understanding of the control algorithm, such as a central difference method (CDM), is important for this method. In this paper, stabilities of the CDM considering two kinds of errors are investigated theoretically and experimentally. It turns out that the convergence criterion of the CDM cannot be changed by constant errors but can be changed by proportional errors. The lowest structural natural period to keep the results stable increases with the increase of the ratio of the displacement error to the interface displacement and the integration time step. At last, the theoretical result of the stability of the CDM considering two kinds of systematic errors are confirmed by the proposed test system with a natural rubber bearing.