Numerical Simulation Of Real-Time Substructure Testing With Shaking Table

High-rise building structures tested on shaking tables typically have to be scaled down due to limited table capacities. However, tests with small scale models may not accurately evaluate the earthquake resistant properties of structures. In order to increase model scales, the shaking table substructure testing method is developed. In this paper, the numerical integration algorithm of the shaking table substructure test is studied, and numerical simulations of shaking table substructure tests are carried out. The contents are described briefly as follows.First of all, this paper investigates the required modification of the standard central difference method (CDM) when applied to real-time substructure testing (RSTing) with the mass of specimen considered. Then the stability of the modified algorithm is analyzed. The results show that the stability of the modified algorithm for the RSTs where the mass of specimen must be considered is not good as the standard CDM.Secondly, the numerical simulation of shaking table substructure tests for specimens without damping are carried out by using the numerical model of the shaking table system. The influences of mass and stiffness of the physical substructure on the accuracy of the tests are analyzed. The results indicate that the accuracy of the shaking table substructure test is satisfactory, when the mass and stiffness of the specimen are in the range of permission, and the integration time interval is short enough. Moreover, the accuracy of the tests is independent on the excitation force.Finally, the effect from the damping of the physical substructure on the accuracy of the shaking table substructure tests is investigated through numerical simulation. The results show that the accuracy of shaking table substructure test for the case of damped dynamic substructure is higher than for the case of dynamic substructure without damping.