A pseudodynamic testing algorithm for obtaining seismic responses of structures

Abstract

A new family method is proposed for pseudodynamic tests. This family method can integrate favourable numerical properties together, such as the unconditional stability, explicit formulation, second-order accuracy and favourable numerical dissipation. Since the proposed family method can generally have an explicit formulation of each time step its pseudodynamic implementation involves no iteration procedure. Hence, the pseudodynamic tests can be easily conducted when compared to an implicit pseudodynamic method, where an iteration procedure must be involved for each time step. On the other hand, the properties of unconditional stability, second order accuracy and numerical dissipation indicate that the proposed pseudodynamic algorithm is promising for solving inertial problems, where the total response is dominated by low frequency modes and the high frequency responses are of no interest. The unconditional stability implies that there is no limitation on step size for the high frequency modes. Besides, the dominated low frequency modes can be reliably integrated by choosing an appropriate time step since the proposed family method can have a second order accuracy. Finally, the spurious growth of high frequency responses can be suppressed or filtered out by the desired numerical dissipation. As a result, the proposed pseudodynamic algorithm is very promising for a general pseudodynamic test or a substructure pseudodynamic test.