Analysis Models and Methods for Structural Response of Spatially Varying Ground Motions

摘要

Two Models, Displacement Input Model and Acceleration Input Model, for analyzing the structural response of earthquake ground motions are discussed. The approaches of using direct integration methods to these models are analyzed. The numerical results presented here illustrate the Displacement Input Model is more accurate than the generally used Acceleration Input Model, given the same direct integration method and time step. This is contrary to the conclusions of Wilson (2000) that there are several new sources of numerical errors associated with the direct application of earthquake displacement loading and a very small time step is required to define the displacement record and to integrate the dynamic equilibrium equation. It is believed in the present paper that Displacement Input Model is more accurate and suitable for analyzing the response of ground motions, especially the response of nonlinear structures subjected to spatially varying ground motions.