Error Analysis for Pseudodynamic Test Method. I: Analysis

Abstract

On-line, pseudodynamic tests are becoming increasingly popular for large-scale seismic performance testing of structures. Such tests provide a means of simulating the effect of compliance of the structure on the inertial loads it will experience in the event of an earthquake, without the need to use a shaking table. One of the difficulties encountered is that the results from pseudodynamic tests can be extremely sensitive to measurement and control errors. Error analyses available to date have focused on implementations based on explicit time-integration schemes. Recently, however, researchers have successfully implemented an implicit integration scheme, which will probably become the preferred technique for pseudodynamic testing. An error analysis for this implicit scheme is presented, using a systematic approach. It is shown that the effect of measurement and control errors can in most cases be greatly reduced by a suitable adjustment of the measured displacements at every time step. The reduction in errors for this case is similar to that achieved in the explicit implementation by using the computed instead of the measured displacements.