STUDY ON THE IMPROVEMENT OF ON-LINE TEST APPLYING THE LINEARLY INTERPOLATION METHOD

摘要

A displacement control error in a loading test of a specimen is related to a gap between target displacement and achieved displacement of the loaded specimen. This problem is one of the major factors which reduce the accuracy of results of an on-line test. It is a hard task to measure restoring force of a specimen at the target displacement accurately due to the displacement control error, even though the response of the specimen is computed based on the measured restoring force in the on-line test. This paper proposes application of the Linearly Interpolation Method (LIM) to control the influences of displacement control errors in the on-line test. The LIM is a very simple method installed to a loading program without any other devices. This paper also presents availability and efficiency of the LIM through on-line tests and an elasto-plastic dynamic analysis. Displacement control errors are generated during the on-line test in which specimen is an R/C column, and the test parameter is whether the LIM is applied or not. The earthquake response of the specimen with no displacement control error is computed by the elasto-plastic dynamic analysis to be substituted for the true response. The specimen is modeled as a single-degree-of-freedom mass system in the analysis. The response of the test applied the LIM is found very similar to the analytical response, while the result of a test without the LIM is disturbed by displacement control errors.