MEASUREMENT OF IMPACT LOAD BY USING AN INVERSE ANALYSIS TECHNIQUE - (COMPARISON OF METHODS FOR ESTIMATING THE TRANSFER-FUNCTION AND ITS APPLICATION TO THE INSTRUMENTED CHARPY IMPACT TEST)

This paper is concerned with a method for measuring an impact load acting on a body of arbirary shape. The present method is estimation of the impact load from strain response of the body by deconvolution. The transfer function between the impact load and the strain response is estimated by dynamic calibration. It is often difficult to obtain a good estimate of the impact load since the deconvolution is mathematically ill-posed and expands noises involved in measured signals. In this paper, we compare five methods to estimate the transfer function so as to obtain a good estimate of the impact load by deconvolution. Moreover, we apply the present method to the instrumentation of a Charpy impact testing machine and demonstrate its effectiveness.