機械・構造物に作用する外力の同定に関する研究

Abstract

The identification of external force acting on a machine or a structure is important for diagnosis. One of the force identification methods is based on the frequency response function (FRF). The method is very useful although it requires the information of the location of acting force. In this study, an identification method is proposed for the case of unknown excitation points. In the method, the inverse problem of force identification is regularized by increase the number of FRF by adding a mass on the target structure. The validity of the method was checked by the numerical example. A simple beam fixed at both ends is considered and four patterns of force distribution are taken up. The number of singular values to solve the inverse problem must be determined. It was shown that the accurate identification results can be obtained when the number of singular values is set under the minimum condition of root mean square of error of the reconstructed responses. Moreover, it was shown that the identification of the concentrated force was more difficult than the one of the distributed force.