Abstract
The vibration and noise problems of machine in operation occur frequently. Various works related to the transfer path analysis (TPA) have been published to improve these problems. The estimation of excitation forces of mechanical structures is one of important issues in TPA. The excitation forces have been generally estimated in frequency domain. However, many researchers recently attempt to estimate excitation forces in time domain. The purpose of this study is the development of an estimation procedure in time domain for the excitation forces. An advantage of the procedure in time domain is the estimation of transient input signals. Therefore, impulsive forces as an transient excitation signal are estimated. An estimation procedure which employed the singular value decomposition and Tikhonov regularization is proposed in this study. The block Toeplitz matrices are assembled from impulse responses of the theoretical and the experimental systems. The procedure is carry out to solve the ill-posed inverse problem. The validity of the proposed procedure is verified by numerical calculations and experiments for a multi degree of freedom system. Finally, the estimation results of implusive excitation forces are considered from the view point of the number of modes constructed the impulse responses.
