Identification of the impact location on a plate using wavelets

This paper presents an experimental method that has been developed for detecting flexural waves in plates by the use of piezoelectric films. The recorded signals are analysed by a 'wavelet transform' to determine arrival times of waves at different frequencies. These arrival times are used in conjunction with an optimisation method to identify the location of the impact (i.e. the x- and y-coordinate of the source location). Also, the time lag between the instant of the impact and the recording of the signals together with the group velocity of the dispersive waves are specified. Close agreement is observed between the experimentally determined results and the exact solutions. This technique is a valuable method for identification of source locations that may be applied to problems related to in-service impact loading of structures, seismic data from earthquakes, and to acoustic emission signals from propagating cracks. (C) 1998 Academic Press.