One sensor linear location of acoustic emission events using plate wave theories

Acoustic emissions (AE) are transient stress waves generated in a material under load upon damage formation. By detecting these waves and analysing th eir properties, information can be obtained about the damage initiation and propagation in loaded structures. The AE technique possesses a number of d istinct advantages, one of which is the possibility to calculate the spatia l source location based on arrival time differences between a number of sen sors. In this way, the use of two sensors allows for a linear source locati on. This paper will demonstrate how taking into account the modal nature of AE signals can be used to reduce the number of sensors needed in AE source location. Using signals obtained during tensile and bending tests performe d on a number of cross-ply and unidirectional carbon fibre reinforced polym er (CFRP) lay-ups, it will be shown how a linear source location can be cal culated using one sensor. To achieve this goal two different plate wave the ories will be used and the results will be compared to the ones obtained by a traditional two sensor linear location scheme. (C) 1999 Elsevier Science S.A. All rights reserved.