A spring model for the simulation of the propagation of ultrasonic pulses through imperfect contact interfaces

A spring model for the simulation of the propagation of ultrasonic pulses in arbitrarily complex heterogeneous media is proposed in the framework of the local interaction simulation approach (LISA). The algorithm used allows us to include heuristically additional local interaction mechanisms. In particular, the problem of propagation of pulses across imperfect contact interfaces is considered. A contact quality tensor, which is expected to be connected, although not necessarily in a trivial way, to the bond quality, is introduced directly into the model in order to treat interface flaws, such as delaminations and/or slipping bonds. To demonstrate the applicability of the technique, which is particularly suitable for parallel processing, a few examples of numerical simulation of pulse propagation in media with various kinds of imperfections are presented. (C) 1998 Acoustical Society of America. [S0001-4966(98)02411-4].