Dept. MMN, Etudes et Recherches, Electricite de France, 92141 Clamart Cedex, France
DER-EDF, 93206 St. Denis Cedex 1, France
Different solutions for the acoustic coupling function from an ultrasonic transducer radiating in a solid with or without flaw are provided. They are obtained by using empirical models [Weight, J. Acoust. Soc. Am. 81, 815--826 (1987); Lhemery, J. Acoust. Soc. Am. 90, 2799--2807 (1991)] or Green's-formulation [Djelouah, J. Acoust. Soc. Am. 92, 2932--2941 (1993)] for transient ultrasonic fields and reciprocity principle. The coupling function is given as the convolution integrals of partial impulse responses and their time derivatives. Comparisons between solutions will be presented, using numerical and experimental results performed with straight and angle ultrasonic transducers.