It is important in ultrasonic testing to quantitatively predict the field radiated by a transducer into a given piece.
Configurations involve wavepaths including reflection or mode-conversion onto the backwall.
The model Champ-Sons is developed at the French Atomic Energy Commission for field prediction. It was limited to planar or cylindrical pieces, in which fields directly transmitted from the coupling to the piece were computed. The paper presents the extension of Champ-Sons to complex structures and wavepaths. At each interface, reflection, transmission and mode-conversion are considered. As intensive use of the computer program is sought, numerical efficiency is required.