A model for predicting ultrasonic fields in complex structures and configurations

Quantitative prediction of the field radiated by a transducer into a given piece is a fundamental tool for inspection qualification and for understanding actual results. Pieces of complex structure are often involved (e.g. welds, cladded components) leading to complex wavepaths including reflection and mode-conversion. The model Champ-Sons is developed at the French Atomic Energy Commission for ultrasonic field prediction. It is semi-analytical for computer efficiency. The theory is first described. The modelling of transducer behaviour is presented for typical transducers used in NDT. Definition of the piece by CAD software is discussed.