Modeling tools for ultrasonic inspection of welds

Developments in quantitative ultrasonic nondestructive testing (NDT) of wel ds require simulation tools for cost-effective research and engineering wor ks. The present paper reviews the specific developments in modeling of weld inspection at the French Atomic Energy Commission (CEA), made in keeping w ith the general pattern of CEA in simulation studies of ultrasonic examinat ion. Two models have been developed for several years at CEA for this purpo se. One is dedicated to the computation of the ultrasonic field radiated by arbitrary transducers into pieces (possibly anisotropic and heterogeneous) under examination. We specifically discuss how the metallurgical structure and associated elastic properties of welds is taken into account. The othe r simulates a testing experiment. It accounts for the interaction of the be am with defects (within a piece made of isotropic material) and specimen bo undaries and simulates the transducer scan over the piece for synthesizing images comparable with measurements. We specifically discuss the influence of the possible complex geometry of the back wall of a weld. Examples of ap plication are given. They demonstrate the usefulness of such modeling tools in ultrasonic NDT of welds to study and optimize testing configurations, a nd to help NDT experts to interpret actual data. (C) 2000 Published by Else vier Science Ltd.