European developments in theoretical modelling of NDE for pipework

Ultrasonic, non-destructive examinations are used to detect and size crack-like defects in a variety of structures such as railway rails, bridges, pressure vessels and pipework. Such inspections are carefully designed to detect cracks which, if not repaired, could lead to loss of the component. If the response from a defect can be calculated then it is possible to examine the inspection strategies and procedures and to demonstrate that they are adequate for the purpose for which they are intended. A survey is given of various problems tackled by European modellers of NDT, concentrating on areas which have not been recently reviewed elsewhere. Emphasis is placed on physical features of defects, such as defect roughness, material ingress, the effects of compressive stress, the effects of crack size, and the implications of variation in the reliability of ultrasonic testing due to these effects for structural integrity.