Effects of surface conditions on an ultrasonic inservice inspection

The primary objective of this research was to develop recommendations to limit the adverse effects of a rough surface and thereby increase the reliability of ultrasonic inservice inspections. To achieve this objective, engineering studies were conducted to validate experimentally a computer code that had been developed to model a pulse echo measurement. After the computer model had been validated, it was used as an engineering tool to study the effect of surface conditions and then used as a basis to develop recommendations relating to inservice inspections. The paper presents a brief description of the computer model, the results of extensive validation experiments, a description of an inservice inspection over a step discontinuity on the surface of a plate, use of the computer code to predict results of such an inspection for a 45 degree shear wave inspection, conclusions from the computer modeling studies, and the recommendations to limit adverse effects of a rough surface