Effects of surface conditions on an ultrasonic inservice inspection

The primary objective of this research was to develop recommendations to li mit the adverse effects of a rough surface and thereby increase the reliabi lity of ultrasonic inse,ice inspections. To achieve this objective, enginee ring studies were conducted to validate experimentally a computer code that had been developed to model a pulse echo measurement. After the computer m odel had been validated, it was used as an engineering tool to study the ef fect of surface conditions and then used as a basis to develop recommendati ons relating to inservice inspections. The paper presents a brief descripti on of the computer model, the results of extensive validation experiments, a description of an inservice inspection over a step discontinuity on the s urface of a plate, use of the computer code to predict results of such an i nspection for a 45 degree shear wave inspection, conclusions from the compu ter modeling studies, and the recommendations to limit adverse effects of a rough surface.