A NEW PERSPECTIVE for the INTERPRETATION of ULTRASONIC RESPONSES and its CONSEQUENCES in the DETERMINATION of „PROBABILITY of DETECTION“ CURVES

One of the most important aspects in the application of the „Damage Tolerant“ design approach to mechanical components is the probability to detect possible in-service defects. In the present paper, a novel approach, recently proposed by the author, to the interpretation of ultrasonic responses is presented. Such approach allows a new way of thinking for a more flexible and versatile procedure for the derivation of „probability of detection” curves. A high number of dedicated UT inspection experiments, carried out on artificial and natural fatigue cracks, are described in order to build up the procedure with the appropriate statistical parameters. Since the experiments typically needed to derive probability of detection curves with proper statistical reliability are expensive, the possibility to exchange part of the experiments with suitable numerical simulation is here considered.