The Potential in Simulations and Meta-Modelling for Understanding and Development of NDE

摘要

By combining detailed mathematical modelling of the physics in NDE with a broader robust engineering approach based on the sequential steps: screening, modelling and optimization, it would be possible to generate meta-models that can support the NDE Engineering efforts to evaluate NDE applicability in a wider context, as a complement before the repeatability, reproducibility and capability studies normally performed. The aim with the initial screening phase is to effectively evaluate and priorities NDE control parameters from a wider perspective relative the demand in the specific application and to fix parameters of less impact on the output response to their most economical and practical level. The aim with the second and third steps is to study how the important parameters influence and to perform sensitivity analysis of reproducibility and repeatability, for example, followed by procedure development, respectively. The methodology is straightforward when it comes to smooth response surfaces of lower order (up to second or third). The recommendation for the screening phase generally is 'to be bold' when it comes to the definition of the experimental range for each parameter –meaning make them as wide as possible relevant for the specific application. For NDE applications not following the Berens assumption for POD studies: large cracks yield large response signal. Such as, the varying signal amplitude from surface breaking notches in ultrasonic testing, for example. The be-bold-screening recommendation may lead to incorrect prioritization of parameters. In this paper this is illustrated by how the width of the experimental range for the control parameters tested during screening actually influence the screening result. Two basic ultrasonic testing set-ups have been compared using the SimSUNDT simulation software package: Surface Breaking Notch (SBN) and Side Drilled Hole (SDH). Even though the result was expected. It points out the need of development of the screening methodology supporting the NDE engineering, when it comes to addressing the applicability issue: does the data collected tell us what we actually want to know about the tested application (or does it only tell us something of the NDE method).