COMMENT

摘要

These are exciting times to be working in non-destructive testing and condition monitoring. Great progress is being made in many technical areas and in bringing these developments to field application. Examples include the continuing rise of ultrasonic phased array techniques, the use of long-range low-frequency ultrasonic guided waves and the increasing use of digital and computed radiography. One of the main drivers for these changes has been greatly increased computing capability, not only in processing power but also in data storage capacity and data transfer speeds. This is very apparent in my own field of theoretical modelling of NDT. When I started working on modelling in the 1980s, numerical techniques such as finite difference and finite element methods were already available, but their practical application was limited by very long run times and high memory storage requirements. So, instead, we sought alternative, semi-analytical approaches to reduce the computing requirements. Today, it is perfectly possible to use numerical modelling techniques in practical applications, and thereby to model geometries and defects that were difficult or impossible with semi-analytical methods.