TWI Industrial Member Report Summary 963/2010
By: J Gao
Shearography is a well-known optical interferometric technique capable of detecting surface deformations of objects with high sensitivity and has been successfully applied to several industrial sectors. Two of the most successful are defect detection in the tyre manufacturing industry and delamination detection in honeycomb composite structures. Thermography is another promising non-contact non-destructive testing (NDT) technique for defect detection in engineering components. Both techniques have the advantage of non-contact area screening with a single shot, making them ideal for on-site NDT inspections. Their successful application largely depends upon the proper means of stressing the components under investigation, but it can be possible to use the same (thermal) stressing system for both techniques, allowing simultaneous deployment and providing extra confidence in the inspection.
Although they are effective in detecting a variety of defects such as voids, disbonds, delaminations, etc, there are limitations. To use these techniques in an engineering environment, it is important to identify their detailed capabilities for defect detection as well as optimal operational procedures. Although there are generic theoretical and numerical simulation analyses on the mechanism of each NDT technique, no systematic studies have been reported so far describing detailed defect detection capabilities. This project aims to establish detailed technical specifications on defect detection for relevant optical/thermal NDT techniques through a series of systematic numerical simulations and theoretical analysis plus selected experimental verification tests and to provide optimised procedures for carrying out NDT inspection using these techniques.
- Investigate the flaw detection capabilities of shearography and thermography through numerical simulations and experimental tests.
- Investigate the effects of different means of stressing on the flaw detection capabilities of shearography and thermography and provide guidance in optimising the operational procedures to maximise their detectioncapabilities.