Progress with the implementation of a shearography system for the testing of technical components

Shearography is an approved and powerful tool for the non-destructive inspection of industrial components with respect to material faults and technical imperfections. An application field of high interest is the in-service inspection of aircraft and automotive components. However, the non-cooperative character of the surface of various technical components has to be taken into account carefully. This paper describes a complete test facility consisting of a shearographic sensor, adapted loading equipment for thermal and mechanical stressing and a new evaluation software ensuring a high sensitivity for fault detection. To increase the performance of the system with respect to industrial applications new components and procedures were implemented and tested recently. To them belong a CMOS-camera to increase the dynamic range of the image sensor, a multiband light source to test the coherence requirements of a shearography system and tunable thermal loading equipment to improve the identification of material faults within components having a bigger wall thickness.

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