Application of grating shearography and speckle shearography to mechanical analysis of composite material

Abstract

The present work aims to compare two foremost shearography techniques for a quantitative experiment of composite material: digital phase-shifting speckle pattern and grating shearography. The chosen object was an open-hole tensile specimen fabricated by a non-crimped fabric. Both techniques of laser shearography measured surface strain and x-slope and revealed defects by catching the defect-induced deformation anomalies. In this comparative experiments, grating shearography had superiority in signal-to-noise ratio and spatial resolution to speckle shearography except the labour of the non-trivial specimen preparation. This comparative study will offer mechanical engineers a Guideline for the reasonable selection of a technique of shearography for a particular test object.