TWI Industrial Member Report Summary 949/2010
by H Shang and J Gao
Optical non-destructive testing (NDT) techniques are based on the development of imaging sensors and computer technologies and provide full-field and non-contact measurement of surface profiles, deformations and temperature changes. They are categorised into four groups: Moiré, holography, speckle-based techniques and thermography. These optical NDT techniques have been used in material characterisation, defect detection, strain measurement, design verification/optimisation, residual stress evaluation, vibration analysis and 3D shape measurement. Optical NDT techniques reveal defects in an object by assessing the response of surface deformation or temperature to defects under stressing, which is closely related to the strength and integrity of the object. It is possible to characterise defects and quantify the associated stress and strain fields. Hence, optical NDT techniques have attracted increasing interest in the NDT community in the past decade and have been applied in a range of industrial sectors to meet the ever-increasing challenges posed by today's engineering components and structures.
A variety of methodologies have been developed within the NDT group in the past decade. The development of optical NDT techniques is a promising research area which can provide solutions to problems associated with the inspection of the new generation of composite materials and structures and tools to compliment existing NDT technologies used in traditional materials.
- Carry out a comprehensive review of optical NDT techniques with an emphasis on their industrial applications.
- Provide a reference document for NDT inspection professionals on selecting optical techniques for industrial NDT.