This project is concerned with measuring the stress-induced birefringence in materials that are opaque at visible wavelengths. We will use THz illumination between 0.3 and 1.5 THz where some fraction is transmitted through a range of non-polar materials including ceramics, plastics and composites. Measuring the stress-induced birefringence will provide information on the internal stress distribution in real components that are opaque at visible wavelengths, removing the need to model it in transparent plastic.
This new unique stress visualisation technique might be considered as 'photoelesticity for opaque objects', although more accurate techniques will be used to measure the phase difference that arises between the polarized components of the illumination. These new techniques will enable in-process control during manufacturing applications and in-service quality assurance, for a range of materials where this is not currently available, enabling step changes in the manufacturing processes used and the components that can be produced.
For more information please contact Professor Andrew Moore, A.J.Moore@hw.ac.uk.