Deformation analysis of aircraft wheels using a speckle shearing interferometer

Speckle shearing interferometry has developed over the last three decades and is used as a non-destructive analysis tool for aerospace engineering.The primary role of the technique has traditionally been for the examination of defects in fibre composite structural materials, but more recent attention has considered strain and displacement measurement.Furtherm ore, aerospace regulatory bodies such as the UK Civil Aviation Authority are demanding better understanding and traceability of the technique. The novel work reported here has investigated the use of a Michelson-based speckle shearing interferometer for the analysis of compression-loaded aircraft wheels and tyres.Whole- field deformation data have been obtained for repeated compression loading of a BAe146 main wheel, providing displacement derivative and displacement data.The quality of the measurement technique has been ascertained through the analysis of the repeatability and reproducibility data, with correlating data being produced using contact displacement transducers.