Depth-resolved measurement of the compression displacement fields on the front and rear surfaces of an epoxy sample

Compression is one of the typical parameters measured in material mechanics. In this research, the compression displacement fields on the front and rear surfaces of an epoxy sample are measured by using a tilt depth-resolved wavenumber-scanning Michelson interferometer. The light source is a distributed feedback laser diode, the wavenumber of which can be modulated to about 1.017 × 10⁴ m^–1 by the temperature without mode hopping. A random-sampling Fourier transform is designed to evaluate the phase differences before and after the applied loads. Experimental results show that the depth-resolved measurement of the compression displacement field is of high accuracy. It can be used to analyze force propagation inside resin-based composites.