A non-contact method for evaluating material properties and structural defects using laser generated ultrasound

This paper describes an innovative non contact technique whereby the mechanical properties of a material sample may be determined. The basic principle is to measure acoustic dispersion curves (Lamb waves) excited using laser generated ultrasound and detected optically. The technique is capable of yielding modulli and Poisson’s ratio with repeatabilities of better than a few percent. It may also be used to detect changes in material characteristics and structural damage. We anticipate application in materials characterisation and damage detectio