Non-contact measurement of acoustic emission in materials by laser interferometry

The non-contact measuring system of acoustic emission (AE) by laser interferometry was developed to detect AE signals and analyze microfracture quantitatively during materials testing. The capability of this system was estimated by comparison between simulated AE signals due to glass capillary breaking and calculations using the finite element method. The systemcould measure AE signals during practical tensile tests of carbon fiber reinforced plastics. This technique was also applied to the thermal cycle test of ceramic/metal coatings, and AE signals during cooling were successfully detected and analyzed by a deconvolution method to evaluate quantitatively the microfracture process.