Sensitivity Analysis of Adaptive Holographic Fiber-Optic Acoustic Emission Sensors during the Registration of Acoustic Waves in a Plate

Abstract

Paper presents the results of studying the features of recording acoustic emission waves by fiber-optic sensors. Fiber-optic sensors are used as an elastic medium that receives acoustic emission waves. Optical fibers were built between the layers of the polymer composite material during the manufacturing process. The measuring system is constructed on the basis of an adaptive interferometer. Optical fibers are part of the interferometer optical scheme. The elastic wave acting on an optical fiber changes its optical density, changing the interference pattern of the optical beam. The work of the holographic interferometer based on the fact that the interference pattern, formed by the object and reference light beams, is a dynamic hologram that is constantly recorded in the photorefractive crystal during the elastic action on the fiber. Sensitivity of fiber-optic sensors based on an adaptive interferometer allows recording acoustic emission waves. The acoustic emission waves were generated by the Hsu-Nielsen source. A significant difference in the speed of sound is explained by the anisotropy of the properties of the composite material. The structure and density of the material's fibers in different directions are different. The wavelet transformation was used to form the signal front.