Application of Michelson Interferometric Fiber-Optic Sensors to CFRP Damage Monitoring

Abstract

This paper describes the application of Michelson interferometric fiber-optic sensors to monitor the damage in fiber-reinforced plastics under tensile loading. The tested material was an unidirectionally aligned carbon fiber reinforced epoxy composite. A fiber-optic sensor was bonded to the surface of the specimen. A He-Ne laser was used as the light source. Optical interference signal, strain as well as acoustic emission were measured during the tensile test. The behavior of the optical interference signal was compared with both strain and acoustic emission data. Optical interference signals with high amplitude and high frequency were detected when damage occurred. The Michelson Interferometric fiber-optic sensor proved to be effective for monitoring the damage processes of the material studied.