COMPOSITES SURFACE STATE ASSESSMENT BY LIF METHOD

摘要

The application of fibre reinforced composites has been increasing in many branches of industry. One of the techniques used for composites joining is adhesive bonding. The joints can be made during both manufacturing and repair. The reliability of the bonding is crucial for safe usage of the structure, therefore it is important to assess the pre-bond state of the surface. The performance of adhesive bonds depends on the physico-chemical properties of the adhered surfaces. This research is focused on characterization of the surfaces before bonding. In-situ examination of large surface materials determine the group of methods that are preferred. The analytical methods should be non-destructive, enabling large surface analysis in relatively short time. In this work a Laser Induced Fluorescence (LIF) method was tested that can be potentially applied for surface analysis. This is a noncontact method allowing for inspection of relatively large surfaces in short time. In the reported work LIF intensity and time characteristics were investigated. The investigated samples were either surface contaminated or overheated. It was shown that laser induced fluorescence method can be useful for non-destructive evaluation of CFRP surface and some of the investigated cases can be easily detected.