Non-destructive evaluation of organic composites: a review

Abstract

Organic composites made of glass-fiber reinforced plastic or carbon-fiber reinforced plastic are largely used as automotive, wind turbine and aeronautics parts. Aim: As the industrial demand for organic composites is experiencing further requisites concerning more lightweight and higher mechanically performing components, greater needs for their quality control and maintenance have emerged. Materials and methods: Intensive investigation has focused then on the inspection techniques as provided by non-invasive testing methods with the purpose to detect, localize and size damage. These include visual inspection, tap testing, acoustic emission, ultrasonics, eddy-currents, shearography, holographic interferometry, X-ray tomography and thermography. Common damage in organic composites includes delamination, debonding, heterogeneities and inclusions. Damage may occur during manufacturing process or during operation because of fatigue, material alteration, lightning and impact of foreign objects. As, fiber reinforced plastic composites have an inherent complex microstructure, non-destructive evaluation techniques for testing them require more efficiency in detection. Moreover, these methods should be robust with regards to uncertainties and cost effective in terms of the inspection charge. Selecting the correct method for carrying out the inspection of organics composites is still a challenging issue. Results: In this work, a review of the basic concept and actual situation of the common non-destructive evaluation methods for inspection of organic composite structures is presented. A comparison of the effectiveness of these methods with respect to the nature of damage to be detected is performed. Conclusion: Recommendations about the adequate method to be used as function of the nature of damage are given.