Analysis of discontinuities effect in relation to attenuation level in glass fibre reinforced polymer composites
Jarosław Bieniaś, Monika Ostapiuk, Barbara Surowska, Karolina Beer
Quarterly No. 1, 2011 pages 70-74
DOI:
keywords: glass/epoxy composites, microstructure, voids, ultrasonic inspection
abstract In recent years, composite structures have become very popular for different applications, predominantly in the aerospace industry. Their mechanical properties provide very useful materials in aviation as a primary structure. It is well known that glass/epoxy polymer composite is characterised by its lightweight and corrosion resistance in comparison to traditional materials. The main aim is to guarantee durability and safety during the manufacturing process in the case of the possible appearance of structural defects. Porosity and delamination detection is a very important factor in solving the problem of quality. One of the basic non-destructive testing methods of detecting discontinuities in structures used in aviation is ultrasonic inspection with C-scan images. Their objective is to analyse the composite structures particularly for quality inspection in aviation. This paper presents research about the relationship between the attenuation level of an NDT technique (C-scan) and void content in glass/epoxy composites. An analysis of the microstructure and characteristics of discontinuities are presented and discussed. The observations have given the results of three distinguished types of microstructures depending on the attenuation level in ultrasonic testing. The level of void content for this specific type of composite was determined from 2% to 5% and this can be classified as a medium quality composite structure. A linear dependence was found between the attenuation level in ultrasonic inspection and the percentage of voids content in a glass fiber reinforced polymer composite. The correlation between ultrasonic inspection and the analysis of microstructure is a useful method in composite structures engineering.