Analytical Methodology for Evaluating Tape Laid Carbon Fibre Reinforced Pa12 Components

Abstract

This paper describes the development of an analytical methodology for evaluating tape-laid carbon fibre/PA12 laminates. In order to generate a picture of the resulting component quality as comprehensively as possible, various methods have been tested and validated. Ultrasonic scanning and imaging techniques provide the opportunity to inspect an entire unit for defects and to represent the imperfections in the form of a grey-value image. A subsequent grey-level analysis allows a quantitative comparison of the components between themselves. Microscopic examinations of microsections permit detailed and qualitative conclusions regarding the quality of a laminate. In the context of the investigations it could be shown that microscopy makes a substantial contribution to understanding the manufacturing process with special regard to the bonding between the individual tape layers, the origin of cavities as well as geometrical parameters such as the surface waviness of a part. In addition to these analytical test methods based on imaging techniques, mechanical tests were realised for determining the flexural strength, flexural rigidity and the apparent interlaminar shear strength as well. DSC studies allowed statements to be made concerning the crystallinity of the thermoplastic matrix. Furthermore, the suitability of the individual test procedures used to assess the component quality for the process analysis will be discussed as well as the advantages and disadvantages of those methods with particular reference to the material combination CF/PA 12. Another objective was the development of as efficient as possible an analytical methodology for FRP which is practicable for other material combinations and manufacturing processes.