Use of 3D non-destructive characterisation for modelling the mechanical properties of as-manufactured composite components

During the composite component design process, and at the manufacturing stage, there is a requirement to understand the effect of defects in terms of their 'knock-down' in the structural performance. The result would be justifiably lighter designs, a better-informed concession process for manufacturing defects and improved in-service repair strategies. Such an understanding has been achieved for bulk-averaged porosity and delaminations but more subtle effects, such as in-plane fibre waviness, out-of-plane ply wrinkling, and 3D variations in fibre-volume fraction or porosity, have not received this level of attention. Recent developments in X-ray CT and ultrasonic 3D characterisation of composites offer the potential for a greater understanding of the effects of these material variations. In the composites community, work has been proceeding on the modelling of mechanical properties and failure modes in the presence of such variations. This paper will demonstrate the use of 3D NDT data to construct materials models of the exact as-built structures, including material variations and defects, in order to predict the effect on performance and better inform the design, concession and repair processes.