CHARACTERIZING THE PROCESSING AND PERFORMANCE OF ALIGNED REINFORCEMENTS DURING PREFORM MANUFACTURE

Liquid moulding processes are now finding a wide range of applications for both structural and semistructural components. This has been faci litated in part by the development of computer-aided engineering tools for structural analysis and process modelling. However, the accuracy of these tools is dependent on the available material property data, w hich are usually determined using two-dimensional flat plaque experime nts. This approach may not be satisfactory for complex component geome tries, as preform manufacture often results in large variations in bot h fibre orientation and volume fraction. In recent years, several auth ors have developed reinforcement deformation or 'drape' models that ma y be used to predict the fibre architecture at the design stage. These models are usually based on the assumption that reinforcement deforma tion is facilitated by inter-fibre shear, whereas in reality a number of mechanisms are available. In this study, reinforcement deformation is characterized using an automatic strain analysis system. This is ap plied to a number of generic components with increasing depth of draw, enabling the validity of the interfibre shear model to be established . The effects of deformation on reinforcement permeability and compone nt structural properties are then established using experiments based on sheared reinforcements.