Shape optimization of thermoformed continuous fibre reinforced thermoplastic products

Abstract

An approach to automated shape optimization of Continuous Fibre Reinforced Thermo-Plastic (CFRTP) products is reported. The methodology combines numerical modelling of the production process and subsequent finite element analyses of the structure. As an optimization technique, the multipoint approximation method is adopted. It is assumed that CFRTP structures are produced by means of a thermoforming process. The CFRTP material consists of single-layered plain weave fabric embedded in a thermoplastic resin matrix. The thermoforming process is modelled by means of a simple kinematically based technique, which considers only the in-plane shear deformation of the fabric and omits the effect of the resin matrix. The effective laminate properties of a CFRTP composite are calculated taking into account the fibre reorientation, as predicted by the thermoforming simulation algorithm. Several numerical examples involving thin-walled CFRTP products restrained to linear structural behaviour are solved to demonstrate the proposed approach. It should be noted that this approach is also applicable to woven preforms without resin matrix, e.g. using Resin Transfer Moulding (RTM).