Simulation Of Forming Processes Of FabricReinforced Thermoplastics

Abstract

Thermoforming is an attractive processing technique to manufacture thermoplastic composites for structural applications supplying the increasing demand in the aerospace industry. To date, the technology has been optimized using trial and error methods. This is neither acceptable nor affordable since the forming tools are very expensive and the procedure is very time consuming. In order to reduce cost and time consumption, numerical simulation can be an effective tool to improve both part design and tool design as well as optimisation of processing conditions. In cooperation with DaimlerChrysler Aerospace Airbus GmbH, the simulation of the thermoforming process of a rib structure for an Airbus aircraft was performed at the Institut fur Verbundwerkstoffe GmbH. In order to obtain the thermomechanical coefficients of both the fabric (5-H satin carbon weave) and the matrix (polyphenylene sulphide, PPS), shear tests of dry and impregnated fabric were carried out. The viscosity of the fabric reinforced PPS and the friction coefficients between the participating materials also were determined. The simulation was divided into two parts. First, the pressure distribution in the rubber pad in contact with the laminate was calculated. Based on these results, the non-isothermal forming process was simulated using PamStampTM from Engineering Systems International Ltd. The simulation was verified by comparing the angle between warp and weft fibres in the individual layers and the thickness distribution of manufactured parts. Advances in Composite Materials and Structures VII, C.A. Brebbia, W.R. Blain & W.P. De Wilde (Editors) © 2000 WIT Press, www.witpress.com, ISBN 1-85312-825-2