Filament winding simulation

This paper will discuss the formulation of the simulator for the filament winding process which describes the temperature and extent of cure in a cross-section of a composite part. The model consists of two parts the kinetic model to predict the curing kinetics of the polymeric system and the heat transfer model which incorporates the kinetic model. A Galerkin finite element code was written to solve the specially and time dependent system. The program was implemented on a microcomputer to minimize computer costs. 

Process models allow composite case manufacturers to determine the affects of process variable settings on final cylinder quality. Because the cost of a composite cylinder can be as great as 500,000, the ability to simulate filament winding can significantly reduce cost and improve quality. Several computer models of the filament-winding process for both thermoset and thermoplastic matrix materials have been developed. These models are based on engineering principles such as conservation of mass and energy. As such, numerous resin systems and fiber materials can be modeled. 

Schlottermiiller, M., Lu, H., Roth, Y., HimmeL N., Schledjewski, R. and Mitschang, R, Thermal residual stress simulation in thermoplastic filament winding process . Journal of Thermoplastic Composite Materials, 2003,16(6), 497. 

Prototype composite vessels (Fig. 12) were manufactured in the conditions used in the FEM simulations using a 6-axes CNC controlled filament winding machine and submitted to hydraulic burst pressure tests. The obtained results have shown that vessel burst occurred for pressures between 8 and 11 MPa. Such results show that conservative results were obtained from FEM analysis probably because failure does not occur by interlaminar shear as other simplified theories, like the netting one, demonstrate. 

Additional patterns have been simulated, including near 0 to about 90 helices. Test cylinders have also been wound with roving. The graphical presentation is effective for conformation before winding and demonstrates the successful development of a numericeiUy controlled, filament winder. 

Winding process simulations for thermoplastic filaments are important for the component quality. Commercial simulation tools are not available yet. Research institutes are developing different process simulation programs to understand the influences of the material and the process on the component quality. Simulation programs from the CCM (University of Delaware, Center for Composite Materials, USA) and from the IVW (Institut fiir Verbundwerkstoffe GmbH, Germany) are presented hereafter. 

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