Résumé | Automated deposition processes for polymer matrix composites, such as forming and AFP, offer effective manufacturing solutions that improve repeatability and enable better tailoring of laminate properties. The introduction of these methods can lead to reduced manufacturing time and cost when compared to more labour-intensive alternatives. Despite the benefits that these methods offer, parts made using automated manufacturing technologies are prone to defects such as wrinkling, that are less common in manual processes such as hand lay-up. These defects may cause manufacturing delays and can ultimately result in scrapping of expensive parts thus overshadowing the benefits of automated manufacturing methods. Traditionally, resource-intensive trial and error approaches are used in industry to determine the optimum processing conditions and minimize the occurrence of defects. However, in recent years process simulation has proven to be an effective tool to provide insight into manufacturing processes and evaluate the effect of process parameters on outcomes. When properly characterized and validated, process simulation can significantly reduce the cost and risk of composite manufacturing.
For forming, it is necessary to simulate large deformations, with the material exhibiting highly non-linear temperature and rate dependent behaviour. In-plane and transverse shear, ply bending, ply/tow slip and separation, and tool-part interaction are among the key deformation mechanisms that the material experiences during a forming process.
To date, the Convergent COMPRO process simulation platform has been used extensively by the composites industry to simulate different aspects of manufacturing of composite structures, and as a next step, a physics-based forming simulation framework has been developed that takes into account all relevant deformation mechanisms and leverages the 3DS Simulia/Abaqus/Explicit solver. Material constitutive models have been developed and implemented to capture the complex non-linear and temperature- and rate-dependent response of plies and their interactions during the forming process.
This simulation framework is employed to model forming of laminates on tools with different geometric features and under various process conditions. It is shown that the models are capable of predicting key forming simulation outcomes, including ply slippage, wrinkling, and the fibre misalignment defects. |
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