Experimental and Numerical Investigation of the Contact Behavior during FE Forming Simulation of Continuously Reinforced Composites in Wet Compression Molding

摘要

Wet compression molding (WCM) provides large-scale production potential for continuously fiber-reinforced structural components due to simultaneous infiltration and draping during molding (viscous draping). Experimental and theoretical investigations proved strong mutual dependencies between resin progression and textile draping. Significant cavity pressures only develop towards the end of the tool stroke, when the cavity is almost filled with resin and fibers. Therefore, the resin's impact on the draping behavior (intra-ply and interface behavior) is of great relevance, since it represents a large share of the draping process. This study extends the work presented by Hüttl et al. [1] with experimental interface tests on dry and infiltrated woven fabrics, which confirm rate-, pressure- and viscosity-dependent tangential contact behavior within the viscous draping stage. Furthermore, experimental results for the ply-ply interface are utilized to parametrizes a contact model, which is subsequently applied to assess and evaluate the process relevance on part level by means of FE forming simulation. Although a relatively simple geometry has been investigated, numerical results show a significant impact of the infiltration-depended tangential contact formulation on part level. Beyond that, an investigation of the ply-ply contact state (pressure or tension) reveal that transversal pressure is only predominate towards the end of the tool stroke. Consequently, contact characterization and parametrization should also include tests at low transversal pressure.