Application of the Abaqus *Fabric Model to Approximate the Draping Behavior of UD Prepregs Based on Suited Mechanical Characterization

The increasing demand for automated manufacturing processes for carbon fiberreinforced polymers necessitates accurate forming simulations. For that purpose, the multi-purpose finite element solver Abaqus provides the phenomenological *Fabric material model. While it is designed for woven materials, both structural directions and shear properties can be independently adjusted. We aim to quantify its applicability to model forming of UD semi-finished prepregs in a diaphragm forming station. We describe the material characterization and modeling and compare the simulation results to experiments using accurate laser scans of manufactured parts. Various simulation aspects are methodically altered to better gauge their impact on the simulated forming result. An accurate calibration of the bending behavior was found to be most important for the forming results. This is realized in the *Fabric material model by softening the compressive stiffness and the limitations of this workaround must be investigated in more detail. Other aspects, like rate-dependent modeling of the transverse direction and anisotropic properties for friction should be considered. Overall, a good agreement with experimental results including regions with fiber bridging or the formation of folds and the
contour of the part could be achieved.