Simulating Mold Filling in Compression Resin Transfer Molding (CRTM) Using a Three-Dimensional Finite-Volume Formulation

Light-weight structural components are increasingly made of continuous fiber reinforced plastics (CoFRP), but their mass production is still very expensive. Because of its high automation potential, especially the Compression Resin Transfer Molding (CRTM) process gains more and more attention. Numerical mold filling simulations help to optimize this process and can avoid expensive experimental studies. Here, we present a new method to simulate mold filling in CRTM using a full three-dimensional finite-volume (FV) method. In comparison to known finite-element (FE) methods, it contains a compressible two-phase/Volume-of-Fluid description of the air- and resin-phase. This approach is combined with a moving mesh to account for the change of cavity height during the process, which results in a change of fiber volume fractions and thus permeabilities. We verify the method by comparison to analytic solutions of the Darcy equation and to solutions of state-of-the-art mold filling simulation software. The presented method enables CRTM mold filling simulation of complex parts, which is shown in two application examples. Furthermore, this shows the potential of using FV-based tools to simulate mold filling in RTM process variants containing non-constant cavity geometries.