Experimental validation of a new adaptable LCM mold filling software

Resin Transfer Molding (RTM) is a manufacturing process suitable for producing thin-walled fiber reinforced polymer composites where dry fibers are placed inside a mold and resin is injected under pressure. During mold design, filling simulations can study different manufacturing concepts (i.e. placement of injection gates and vents) to guarantee complete filling of the part and avoid air entrapment where flow fronts converge. In the past, numerous models have been implemented in different software packages to perform filling simulations for RTM. In this work, a novel software tool LCMsim, which was implemented by the authors, is benchmarked against other tools as well as real-world flow experiments. Its development was driven by two ideas: Easy-of-use for the mold engineer and maximum flexibility for the researcher. This means that the simulation shall run robustly and independent of numerics-related input. The porous cavity is fully described by a mesh of the part’s mid-surface and cell sets define injection gates, vents and regions with different preforms. Additional equations (e.g. for modeling the temperature or the degree-of-cure) can be added with equations of the same type and additional functionalities can be added by modifications of existing equations (e.g. Vacuum-Assisted Resin Infusion, VARI) or boundary conditions. Two experiments were used for validation. In the first, zones with different preform properties were present and in the second, race-tracking was enforced. Flow fronts from LCMsim and experiment agree with 7% error and simulated flow fronts from LCMsim and the commercially available software PAM-RTM agree with 3% error.