PHYSICAL AND NUMERICAL MODELING OF MOLD FILLING IN RESIN TRANSFER MOLDING

Finite element modeling and experimental investigation of mold filling in resin transfer molding (RTM) have been performed. Flow experiments in the molds were performed to investigate resin flow behavior into m olds of rectangular and irregular shapes. Silicone fluids with viscosi ty of 50 and 100 centistoke as well as EPON 826 epoxy resin were used in the mold filling experiments. The reinforcements consisted of sever al layers of woven fiberglass and carbon fiber mats. The effects of in jection pressure, fluid viscosity, type of reinforcement, and mold geo metry on mold filling times were investigated. Fiber mat permeability was determined experimentally for the five-harness and eight-harness w oven mats. Resin flow through fiber mats was modeled as flow through p orous media. Pressure distributions inside both types of molds were al so determined numerically. In the case of resin now into rectangular m olds, numerical results agreed well with experimental measurements. Co mparison between the experimental and numerical results of the resin f ront position indicated the importance of edge effects in resin flow b ehavior in small cavities with larger boundary areas. Reducing the res istance to resin flow at the edge region in the numerical model allowe d for good agreement between the numerical simulation and the physical observations of the resin front position and mold filling time.