Modeling fiber preforming for resin transfer molding

In the manufacture of fiber-reinforced composite parts by Resin Transfer Molding (RTM), the fabrication of the fiber preform is critical to both part quality and production efficiency. During the fiber preforming process, a sheet of fibers is deformed by stretching and pressing to conform to the surface of the mold. The deformation induced by preforming introduces porosity and permeability variations which affect mold filling, determine mechanical properties in the final part, and often results in defects (tears and wrinkles) in the fiber mat. In this study, a mathematical model for analyzing fiber preforming is discussed. Such models may be used to optimize the process in order to reduce defects and obtain the desired mechanical properties in the preform.