The goal of this award is to simulate the molding of polymeric fluids containing long fibers with the emphasis on predicting fiber orientation, fiber configuration and stresses generated during flow. Novel experimental rheological techniques will be developed which will allow one to assess the theories for predicting long fiber configuration and orientation under well-defined flow conditions and to determine model parameters which are needed for the numerical simulations. Predictions for fiber orientation and configuration from a numerical simulation of molding operations will be compared against experimentally determined values taken from molded parts. This work is an extension of our previous effort on short fiber suspensions but requires the development of improved rheological techniques, extension and modification of theories for long flexible fiber configuration and modification of techniques for measuring fiber orientation.
If successful, the results of this research will lead to an improved understanding of the relation between flow and fiber configuration and orientation for concentrated long fiber suspensions. From this understanding, theories for polymeric fluids containing concentrated levels of long fibers in which stress and particle orientation are directly related will be modified and improved. A numerical scheme for simulating the orientation of long flexible fibers in complex flows based on input from basic flow behavior will arise from this research. Information from the basic flow experiments will then be incorporated into a simulation package modeling molding operations, which will be made available to various companies (e.g. automotive, aerospace, etc.) and agencies for predicting mold design for obtaining parts with optimum performance. Graduate students will learn about the modeling, experiments, and numerical simulations of polymeric suspensions containing high aspect ratio particles. Undergraduate students will be integrated into the research efforts where they will learn the importance of process design for delivering parts with optimum performance.
