A three-dimensional finite element model for predicting pressure rise and velocities in a pultrusion die

Over the past decade, composite materials have moved to the forefront in a variety of industries such as the automotive, aircraft, and medical industries. One of the most important manufacturing processes for composite materials is the pultrusion process. The heart of the pultrusion process is the die region through which the resin impregnated fibers are pulled. The quality of pultruded composite materials depends upon the manufacturing process control parameters and factors such as the resin pressures and resin velocities inside the die. During the pultrusion process, high fluid pressure is generated inside the die region which is very important in producing a quality end product. These fluid pressures can be effectively controlled by properly selecting the appropriate process control parameters. The resin pressure in the die inlet contributes in suppressing void formation and improving the fiber wet-out of the final product.; Based on Darcy's law, a Galerkin's finite element model was developed in a three-dimensional cartesian coordinate system to predict the pressure and velocities inside a die with a wedge shaped inlet. The model developed in this research is capable of predicting the field variables (resin pressure and resin velocities) for variations in different process control parameters. The control parameters that have been studied in this research are the preform plate area ratio, the fiber pull speed, the fiber volume fraction, and the resin viscosity. The model also considers anisotropy in the permeability for the fiber-resin mixture inside the computational domain.; The objective of this research was to analyze the pultrusion die geometry in three-dimensional form. The study focused on pultrusion manufacturing of glass/epoxy and graphite/epoxy composites. The findings centered on the three-dimensional effects of pressure and velocity variation inside the die. The results of this study will be useful in improving the pultrusion manufacturing process as well as the quality of the final product.