Thermal Model for Three-Dimensional Irregular Shaped Pultruded Fiberglass Composites

Abstract

Computer simulation of the manufacturing of pultruded composite materials has been limited strictly to one or two-dimensional modeling of simple flat or circular shaped composites. This research presents the modeling of unsteady-state temperature and degree of cure distributions for the manufacturing of fiberglass-epoxy composite materials with irregular cartesian geometries in three-dimensions. The model is capable of predicting temperature and degree of cure distributions for composites with cartesian shapes in three dimensions, and temperature profiles in pultrusion dies without the aid of predetermined temperature values used as die wall boundary conditions. One of the benefits of this model is in designing the heating section of pultruder machines. Using a differential scanning calorimeter (DSC) the chemical kinetic parameters for Shell EPON 9420 epoxy resin were obtained. A finite difference control volume technique was utilized in the development of the numerical model for solving the governing energy and species equation used in modeling the entire heating section of the pultruder. The combinations of pull speed, fiber volume, and die temperature profiles can be modeled very economically in manufacturing composites for very specific needs. Since this research is not limited in terms of predetermined temperature values, it can be easily tailored to predict a multitude of temperature profiles suited for a pultrusion process. This research is also important because it provides realistic modeling of irregular cross-sectional geometries.