RESIN FLOW, CURE AND HEAT-TRANSFER ANALYSIS FOR PULTRUSION PROCESS

This work presents temperature and degree of cure profiles within a pu ltruded composite and focuses on the development of different models u sed for predicting the velocity profile including a slip velocity mode l. This study uses a variable viscosity model and highlights the resul ts for the velocity profile, viscosity of resin within a pultrusion di e, gelation lengths, iso-gelation lines, and axial pressure profile. G elation was predicted to occur at about one-third the distance down th e die length and the degree of cure at gelation was computed to be abo ut 0.34. The composite systems considered in this study are graphite/e poxy and fiberglass/epoxy. A comprehensive two-dimensional mathematica l model in cylindrical coordinates was developed for resin flow, cure and heat transfer associated with the pultrusion process. A control-vo lume-based finite difference method (Patankar method) was used for sol ving the governing equations. The model can be utilized for ascertaini ng the effects of pultrusion process variables on the characteristics of the cured composite; this primarily reduces to a large extent the t rial and error experimentation often required. Moreover, insight for c haracterization and optimization of the pultrusion process is a direct result of this modeling.