(403e) Improvement in Simulation of Highly Concentrated Fiber-Reinforced Composites

Actual capabilities of mold design simulation for injection molded fiber-reinforced composites only reach qualitative agreement with experimental results. This paper presents a method to improve the prediction of fiber orientation within a commercial concentration range. This method combines a time-delayed orientation evolution equation and their material parameters determined from rheometry with a 2D coupled Hele-Shaw flow approximation. Experimental orientation is measured at several radial positions for a 30 wt% short glass fiber PBT center-gated disk. The simulation discretizes the flow and orientation evolution equations using Galerkin and discontinuous Galerkin Finite Elements. A reduction in the discrepancy between experimental and predicted fiber orientation is observed by using orientation at the gate as the initial condition. However, the model is unable to reproduce the asymmetry of fiber orientation profile far from the gate. Therefore the model requires changes to find the threshold location for the stable structure of orientation.