Prediction and Validation of Short Fiber Orientation in a Complex Injection Molded Part with Chunky Geometry

The paper shows the capability of state-of-the-art models and software to predict the fiber orientation distribution (FOD) on injection molded parts with a complex and thick-walled geometry. Predictions by the standard Folgar-Tucker model and the Reduced Strain Closure model were compared to measurements of the fiber orientation distribution obtained by X-ray Computed Tomography. Measurements and simulations were performed under different processing conditions to investigate the influence of injection velocity and packing pressure on the FOD. It was found that the predicted fiber orientation is in good qualitative agreement with the measurements. The measured orientation shows a distinct shell-core structure with high alignment of the fibers in flow direction in the shell layer and a orientation perpendicular to the flow direction in the core layer. While the orientation in the shell layer is predicted fairly well, a significant deviation is found in the prediction of the orientation in the core layer.