Numerical Predictions of Fiber Orientation for Injection Molded Rectangle Plate and Tensile Bar with Experimental Validations

Fiber composites are the pinnacle of lightweight materials in the automotive industry. The orientation of the reinforcing fibers strongly affects the mechanical performance of the finished part. However, fiber orientation prediction with high accuracy is difficult for a complex flow field in practical injection molding. Recently, an objective model, iARD-RPR (Improved Anisotropic Rotary Diffusion and Retarding Principal Rate), has been significant to provide anisotropic distribution of fiber orientation, such as the well-known skin-shell-core structure. Micro-computed tomography (micro-CT) scan is a state-of-the-art technique for measuring a very high 3D resolution of a specimen's fiber orientation data. According to the micro-CT experiments and injection molding simulations with the iARD-RPR computation, we investigate changes in fiber orientation distributions at different concentrations in a rectangle plate, while the alignment of fibers found in weld line is revealed for tensile bar. Comparisons of the fiber orientation predictions with the validated experimental data are also presented herein.