Generation of Initial Fiber Orientation States for Long Fiber Reinforced Thermoplastic Compression Molding Simulation

The prediction of the fiber orientation state (FOS) is of utmost interest for compression molded long fiber reinforced thermoplastics as the part's properties strongly depend on it. Besides the position of the initial plastificate in the mold cavity and the process settings, detailed knowledge of the initial FOS is essential. During compounding, the fibers align depending on the extruder screw configuration yielding a non-uniform local FOS. For process simulation, a common approach is to neglect this effect and assume an isotropic or planar-isotropic FOS of the initial plastificate. A more sophisticated approach consists of micro-computed tomography (µCT-) scans of slices of the initial plastificate and the derivation of the initial FOS from the three-dimensional image data. This approach can yield accurate predictions but is quite cumbersome and expensive. In this paper, we present a novel approach to account for the FOS of the initial plastificate. The approach is motivated by experimental observations and based on geometric assumptions. Depending on the extruder type and the dimensions of the initial plastificate, the developed tool generates a three-dimensional data set containing the mesh information alongside the initial FOS in a tensorial representation. ... mehrTo investigate the influence of the initial FOS for different flow regimes, we conducted compression molding simulations on a planar part.