Simulating Prepreg Platelet Molding Compound Flexure Coupons in LS-DYNA® Using MAT54

Prepreg platelet molding compound (PPMC) is a composite material system primarily for compression molding comprised of rectangular platelets made from slit and chopped unidirectional prepreg. Prior to processing, the platelets are assumed to be in a planar random orientation state; however, this changes during molding as the platelet orientation state evolves in response to flow. The final orientations of the platelets affect the mechanical performance of manufactured components. As such, it is necessary to incorporate platelet orientations in simulations of PPMC parts to capture the material system behavior. This work introduces a modeling method for simplified PPMC geometries using MAT54 in LS-DYNA. A platelet generation code creates virtual PPMC samples with varying global orientation distributions. These orientations are input into LS-DYNA models of flexure coupons. A study is completed to understand how global platelet orientation affects the flexural stiffness and strength of the virtual samples. In addition, the results of the flexure simulations are compared to experimental results of flow-aligned PPMC coupons to validate the modeling method. The simulation study reveals that an increase in platelet alignment along the longitudinal axis of the sample results in an increase in flexural stiffness and strength in the models. This trend is confirmed experimentally, and the accuracy of the modeling method is discussed.