Journal of Rheology, Vol.62, No.6, 1443-1455, 2018
Simulation of prepreg platelet compression molding: Method and orientation validation
Prepreg platelet molding compounds (PPMCs) offer improved performance potential as compared to short-fiber composites and increased geometrical complexity as compared to continuous fiber composites. The increased adoption of PPMCs in automotive and aerospace applications necessitates the development of predictive tools for determining the final orientation state in complex geometries produced through molding flows. Due to the large geometric scale of platelets as compared to molded geometry scales, the orientation structure of PPMCs is spatially nonsmooth, thereby eliminating the requisite separation of scales utilized by typical molding simulation approaches. Additionally, the large fiber volume fraction and fiber length in platelets yield highly anisotropic flow behavior, as manifested in the resistance to stretching deformations along platelet fiber directions. Thus, the goal of this work is to present the development, implementation, and validation of a flow simulation approach for PPMCs accounting for fiber direction and platelet normal direction evolution with coupled anisotropic viscous behavior. The simulation approach is implemented using the smoothed particle hydrodynamics method. To validate the proposed approach, a pin bracket geometry is manufactured from a charge with the orientation state measured by computed tomography (CT). The final orientation state determined by the flow simulation predictions and by measuring the orientation state of the final bracket by CT is compared to validate the predictions. (C) 2018 The Society of Rheology.