Numerical Simulation for the Hybrid Process of Sheet Metal Forming and Injection Molding Using Smoothed Particle Hydrodynamics Method

An innovative process to produce polymer-sheet metal components in one single operation is analyzed in this paper. Polymer Injection Forming (PIF) is a hybrid process which combines best in class manufacturing processes viz. sheet metal forming and injection molding process. Consequently, this unique process is characterized by a substantial reduction in capital costs and production time and planning effort while also eliminating the need for maintaining tight manufacturing tolerances. To make use of these capabilities in high-speed injection molding process, understanding the dynamic characteristic of the melt flow is required, which cannot be achieved with regular mesh-based Finite Element (FE) methods due to their need for high computational effort and mesh distortion issue. Hence, in this study, the high-speed injection of the polymer melt is simulated using Smoothed Particle Hydrodynamics (SPH), a mesh-free fully-Lagrangian method which eliminates mesh distortion inevitable in high deformation rates of the polymer melt. The SPH method for polymer melt simulation is coupled with the FE method to analyze the elastoplastic deformation of sheet metal. Finally, Comparisons were made between the simulation and experimental results for AA1100-O and a Polypropylene-Olefin compound with different process parameters settings.