The flowability of resins and fibers during the formation of short-fiber-reinforced plastics was evaluated via moving particle semi-implicit (MPS) particle simulation. Extensive design parameters are associated with the injection molding of short-fiber-reinforced plastics. It is time-consuming and expensive to optimize these parameters using experimental procedures. A numerical prediction based on MPS particle simulation was demonstrated in the present study. Here, a novel analysis method for the local flow, accompanied by variations in the time and analysis area, was developed. Using this method, the discrepancies in the velocity distribution between the global injection area and local flow area were addressed. The numerical results indicated that the resin flow during injection molding exhibited similar characteristics for both global injection-molding analysis and the proposed analysis method. The fiber orientation derived via the proposed analysis method was similar to that indicated by the experimental results of a previous study. A model conforming to the experiment of injection molding was constructed, and verification analysis was performed. Thus, the validity of the proposed analysis method was verified. It was concluded that the proposed method facilitated the evaluation of the resin flow and fiber orientation during the injection molding of short-fiber-reinforced plastics.
