Hybrid mesh generation for the thin shell of thin-shell plastic parts for mold flow analysis

Thin-shell plastic parts exist in many products and are frequently manufactured by injection molding. A thin-shell part typically has a thin shell, on which protrusion features reside. In mold flow analysis, the thin shell is typically meshed with tetrahedral meshes as they can be generated automatically, but they are not easy to meet the requirement of the analysis solver, and hence may easily result in either divergent or irrational results. The purpose of this study was to develop a method for automatic generation of prismatic and hexahedral meshes for thin-shells, with all protrusion features considered separately. In the proposed algorithm, the internal surface of a thin shell was divided into tightly neighboring inner contours. Each inner contour was then projected onto outer faces to find a corresponding outer contour. Some of the projected edges were adjusted to ensure that all neighboring outer contours were also tightly neighboring to each other. Each inner-and-outer contour pair could form a volume, by which a set of solid meshes was generated. The remaining un-specified volumes were finally detected and meshed. A detailed description of the procedures in each step of the proposed algorithm is provided. Twelve CAD models and analysis results are also presented to demonstrate the feasibility of the proposed hybrid meshing method.