Design Analysis and Modification of Ribs and Tubes on Thin-Wall Parts for Mold Flow Analysis

A DFM analysis and design modification system for plastic injection molding was developed in this study. It mainly included a feature recognition algorithm to extract tube and rib features for analysis, a DFM analysis algorithm for the optimization of feature dimensions, and a design modification algorithm to modify unqualified ribs and tubes automatically. The proposed feature recognition algorithm recognized auxiliary faces, including translation, wall and bottom faces, on the inner surface of a thin-wall part, and then grouped each set of protrusion faces. Tubes and ribs were then recognized with separate recognition algorithms. The proposed DFM analysis algorithm provided a data structure of fillet, rib and tube features for the evaluation of rib and tube dimensions. The optimization of feature dimensions included thickness, height, draft angle, base radius, and space for both ribs and tubes in accordance with various design guides. Finally, the design modification algorithm could modify all unqualified ribs and tubes automatically. This enables the CAE engineer to perform a trial-and-error analysis and the modification of the CAD design during the CAE analysis stage.