Integrated simulations of gas injection molding process and part structural performance under a unified CAE model

Integrated simulations of gas injection molding process and part structural performance under a unified CAE model were carried out. An analysis algori thm based on DKT/VRT elements superimposed with beam elements representing gas channels of various section geometries was first developed to evaluate the structural reinforcement of gas channel in the design stage. During mel t/gas filling process, a mixed control-volume/finite-element/finite-differe nce method combined with dual-filling-parameter technique was implemented t o trace the advancement of melt and gas fronts. For the prediction of secon dary gas penetration, flow model of isotropic-shrinkage origin was introduc ed. Mold cooling analysis was executed utilizing cycle-averaged boundary el ement method considering the cooling system. Both cooling channel and the h ollowed core gas channel were modeled using line-source approach. Thermal r esidual stresses calculated from part temperature distribution were then co mbined with the structural analysis to predict part warpage. The monitor su pport was used as the case study. The analysis accuracy from this unified m odel of 2-1/2D characteristics were examined experimentally. The only diffe rence between process simulation and structure/warpage analyses is that dif ferent values of equivalent diameters assigned to a circular pipe represent ing gas channel should be used, respectively.