SIMULATION ON THE PART WARP AGE AND PHOTOELASTIC STRESS WHEN MOLDING DISCONTINUOUS-THICKNESS-VARIATION PARTS COMBINED WITH DIFFERENTIAL MOLD COOLING

摘要

Discontinuous-Thickness-Variation (DTV) is used to interrupt the continuous shrinkage locally to minimize warpage. Matching of DTV with various mold temperature differences between the mold core and cavity sides was performed. The combined effect can be quantitatively described by a design guide chart. Case studies also verify its effectiveness. Simulations were conducted to calculate the neutral axis shift and the frozen layer thickness difference due to the unbalanced cooling. The analysis indicates that variation in thickness will pull the deviated neutral axis and photo-elastic stress due to unbalanced cooling back to the center line, leading to a significant part warpage reduction.