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http://dx.doi.org/10.3795/KSME-A.2002.26.11.2342

Numerical Analysis of ]Residual Stresses and Birefringence in Injection/Compression Molded Center-gated Disks (I) - Modeling and Basic Results -  

Lee, Young-Bok (포항공과대학교 기계공학과)
Kwon, Tai-Hun (포항공과대학교 기계공학과)
Yoon, Kyung-Hwan (단국대학교 기계공학과)
Publication Information
Transactions of the Korean Society of Mechanical Engineers A / v.26, no.11, 2002 , pp. 2342-2354 More about this Journal
Abstract
The present study has numerically predicted both the flow -induced and thermally-induced residual stresses and birefringence in injection o. injection/compression molded center -gated disks. Analysis system for entire molding process was developed based on an ap propriate physical modeling including a nonlinear viscoelastic fluid model, stress-optical law, a linear viscoelastic solid model, free volume theory for density relaxation phenomena and a photoviscoelasticity and so on. Part I presents physical modeling a nd typical numerical analysis results of residual stresses and birefringence in the injection molded center-gated disk. Thermal residual stress was found to be extensional near the center, compressive near the surface and tend to become toward tensional at the surface. A double-hump profile was obtained across the thickness in birefringence distribution: nonzero birefringence is found to be thermally induced, the outer peak is due to the shear flow and subsequent stress relaxation during the filling stage a nd the inner peak is due to the additional shear flow and stress relaxation during the packing stage. Predicted birefringence including both the flow -induced and thermally-induced one becomes quite similar to the experimental one.
Keywords
Rsidual Sress; Brefingence; Injection Molding; Injection/compression Molding; Free Volume Theory; Viscoelasticity; Photoviscoelasticity;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
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