An inverse design method has been developed to obtain an optimum mold-wall-temperature history that produces an injection-molded part with minimum residual-stress distribution. Optimization has been formulated within the framework of nonlinear least squares and a modified Gauss-Newton method with a zeroth-order regularization technique. The transient temperature field has been generated based upon a purely viscous formulation of the filling and post-filling stages, and the cooling-induced residual stresses have been calculated employing a thermo-rheologically simple, linear viscoelastic model. The present study shows that, with an optimum cooling history, maximum residual-stress levels can be reduced significantly for both unconstrained and constrained vitrification with holding pressure.
Bibliographical noteFunding Information:
Received 30 October 1996; accepted 14 October 1997. This work was supported by the Industrial Consortium of the Cornell Injection Molding Program. Address correspondence to Shinill Kang, Department of Mechanical Design and Production Engineering, School of Engineering, Yonsei University, 134 Shinchon-Dong, Seodaemun-Ku, Seoul, Korea. E-mail: SNLKANG@bubble.yonsei.ac.kr
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics