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| Optimal design for polymer sheeting dies |
| Revised:June 25, 2002 |
| View Full Text View/Add Comment Download reader |
| DOI：10.7511/jslx20042046 |
| KeyWord:sheeting die,numerical simulation,sensitivity analysis,optimal design,SQP |
| Yu Xiaorong Shen Changyu~* Liu Chuntai Wang Lixia |
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| Abstract: |
| Polymer sheeting dies are commonly used for the extrusion of plastic sheets and films. The key of designing sheeting dies is the invariance of distribution to flow rate on the exit. In this paper an optimal design approach for polymer sheeting dies was developed which combines polymer process modeling, design sensitivity analysis and numerical optimization. A nonlinear constrained optimization problem was put forward which minimizes the inlet pressure P_(in) subject to a constraint on the exit velocity variation. Analytical design sensitivities were derived to quantify the relationship between design parameter, cost and constraint functions using direct methods. The analytical design sensitivities are combined with a sequential quadratic programming (SQP) algorithm to systematically traverse the design space towards the optimal values. An example shows that using this method can obtain a uniform velocity profile across the die and minimize pressure drop. |
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