No / High temperature reversion tests have revealed a state of pre-existing molecular orientation in extruded polyethylene sheet. This state is related to differences in stress-deformation behaviour when specimens of the sheet are stretched along different angles with respect to the extrusion direction. An established large deformation, rate-dependent constitutive equation has been developed to model this material, by incorporating the pre-orientation by the addition of a strained Gaussian network. The level of pre-orientation is deduced from the dimensional changes on shrinkage. The constitutive equation is incorporated into the finite element package , and the shapes and drawing forces of tensile specimens extended at various angles to the extrusion direction are modelled.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/3440 |
| Date | January 2002 |
| Creators | Sweeney, John, Caton-Rose, Philip D., Coates, Philip D. |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Article, No full-text in the repository |
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