| Dependence of crack trajectories on stress distributions in the surfaces of injection moldings produced under high packing pressure.: An article from: Polymer Engineering and Science | Digitalby J. Tirosh (Author), R.P. Kambour (Author)
| List Price: | $5.95 | | | Available: | Available for download now |
| | Binding: | Digital | | Publisher: | Society of Plastics Engineers, Inc. | | Page Count: | 9 Pages | | Publication Date: | December 15, 1996 |
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Product Description
This digital document is an article from Polymer Engineering and Science, published by Society of Plastics Engineers, Inc. on December 15, 1996. The length of the article is 2650 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser.From the author: The curved trajectories of solvent-induced cracks in the surfaces of polycarbonate injection moldings produced under high packing pressures have been rationalized in terms of the residual body stresses that exist largely in a thin surface layer. The analysis indicates that the residual tensile stress in the skin of the molded plaque can reach values as large as 5 MPa and the tangential tensile stress values as large as 12 MPa, depending on location in the plaque and on molding conditions. The inward penetration of the crack is stopped eventually by the interior compressive stresses that counterbalance the tensile stresses in the "skin." The crack tends to turn sideways and grow further in Mode II as a result of the intense interlayer shear stress set up at the crack tip by the difference between the skin tension and core compression. The most important practical conclusion from this analysis is that in the absence of externally applied stress, these so-called edge cracks are unlikely to penetrate the molding's interior since the tensile stress in the surface layer is necessarily counterbalanced by the subsurface compression.Citation DetailsTitle: Dependence of crack trajectories on stress distributions in the surfaces of injection moldings produced under high packing pressure.Author: J. TiroshPublication: Polymer Engineering and Science (Refereed)Date: December 15, 1996Publisher: Society of Plastics Engineers, Inc.Volume: v36 Issue: n23 Page: p2875(6)Distributed by Thomson Gale |
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