Ductile failure as a result of a void-sheet instability: Experiment and computational modeling

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• 作者：Bandstra ; J.P. ; Goto ; D.M. ; Koss ; D.A.
• 关键词：Ductile failure ; Void-sheet instability ; HY-100 steel
• 刊名：Materials Science and Engineering: A
• 出版年：1998
• 出版时间：June 30, 1998
• 年：1998
• 卷：249
• 期：1-2
• 页码：46-54
• 全文大小：925 K

文摘

The ductile fracture of circumferentially notched HY-100 steel specimens tested at high stress triaxiality is characterized by a fracture surface with a zig-zag profile created by large elongated voids separated by inclined sheets of microvoids. The failure path suggests that a local deformation instability, triggered by the growth of MnS inclusion-nucleated voids, may be responsible for this form of fracture. Measurements show that the failure strains are small and decrease slowly with increasing stress triaxiality as compared to a more global void coalescence. Micro-mechanical modeling by finite element analysis of a geometry based on the observed metallurgical microstructure shows a distinct localization of plastic flow. The localization of plastic flow leads to a void-sheet failure prediction and the experimental results are correctly characterized by the computational model.