Yielding and post-yield behaviour of closed-cell cellular materials under multiaxial dynamic loading

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• 作者：Matej Vesenjak ; Zoran Ren
• 刊名：Metals and Materials International
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：22
• 期：3
• 页码：435-442
• 全文大小：1,439 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Metallic Materials
  Operating Procedures and Materials Treatment
  
• 出版者：The Korean Institute of Metals and Materials, co-published with Springer Netherlands
• ISSN：2005-4149
• 卷排序：22

文摘

The paper focuses on characterisation of yielding and post-yield behaviour of metals with closed-cell cellular structure when subjected to multiaxial dynamic loading, considering the influence of the relative density, base material, strain rate and pore gas pressure. Research was conducted by extensive parametric fully-coupled computational simulations using the finite element code LS-DYNA. Results have shown that the macroscopic yield stress of cellular material rises with increase of the relative density, while its dependence on the hydrostatic stress decreases. The yield limit also rises with increase of the strain rate, while the hydrostatic stress influence remains more or less the same at different strain-rates. The macroscopic yield limit of the cellular material is also strongly influenced by the choice of base material since the base materials with higher yield limit contribute also to higher macroscopic yield limit of the cellular material. By increasing the pore gas filler pressure the dependence on hydrostatic stress increases while at the same time the yield surface shifts along the hydrostatic axis in the negative direction. This means that yielding at compression is delayed due to influence of the initial pore pressure and occurs at higher compressive loading, while the opposite is true for tensile loading.Keywordscellular materialsmechanical propertiesplasticitystrain ratecomputer simulation