Effect of inner gas pressure on the elastoplastic behavior of porous materials: A second-order moment micromechanics model
Effect of inner gas pressure on the elastoplastic behavior of porous materials: A second-order moment micromechanics model
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DOI：
10.1016/j.ijplas.2008.10.001
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发表时间：
2009-07
影响因子：
9.8
通讯作者：
Weixu Zhang;Weixu Zhang;Zhimin Xu;Tiejun Wang;Xiangshan Chen
中科院分区：
文献类型：
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作者：
Weixu Zhang;Weixu Zhang;Zhimin Xu;Tiejun Wang;Xiangshan Chen
建立了一种新的基于二阶应力矩的细观力学模型，研究了气体压力对多孔材料非线性宏观本构关系的影响。该分析方法与基于有限元方法的数值模拟结果吻合较好。通过系统的研究发现，气体压力对多孔材料的非线性变形行为有显著影响。气体压力会引起单轴应力-应变曲线和名义泊松比上的拉-压不对称。孔压显著降低了多孔金属的初始屈服强度和破坏强度，特别是当材料的相对密度较小时。随着温度的升高，气相对复合材料的强度也有很大的影响。该模型可用于评价不同工作条件和工作温度下多孔材料的力学完整性。
A new micromechanics model based on the second-order moment of stress is established to investigate the effect of gas pressure on the nonlinear macroscopic constitutive relationship of the porous materials. The analytical method agrees well with numerical simulation based on the finite element method. Through a systematic study, we find that the gas pressure has a prominent effect on the nonlinear deformation behavior of the porous materials. The gas pressure can cause tension–compression asymmetry on the uniaxial stress–strain curve and the nominal Poisson’s ratio. The pore pressure significantly reduces the initial yield strength and failure strength of the porous metals, especially when the relative density of the material is small. The gas phase also strongly compromises the composite strength when the temperature is increased. The model may be useful for the evaluation of mechanical integrity of porous materials under various working conditions and working temperatures.