J-integral and crack driving force in elastic–plastic materials
J-integral and crack driving force in elastic–plastic materials
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DOI：
10.1016/j.jmps.2008.04.003
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发表时间：
2008-09
影响因子：
5.3
通讯作者：
N. Simha;F. Fischer;G. Shan;C. R. Chen;O. Kolednik
中科院分区：
文献类型：
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作者：
N. Simha;F. Fischer;G. Shan;C. R. Chen;O. Kolednik
本文讨论了弹塑性材料中的裂纹驱动力，特别强调增量塑性。使用配置力的方法，我们确定了一个“塑性影响项”，描述裂纹尖端屏蔽或反屏蔽由于在体内的塑性变形。有限应变以及小应变增量塑性的标准本构模型被用来获得显式表达式的塑性影响项在二维设置。体中的总耗散与近端和远场J积分以及塑性影响项有关。在变形塑性的特殊情况下，塑性影响项完全消失，而对于刚性塑性和弹性理想塑性，裂纹驱动力完全消失。对于增量弹塑性材料中的稳态裂纹扩展，塑性影响项等于单位裂纹扩展塑性功的负值，裂纹扩展和塑性变形在体中的总耗散由远场J积分决定。对于非稳态裂纹扩展，塑性影响项可以在常规有限元应力分析之后通过后处理来评估。理论和计算应用于C（T）试件中的静止裂纹，以检查包含，不包含和一般屈服的影响。提出了一种新的增量塑性条件下J积分的计算方法。增量塑性近端和远场J积分相比，传统的变形塑性和实验J积分。
This paper discusses the crack driving force in elastic–plastic materials, with particular emphasis on incremental plasticity. Using the configurational forces approach we identify a “plasticity influence term” that describes crack tip shielding or anti-shielding due to plastic deformation in the body. Standard constitutive models for finite strain as well as small strain incremental plasticity are used to obtain explicit expressions for the plasticity influence term in a two-dimensional setting. The total dissipation in the body is related to the near-tip and far-field J-integrals and the plasticity influence term. In the special case of deformation plasticity the plasticity influence term vanishes identically whereas for rigid plasticity and elastic-ideal plasticity the crack driving force vanishes. For steady state crack growth in incremental elastic–plastic materials, the plasticity influence term is equal to the negative of the plastic work per unit crack extension and the total dissipation in the body due to crack propagation and plastic deformation is determined by the far-field J-integral. For non-steady state crack growth, the plasticity influence term can be evaluated by post-processing after a conventional finite element stress analysis. Theory and computations are applied to a stationary crack in a C(T)-specimen to examine the effects of contained, uncontained and general yielding. A novel method is proposed for evaluating J-integrals under incremental plasticity conditions through the configurational body force. The incremental plasticity near-tip and far-field J-integrals are compared to conventional deformational plasticity and experimental J-integrals.