Finite element analysis of void growth in elastic-plastic materials
Finite element analysis of void growth in elastic-plastic materials
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DOI：
10.1007/bf00018610
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发表时间：
1990
影响因子：
2.5
通讯作者：
R. McMeeking;C. Hom
中科院分区：
文献类型：
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作者：
R. McMeeking;C. Hom
三维有限元计算已经进行了增长的初始球形空洞在周期性的立方阵列和初始球形空洞前面的钝化模式I平面应变裂纹尖端。数值方法是基于有限应变理论和计算是三维的。孔洞立方体阵列受到宏观均匀的单轴拉伸，纯剪切和高三轴应力场。宏观应力-应变行为和空隙体积的变化，得到两个初始空隙体积分数。计算结果表明，空洞形状，空洞相互作用和承载能力的损失强烈地依赖于应力场的三轴度。将有限元计算结果与几种多孔材料塑性连续体模型进行了比较。没有一个模型完全符合有限元计算。与任何特定的本构模型的有限元结果的协议取决于宏观应变的水平和远程均匀应力场的三轴性。对于钝化Ⅰ型平面应变裂纹尖端正前方的初始球形孔洞问题，假定了小范围屈服条件。得到了理想塑性材料在不同孔洞尺寸与间距比下的近端应力场和变形场。计算结果表明，孔向裂纹尖端和彼此之间的扩展速度比它们在拉伸方向上的伸长速度快。计算出的空隙增长率进行了比较与以前的模型空隙增长。
Three-dimensional finite element computations have been carried out for the growth of initially spherical voids in periodic cubic arrays and for initially spherical voids ahead of a blunting mode I plane strain crack tip. The numerical method is based on finite strain theory and the computations are three-dimensional. The void cubic arrays are subjected to macroscopically uniform fields of uniaxial tension, pure shear and high triaxial stress. The macroscopic stress-strain behavior and the change in void volume were obtained for two initial void volume fractions. The calculations show that void shape, void interaction and loss of load carrying capacity depend strongly on the triaxiality of the stress field. The results of the finite element computation were compared with several dilatant plasticity continuum models for porous materials. None of the models agrees completely with the finite element calculations. Agreement of the finite element results with any particular constitutive model depended on the level of macroscopic strain and the triaxiality of the remote uniform stress field. For the problem of the initial spherical voids directly ahead of a blunting mode I plane strain crack tip, conditions of small scale yielding were assumed. The near tip stress and deformation fields were obtained for different void-size-to-spacing ratios for perfectly plastic materials. The calculations show that the holes spread towards the crack tip and towards each other at a faster rate than they elongate in the tensile direction. The computed void growth rates are compared with previous models for void growth.