Synergistic effects of plastic anisotropy and void coalescence on fracture mode in plane strain
Synergistic effects of plastic anisotropy and void coalescence on fracture mode in plane strain
复制标题
塑性各向异性和空隙合并对平面应变断裂模式的协同效应
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
A. Pineau
中科院分区：
文献类型：
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作者：
A. Benzerga;J. Besson;R. Batisse;A. Pineau
韧性材料在平面应变下的宏观断裂是剪切型的。在大多数结构材料中，断裂开始后，扩散颈缩，在试样的中心，由微孔聚结引起的宏观剪切断裂模式。本文用数值方法分析了平面应变条件下，剪切带的合并对剪切带发展和相应断裂模式的影响。计算使用最近的弹粘塑性Gurson模型，占空隙形状的演变，合并和合并后的微观力学沿着与各向同性硬化和正交各向异性塑性的矩阵行为。后者被引入来代表热加工材料的实际流动性能。没有运动硬化或成核配方使用，以集中注意力的聚结效应和讨论，相对于实验，发表的结果的基础上运动硬化和成核效应。最重要的发现是协同效应的塑性各向异性和后聚结屈服面曲率后，在断裂后的剪切带的发病集在试样的中心。
The macroscopic fracture in plane strain is known to be shear-like in ductile materials. In most structural materials, fracture starts after diffuse necking, at the centre of the specimen, by micro-void coalescence giving rise afterwards to the macroscopic shear fracture mode. In this paper, the effect of coalescence on shear band development and on associated fracture mode in plane strain is analysed numerically. The calculations are performed using a recent elastic-viscoplastic Gurson-like model that accounts for void shape evolution, coalescence and post-coalescence micromechanics along with isotropic hardening and orthotropic plasticity for the matrix behaviour. The latter is introduced to represent the actual flow properties of hot-worked materials. No kinematic hardening or nucleation formulation is used in order to focus attention on coalescence effects and to discuss, with respect to experiments, published results based on kinematic hardening and nucleation effects. The most important finding is the synergistic effect of plastic anisotropy and post-coalescence yield surface curvature upon the onset of a shear band after the fracture sets in at the centre of the specimen.