Ductile failure modeling
Ductile failure modeling
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DOI：
10.1007/s10704-016-0142-6
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发表时间：
2016-09-01
影响因子：
2.5
通讯作者：
Tvergaard, Viggo
中科院分区：
文献类型：
--
作者：
Benzerga, Ahmed Amine;Leblond, Jean-Baptiste;Tvergaard, Viggo
结构金属的韧性断裂主要通过孔洞的形核、长大和聚合而发生。在此，对这类失效的连续介质模型进行了综述。描述了目前应用最广泛的框架，并讨论了其局限性。很多工作集中在扩展孔洞长大模型，以考虑非球形初始孔洞形状以及长大过程中的形状变化。这包括极低应力三轴度的情况，在此情况下，在失效过程中孔洞可闭合形成微裂纹。孔洞长大模型也已被扩展以考虑塑性各向异性的影响，或者将材料尺寸尺度引入模型的非局部效应的影响。通常，材料中一开始并不存在孔洞，因此符合实际的形核模型很重要。相邻孔洞聚合的最终失效过程是近来备受关注的一个问题。在韧性断裂时，塑性流动的局部化往往很重要，会导致通过孔洞片机制失效。给出了各种应用以说明这些模型，包括焊接试样、蝶形试样的剪切试验以及裂纹扩展分析。
Ductile fracture of structural metals occurs mainly by the nucleation, growth and coalescence of voids. Here an overview of continuum models for this type of failure is given. The most widely used current framework is described and its limitations discussed. Much work has focused on extending void growth models to account for non-spherical initial void shapes and for shape changes during growth. This includes cases of very low stress triaxiality, where the voids can close up to micro-cracks during the failure process. The void growth models have also been extended to consider the effect of plastic anisotropy, or the influence of nonlocal effects that bring a material size scale into the models. Often the voids are not present in the material from the beginning, and realistic nucleation models are important. The final failure process by coalescence of neighboring voids is an issue that has been given much attention recently. At ductile fracture, localization of plastic flow is often important, leading to failure by a void-sheet mechanism. Various applications are presented to illustrate the models, including welded specimens, shear tests on butterfly specimens, and analyses of crack growth.