A new failure criterion for the Gurson-Tvergaard dilational constitutive model
A new failure criterion for the Gurson-Tvergaard dilational constitutive model
复制标题
Gurson-Tvergaard 扩张本构模型的新失效准则
DOI：
10.1007/bf00032450
复制
发表时间：
1994
影响因子：
2.5
通讯作者：
E. Niemi
中科院分区：
文献类型：
--
作者：
Zhiliang Zhang;E. Niemi
在Gurson-Tvergaard模型中，必须使用失效准则来表示空隙聚结。在文献中，常临界空泡体积分数准则已被广泛使用。然而，它是值得怀疑的临界空隙体积分数是否是一个材料常数，此外，它也是很难在实践中确定的“常数”。本文通过对Gurson-Tvergaard模型的修正，提出了一个与Gurson-Tvergaard模型完全相容的新的破坏准则。在本准则中，已被认为是由内部颈缩的空洞合并的故障机制和材料的故障是一个自然的结果的发展的双重本构，稳定和不稳定的，响应。在本准则的实际应用中，不需要预先确定临界空隙体积分数，无论是数值或实验。此外，根据新准则，对应于空穴合并的空穴体积分数不是材料常数，而是应力三轴度的函数。使用本准则的预测已被比较与有限元结果由科普利克和Needleman，观察到非常好的协议。讨论了这一准则的潜在优点和其他相关问题。
In the Gurson-Tvergaard model a failure criterion has to be used to signify the void coalescence. In the literature, a constant critical void volume fraction criterion has been widely used. However, it is questionable whether the critical void volume fraction is a material constant and, furthermore, it is also difficult in practice to determine the ‘constant’. By modifying Thomason's plastic limit-load model, a new failure criterion which is fully compatible with the Gurson-Tvergaard model, is presented in this study. In the present criterion, the void coalescence failure mechanism by internal necking has been considered and the material failure is a natural result of the development of dual constitutive, stable and unstable, responses. In practical application of the present criterion, no critical void volume fraction needs to be pre-determined either numerically or experimentally. Furthermore, according to the new criterion, the void volume fraction corresponding to void coalescence is not a material constant, rather a function of stress triaxiality. The predictions using the present criterion have been compared with the finite element results by Koplik and Needleman, and very good agreement is observed. The potential advantage of this criterion and other related issues are discussed.