Experimental evaluation and constitutive modeling of non-proportional deformation for asymmetric steels
Experimental evaluation and constitutive modeling of non-proportional deformation for asymmetric steels
复制标题
DOI：
10.1016/j.ijplas.2010.04.002
复制
发表时间：
2011
影响因子：
9.8
通讯作者：
R. Verma;T. Kuwabara;K. Chung;A. Haldar
中科院分区：
文献类型：
--
作者：
R. Verma;T. Kuwabara;K. Chung;A. Haldar
近年来，非比例变形越来越受到金属变形实验和计算模拟领域研究人员的关注。然而，它们大多是数值性质的，可用的实验数据有限，这使得对非比例变形进行建模变得更加困难。本文对超低碳高强度汽车用钢进行了两级单轴试验、单轴循环试验和不同应力比的双轴试验，以评价其变形行为。在该钢中观察到了交叉效应和硬化停滞等行为，这些行为归因于复杂的位错结构的演变。还注意到，这种钢表现出拉压不对称。在本构模型方面，提出了一种修正的非对称屈服函数，并将其与各向同性-运动强化模型相结合。提出了反向加载时的硬化停滞和两阶段变形时的交叉效应的解释方法。所建立的本构模型与实验结果吻合较好。
Recently non-proportional deformation has received increased attention from researchers working in the area of experimental and computational modeling of metal deformation. However, most of them are numerical in nature with limited experimental data available, making it further difficult to model non-proportional deformation. In the present work, two-stage uniaxial tests, along with uniaxial cyclic and biaxial tests for different stress ratios, have been performed to evaluate deformation behavior of ultra-low carbon high strength automotive steel. Behaviors like cross-effect and hardening stagnation, which are attributed to the evolution of complex dislocation structures, were observed in this steel. It was also noticed that this steel exhibits tension–compression asymmetry. As for constitutive modeling, a modified asymmetric yield function is proposed to be used with a combined isotropic–kinematic hardening model. Also methods to account for the hardening stagnation during reverse loading and the cross-effect during two-stage deformation are proposed. The resulting constitutive model showed reasonably good agreement with experimental results.