G.Z. Kang
,
Q. Gao
,
X.J.Yang and Y.F. Sun(Department of Applied Mechanics and Engineering
,
Southwest Jiaotong University
,
Chengdu 610031
,
China)
金属学报(英文版)
An experimental study was carried out of the cyclic behavior of U71Mn rail steel subjected to uniaxial strain and stress. The effects of cyclic struin amplitude, mean struin,strain loading rate and their histories on the strain cyclic characteristics were studied.Under the asymmetrical stress cycling, the effects of stress amplitude, mean stress,stress loading rate and their histories on the ratcheting were analyzed. The interaction between strain cycling and stress cycling was also discussed. It is shown that either the cyclic characteristics under strain cycling or the ratcheting under asymmetrical stress cycling depends not only on the cumnt loading state, but also on the previous loading history. Some significant results are obtained.
关键词:
cyclic plasticity
,
null
,
null
张克实石艳柯许凌波蔚夺魁
金属学报
doi:10.3724/SP.J.1037.2011.00110
考虑金属材料晶体细观塑性变形流动的各向异性性质以及晶体滑移的非线性运动硬化,以Voronoi多晶集合体作为材料的代表性单元(RVE), 用晶体塑性模型描述金属材料的细观本构关系, 对多晶纯Cu进行了晶粒尺度的对称应变循环细观分析.证实了本文模型和方法可以用于描述多晶金属材料不同应变幅的循环滞回特性,并可以用于估计金属材料在循环加载过程中后继屈服面形状和曲率与预加载方向相关的变化. 分析发现: 在对称应变循环中, 随循环数增加, 多晶材料宏观拉伸方向的内部细观应变分量的统计变异系数(COV)不断增加, 材料内部晶格的不均匀细观转动也越来越显著. 这些结果表明, 循环过程中应变分布差异和晶格转动差异逐渐增大,从而导致材料内部微结构越来越不均匀.
关键词:
循环塑性
,
slipping
,
anisotropic yielding and hardening
,
inhomogeneous deformation
