Investigation on position of kink band formation in single crystal of Mg-based LPSO phase using dislocation-based crystal plasticity simulation
Investigation on position of kink band formation in single crystal of Mg-based LPSO phase using dislocation-based crystal plasticity simulation
复制标题
使用基于位错的晶体塑性模拟研究镁基 LPSO 相单晶中扭结带形成的位置
DOI：
10.2472/jsms.65.220
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
K. Shizawa
中科院分区：
文献类型：
--
作者：
Ryo Ueta;K. Shizawa
采用基于位错的晶体塑性模型，对镁基LPSO相单晶的扭折带形成位置进行了二维有限元模拟。我们考虑到活动的基础，棱柱和第二金字塔滑移系统，并假设LPSO阶段是简单的HCP晶格简单。然而，HCP晶体如Mg和LPSO晶体的区别在于滑移系的临界分辨剪切应力的大小和变形孪晶的消除。此外，为了在连续介质力学的框架内表达扭结带中的晶体缺陷，GN位错密度、SS位错密度和GN不相容性（向错密度）被纳入硬化规则。我们进行了FE模拟。首先，我们将初始位错密度均匀地分配给模拟中使用的试样。结果表明，在试样中心形成了一个扭折带，孤立位错、位错对和向错的密度分布可用现有的晶体缺陷模型来描述。其次，在初始位错密度分布中引入非均匀性，研究了总弹性应变能对扭结变形的影响。结果，扭折带形成的位置改变，使得能量在结构上最小化。
Two-dimensional FE simulations on prediction of position of kink band formation for a single crystal of a Mg-based LPSO phase are performed using a dislocation-based crystal plasticity model. We take account of activities of basal, prismatic and 2nd-pyramidal slip systems and assume that the LPSO phase is simply composed of HCP lattices for simplicity. However, a HCP crystal such as Mg and the LPSO crystal are distinguished by magnitude of critical resolved shear stresses of the slip systems and elimination of deformation twins. In addition, to express crystal defects in the kink band within the framework of continuum mechanics, GN dislocation density, SS dislocation density and GN incompatibility (disclination density) are incorporated into the hardening rule. We carry out the FE simulation. First, we assign initial dislocation density homogeneously to a specimen used in the simulation. The result shows that a kink band is formed in the center of the specimen and distributions of densities of isolated dislocations, dislocation pairs and disclinations are appropriately expressed by the present models of crystal defects. Next, introducing a heterogeneity into the distribution of the initial dislocation density, we investigate the effects on kink deformation in terms of total elastic strain energy. As a result, the position of a kink band formation changes so that the energy is structurally minimized.
影响因子：
1.2
作者：
Kawamura, Y;Hayashi, K;Masumoto, T
通讯作者：
Masumoto, T
影响因子：
1.2
作者：
D. Egusa;M. Yamasaki;Y. Kawamura;E. Abe
通讯作者：
D. Egusa;M. Yamasaki;Y. Kawamura;E. Abe