MULTISCALE DISLOCATION DYNAMICS PLASTICITY
MULTISCALE DISLOCATION DYNAMICS PLASTICITY
复制标题
多尺度位错动力学塑性
DOI：
10.1615/intjmultcompeng.v1.i1.70
复制
发表时间：
2003
影响因子：
1.4
通讯作者：
G. Karami
中科院分区：
文献类型：
--
作者：
H. Zbib;M. Shehadeh;S. M. Khan;G. Karami
H. M. Zbib，M. Sh ehadeh，S. M. A. Khan和G. Karami机械与材料工程学院，华盛顿州立大学，普尔曼，WA 99164 - 2920（509）335 - 7832，zbib@wsu.edu摘要综述了Zbib及其同事最近开发的用于晶体材料的离散位错动力学（DD）模型与有限元（FE）分析耦合。三维弹粘塑性有限元方程采用DD模拟代替常规的塑性本构关系，得到了多尺度位错动力学塑性模型（MDDP）。耦合涉及到一个非平凡的均匀化，以获得局部塑性应变的贡献离散塑性事件中捕获的DD。利用叠加原理研究了边界（自由边界、刚性边界和界面）对位错运动的影响。所开发的计算机代码可以有效地处理尺寸依赖的小尺度塑性现象和相关的材料不稳定性在各种长度尺度范围从纳米-微米尺度到介观尺度。DD建模是基于位错运动及其与各种缺陷、界面和外部载荷的相互作用的基本物理定律。考虑的多尺度框架合并了两个尺度的纳米-微米尺度，其中确定塑性，和连续尺度，其中能量传输的基础。为了说明这种方法在调查广泛的塑性现象的有用性，一组案例研究的结果。这包括，在bcc和fcc单晶纳米压痕过程中的变形和位错结构，分析有关的位错边界的形成在大变形，位错与冲击波的相互作用，在冲击载荷条件下，和位错缺陷的相互作用。
H. M. Zbib, M. Sh ehadeh, S. M. A. Khan and G. Karami School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164 -2920 (509) 335 -7832, zbib@wsu.edu SUMMARY A discrete Dislocation Dynamics (DD ) model for crystalline materials coupled with finite elements (FE) analysis developed recently by Zbib and co-workers is reviewed. The three-dimensional continuum-based FE formulation for elastoviscoplasticity incorporates the DD simulation replacing the usual plasticity constitutive relations, leadi ng to what is called a Multiscale Dislocation Dynamics Plasticity (MDDP ). The coupling involves a non-trivial homogenization to obtain local plastic strains from the contributions of discrete plastic events captured in DD . The superposition principle is utilized in order to find the effects of the boundaries (free, rigid or interfaces) on the dislocation movement. The developed computer code can efficiently handle size -dependent small-scale plasticity phenomena and related material instabilities at various length scales ranging from the nano-microscale to the mesoscale. The DD modeling is based on the fundamental physical laws governing dislocation motions and their interactions with various defects, interfaces, and external loadings. The multi-scale frame of consideration merges the two scales of nano-microscale, where plasticity is determined, and the continuum scale, where the energy transport is based. In order to illustrate the usefulness of this approach in investigating a wide range of plasticity phenomena, results for a set of case studies are presented. This includes, the deformation and dislocation structure during nanoindentation in bcc and fcc single crystals, analyses pertaining to the formation of dislocation boundaries during heavy deformation, dislocations interaction with shock-waves during impact loading conditions, and dislocation-defect interaction.