A coupled dislocation dynamics-continuum barrier field model with application to irradiated materials
A coupled dislocation dynamics-continuum barrier field model with application to irradiated materials
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DOI：
10.1016/j.ijplas.2018.01.015
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发表时间：
2018-05-01
影响因子：
9.8
通讯作者：
Ghoniem, Nasr M.
中科院分区：
文献类型：
--
作者：
Cui, Yinan;Po, Giacomo;Ghoniem, Nasr M.
发展了一种新的势垒强化材料三维离散位错动力学（DDD）计算方法。我们耦合的离散三维DDD框架与有限元法（FEM）的连续场方程的离散障碍的演变的解决方案。耦合模型参数从详细的统计分析的3D DDD模拟单位错势垒相互作用。我们开发了一种基于晶格的连续体材料点排列方法，以精确地分布局部塑性应变作为位错势垒相互作用的结果，使该方法是晶体结构敏感。该模型被证明是由应用程序的物理学的位错通道的形成和辐照材料的塑性不稳定现象的研究。结果表明，与辐射硬化的幅度和塑性不稳定性的发病实验。在高辐照剂量下，辐照材料的塑性流动局部化更为普遍。该方法使未来的研究在沉淀强化合金，氢脆材料的塑性变形，和辐照材料的塑性。
A new computational methodology for 3-dimensional (3D) Discrete Dislocation Dynamics (DDD) in barrier-strengthened materials is developed. We couple the discrete 3D DDD framework with the Finite Element Method (FEM) solution of a continuum field equation for the evolution of dispersed barriers. Coupled model parameters are obtained from detailed statistical analysis of 3D DDD simulations of single dislocation-barrier interactions. We develop a crystal lattice based continuum material point arrangement method to precisely distribute localized plastic strain as a result of dislocation-barrier interactions, enabling the method to be crystal-structure sensitive. The model is demonstrated by an application to the study of the physics of dislocation channel formation and plastic instability phenomena in irradiated materials. The results are shown to be in agreement with experiments on the magnitude of radiation hardening and the onset of plastic instability. Plastic flow localization in irradiated materials was shown to be more prevalent at high irradiation dose. The method enables future studies of the plastic deformation in precipitation-strengthened alloys, hydrogen-embrittled materials, and the plasticity of irradiated materials.