• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>International journal of nanomechanics science and technology >DIRECT CRYSTAL PLASTICITY MODEL FOR DESCRIBING THE DEFORMATION OF SAMPLES OF POLYCRYSTALLINE MATERIALS: INFLUENCE OF EXTERNAL AND INTERNAL BOUNDARIES OF SAMPLES
【24h】

DIRECT CRYSTAL PLASTICITY MODEL FOR DESCRIBING THE DEFORMATION OF SAMPLES OF POLYCRYSTALLINE MATERIALS: INFLUENCE OF EXTERNAL AND INTERNAL BOUNDARIES OF SAMPLES

机译：用于描述多晶材料样品变形的直接晶体塑性模型：样品外部和内部边界的影响

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This paper presents the structure and basic relations of a direct crystal plasticity (elastoviscoplasticity) model of a polycrystalline sample. This model was used to carry out a number of numerical experiments on tensile deformation of polycrystalline samples. The purpose of these experiments was to reveal the influence of external (free) and internal (intergrain) boundaries of samples, grain size, and sample size on the macroscopic properties and the evolution of the internal structure of the material in different regions of the sample. The initial grain structure of the sample (from 500 to 1000 grains) was formed using the Neper software product, then the crystal grains were approximated by a set of finite elements (about 2000 per grain) using the Gmsh software package. In order to directly solve the boundary-value problem, a proprietary software package was used to implement an algorithm for solving the crystal elastoviscoplastic problem formulated in the rate-form by the finite element method. The results of numerical experiments on samples tension show that the presence of a free surface makes the deformation process significantly nonuniform and affects the evolution of the material internal structure, both directly in the near-surface regions and in the volume of the sample. Plastic deformations are initiated in the near-surface layers of the sample and penetrate into deeper layers of the material during the process. Inhomogeneous plastic deformation, which occurs within grains, gives rise to rotation and misorientation of the subregions of individual grains that are also initiated in the near-surface layers, which leads to fragmentation and refinement of grains at large strains. It is shown that the significant parameter for the sample is the average grain size, with a decrease in which the fraction of the internal grain boundaries and, accordingly, the hardening rate increase as follows: for grain sizes in the range from 13 to 108 mu m, it is shown that the hardening rate is inversely proportional to the average grain size raised to the power of 1/2.
机译：本文介绍了多晶样品的直接晶体塑性（Elastoviscoplicity）模型的结构和基本关系。该模型用于对多晶样品的拉伸变形进行多种数值实验。这些实验的目的是揭示样品，晶粒尺寸和样品大小对宏观性质上的外部（自由）和内部（凝纹）的影响以及样品中不同区域中材料内部结构的进化。使用Neper软件产品形成样品（从500〜1000粒）的初始晶粒结构，然后使用GMSH软件包通过一组有限元（约2000粒）近似晶粒。为了直接解决边值问题，使用专有软件包来实现一种通过有限元方法求解速率形式以速率形式配制的晶体弹性囊泡问题的算法。样品张力的数值实验结果表明，自由表面的存在使得变形过程显着不均匀，并影响材料内部结构的进化，两者在近表面区域和样品的体积中。在样品的近表面层中引发塑料变形，并在该过程中渗透到更深的材料层中。发生在晶粒内的不均匀塑性变形，其在近表面层中也引发的单个颗粒的旋转和误报，这导致大菌株的颗粒的破碎和改进。结果表明，样品的显着参数是​​平均晶粒尺寸，下降的分数和相应地，固化速率如下：对于13至108亩的晶粒尺寸M，示出了硬化速率与升高到1/2的电力的平均晶粒尺寸成反比。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号