In situ measurement of local strain in a metal matrix composite by the object grating technique
In situ measurement of local strain in a metal matrix composite by the object grating technique
复制标题
利用物栅技术原位测量金属基复合材料中的局部应变
DOI：
10.1016/s1359-6462(97)00013-4
复制
发表时间：
1997
影响因子：
6
通讯作者：
G. Fischer
中科院分区：
文献类型：
--
作者：
Y. L. Liu;G. Fischer
当金属基复合材料（MMC）受到应变时，变形高度局部化在增强颗粒附近（l-5）。变形过程中的应力/应变局部化影响整体应变硬化行为，并与微损伤的发生直接相关。它一直是理论界和实验界非常关注的课题。有限元模拟（FEM）（1、2、4、5）已被用于预测复合材料的局部应力场。另一方面，人们开发了各种实验方法来测量MMCs的应力/应变局部分布，以便与有限元模拟进行直接比较。TEM和EBSP （SEM）等已被用于确定局部位错密度，作为局部塑性应变的间接测量（3,6,7）。在过去的几十年里，各种物体光栅方法（8-12）已经发展到表征非均匀材料试样表面的应变场。该技术结合了光学或扫描电子显微镜下的应力装置，可以在原位研究局部应变分布（10-12）。该技术的最新发展是利用微网格（距离几微米）和计算机图像分析，从而提高了横向分辨率，应变测量精度和计算速度。
When the metal matrix composite (MMC) material is strained, deformation is highly localized in the vicinity of the reinforcement particles (l-5). The stress/strain localization during deformation affects the overall strain hardening behaviour and is directly related to the initiation of microdamage. It has been a subject which attracts a great attention theoretically and experimentally. Finite Element Modelling (FEM) simulations (1, 2, 4, 5) have been used to predict the local stress/strain fields in MMCs. On the other hand various experimental methods have been developed to measure the local distribution of stress/strain m MMCs for direct comparison with FEM simulations. TEM and EBSP (SEM), among others, have been used to determine the local dislocation density as an indirect measure of the local plastic strain (3, 6, 7).Various object grating methods (8-12) have been developed to characterize the strain fields on the specimen surface of inhomogeneous materials in the past decades. This technique combined with a stress-rig in an optical or a scanning electron microscope allows the local strain distribution studied insitu (10-12). The recent development of this technique is the use of microgrids (a few microns in distance), and computerized image analysis, which lead to improvements in the lateral resolution, strain measuring accuracy and calculating speed.