Measurement of strain distribution in metals for tensile test using digital image correlation method and consideration of stress-strain relation
Measurement of strain distribution in metals for tensile test using digital image correlation method and consideration of stress-strain relation
复制标题
使用数字图像相关法测量拉伸试验金属中的应变分布并考虑应力-应变关系
DOI：
10.1299/mej.16-00141
复制
发表时间：
2016
影响因子：
4.4
通讯作者：
A. Kato
中科院分区：
文献类型：
--
作者：
A. Kato
摘要采用数字图像相关法测量了铝合金板试件拉伸过程中的位移分布，并根据位移分布推导了应变分布。得到了整个拉伸过程中应变分布的变化。在屈服应力之前，试样开始出现局部集中应变，随着变形的进行，局部应变逐渐增大，而试样其它区域的应变基本不变。考虑到应力-应变关系，由试样均匀区域的常规平均应力得到的真应力在保证应力之后随真应变的增大而减小。由最大应变导出的真应力随真应变的增加而增加，并发现存在加工硬化。将铝的应力-应变关系与作者已发表的钢的结果进行了比较。结果表明，要准确评价应力-应变关系，必须测量应变分布并考虑局部最大应变。
0123456789 Abstract Displacement distribution in plate specimen of aluminum during tensile test was measured with digital image correlation method and strain distribution was derived based on the displacement distribution. Change of strain distribution was obtained during whole tensile test. Local concentrated strain starts to appear before proof stress and the local strain becomes larger as the deformation proceeds and strain at other area in the specimen almost does not change. In consideration of stress-strain relation, true stress derived from the conventional average stress in uniform area of the specimen decreases after proof stress with increase of true strain. True stress derived from the maximum strain in specimen increases with increase of true strain and it is found that work hardening exists. Stress-strain relation for aluminum was compared with the result for steel which the author already published. It was found that we have to measure strain distribution and consider local maximum strain to evaluate stress-strain relation accurately.