摘要
基于亚像素角点检测的图像测量技术能够记录试样表面方块角点每一时刻的位移,从而获得试样的表面应变场。将基于试样表面6行方块分别计算的应变与基于全部6行方块的整体平均计算得到的结果进行比较,显示中间4行方块区域的变形基本不受端部约束影响。还对采用试样上、中、下三个部分与整个试样的测量结果获得的应力与应变特性进行了对比分析。该方法能够测量任意时刻试样的轴向应变场,通过轴向应变场的变化可以准确地描述试样剪切带的产生、发展以及完全形成的全过程。
Based on the sub-pixel accurate corner locator in the digital image measurement system,every moment displacement on the sample surface square corner can be recorded,and the specimen surface strain field can be get.The radial strains calculated respectively on 6 lines of squares are compared with the strain calculated on whole six lines squares.The results show that the deformations on middle four lines of square field are basically not influenced by the end restraint.The characteristics of the stress and strain calculated by testing on the top,the middle,the bottom and the whole of the samples are comparatively analyzed.This method can measure the axial strain field at any time.The whole process of initial produce, development and fully-formation of the sample shear band are accurately described by the change of axial strain field.
出处
《西北地震学报》
CSCD
北大核心
2011年第B08期175-180,共6页
Northwestern Seismological Journal
基金
国家自然科学基金青年基金(50808033)
关键词
亚像素角点检测
数字图像测量
端部约束
应变场
剪切带
Sub-pixel accurate corner locator
Digital image measuring
End restraint
Strain field
Shear band