摘要
本文介绍了测量裂纹扩展的直流电位法中的Ｊｏｈｎｓｏｎ公式。对两侧切槽紧凑拉伸试样的标定实验和经疲劳予制裂纹试样实测表明，直流电位法的精度对试样裂纹宽度比较敏感。疲劳裂纹试样经裂端钝化效应修正后。
Some research works indicated that a straight crack growth front can be got when using side grooved compact (CT) specimen for tough steel materials.Whether or not the Johnson′s formalu is suitable for measuring the crack extension of side grooved CT specimen will now be explored in this paper. Comparing the test results and the results obtained from FEM it is indicated that the Johnson′s formula is also suitable for measuring the crack extension of side grooved CT specimen provided the crack width is small enough.After blunting correction using ΔU/U 0 instead of U/U 0 in Johnson′s formula,the relative error betweeen Johnson′s formula and optical measurement are within 10% and absolute error within 2.0mm for two different materials,diffrent initial crack (a 0/W),different crack extension (3.06 21.36mm) and different specimen net thickness.
出处
《实验力学》
CSCD
北大核心
1997年第1期23-28,共6页
Journal of Experimental Mechanics
关键词
断裂力学
裂纹扩展
直流电位法
切槽试样
fracture mechnical,crack growth,DC potential drop method,Johnson′s formula,side grooved compact specimen,blunting correction.
