The strain Gage Methods for Determining of a Stress Intensity Factor of a Crack

用应变片实验测定应力强度因子对工程有重要意义。应力强度因子是断裂力学中的参数，本研究发展了应变片法测定裂纹应力强度因子的方法，包括以下三种方法：1.第一种是用由5个测栅组成的极小尺寸应变片测定开模应力强度因子K_1的方法.二是确定共享模式应力强度因子K_的方法<II>。本研究分以下两种类型进行实验。(1)采用紧凑型剪切试件进行拉剪试验。(2)对含裂纹圆柱壳进行了扭转试验.第三种是用0/90度法分离混合模式下的Ⅱ型应力强度因子。环形磁芯应变计。

It is important for Engineering to determine stress intensity factor by using strain gages experimentally. The stress intensity factor is the parameter of a fracture mechanics.This research developes the strain gage method for determining the stress intensity factor of crack.The method to be developes in this researches consist of three methods as follows.1. The first is the method to determine the opening-mode stress intensity factor K_1 with using extremely small sized strain gage consisting of 5 measuring grids.2. The second is the method to determine the sharing-mode stress intensity factor K_<II>. This resrearch is made experimets of two types as follow.(1) The tensile shear tests are carried with using compact shear specimens.(2) The torsional tests are carried with using cylindrical shell with a crack.3. The third is the separable method of mode II stress intensity factor in a mixed mode by using 0/90 deg. ring core rosette strain gages.