疲劳损伤的激光检测及细观初探

FATIGUE DAMAGE DETECTION BY LASER AND MICROSCOPIC TEST

利用一种非接触、非破坏的激光衍射谱谱面光强检测方法，对ＬＹ１２ＣＺ铝合金板材试样进行了拉—拉非对称循环疲劳损伤检测。证明谱面光强比对疲劳损伤是敏感的；衍射光强比Ｋ随循环次数Ｎ的增加单调下降；损伤变量Ｄ则随Ｎ的增加单调增加，当Ｄ达到其临界值Ｄｃ时疲劳破坏发生。同时对不同循环次数下试样表面进行电镜扫描分析。

In this paper,the author make use of a physical quantity directly connected with surface roughness of metal.It is intensity ratio K of laser diffraction spectrum.The specimen surface for different fatigue cycles is observed by Scanning Electron Microscope.The relationshop between D and N (is number of the fatigue cycle) can be used to detect fatigue damage and to estimate surplus life for metal materials.