焊缝几何对焊趾疲劳裂纹扩展行为的影响

INFLUENCES OF WELD GEOMETRY ON BEHAVIOR OF FATIGUE CRACK GROWTH AT WELD TOES

根据实测的焊趾疲劳裂纹形核点处的焊缝几何参数及其统计分布，通过建立焊缝几何参数与焊趾裂纹应力强度因子解之间的关系，用统计模拟方法研究了焊缝几何参数的统计涨落性质对焊趾疲劳裂纹扩展行为的影响．结果表明，焊趾曲率半径的统计涨落对焊趾疲劳裂纹扩展分散性的影响最大；调整焊趾角度对焊趾疲劳裂纹扩展的增寿作用最显著．

According to the weld geometry parameters (WGP) and their statistical distributions measured practically at the initial points of fatigue cracks at weld toes, this paper investigates, by establishing the relationship between the WGP and the stress strength factor for weld toe cracks, the influences of statistical fluctuation of WGP on behavior of fatigue crack growth (FCG) at weld toes by means of the method of statistical simulation. The results show that it is the statistical fluctuation of weld toe radius whose influence on the scatter of FCG at weld toes is the largest, and it is to improve the weld toe angle whose effect to increase the life of FCG at weld toes is the most marked.