半椭球蚀坑对圆棒应力集中的影响

Effect of Semi-elliptical Pit on Stress Concentration of Round Bar

利用数值分析方法讨论了在轴向拉伸或弯曲载荷作用下，圆棒试件表面半椭球形蚀坑深径比 （a/2c） 对应力分布及应力集中系数 （Kt） 的影响。取蚀坑直径 （2c） 范围80~1200 μm，蚀坑深度 （a） 范围80~1100 μm，建立一系列具有表面半椭球蚀坑的三维圆棒模型，通过ANSYS模拟分析，发现应力集中系数受到蚀坑深径比和加载形式的影响。通过分析曲线变化趋势，得到Kt随a/2c的变化规律，并对照文献数据进行了验证分析，最后通过拟合得到了Kt与a/2c的数值计算公式。

The paper numerically discusses the influence of various aspect ratios （a/2c） of semi-elliptical corrosion pits on stress distribution and stress concentration factor （Kt） in round bars under tension or bending loading. By constructing a series of three-dimensional semi-elliptical pitted models with different pit diameter （2c） between 80 and 1200 μm, and pit depth （a） between 80 and 1100 μm systematically, it can be seen that stress concentration factor is not only affected by pit aspect ratio, but also the type of loading mode. Therefore, the rules of stress concentration factor can be established for a wide range of aspect ratio of corrosion pits. Then the comparison the present results with that of Cerit is conducted. At last, a fitted formulation of the relationship between Kt and a/2c is obtained, by which it is expected to be of convenience to find the value of stress concentration factor in practice of engineering and research.