Abstract: Using frozen,stress photoelastic method,stress intensity factors of internal surfacecracks in spherical shells and spherical shells with geometric defects(misalignment or angular distortion) were studied.In order to compare with the solutions of stress intensity factorsof cracks in flat plates,a new definition of internal surface crack shape in spherical shells wasproposed. In this paper,the variations of stress intensity magnification factors with crack depth tocrack length ratio,crack depth to wall thickness ratio, wall thickness to inner diameterratio, and along the crack front were analysed. Mixed mode K_Ⅰ and K_Ⅱ of misalignmentin spherical shells were discussed.The stress intensity factors of cracks in spherical shellswere compared with the solutions of that in flat plates,and an empirical formula of curvaturecorrection factor was presented.They are very useful for the safety of spherical shells.

Key words: spherical shells, crack, stress analysis, crack mechanics

摘要： 本文提出一种薄壁球形容器内表面裂纹的定义方法;研究了球壳和带有错边或角变形几何缺陷的球壳内表面裂纹尖端应力强度因子随裂纹形状、深度、壁率和沿裂纹前沿变化的规律,裂纹扩展的规律;在与目前常用的平板解作比较的基础上,研究了曲率及几何缺陷对应力强度因子的影响,并提出了一种曲率修正系数的经验计算式.

关键词: 球形罐, 裂缝, 应力分析, 断裂力学