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筒形壳体通常有非理想圆截面、非理想圆柱体、凹陷、鼓起等几何形状的缺陷。这些几何缺陷将导致筒形薄壳屈曲强度的降低。本文只考虑短筒形壳体(Lc/Rc≈1,Rc/t=117,175,280)的凹陷缺陷对其强度的影响。通过改变壳体上半高处凹陷的不同倾斜角度和长度,研究此类壳体的静力非线性屈曲问题。研究表明,虽然短或长凹陷都会显著降低筒形壳体的静力屈曲强度,但是当凹陷比较短时,凹陷的面积和凹入的角度对圆柱形薄壳的屈曲强度没有太大的影响;当凹陷比较长时,凹陷的面积和凹入的角度对圆柱形薄壳的屈曲强度有显著影响。在凹陷尺寸和位置都不变的情况下,圆柱形薄壳越厚,其屈曲强度降低越大。
Cylindrical shell usually have non-ideal circular cross-section, non-ideal cylinder, depression, bulge and other geometric defects. These geometric defects will result in a decrease in the buckling strength of the cylindrical shell. In this paper, only the influence of the concave defects on the short cylindrical shell (Lc / Rc≈1, Rc / t = 117,175,280) is considered. The static nonlinear buckling problem of such shells is studied by changing the different inclination angles and lengths of dimples on the upper half of the shell. The results show that although short or long depressions can significantly reduce the static buckling strength of cylindrical shell, when the depressions are short, the area of the depressions and the concave angle have no significant effect on the buckling strength of the cylindrical shell. When the depression is longer, the area of the depression and the angle of the depression have a significant effect on the buckling strength of the cylindrical shell. In the case of the same concave size and position, the thicker the cylindrical shell, the greater the decrease of buckling strength.