A Study On Stress Concentration In Thin Cylindrical Shells With Circular Openings

In this paper, the problems are studied about stress concentration in a thin cylindrical shell with a free circular opening under axial tension or internal pressure. Based on Donnell' s governing equation of linear shallow shell theory and the paper 《Application of the method of the least squares and point collocation to stresses concentrations in a cylindrical shell with a circularopening 》 .The computer program and the results of r₀/R≤0.6 are given. Bycomparison to the results we get, the analytical results and the ANSYS results, it shows good consistency and accuracy. The feasibility of this method and the universality of the program approve.Analyzing a thin cylindrical shell with a free circular opening based ondifferent r₀/R or different Poisson's ratio and a thin cylindrical shell with astrengthened circular opening under axial tension, we can draw the following conclusion:(1)The normal opening:(1)The stress concentration factors round the opening edge of a cylindricalshell with a free cutout are related to R/t and a=r₀/(Rt)^1/2.(2)The Poisson's ratio does not influence the stress concentration factors much.(3_The accuracy and the collection rate lie on the trial function we select.(4)The solutions are applicable for r₀/R≤1/2 .(2)The strengthened opening:(1)The maximal stress concentration factor round the opening edge reduce obviously. The changing trend of maximal stress concentration factor round the opening edge becomes not sharp.(2)In the direction of r, the changing trend of maximal stress concentration factor becomes not sharp far away from the opening.We offer a simple method to get the stress concentration factors in a thin cylindrical shell with a free circular opening in this paper.