The stability of conical end caps with spherical tips as end closures for pressure vessels

• Published in: The International journal of pressure vessels and piping Vol. 64; no. 1; pp. 11 - 16
• Main Authors: Khan, Raisuddin, Uddin, Wahhaj
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1995; Elsevier
• Subjects: Applied sciences; Buckling; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Mechanical engineering. Machine design; Physics; Solid mechanics; Static buckling and instability; Steel design; Steel tanks and pressure vessels; boiler manufacturing; Structural and continuum mechanics; Stress concentration; Discontinuity; Geometrical shape; Spherical shape; Pressure vessels; Conical shape; Shells; Buckling; Axial symmetry
• ISSN: 0308-0161; 1879-3541
• DOI: 10.1016/0308-0161(94)00033-F

The instability under pressure of conical end caps with spherical tips when used as end closures to pressure vessels is studied in this paper. The spherical tip of the conical end cap was assumed to be attached in such a way that continuity of the slope at the cone/sphere junction was maintained. The geometrical parameters of the spherical-tip conical end closure are the ratio r R ; the apex angle Ψ of the conical frustum; and the thickness ratio R h , where r and R are respectively the radius of the cone at the sphere/cone and vessel/cone junctions and h is the thickness of the shell. Governing nonlinear differential equations of axisymmetric deformation which ensure the unique states of lowest potential energy under given pressure have been solved by using the method of multisegment integration, developed by Kalnins and Lestingi. 1 The results show that the critical pressure for the end closure decreases with increasing apex angle at constant values of R h and r R . At constant values of Ψ and R h , the critical pressure remains constant over a considerable range of r R and then decreases to a minimum value at r R = 1·0 which corresponds to a purely spherical end cap without the conical extension.