An extended shakedown theory on an elastic–plastic spherical shell

The design margin against collapse for Division 3 is based on Nadal’s equation. For high strength material this method is adequate. However for material with a lower ratio of Sy/Su this method has additional margin from yielding through the thickness to final collapse or burst. The experimental burst test results for closed-end cylinder show the excessive margin for these materials as stated in former paper. Therefore the development of alternate methods for establishing design margin for all materials is desirable. The design margin of 1.5 in equation for open-end cylindrical shell and spherical shell in current code is different from that of 1.732 for closed-end cylindrical shell. The design margin of elastic-plastic analysis is 1.732. Therefore the consistent design margins of equations and elastic-plastic analysis for open-end cylindrical shells and spherical shells are also desirable. In this paper new equations for design pressure of cylindrical shell and spherical shell are proposed by investigation of burst test results and case studies of various methods.

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Elastic-plastic state of a variable thickness spherical shell with a reinforced central hole

Soviet Applied Mechanics ◽

10.1007/bf00901851 ◽

1970 ◽

Vol 6 (5) ◽

pp. 551-553 ◽

Cited By ~ 3

Author(s):

V. S. Babyak ◽

A. G. Makarenkov ◽

I. S. Chernyshenko

Keyword(s):

Spherical Shell ◽

Variable Thickness ◽

Central Hole ◽

Plastic State ◽

Elastic Plastic

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The expansion of the elastic-plastic spherical shell with nonlinear hardening

International Journal of Mechanical Sciences ◽

10.1016/0020-7403(88)90015-x ◽

1988 ◽

Vol 30 (6) ◽

pp. 415-426 ◽

Cited By ~ 23

Author(s):

U. Gamer

Keyword(s):

Spherical Shell ◽

Elastic Plastic ◽

Nonlinear Hardening

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Elastic-Plastic Analysis of a Spherical Shell Loaded Radially Through a Flexible Cylindrical Nozzle

Journal of Pressure Vessel Technology ◽

10.1115/1.2928629 ◽

1990 ◽

Vol 112 (3) ◽

pp. 296-302 ◽

Cited By ~ 1

Author(s):

C.-P. Leung ◽

G. N. Brooks

Keyword(s):

Spherical Shell ◽

Efficient Solution ◽

Yield Condition ◽

Geometric Parameters ◽

Plastic Behavior ◽

Elastic Plastic ◽

Cylindrical Nozzle ◽

Tresca Yield Condition ◽

Failure Loads ◽

Range Of Values

This study investigates the elastic-plastic behavior of a shallow spherical shell loaded radially through a flexible cylindrical nozzle. Both the sphere and the cylinder can yield and exhibit plastic deformation. The Tresca yield condition is employed to derive elastic-plastic moment-curvature relationship in a simple form which is implemented in an efficient solution scheme. Three geometric parameters represent the relative dimensions of the structure. Numerical results are obtained for a range of values of these parameters. Various situations involving the failure of the sphere and/or the cylinder are studied. The ultimate or failure loads of the structure are plotted as functions of the geometric parameters.

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