Shakedown and stress range of torispherical heads under cyclic internal pressure

Conference · Sun Dec 01 04:00:00 EST 1996

OSTI ID:404233

Kalnins, A; Updike, D P ^[1]

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1. Lehigh Univ., Bethlehem, PA (United States). Mechanical Engineering and Mechanics

Two effects on shakedown of torispherical heads are addressed in this paper: (1) changing geometry, and (2) initial pressurization, such as by a hydro (or proof) test. Shakedown and the cycled stress intensity range are calculated for two head geometries, having diameter-to-thickness ratios of 238 and 192. The calculations are carried out following two approaches: (1) using a nonlinear, elastic-plastic algorithm that accounts for changes in geometry, and (2) using elastic stresses in the undeformed geometry, which is the commonly used approach. The results show that, when the two geometries are subjected to the same initial and cyclic pressures, shakedown is achieved by the first approach but not by the second. Since real heads do benefit from geometry changes, and since most design codes require hydro (or proof) tests before operation, the first approach is recommended for the design of torispherical heads.

• OSTI ID: 404233
• Report Number(s): CONF-960706--; ISBN 0-7918-1786-5
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
DEFORMATION
DESIGN
NONLINEAR PROBLEMS
PRESSURE DEPENDENCE
PRESSURE VESSELS
STANDARDS
STRESS INTENSITY FACTORS
TESTING
YIELD STRENGTH