In the optimal design of a modern gun barrel, there are two main objectives to be achieved: increasing its strength-weight ratio and extending its fatigue life. This can be carried out by generating a residual stress field in the barrel wall, a process known as autofrettage. It is often necessary to machine the autofrettaged cylinder to its final configuration, an operation that will remove some of the desired residual stresses. In order to achieve a residual stress distribution which is as close as possible to the practical one, the following assumptions have been made in the present research on barrel analysis: A von Mises yield criterion, isotropic strain hardening in the plastic region in conjunction with the Prandtl-Reuss theory, pressure release taking into consideration the Bauschinger effect and plane stress conditions. The stresses are calculated incrementally by using the finite difference method, whereby the cylinder wall is divided into N-rings at a distance Δr apart. Machining is simulated by removing rings from both sides of the cylindrical surfaces bringing the cylinder to its final shape. After a theoretical development of the procedure and writing a suitable computer program, calculations were performed and a good correlation with the experimental results was found. The numerical results were also compared with other analytical and experimental solutions and a very good correlation in shape and magnitude has been obtained.

Issue Section:
Technical Papers
Keywords:
weapons, elastoplasticity, internal stresses, stress-strain relations, fatigue testing, wear, work hardening, optimisation, Bauschinger effect, finite difference methods
Topics:
Cylinders, Pressure, Residual stresses, Stress, Autofrettage, Work hardening, Finite difference methods, Stress concentration
1.
Hill, R., 1950, The Mathematical Theory of Plasticity, Oxford University Press, New York.
2.
Benet, R., and Laboraties, E., 1970, Autofrettage Design Manual of Gun Tubes, Watervliet Arsenal, Watervliet, N.Y.
3.
Davidson, T. E., Kendall, D. P., and Reiner, A. N., 1963, “Residual Stresses in Thick-Walled Cylinders Resulting From Mechanically Induced Overstrain,” Experimental Mechanics, 3, pp. 253–262.
4.
Kendall, D. P., 1970, The Effect of Material Removal on the Strength of Autofrettaged Cylinders, Watervliet Arsenal, Watervliet, N.Y.
5.
Clark, G., 1982, “Residual Stresses in Swage Autofrettage Thick-Walled Cylinders,” Report MRL-R-847, Department of Defense Support, Melbourne, Australia.
6.
Parker
,
A. P.
,
2001
, “
Autofrettage of Open-End Tubes-Pressures, Stresses, Strains, and Code Comparisons
,”
ASME J. Pressure Vessel Technol.
,
123
, pp.
271
–
281
.
7.
Parker
,
A. P.
,
Underwood
,
J. H.
, and
Kendall
,
D. P.
,
1999
, “
Bauschinger Effect Design Procedures for Autofrettaged Tubes Including Material Removal and Sachs’ Method
,”
ASME J. Pressure Vessel Technol.
,
121
, pp.
430
–
437
.
8.
Chen
,
P. C. T.
,
1986
, “
The Bauschinger and Hardening Effect on Residual Stresses in an Autofrettaged Thick-Walled Cylinder
,”
ASME J. Pressure Vessel Technol.
,
108
, pp.
108
–
112
.
9.
Bauschinger
,
J.
,
1881
, “
Ueber die Veranderung der Elasticitatagrenze und dea Elasticitatamoduls Verschiadener Metalle
,”
Zivilingenieur
,
27
, pp.
289
–
348
.
10.
Timoshenko, S., 1956. Strength of Materials, Part II, Princeton University, Princeton, NJ.
11.
Malvern, L. E., 1969, Introduction to the Mechanics of a Continuous Medium, Prentice-Hall, Englewood Cliffs, NJ.
12.
Na, T. Y., 1979, Computational Methods in Engineering Boundary Value Problems, Academic Press, New York, N.Y.
13.
Weiss, V., 1956, “Residual Stresses in Cylinders,” Syracuse University Research Institute Report No. MET 345–563 T2, New York.
Copyright © 2003
 by ASME
You do not currently have access to this content.