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
Dr 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. @DOI: 10.1115/1.1593078#
Introduction
Increased strength-weight ratio and extended fatigue life are the
main objectives of optimal design for the modern gun barrel.
These can be carried out by generating a residual stress field in the
barrel wall, a process known as autofrettage.
There are two principal autofrettage processes. One is ‘‘hydrostatic,’’
based on the use of high hydrostatic pressure that is applied
inside the tube and the second is ‘‘swaging,’’ which is based
on the use of an oversized mandrel forced through the tube bore,
thereby causing it to expand.

یک مطلب دیگر :

The residual stresses, which have a compressive effect on the
internal barrel surface, increase the barrel elastic strength pressure
and slow down the development of cracks. Furthermore, it is
sometimes necessary to machine the barrel to its final dimensions,
which reduces the contribution of residual stresses.
Since the basic data for calculating elastic strength pressure and
fatigue life are derived from a precise distribution of the residual
stresses, a theoretical solution for these stresses must be as close
as possible to the practical one. Although there are many solutions
which deal with the problem of determining stress distribution,
none of them are completely satisfactory, since they are all based
on certain assumptions on yield criteria and other effects.
The simplest and most general theoretical treatment of the partially
plastic thick-walled cylinder has been the use of the Tresca