Bauschinger Effect’ Influence on the Componud Cylinder Containing an Autofrettaged Layer

Abstract

Autofrettage is used to introduce advantageous residual stresses into cylinders. The Bauschinger effect can produce less compressive residual hoop stresses near the bore than are predicted “ideal” autofrettage solutions. A723 steel is used for compound cylinder. This paper extends the analysis to material the addition of pressure or of shrink-fitting to the cylinders, providing associated residual stress profiles following various amounts of further yielding due to a net external pressure. The Bauschinger effects for “realistic” – Bauschinger effect dependent autofrettage are obtained. The 2-D analysis is performed via the finite element method. The Bauschinger effect is found to significantly lower the beneficial stress due to autofrettage.

Machining effect of the autofrettaged compound cylinder under varying overstrain levels

“…In the compound cylinder, this pressure affects the outer cylinder as internal pressure, and the inner cylinder as external pressure. From this fact, we predict the residual stress distribution using the Tresca theory (Lee et al, 2007). Radial residual stress and tangential residual stress are in the plastic region (a ≤ r ≤ ).…”

“…Koh et al (1995) investigated thick-walled cylinder's residual stress by using the Tresca yield criterion. Lee et al (2007) studied analytical analysis and the Bauschinger effect on a compound cylinder. Most of today's gun barrels are swaged autofrettaged.…”