Accession Number:

ADA167633

Title:

A New Method of Predicting Residual Stresses in Autofrettaged Gun Barrels.

Descriptive Note:

Final rept.,

Corporate Author:

ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY CLOSE COMBAT ARMAMENTS CENTER

Personal Author(s):

Report Date:

1986-04-01

Pagination or Media Count:

29.0

Abstract:

The determination of residual stresses in autofrettaged gun barrels has been considered by many investigators using different mathematical methods and material models. Most of the earlier solutions were based on the assumption that the material behaves elastically on the release of the autofrettaged pressure. However, many materials, particularly the quenched and tempered, low alloy steels generally used for high pressure vessels, exhibit a significant Bauschinger effect. In a recent paper, this author presented a closed-form solution of residual stresses in autofrettaged tubes based on a theoretical model considering the Bauschinger and hardening effects during unloading, but neglecting the strain-hardening during loading. A more general theoretical model without this restriction was proposed earlier, but only part of the final results were shown. In the present report, the complete method of stress and deformation analysis based on the general theoretical model is stated. The new model is a better representation of the actual loadingunloading behavior is a high strength steel. The Bauschinger effect factors is treated as a function of overstrain. The strain-hardening effect is taken into account with different parameters used for loading and unloading processes. The formulas for calculating stresses, strains, and displacements are given. The new results indicate that the influence of the Bauschinger and hardening effects on residual stresses is significant. A comparison with two experimental results has been made.

Subject Categories:

  • Guns
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE