Accession Number:

AD1027591

Title:

THE COMBINED EFFECTS OF STRESS CONCENTRATION AND TENSILE STRESSES FROM AUTOFRETTAGE ON THE LIFE OF PRESSURE VESSELS

Descriptive Note:

Technical Report

Corporate Author:

ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER PICATINNY ARSENAL NJ PICATINNY ARSENAL United States

Personal Author(s):

• Troiano,E.
• Vigilante,G. N.
• Smith,L. B.
• Izzo,J. H.

Report Date:

2017-02-22

Pagination or Media Count:

12.0

Abstract:

Thick walled pressure vessels are often hydraulically or mechanically overstrained in order to impart favorable near bore residual compressive hoop stresses in an attempt to enhance fatigue life. As a result of imparting these favorable near bore compressive stresses, self-compensating tensile residual stresses result, which in some case can be detrimental. In the early stages of development of each system, multiple full size vessels are hydraulically fatigue tested and a safe life is determined. Recent developments have pushed these vessels into longer years of service. In some cases, this has caused unanticipated field issues and resulted in field service lives that are less than the original safe lives. These service issues have several common threads which link them together including tensile residual stresses from autofrettage, outside diameter stress concentration effects including features designed into the vessel as well as unanticipated effects from inadequate material quality, and long term effects from corrosion and pitting. This paper will present several case studies which will identify the cause of the reduced lives and propose corrective action.

Descriptors:

• THICK WALLS
• PRESSURE VESSELS
• Autofrettage
• residual stress
• stress concentration
• tensile stress
• fatigue life
• stress corrosion
• stresses
• corrosion
• CRACKING (FRACTURING)
• PITTING

Subject Categories:

• Structural Engineering and Building Technology
• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE