Establishment of a Critical Flaw Size for the 120-MM Stub Case

Abstract

The 120-mm stub case is the steel rear section of a cartridge case. It provides the seal for propellant gases and is supported by the breech block. Observations have shown that defects exist on the interior surfaces of this item. the question that needs to be answered is: How long and how deep can these defects be and still not cause a catastrophic brittle failure of the case? Test specimens were fabricated from 120-mm stub cases. The test specimens were used to measure mechanical properties (tensile strength, yield strength) and fracture properties (KIc and JIc). These experimental results were used in conjunction with a finite element stress analysis to calculate a critical flaw size for the 120-mm stub case. The stub case was divided into three zones and a different flaw size was established for each zone.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1988
Accession Number
ADA197745

Entities

People

  • J. A. Kapp
  • M. A. Scavullo
  • M. D. Witherell

Organizations

  • United States Army Armament Research, Development and Engineering Center

Tags

Communities of Interest

  • Energy and Power Technologies
  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force
  • Cartridge Cases
  • Engineering
  • Fracture (Mechanics)
  • Materials
  • Mechanical Properties
  • Mechanics
  • Military Research
  • Orientation (Direction)
  • Stress Analysis
  • Stress Intensity Factors
  • Stresses
  • Tensile Properties
  • Tensile Strength
  • Tensile Stress
  • Toughness
  • Yield Strength

Readers

  • Materials Science (Mechanical Engineering).
  • ballistics.