A Comparison of Single Cycle Overload Effect on Al-Li 2091-T81 Plate and 2091-T83 Sheet

Abstract

Previous researchers have established that for identical fatigue test conditions fatigue crack growth rate in aluminum-lithium alloy 2091 plate is far slower than in sheet, due to the development of a coarser fracture surface in the plate producing crack tip shielding resulting in a reduced effective crack driving parameter. Based on these results one would anticipate the plate material to exhibit a greater number of post-overload delay cycles than the sheet. This study was undertaken to quantify the effect of a single tensile overload fatigue cycle on the crack velocity of both product forms. The test procedure consisted of shedding the dynamic loads to a stress intensity range where a single 60 percent overload fatigue cycle was applied, followed by resumption of the pre-overload loading conditions.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1991
Accession Number
ADA240627

Entities

People

  • Kumar V. Jata
  • Russell R. Cervay

Organizations

  • University of Dayton

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Alloys
  • Crack Tips
  • Cracks
  • Engineering
  • Fatigue Tests (Mechanics)
  • Grain Size
  • Lithium
  • Lithium Alloys
  • Materials
  • Materials Engineering
  • Overload
  • Security
  • Shielding
  • Surface Roughness
  • Tensile Properties
  • Tensile Strength
  • Thickness

Readers

  • Materials Science (Mechanical Engineering).
  • Systems Analysis and Design