An Experimental Evaluation of Tearing Instability Using the Compact Specimen.

Abstract

The objective of this investigation was to produce experimental verification of the tearing instability theory proposed by Paris and coworkers. This theory states that ductile crack extension will occur in an unstable fashion whenever the applied tearing force is greater than the material tearing resistance. In this investigation, a series of compact specimens of aluminum, titanium, and steel alloys were tested in a variably compliant test machine to generate a range of applied tearing forces. The material tearing resistance was measured from the JI-R curves of the stable specimens and compared to the applied tearing force necessary to generate ductile tearing instability in each material. The Paris theory was found to accurately predict the onset of gross instability behavior. Some limited instability behavior was found, however, at values of tearing force less than the average material tearing resistance obtained from an unloading compliance JI-R curve test. Limited instability behavior was characterized by repeated short steps of rapid but ductile crack extension, separated by regions of slow stable tearing. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1981
Accession Number
ADA107633

Entities

People

  • James A. Joyce
  • Michael G. Vassilaros

Tags

Communities of Interest

  • Air Platforms
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Aluminum
  • Aluminum Alloys
  • Computers
  • Crack Tips
  • Cracks
  • Displacement
  • Elements
  • Fracture (Mechanics)
  • Geometry
  • Integrals
  • J Integrals
  • Materials
  • Mechanical Properties
  • Mechanics
  • Modulus Of Elasticity
  • Stiffness
  • Unloading

Readers

  • Library and Information Science/ Studies, Southeast Asia Studies, Bibliography of Vietnam and Lao Studies.
  • Mechanical Engineering/Mechanics of Materials.
  • Plasma Physics / Magnetohydrodynamics