Exploratory Investigation of Rapid Crack Propagation and Crack Arrest.

Abstract

The experimental program was undertaken to study aircraft structural alloys. Materials tested included 2219-T851 and 7075-T6 Aluminum, 6Al-4V beta-annealed Titanium, 9Ni-4Co-0.2C and 4340 steel alloys. Tests were conducted with radially flared and uniform height DCB (Double Cantiler Beam) specimens containing either sharp cracks or notches with finite root radii. The specimens were instrumented to measure crack velocity, crack length, crack opening displacement, instantaneous load, strain and crack lengths and the stress intensity factors at the initiation and the arrest of the crack propagation. An instrumentation system for the measurement of crack velocities from zero to several thousands of feet per second is presented. Experimental results indicate that a cracked DCB specimen of any configuration under static loading is not suitable for investigating the dynamic behavior of rapidly running cracks or crack arrest conditions. Recommendations for suitable test specimens are provided. (Modified author abstract)

Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1973
Accession Number
AD0778822

Entities

People

  • R. C. Shah

Organizations

  • Boeing

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Abstracts
  • Aircrafts
  • Aluminum
  • Crack Propagation
  • Cracks
  • Displacement
  • Instrumentation
  • Intensity
  • Materials
  • Measurement
  • Measuring Instruments
  • Physical Properties
  • Stress Intensity Factors
  • Stresses
  • Titanium

Readers

  • Combustion and Flow Dynamics.
  • Materials Science (Mechanical Engineering).