Impact Damage on Various Metal Leading Edges from Small Hard Objects.

Abstract

Impact damage on various metal leading edge configurations was studied by performing a series of hard particle impact tests and characterizing the damage. Fatigue tests were used to assess the damage and the concept of an equivalent elastic stress concentration factor was used to characterize severity of damage. Notch fatigue specimens were also fatigue tested in tension to provide baseline data for each material investigated. The materials investigated included 8Al-1Mo-1V titanium, 4130 steel in the annealed and heat-treated conditions, and 7075-T651 aluminum. The data demonstrated good reproducibility and showed that the extent of a particular type of damage could be categorized in terms of an equivalent elastic stress concentration factor. Based on the results, the 4130 steel was superior in performance with the highest critical velocity values and being less sensitive to fatigue degradation than the other materials. No correlation could be established between the critical velocity and the target material parameters of density, modulus, or yield strength. The concept of geometric scaling was investigated by performing a series of tests using different leading edge thickneses and projectile sizes. Observation of the type of damage and plots of critical velocity versus particle size (in relation to leading edge thicknesses) appeared to validate the scaling concepts. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1981
Accession Number
ADA109676

Entities

People

  • Robert S. Bertke

Organizations

  • University of Dayton

Tags

DTIC Thesaurus Topics

  • Air Force
  • Air Force Facilities
  • Angle Of Incidence
  • Failure Mode And Effect Analysis
  • Fatigue Tests (Mechanics)
  • Foreign Object Damage
  • Geometry
  • Impact Tests
  • Materials
  • Mechanical Properties
  • Mechanics
  • Modulus Of Elasticity
  • Particle Size
  • Shot Peening
  • Stress Concentration
  • Tensile Strength
  • Yield Strength

Fields of Study

  • Physics

Readers

  • Fluid Mechanics and Fluid Dynamics.
  • Materials Science and Engineering.
  • Structural Health Monitoring of Composite Structures.