The Effect of Impact Damage and Circular Holes On the Compressive Strength of A Graphite-Epoxy Laminate,

Abstract

An experimental investigation was conducted to determine the effect of low-velocity impact damage and circular holes on the compressive strength of a 48-ply orthotropic graphite-epoxy laminate. Specimens were impacted by 1.27-cm-diameter aluminum spheres with speeds ranging from 52 to 101 m/s. Some specimens were impacted without any applied compressive load and then loaded to failure to determine their residual strength. Other specimens were loaded to a prescribed axial compressive strain and impacted while at that applied load. Loaded specimens that did not fail catastrophically on impact were subsequently loaded to failure to determine their residual strength. Low-velocity impact damage was found to degrade seriously the laminate static compressive strength. Low-strain compression-compression cyclic loading was found to degrade further the compressive strength of impact-damaged specimens. Specimens with circular holes having diameters up to a third of the specimen width were loaded to failure in compression. It was found that circular holes can also degrade the static compressive strength of the laminate. The effects of circular holes and impact damage on the compressive strength of the laminate are compared. (MM)

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1978
Accession Number
ADA305031

Entities

People

  • James H. Starnes Jr.
  • Jerry G. Williams
  • Marvin D. Rhodes

Organizations

  • Langley Research Center

Tags

DTIC Thesaurus Topics

  • Aluminum
  • Composite Materials
  • Compression
  • Compressive Strength
  • Diameters
  • Epoxy Laminates
  • Graphitic Materials
  • Laminates
  • Materials
  • Physical Properties
  • Residuals

Fields of Study

  • Materials science

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Structural Health Monitoring of Composite Structures.