Indentation Law for Composite Laminates.

Abstract

Static indentation tests are described for glass/epoxy and graphite/epoxy composite laminates with steel balls as the indentor. Beam specimens clamped at various spans were used for the tests. Loading unloading and reloading data were obtained and fitted into power laws. Results show that (1) contact behavior is not appreciably affected by the span; (2) loading and reloading curves seem to follow the 1.5 power law; and (3) unloading curves are described quite well by a 2.5 power law. In addition values were determined for the critical indentation, alpha sub cr, which can be used to predict permanent indentations in unloading. Since alpha sub cr only depends on composite material properties, only the loading and an unloading curve are needed to establish the complete loading-unloading-reloading behavior. (MM)

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Document Details

Document Type
Technical Report
Publication Date
Jul 31, 1981
Accession Number
ADA306043

Entities

People

  • Chintech Sun
  • S. H. Yang

Organizations

  • Purdue University

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Aeronautics
  • Air Force
  • Aircrafts
  • Composite Materials
  • Elastic Properties
  • Engineering
  • Epoxy Composites
  • Epoxy Laminates
  • Experimental Data
  • Graphitic Materials
  • Jet Propulsion
  • Laminates
  • Materials
  • Materials Laboratories
  • Mechanics
  • Modulus Of Elasticity
  • Navy

Readers

  • Fluid Dynamics.
  • Reinforced Composite Materials
  • Structural Dynamics.