Effects of Cyclic Frequency on the Mechanical Properties of Composite Materials.

Abstract

Strain controlled cyclic stress-strain and fatigue tests are conducted on specimens of boron-epoxy and boron-aluminum at cyclic frequencies between 0.5 Hz and 45 Hz. The specimens are cross-ply laminates with a (0 degree, plus or minus 45 degree, 0 degree), fiber orientation and have a 0.25 inch hole in the center. The results of data obtained from both types of tests show the response of the material to be frequency and cycle dependent. The marked difference in behavior of the material at 15 Hz and 30 Hz suggests the presence of a transition frequency (or frequency range) at which the properties of the material are greatly influenced by frequency controlled mechanism. At a given frequency, changes in properties occur with increasing cycles and correlate with acoustic emissions monitored during the test. (Author-PL)

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1973
Accession Number
AD0768614

Entities

People

  • Kenneth L. Reifsnider
  • Larry A. Marcus
  • Richard S. Williams
  • Wayne W. Stinchcomb

Organizations

  • Virginia Tech

Tags

DTIC Thesaurus Topics

  • Acoustic Emissions
  • Aluminum
  • Composite Materials
  • Emission
  • Fatigue Tests (Mechanics)
  • Frequency
  • Laminates
  • Materials
  • Materials Testing
  • Mechanical Properties
  • Orientation (Direction)
  • Physical Properties

Fields of Study

  • Materials science

Readers

  • Mathematics or Statistics
  • Structural Health Monitoring of Composite Structures.