Accession Number:

ADA196485

Title:

The Effects of Ply Dropoffs on the Tensile Behavior of Graphite/Epoxy Laminates

Descriptive Note:

Master's thesis

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s):

Report Date:

1988-01-01

Pagination or Media Count:

177.0

Abstract:

The effects of ply dropoffs on the stress-strain behavior, fracture modes and fracture strength of graphiteepoxy laminates in tension were investigated. Seven different layups with ply dropoffs were manufactured and tested to failure in uniaxial tension. Test variables included the number, order, angular orientation, and effective ply thickness of dropped plies. With six of the ply dropoff laminates, one side of the laminate was flat, with the outer plies of the other side of the laminate curving over the ply dropoff from the undropped, or thicker, section to the dropped section. This type of laminate is geometrically unsymmetric, and therefore bending stresses are induced in the laminate during testing. The analysis method developed was a one-dimensional model which allows the calculation of first ply failure of a ply dropoff laminate taking into account this induced bending effect. Theses.

Subject Categories:

  • Laminates and Composite Materials
  • Plastics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE