Accession Number : ADA137737

Title :   Analysis of Local Delaminations and Their Influence on Composite Laminate Behavior.

Descriptive Note : Technical memo.,

Corporate Author : ARMY RESEARCH AND TECHNOLOGY LABS HAMPTON VA STRUCTURES LAB

Personal Author(s) : O'Brien,T K

PDF Url : ADA137737

Report Date : Jan 1984

Pagination or Media Count : 30

Abstract : An equation was derived for the strain energy release rate, G, assoicated with local delamination growth from a matrix ply crack. The critical G sub C edge delamination onset in + OR - 25/902s graphite epoxy laminates was measured and used in this equation to predict local delamination onset strains in + OR - 25/90Ns, n =4, 6, b laminates. A simple technique for predicting strain concentrations in the primary load bearing plies near local delaminations was developed. These strain concentrations were responsible for reduced laminate nominal failure strains in laminates containing local delaminates. The influence of edge delamination and matrix crack tip delmaination on laminate stiffness and strength was compared.

Descriptors :   *Composite materials, *Epoxy laminates, *Graphited materials, *Strain rate, Behavior, Stiffness, Crack propagation, Fatigue(Mechanics), Strength(Mechanics), Fracture(Mechanics), Defects(Materials), Predictions

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE