Rate Dependent Cohesive Zones

Abstract

In work under another contract, we had studied the initiation of mode I tensile cracks (not delamination cracks) that tunnel down individual plies in brittle matrix laminates or woven textiles and then turn into plane cracks spreading across many plies en route to part failure. Under this contract, we unified this modeling with our models of cracks bridged by creeping fibers. In the absence of fiber creep, the plane strain phase of crack propagation often (and desirably) ends in crack arrest, because the plane strain crack grows into a lengthening bridging zone as the crack traverses plies. However, fiber creep relaxes the bridging and allows crack growth to resume, which leads to failure at undesirable low stresses. We developed comprehensive solutions to this mode of crack growth.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1997
Accession Number
ADA330185

Entities

People

  • B. N. Cox

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Weapons Technologies

DTIC Thesaurus Topics

  • Ceramic Matrix Composites
  • Composite Material Fabrication
  • Composite Materials
  • Failure Mode And Effect Analysis
  • Laminates
  • Material Degradation Processes
  • Materials Laboratories
  • Materials Processing
  • Materials Science
  • Materials Testing
  • Mechanical Properties
  • Mechanical Working
  • Mechanics
  • Micromechanics
  • Polymer Matrix Composites
  • Tensile Strength

Readers

  • Educational Psychology
  • Materials Science (Mechanical Engineering).
  • Reinforced Composite Materials