Dynamic Cracking and Energy Absorption in Laminates Containing Through-Thickness Reinforcement

Abstract

We report several fundamental results in the delamination resistance of through-thickness reinforced structures under dynamic load conditions. The main results are: (1) An elaborate micromechanical model shows how a bridging tow should behave if it is initially inclined to the fracture plane and subject to mixed mode quasistatic loading (2) A bridging law for fiber reinforced composites under dynamic crack propagation conditions has been derived. INertial effects in the mechanism of fiber pullout during dynamic propagation of a bridged crack are critically examined for the first time. (3) The dynamic delamination cracking behavior and the energetics of crack growth in through thickness double cantilever beam specimens has been analyzed. Steady state crack growth is attainable provided certain conditions are satisfied. Guidelines for design of experiments to probe the efficacy of bridging on improving the dynamic fracture toughness of through thickness reinforced structures are established. In summary, these results form a sound fundamental basis for design and life prediction of through thickness reinforced structures.

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Document Details

Document Type
Technical Report
Publication Date
Apr 18, 2001
Accession Number
ADA390067

Entities

People

  • B. N. Cox
  • S. Narayanaswamy

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Cantilever Beams
  • Ceramic Matrix Composites
  • Composite Materials
  • Crack Propagation
  • Cracks
  • Delamination
  • Dynamic Loads
  • Elastic Properties
  • Fiber Reinforced Composites
  • Geometry
  • J Integrals
  • Laminates
  • Materials
  • Materials Science
  • Mechanics
  • Micromechanics
  • Steady State

Readers

  • Materials Science (Mechanical Engineering).
  • Structural Health Monitoring of Composite Structures.
  • Theoretical Analysis.