The Role of Interfaces in the Fracture of Functionally Graded Materials

Abstract

The research focuses on establishing conditions when interfaces between interlayers are important in governing fracture processes in composites with graded compositions. A theoretical framework is sought that could ultimately quantify the role of interfaces when their presence dominates behavior. Initial work is driven towards establishing general trends. Experimentally, multilayer composites have been fabricated by several techniques that aim at modifying interface characteristics. The competition between fracture at notches of particular depth parallel to the interface and interface fracture is examined. A numerical model is being constructed to obtain crack tip and interface/free edge stress fields to better understand experimental trends. Also, models are being devised to examine how the presence of the interface modifies the stress field of an edge crack parallel to the interface. Experiments in which cracks are extended from notches placed near interfaces have been conducted utilizing optical moir interferometry (conducted at INEEL). The crack driving force and mode mixity as a function of type of interface and proximity to interface are being determined.

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Document Details

Document Type
Technical Report
Publication Date
Feb 22, 2005
Accession Number
ADA430458

Entities

People

  • Ivar Reimanis
  • John Berger

Organizations

  • Colorado School of Mines

Tags

DTIC Thesaurus Topics

  • Colorado
  • Competition
  • Composite Materials
  • Computational Science
  • Computer Science
  • Crack Propagation
  • Crack Tips
  • Cracks
  • Engineering
  • Heat Transfer
  • Interferometry
  • Materials
  • Mechanical Properties
  • Mechanics
  • Residual Stress
  • Stresses
  • Students

Readers

  • Computational Fluid Dynamics (CFD)
  • Database Systems and Applications
  • Materials Science (Mechanical Engineering).