Experimental Mechanics

, Volume 22, Issue 10, pp 383–391 | Cite as

Crack propagation at material interfaces: II experiments on mode interaction

Optical interferometry is used to examine the validity of linearized field theories and criteria for stationary and propagating interfacial cracks
  • K. M. Liechti
  • W. G. Knauss
Article

Abstract

Optical interferometry is used to measure crackopening profiles for interfacial cracks in a model adhesive joint. Application of boundary displacements with a resolution of 0.16 μm is achieved through a combination of thermal expansions and optical control in a servo loop. The degree of nonlinear deformation accompanying small levels of normal and shear strain across the bond is documented, and crackfront displacement fields are exploited to evaluate possible criteria for crack growth under combined normal and shear loading. Within the accuracy afforded by the crack-propagation investigation it appears that crack growth is governed by the vectorial crack-tip displacements, namely by the vector sum of the local normal and tangential displacement components. In the limit of infinitesimal strains this criterion reduces to the strain energy-release-rate criterion of linear fracture mechanics.

Keywords

Shear Strain Interfacial Crack Shear Loading Displacement Component Adhesive Joint 

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Copyright information

© Society for Experimental Mechanics, Inc. 1982

Authors and Affiliations

  • K. M. Liechti
    • 1
  • W. G. Knauss
    • 2
  1. 1.Aerospace Engineering and Engineering MechanicsUniversity of TexasAustin
  2. 2.California Institute of TechnologyPasadena

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