Stress Intensity Factors and Crack Mouth Openings for Bridged Cracks Emanating from Circular Holes,

Abstract

Muskhelishvili's method of complex potentials has been applied to the problems of one crack, and two diametrically opposed (symmetrical) cracks emanating from a circular hole of radius R, subjected to a biaxial load. The cracks of length a, are orthogonal to the principal applied stress omega, with transverse stress omega = lambda/omega.This work extends previous work through the inclusion of linear springs with spring constant k bridging the crack opening. Analysis focussed on the (normalized) design parameters of crack tip stress intensity factor F(n) and crack mouth opening V(n). Their dependencies on biaxiality lambda, normalized spring stiffness ka, and the geometry specified by a/n = a/(a + R), were investigated. Interpolation formulae with parameters depending on were fitted to the high and low ka limits of F(n) and V(n). These provided a simple means for calculating F(n) and V(n), in most cases to within a few percent of the numerically calculated values. An interesting comparison of the symmetrically cracked hole to the partially bridged centre crack, showed that the latter had a lower stress intensity factor in all but the very short crack cases. (AN)

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1994
Accession Number
ADA291131

Entities

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  • C. R. Pickthall

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  • Defence Science and Technology Group

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Communities of Interest

  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Airframes
  • Australia
  • Boundaries
  • Composite Materials
  • Crack Tips
  • Department Of Defense
  • Elements
  • Engineering
  • Geometry
  • Integral Equations
  • Materials
  • Modulus Of Elasticity
  • Perturbation Theory
  • Shear Modulus
  • Stress Intensity Factors
  • Stresses
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  • Graph Algorithms and Convex Optimization.
  • Materials Science (Mechanical Engineering).
  • Structural Dynamics.