PHOTOELASTIC DETERMINATION OF MIXED MODE STRESS INTENSITY FACTORS,

Abstract

Using an idea proposed by G. R. Irwin, equations were developed for the maximum in-plane local shearing stress Tau sub m and average fringe loop inclination Theta sub m near the crack tip in terms of the Mode 1 and Mode 2 stress intensity factors K1 and K2 and polar coordinates r and Theta measured from the crack tip. A series of photoelastic experiments was performed on specimens exhibiting various edge crack configurations in finite strips under remote tensile loading. Measurements of Tau sub m and Theta sub m were made for progressively smaller fringes and used in the above mentioned equations to solve for K1 and K2 on a digital computer. Plots of apparent K versus r/a were made and extrapolated to the crack tip to yield the true values of K1 and K2. Results compared favorably with numerical results of Wilson. New results for 'angle' cracks were also obtained. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1970
Accession Number
AD0712298

Entities

People

  • C. W. Smith
  • Dallas G. Smith

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Computers
  • Continuum Mechanics
  • Crack Tips
  • Cracks
  • Digital Computers
  • Equations
  • Fracture (Mechanics)
  • Intensity
  • Measurement
  • Mechanics
  • Physics
  • Stress Intensity Factors
  • Stresses

Readers

  • Analytical Mechanics
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Materials Science (Mechanical Engineering).