An Experimental Weight Function Method for Stress Intensity Factor Calibration.

Abstract

The weight function procedure allows one to convert stress intensity factors K and crack displacement information obtained for one crack configuration and loading into the stress intensity factor solution for the same geometry and another loading. The feasibility of using the weight function idea for a two-dimensional case with experimental results is demonstrated in this work. Mode I stress intensity factor K(I) measurements obtained by a laser interferometric technique, and 'crack mouth' opening displacement measurements were taken for an edge cracked strip subjected to four point bending. These results were used to construct (numerically) a weight function with the aid of a computer program written for this purpose. Results of K(I) for the same geometry with two different loading configurations, uniform tension and three point bending (with two different length to width ratios) were computed. These results agree favorably with the known solutions and demonstrate that a set of experiments for a single loading can accurately predict the stress intensity factor for any other loading configuration of the same geometry. The advantage of the weight function method would be particularly important if these loading configurations are difficult or impossible to reproduce in the laboratory. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1979
Accession Number
ADA079854

Entities

People

  • Dan Bar-tikva

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Accuracy
  • Air Force
  • Computations
  • Computer Programs
  • Computers
  • Crack Propagation
  • Crack Tips
  • Data Reduction
  • Experimental Data
  • Fracture (Mechanics)
  • Geometry
  • Materials
  • Measurement
  • Mechanics
  • Numerical Integration
  • Stress Intensity Factors
  • Two Dimensional

Readers

  • Calculus or Mathematical Analysis
  • Materials Science (Mechanical Engineering).
  • Reinforced Composite Materials

Technology Areas

  • Directed Energy