Fatigue Crack Propagation in Cylindrical Shells

Abstract

This report presents some of the results of the experimental and theoretical studies on the fatigue crack propagation in cylindrical shells subjected to fluctuating internal pressure. Most of the fatigue tests are performed on 6063-T6 aluminum alloys. Some 2024-T3 aluminum and mild steel specimens are also tested. Plexiglas specimens are used for static experiments. In the analysis of the experimental results, the stress intensity factor is used as the correlation parameter. A modified crack propagation model is developed to take into account the effect of bending stresses, which are superimposed on membrane loads around the crack in shells. To evaluate the stress intensity factor, the integral equations obtained by Folias are solved numerically after separating the singularities. Partly to verify the theoretical results, strain measurements were made around the crack tip on the outside of the aluminum and inside and outside of the plexiglas cylinders. The results indicate that over the range of crack propagation data covering 10(exp -7) to 0.001 in/cycle, the model adopted in this study seems to be highly satisfactory.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1968
Accession Number
ADA382250

Entities

People

  • F. Erdogan
  • W. M. Catanach Jr.

Organizations

  • Lehigh University

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Space

DTIC Thesaurus Topics

  • Bending Stress
  • Bessel Functions
  • Cartesian Coordinates
  • Coefficients
  • Computer Programs
  • Crack Propagation
  • Differential Equations
  • Integral Equations
  • Internal Pressure
  • Materials
  • Measurement
  • Mechanical Properties
  • Modulus Of Elasticity
  • Pressurization
  • Simultaneous Equations
  • Strain Gages
  • Stress Intensity Factors

Readers

  • Materials Science (Mechanical Engineering).
  • Mechanical Engineering/Mechanics of Materials.
  • Structural Dynamics.