Prediction of Plasticity Characteristics for Three-Dimensional Fracture Specimens Comparison with Experiment,

Abstract

A center-cracked panel of 7075-Aluminum alloy which has overaged from the T651 condition was loaded in tension and subsequently unloaded to zero applied load. The permanent surface deformation was measured close to the intersections of the crack front with the free surfaces. The permanent deformation (being a good indicator of the extent of plastic deformation) was used to measure the accuracy of finite element analyses. The same specimen was modeled using 20-node three-dimensional isoparametric elements. A fully incremental elastic-plastic formulation was employed in the stress analysis. The residual surface deformations after unloading were compared to the experimental results. The average experimental results compare quite favorably with the finite element predictions. The average results were employed to minimize the influence of material inhomogeneity, load misalignment, and lack of symmetry in the fatigue crack. The scatter in the results from measuring the different sides is discussed. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1985
Accession Number
ADA156425

Entities

People

  • E. T. Moyer Jr.
  • H. Liebowitz
  • P. K. Poulose

Organizations

  • George Washington University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Accuracy
  • Coordinate Systems
  • Crack Tips
  • Engineering
  • Equations
  • Finite Element Analysis
  • Geometry
  • Grids
  • Measurement
  • Mechanics
  • Standards
  • Strain Rate
  • Stress Analysis
  • Stress Strain Relations
  • Stresses
  • Tensile Strength
  • Three Dimensional

Fields of Study

  • Physics

Readers

  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Mechanical Engineering/Mechanics of Materials.
  • Structural Health Monitoring of Composite Structures.