Micromechanics f an Extrusion in High-Cycle Fatigue With Creep

Abstract

A most favorably oriented crystal located at a free surface of a f.c. c. polycrystal subject to creep under cyclic tension and compression of high- cycle fatigue is considered. An extrusion in this crystal is shown to be produced by a positive slip in one thin slice 'P' and a negative slip in a closely located slice 'Q'. An initial tensile strain in the thin slice 'R' sandwiched between P and Q causes a positive initial shear stress in P and a negative one in Q. It is shown that the extrusion growth causes a tensile strain in R, which can activate second slip system giving a creep stain with a tensor component. It has the same effect as the initial strain in causing this difference in shear stresses in P and Q and gives much additional extrusion growth. The extent of intrusion and extrusion is important in this study of crack initiation. Keywords: Single crystals.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1988
Accession Number
ADA213509

Entities

People

  • S. R. Lin
  • T. H. Lin
  • Xiaoqin Wu

Organizations

  • University of California, Los Angeles

Tags

Communities of Interest

  • Air Platforms
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Civil Engineering
  • Creep
  • Crystals
  • Differential Equations
  • Engineering
  • Equations
  • Extrusion
  • Frequency
  • Grids
  • Intrusion
  • Mechanics
  • Military Research
  • Residual Stress
  • Shear Stresses
  • Single Crystals
  • Stresses
  • Tensile Strain

Readers

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