The effect of residual stresses arising from laser shock peening on fatigue crack growth

A. Chahardehi, F. P. Brennan, A. Steuwer

Research output: Contribution to journalArticle

58 Citations (Scopus)

Abstract

Residual stresses have in the past been introduced to manipulate growth rates and shapes of cracks under cyclic loads. Previously, the effectiveness of shot peening in retarding the rate of fatigue crack growth was experimentally studied. It was shown that the compressive residual stresses arising from the shot peening process can affect the rate of crack growth. Laser shock peening can produce a deeper compressive stress field near the surface than shot peening. This advantage makes this technique desirable for the manipulation of crack growth rates. This paper describes an experimental program that was carried out to establish this effect in which steel specimens were partially laser peened and subsequently subjected to cyclic loading to grow fatigue cracks. The residual stress fields generated by the laser shock peening process were measured using the neutron diffraction technique. A state of compressive stress was found near the surface and tensile stresses were measured in the mid-thickness of the specimens. Growth rates of the cracks were observed to be more affected by the tensile core than by the compressive surface stresses.

Original languageEnglish
Pages (from-to)2033-2039
Number of pages7
JournalEngineering Fracture Mechanics
Volume77
Issue number11
DOIs
Publication statusPublished - 1 Jul 2010
Externally publishedYes

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Keywords

  • fatigue crack growth
  • laser peening
  • neutron diffraction
  • residual stress

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