The Effect of Strain History on Crack Initiation Under Dynamic Loading

  • Nils-Gunnar Ohlson

Abstract

Paper describes an experimental investigation of crack initiation at high loading rates. Three metals were tested. The material was subjected to various types of preloading, namely, uni-axial as well as bi-axial tension beyond the yield point and cyclic loading (fatigue). The specimen was made in the form of a thin-walled tube, loaded with interior pressure in a split Hopkinson bar of special design. Crack initiation data were evaluated, using linear and non-linear fracture mechanics (KC dyn and JC dyn). Results indicate that JC dyn may be used in an initiation criterion. JC dyn is reduced by pre-loading and it is smaller than the corresponding JC static for the materials tested.

Keywords

Fatigue Grease 

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Copyright information

© Plenum Press, New York 1981

Authors and Affiliations

  • Nils-Gunnar Ohlson
    • 1
  1. 1.Department of Solid MechanicsRoyal Institute of TechnologyStockholmSweden

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