Fracture Mechanic's Approach on Retardation Behaviors under Overloading

과대하중작용 시 균열성장 지연거동에 대한 파괴역학적 정리

  • 강용구 (금오공과대학교 기계설계공학과) ;
  • 박준영 (금오공과대학교 기계설계공학과)
  • Published : 2012.08.31

Abstract

In order to clarify the effect of overload on crack growth behaviors, fatigue tests for overload were carried out for round plain specimens of SM45C steel. In the experiment, typical semi-elliptical crack shape was found and further crack growth behaviors were tested. Using three types of single overload fatigue tests, Crack growth retardation phenomenon were examined. The growth rate of surface crack(da/dN) during retardation period was analyzed in terms of ${\Delta}K$ and ${\Delta}K_{eff}$. On the growth rate of surface crack analyzed by ${\Delta}K$, the dependence of overload stress levels appears. However, on the growth rate by ${\Delta}K_{eff}$ obtained by Willenborg analysis, there is a liner relationship between da/dN and ${\Delta}K_{eff}$ with narrow scatter band.

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References

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