Journal of Ocean Engineering and Technology (한국해양공학회지)

Korean Society of Ocean Engineers (한국해양공학회)
권호 표지

A Study on Fatigue Crack Growth Retardation Phenomena of Al 7075--T6 Alloy under Multiple overload(I)

다중 과하중에 의한 A1 7075-T6 합금의 피로균열 성장지연현상에 관한 연구

  • 이택순 (영남대학교, 정밀기계공학과) ;
  • 이유태 (영남대학교 정밀기계공학과)
  • Published : 1992.06.01
Download PDF
⟨ Previous Next ⟩

Abstract

Aircraft structures and engineering structures are always subject to variable amplitude loads. Variable amplitude loads include some kind of loading history; for example, constant amplitude load, single peak overload and block overload etc. Crack growth under variable amplitude loading exhibits retardation effect. In this study, the 4 point bending fatigue test was performed by hydrolic servo fatigue testing machine on 7075-T6 Al-alloy. The retardation effect of overload ratio and numbers of overload cycle was quantitatively studied. 1) Change of retardation effect against increment of overload ratio is more evident when the multiple overload is applied than single overload is done. 2) The number of overload cycle is very important factor about the crack growth retardation effect when the overload ratio is more than 1.75; that is not when the overload ratio is less than 1.75. 3) Overload affected zone size increased gradually by increment of crack growth retardation effect. 4) Crack driving force is more greatly reduced when the crack tip branched off two direction than it sloped to one direction.

Keywords

References

  1. Metal Fatigue Christensen,R.H.
  2. Engineering Fracture Mechanics v.5 Fatigue Crack Retardation after Single Cycle Peak Overload in Ti-6Al4V Titanium Alloy Jones,R.E.
  3. Aircrapt Engineering v.34 The Result of a Test Programme Based on a Gust Spectrum with Variable Amplitude Loading Shijve,J.;Broek,D.
  4. Engineering Fracture mechanics v.18 no.3 Micro Mechanisms of Fatigue Crack Growth Retardation Following Overloads Suresh,S.
  5. ICF v.5 no.4 Advances in Fracture Research Powell,P.M.;Forshyth,P.J.E.;Williams,T.R.G.
  6. ASTM STP 486 The Signifiance of Fatigue crack closure Elber,W.
  7. E.F.M. v.2 Fatigue Crack Closure under Cyclic Tension Elber,W.
  8. ASTM STP 513 Delay Effects in Fatigue Crack Propagation Euw Von.E.F.J.;Hertzberg,R.W.;Roberts,R.
  9. ASTM STP 924 Kendall,J.M.;Knott,J.F.
  10. Pub AIME Fatigue Crack Growth Threshold Concept Vanable,R.A.;Hicks,M.A.;King,J.E.
  11. ASTM STP 595 Observations on the Prediction of Fatigue Crack Growth Propagation Under Variable Amplitude Loading Schijve,J.
  12. Engineering Fracture Mechanics v.32 no.4 Mechanismas associated with Transient Fatigue Crack Growth Under Variable-Amplitude Loading: An Experimental and Numberical Study C.M.Ward-Close;A.F.Blom;R.O.Ritchie
  13. Engineering Fracture Mechanics v.30 Drew,M.W.;Tomson,K.R.L.
  14. ASTM STP 924 Fleck,N.A.
  15. International Journal of Fracture Upper and Lower Bounds for the Lengths of Non-propagation Cracks Cameron,a.d.;Smith,R.A.
  16. Engineering Fracture Mechanics v.8 The Effective of Pre-strain on Fatigue Crack Growth and Crack Closure Schijve,J.
  17. Engineering Fracture Mechanics v.32 no.5 Effect of Prestrain on Material and Single Tensile Overload Cycles on Crack Closure Raghuvir Kumar;Garg,S.B.L.
  18. Engineering Fracture Mechanics v.13 The Influence of Sheet Thickness on Delayed Retardation Phenomena in Fatigue Crack Growth in HT 80 steel and A5083 Aluminium Alloy Masuoka,S.;Tanaka,K.
  19. ASTM STP 595 Mechanisms of Overload Retardation During Fatigue Crack Propagation Bernard,P.J.;Lindley,T.C.;Richards,C.E.
  20. Engineering Fracture Mechanics v.32 no.4 Mechanisms Associated with Transient Fatigue Crack Growth under Variable Amplitude Loading : An Experiemental and Numberical Study Ward-Close,C.M.;Blom,A.F.;Ritchie,R.O.
  21. Engineering Fracture Mechanics v.11 Four Lecture on Fatigue Crack Growth Schijve,J.