Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Spatial Randomness of Fatigue Crack Growth Rate in Friction Stir Welded 7075-T651 Aluminum Alloy Welded Joints (Case of LT Orientation Specimen)

마찰교반용접된 7075-T651 알루미늄 합금 용접부의 피로균열전파율의 공간적 불규칙성 (LT 방향의 시험편에 대하여)

  • Jeong, Yeui Han (Dept. of Mechanical Design Engineering, Graduate School, Pukyong Nat'l Univ.) ;
  • Kim, Seon Jin (Dept. of Mechanical & Automotive Engineering, Pukyong Nat'l Univ.)
  • 정의한 (부경대학교 대학원 기계설계공학과) ;
  • 김선진 (부경대학교 기계자동차공학과)
  • Received : 2013.03.07
  • Accepted : 2013.07.08
  • Published : 2013.09.01
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Abstract

This study aims to investigate the spatial randomness of fatigue crack growth rate for the friction stir welded (FSWed) 7075-T651 aluminum alloy joints. Our previous fatigue crack growth test data are adopted in this investigation. To clearly understand the spatial randomness of fatigue crack growth rate, fatigue crack growth tests were conducted under constant stress intensity factor range (SIFR) control testing. The experimental data were analyzed for two different materials-base metal (BM) and weld metal (WM)-to investigate the effects of spatial randomness of fatigue crack growth rate and material properties, the friction stir welded (FSWed) 7075-T651 aluminum alloy joints, namely weld metal (WM) and base metal (BM). The results showed that the variability, as evaluated by Weibull statistical analysis, of the WM is higher than that of the BM.

본 연구의 목적은 마찰교반용접된 7075-T651 알루미늄 합금 용접부에 대한 피로균열전파율의 공간적 불규칙성을 고찰하기 위한 것이다. 본 연구에서는 이전의 피로균열전파 실험 데이터를 활용하였다. 피로균열전파율의 공간적 불규칙성을 명확히 이해하기 위하여, 피로균열전파 실험은 일정 응력확대 계수범위 제어하에서 수행되었다. 재질, 즉 마찰교반용접된 7075-T651 알루미늄 합금 용접부의 용접재와 모재에 대하여 피로균열전파율의 공간적 불규칙성을 조사하기 위하여 실험 데이터가 해석되었다. 결론적으로 용접재의 변동성이 모재의 변동성보다 높게 나타났으며, Weibull 통계 해석에 의하여 변동성을 평가할 수 있음을 알았다.

Keywords

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  2. Effect of Specimen Orientation on Fatigue Crack Growth Behavior in Friction Stir Welded Al7075-T651 Joints vol.38, pp.12, 2014, https://doi.org/10.3795/KSME-A.2014.38.12.1317
  3. Effect of Initial Crack Location on Spatial Randomness of Fatigue Crack Growth Resistance in Friction Stir Welded AA7075-T651 Plates vol.38, pp.9, 2014, https://doi.org/10.3795/KSME-A.2014.38.9.999