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Fractographic Analysis Method of Fatigue Fracture Surface under Program and Random Loading for Aluminum Alloy

알루미늄 합금의 랜덤하중 하에서 발생한 피로파면 해석 방법

  • 김상태 (영남대학교 기계공학부) ;
  • 최성종 (영남대학교 기계공학부) ;
  • 양현태 (영남대학교 대학원) ;
  • 이희원 (영남대학교 대학원)
  • Published : 2003.12.01

Abstract

Striation is a typical pattern observed on the fatigue fracture surface and the spacing is known to correspond to a macroscopic fatigue crack growth rate, and many models for the predict in the formation of such striation have been proposed. However, these theories and methods can't be applied under random loading spectrum. In this study, the fatigue tests were carried out on aluminum alloy under random loading spectrum. The fatigue fracture surfaces were observed in the scanning electron microscope (SEM) and great quantities of SEM micrographs were synthesized and saved in computer system. The space and morphology of several large-scale striations, which are expected to from at the relatively greater load range in loading block, were observed. The crack length for each loading blocks was decided in consideration of regularity and repetition of those striations. It is shown that the applicability of fractographic methods on the fatigue fracture surface under random loading spectrum.

Keywords

Fractography;Micro-Fractography;Fatigue;Striation;Random Loading

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