Transactions of the Korean Society for Noise and Vibration Engineering (한국소음진동공학회논문집)

The Korean Society for Noise and Vibration Engineering (한국소음진동공학회)
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Experimental Study on Detection of Crack for Coupled Bending-torsional Vibrations of L-beams

횡-비틀림 연성진동하는 L형 단면 보의 크랙 검출에 대한 실험적 연구

  • 손인수 (동의대학교 기계공학과) ;
  • 이두호 (동의대학교 기계공학과) ;
  • 노태우 (동의대학교 대학원 기계공학과)
  • Received : 2010.12.17
  • Accepted : 2011.01.26
  • Published : 2011.02.20
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Abstract

In this paper, the natural frequency of a cracked cantilever L-beams with a coupled bending and torsional vibrations is investigate by theory and experiment. In addition, a method for detection of crack in a cantilever L-beams is presented based on natural frequency measurements. The governing differential equations of a cracked L-beam are derived via Hamilton's principle. The two coupled governing differential equations are reduced to one sixth order ordinary differential equation in terms of the flexural displacement. Futher, the dynamic transfer matrix method is used for calculation of a exact natural frequencies of L-beams. The crack is assumed to be in the first mode of fracture and to be always opened during vibrations. In this study, the differences between the actual and predicted positions and sizes of crack are less than about 10 % and 39.5 % respectively.

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References

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