• Title/Summary/Keyword: 진동 국부화

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Comparison Study on Mode and Response Localizations (모드 국부화와 응답 국부화의 비교연구)

  • 하동진;유홍희
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.6
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    • pp.478-485
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    • 2004
  • Vibration localization characteristics of mistuned repeated structures are investigated. The mistuning often creates significant response discrepancies among subcomponents of a repeated structure. As the result of the discrepancies, critical fatigue often occurs in a repeated structure. Therefore, it is of great importance to predict the vibration response of the mistuned repeated structures accurately. In this paper, a simplified model is employed and dimensionless parameters that influence the localization characteristics are identified. Through parameter study, two localization phenomena are investigated and compared.

Vibration Localization due to Mistuned Coupling Effects Among Repeated Structures (반복 구조간 연성 효과의 불균일성에 의한 진동 국부화)

  • Kang, Min-Kyoo;Yoo, Hong-Hee
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.12
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    • pp.994-1000
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    • 2002
  • In periodically repeated cyclic structures, small property irregularity of their substructures often causes significant difference in their dynamic responses. which results in unpredicted premature failures. The small irregularity and the resulting phenomenon are called the mistuning and the vibration localization. respectively. In this paper, the vibration localization phenomena due to mistuned coupling effects are investigated. To effectively achieve the objective, a simple coupled multi-pendulum system Is employed. The results show that if there exists some coupling stiffness irregularity, vibration localization may occur and becomes more predominant as the number of substructures increases.

The Effects of the Stiffness Mistuning and the Excitation Force Phase Difference on the Vibration Localization of Cyclic Structures (순환 구조물의 진동 국부화에 미치는 강성 불균일 및 가진력 위상차의 효과)

  • Kang, Min-Kyoo;Yoo, Hong-Hee
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.8
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    • pp.1347-1352
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    • 2003
  • In periodic cyclic structures, small property irregularity of their substructured often causes significant difference in their dynamic responses, which results in unpredicted premature failures. The small irregularity and the resulting phenomenon are called the mistuning and the vibration localization, respectively. In this paper a simple coupled multi-pendulum system is employed to investigate the effects of the stiffness mistuning and the phase difference in excitation force on the vibration localization of periodic cyclic structures.

Dynamic Response Localization of Simple Periodic Structures Undertaking External Harmonic Forces (조화 외력을 받는 간단한 주기적 구조물의 동적 응답 국부화)

  • 김재영;유홍희
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.11 no.6
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    • pp.175-180
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    • 2001
  • Dynamic response localization of simple mistuned periodic structures is presented in this paper Mistuning in periodic structures can cause forced responses that are much larger than those of perfectly tuned structures. So mistuning results in the critical impact on high cycle fatigue of structures. Thus, it is of great importance to predict the mistuned forced response in an efficient way. In this paper, forced responses of coupled pendulum systems are investigated to identify the localization effect of periodic structures. The effects of mistuning and damping on the maximum forced response are examined. It is found that certain conditions of mistuning and coupling can cause strong localization and the localization becomes significant under weak damping. It is also found that the maximum forced response increases as the number of Periodic structures increases.

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Vibration Localization of Open Loop Repeated Structures (개방형 반복구조물의 진동국부화)

  • Ha, Dong-Jin;Yoo, Hong-Hee
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.12
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    • pp.911-917
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    • 2003
  • Vibration localization characteristics of open loop repeated mistuned structures are investigated. The mistuning often creates significant response discrepancies among subcomponents of the repeated structures. As a result of the discrepancies, critical fatigue problems often occur in repeated structures. Therefore. it is of great importance to predict the vibration response of the mistuned repeated structures accurately in this Paper, a simplified model for an open-loop repeated structure is introduced and dimensionless parameters that influence the localization characteristics are identified. The effects of the parameters on the localization characteristics are investigated through numerical study.