• Title/Summary/Keyword: Impact vibration

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Vibrations and Impact Factors for Highway Girder Bridges (도로형교의 진동 및 충격계수)

  • 장동일;이희현;전진창
    • Computational Structural Engineering
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    • v.5 no.3
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    • pp.139-146
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    • 1992

  • Vibrational behaviors of highway girder bridges due to heavy traffics are discussed, and empirical formulae for impact factors are suggested in this paper. Appropriate vehicle model for vibration analysis is found and impact factors are calculated with different surface roughnesses, vehicle speeds and span lengths. It is shown that the present codes tend to underestimate impact factors.

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Vibrations and Impact Factors for Highway Girder Bridges (도로형교의 진동 및 충격계수)

  • 장동일;이희현
    • Computational Structural Engineering
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    • v.5 no.2
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    • pp.87-91
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    • 1992

  • Vibrational behaviors of highway girder bridges due to heavy traffics are discussed, and empirical formulae for impact factors are suggested in this paper. Appropriate vehicle model for vibration analysis is found and impact factors are calculated with different surface roughnesses, vehicle speeds and span lengths. It is shown that the present codes tend to underestimate impact factors.

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Dynamic characteristics and wind-induced vibration coefficients of purlin-sheet roofs

  • Zhang, Yingying;Song, Xiaoguang;Zhang, Qilin
    • Steel and Composite Structures
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    • v.22 no.5
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    • pp.1039-1054
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    • 2016

  • This paper presents the dynamic characteristics analysis of the purlin-sheet roofs by the random vibration theories. Results show that the natural vibration frequency of the purlin-sheet roof is low, while the frequencies and mode distributions are very intensive. The random vibration theory should be used for the dynamic characteristics of the roof structures due to complex vibration response. Among the first 20th vibration modes, the first vibration mode is mainly the deformations of purlins, while the rest modes are the overall deformations of the roof. In the following 30th modes, it mainly performs unilateral local deformations of the roof. The frequency distribution of the first 20th modes varies significantly while those of the following 30th modes are relatively sensitive. For different parts, the contributions of vibration modes on the vibration response are different. For the part far from the roof ridge, only considering the first 5th modes can reflect the wind-induced vibration response. For the part near the ridge, at least the first 12 modes should be considered, due to complex vibration response. The wind vibration coefficients of the upwind side are slightly higher than that of the leeward side. Finally, the corresponding wind vibration coefficient for the purlin-sheet roof is proposed.

  • https://doi.org/10.12989/scs.2016.22.5.1039 인용 KSCI