Journal of Wind Engineering
Online ISSN : 1349-340X
Print ISSN : 1349-3507
ISSN-L : 1349-340X
Volume 45 , Issue 3
[No. 164]
Showing 1-3 articles out of 3 articles from the selected issue
Technical Paper
  • Yosuke NAGUMO, Takeshi ISHIHARA
    2020 Volume 45 Issue 3 Pages 79-92
    Published: July 31, 2020
    Released: January 24, 2021
    In this study, uncertainties of aerodynamic force, gravitational force, excessive centrifugal force and lateral vibration induced inertial force acting on the train cars are investigated based on the measured data. A performance function is then proposed based on the reliability theory and the safety indexes are assessed when the train operation regulations are performed. The code calibration is carried out to obtain an acceptable safety index and a formula with partial factors is proposed to calculate critical wind speeds of overturning. Finally, the safety indexes for several train operation conditions are assessed based on the critical wind speed of overturning predicted by three formulas. It is found that the safety indexes obtained by the proposed formula are nearly constant values, while those by the conventional formula show different values for different train operation conditions.
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  • Naoki DANGURI, Kazuyoshi NISHIJIMA
    2020 Volume 45 Issue 3 Pages 93-102
    Published: July 31, 2020
    Released: January 24, 2021
    For the design of structures against wind-induced fatigue not only maximum wind speed but also the time series of wind speed and direction are generally required. Currently, no rationale exists for selecting realistic typhoons to be used for determining such time series for the use of the design. Further, it is not known on how the selection of these typhoons affect the evaluation of the accumulated fatigue damages of structural components. Therefore, this study first proposes a concept and methodology for identifying most-likely typhoon (ML typhoon) with a given hazard level specified in terms of maximum wind speed. Then, using the ML typhoon and other likely typhoons, which together constitute a set of realistic typhoons, characteristics of the time series of wind speed and wind direction with given hazard levels are investigated. Thereafter, a sensitivity analysis is conducted in order to evaluate the variation of the accumulated fatigue damages induced by those typhoons, taking its basis with a hypothetical seismically base isolated building. It is found that significant difference in the evaluated accumulated fatigue damages are observed for typhoons with a common hazard level and the same likelihood. This implies selecting the design typhoon(s) requires more care not only for the maximum wind speed but also other characteristics of typhoons.
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