斜拉索风致振动疲劳的分析

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振动与冲击 ›› 2009, Vol. 28 ›› Issue (9) : 135-138,.

论文

斜拉索风致振动疲劳的分析

李春祥,李薇薇

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Analysis of wind-induced fatigue of inclined cables

Li Chunxiang, Li Weiwei

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文章历史 +

摘要

本文研究了斜拉索的风致振动疲劳问题。首先，假设在任一应力循环周期内, 考察点的最大与最小应力之差符合Rayleigh分布。其次，推导出斜拉索的疲劳可靠度计算公式；根据桥梁结构的疲劳目标可靠度, 给出简单明了的斜拉索疲劳寿命计算公式。第三，在目前既有研究的基础上，进一步评价不同的风攻角对疲劳可靠度和疲劳寿命的影响。最后，论文以松花江斜拉桥中的斜拉索为实例，计算分析了在不同的风攻角情况下斜拉索上各节点应力时程和位移时程，并得出在不同风攻角下各节点的应力响应根方差。于是，根据最危险工况作为疲劳寿命评估的考察点计算出斜拉索的最短疲劳寿命，以验证其风致振动疲劳的性能。

Abstract

The main objective of the present paper is to analyze the wind-induced fatigue of inclined cables. Firstly, it is hypothesized that within the random stress cycle, the dispersion of between the maximum and minimum stress of the nodes contents with the Rayleigh distribution. Subsequently, the formula of fatigue reliability is formulated. Likewise, based on the fatigue objective reliability of bridge structures, the simple formulas for the estimation of fatigue life are then presented. Thirdly, on the basis of present researches, the influences of different wind attack angles are further assessed on both the fatigue reliability and fatigue life. Finally, taking the inclined cable in Songhuajiang Cable-stayed Bridge as an example, the time history stress and displacement of several positions in the cable at different wind attack angles, as well as the stress standard deviations, are calculated. With resorting to the stress and displacement under the most dangerous condition, the fatigue life is thus obtained so as to examine the wind-induced fatigue performance of the cable.