摘要
斜拉索风雨激振严重地影响斜拉桥的安全运营,而来流湍流度是影响风雨激振的一个重要因素。采用理论分析方法,研究来流湍流对斜拉索风雨激振响应的影响。引入2种类型的风场,首先,假设来流为简谐脉动风场,然后,采用谐波合成方法,将Kaimal风谱作为目标谱,模拟来流随机脉动风场。采用上述2种来流风场,在已建立的两质量三自由度理论模型的基础上,研究各种湍流度下拉索和水线的风雨激振振动规律。计算结果表明,当湍流度达到15%时,水线不能在拉索表面稳定地存在,风雨激振能得到有效的抑制;水线运动的脉动成分主要受来流风脉动成分的影响,拉索运动对水线运动有一定的影响,但影响较小;随着紊流度的增加,起振风速也增大。
Rain-wind induced vibrations of stay cables seriously affect the safety of cable-stayed bridges, and turbulence intensity in the approaching flow plays an important role in rain-wind induced vibrations. The effects of turbulence intensity of approach flow on rain-wind induced vibrations are investigated. Two types of fluctuating flows are adopted. First, the approaching flow is modeled as a sinusoidal function. Subsequently, fluctuations in wind are simulated as a random process based on the classical Kaimal spectra. The rain-wind induced vibrations under these two approach flows are evaluated on the basis of a theoretical model developed by the authors. The results show that large amplitude cable vibrations will be mitigated if the turbulence intensity reaches 15% due to the vanishing of the rivulet. The rivulet is strongly impacted by the fluctuating component of the approaching flow whereas the motion of the cable has some degree of influences on the motion of the rivulet. The minimum wind velocity of rain-wind induced vibration increases when turbulence intensity increases
出处
《土木工程学报》
EI
CSCD
北大核心
2012年第6期132-138,共7页
China Civil Engineering Journal
基金
国家自然科学基金(50708035)
关键词
斜拉索
风雨激振
湍流度
理论研究
stay cable
rain-wind induced vibration
turbulence intensity
theoretical analysis
