基于谱分解法的自锚式悬索桥桥梁风致抖振计算分析

发布时间：2018-09-13 10:35

【摘要】：自锚式悬索桥是一种大跨度柔性结构体系,该桥型经受脉动风作用时容易发生较大的抖振响应,对于该种桥型进行风致抖振的研究探讨具有较强的实际意义。以自锚式悬索桥武汉汉江六桥为工程实例,进行风致抖振分析。具体分析流程为:通过计算流体力学软件对桥梁进行气动分析,得到桥梁抗风分析方程中的重要参数静力三分力系数。通过对桥址处风场资料的分析,采用规范规定的风谱密度函数,利用谱分解法将脉动风谱转换成脉动风时程,同时结合准定常气动理论将风时程转换成风力时程实现气动力的时域化。利用有限元软件建立桥梁的空间模型并分析自锚式悬索桥动力特性。通过自编数值程序和有限软件的结合将风力时程加载在桥梁模型上,实现桥梁在时程风力作用下抖振响应的数值模拟。其计算结果表明:该桥在风致抖振作用下性能良好,结构具有良好的气动性。结合计算流体力学软件、数值分析软件、有限元软件的桥梁抗风计算方法和模式,可以在其他自锚式悬索桥风致抖振计算中参考使用。
[Abstract]:Self-anchored suspension bridge is a kind of long-span flexible structure system. It is easy to occur larger buffeting response when the bridge is subjected to pulsating wind, so it is of great practical significance to study the wind-induced buffeting of this type of bridge. Wind-induced buffeting analysis was carried out on Wuhan Hanjiang sixth Bridge, a self-anchored suspension bridge. The detailed analysis flow is as follows: the aerodynamic analysis of the bridge is carried out by computational fluid dynamics software, and the static three-point force coefficient of the important parameter in the bridge wind analysis equation is obtained. By analyzing the wind field data at the bridge site and adopting the wind spectrum density function prescribed by the specification, the pulsating wind spectrum can be converted into the pulsating wind history by the spectral decomposition method. At the same time, combined with the quasi-steady aerodynamic theory, the wind time history is converted into the wind time history to realize the time domain of the aerodynamic force. The spatial model of the bridge is established by using finite element software and the dynamic characteristics of the self-anchored suspension bridge are analyzed. The wind time history is loaded on the bridge model by the combination of self-compiled numerical program and finite software, and the buffeting response of the bridge under the action of time-history wind is simulated numerically. The results show that the bridge has good performance and aerodynamic performance under wind-induced buffeting. Combined with computational fluid dynamics software, numerical analysis software and finite element software, the bridge wind resistance calculation method and model can be used in other self-anchored suspension bridge wind-induced buffeting calculation.
【作者单位】：西南交通大学土木工程学院;
【分类号】：U441.3;U448.25

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