斜拉索风雨激振建模与分析.pdf

第八届全国振动理论及应用学术会议论文集，上海，2003 年 11 月 斜拉索风雨激振建模与分析 马 星 仲 政 李丹达 （同济大学工程力学与技术系，上海，200092） 摘 要： 本文在文献[1]多振型自由度索单元理论的基础上，进一步研究斜拉索风雨激振的力学机理。忽 略拉索弦向及平面外振动的影响，仅考虑拉索平面内振动以及振动水线对拉索气动特性的影响，建立了系统 两自由度非线性振动模型，得到了振幅的计算公式。引入 Hurwitz 判别式考察系统运动的稳定性，发现风雨 激振的本质是系统出现负阻尼或负刚度而引发拉索的自激振动，该非线性系统存在极限环，因此系统存在稳 态自由振动。采用时间平均法，分别计算了系统非内共振和内共振时的振动特性。在算例中对稳态振幅进行 了计算，结果表明本文的模型是合理有效的。 关键词： 斜拉索；风雨激振；自激振动；内共振；时间平均法 Formulation and solution for rain-wind induced vibration of inclined cables MA Xing ZHONG Zheng LI Dan-da (Dept. of Engineering Mechanics and Technology, Tongji University, Shanghai, P.R. China) Abstract: In this paper, the mechanism of rain-wind-induced vibration of inclined cables is further studied based on the theory of multi-mode--freedom cable element[1]. Both influence of axial and out-of-plan vibrations of cable are neglected. The in-plan vibrations of cable are studied and the influence of water rivulet on aerodynamic forces are considered. A two degree-of-freedom nonlinear model of the coupling system is developed and the governing equations for the vibration amplitude are derived. Then Hurwitz discriminant is used to evaluate the kinematic stability of the system. When the damper or the stiffness of the system is negative, self-excited vibrations of the cable will occurs, which is the essence of 基金资助：国家杰出青年科学基金（批准号和高等学校优秀青年教师教学科研奖励基金 作者简介：马星（1973-），男，河南沈丘人，讲师，工学博士 1 rain-wind-induced vibration. Because there exits a limited cycle, the free vibration of the nonlinear system has a steady amplitude. By means of the time averaging method, the dynamic responses of the system are calculated respectively for the cases of non-inner resonance and