斜拉桥拉索在轴向窄带随机激励下的振动响应

导出了拉索在考虑垂度以及索张力沿索长变化时的参激随机微分方程，进一步给出了预测拉索在窄带随机激励下响应的近似理论解------用统计矩截断法求解矩方程，获得高斯闭合解和一阶非高斯闭合解. 以南京长江二桥约330米长的A20拉索为研究对象，对以上高斯闭合解和一阶非高斯闭合解进一步进行数值求解以获得拉索的响应，并采用Monte-Carlo数值方法对求解进行验证. 分析了拉索振动的一般特征，特别分析了激励中心频率和拉索频率比为1和2时的响应随激励带宽的变化特征，得到了一些新的结论. 

VIBRATION RESPONSE OF STAY CABLES INDUCED BY AXIAL NARROW-BAND RANDOM EXCITATION

In this paper, the stochastic differential equations of stay cables under axial narrow-band random excitations are derived with the consideration of cable sag and variation of cable tension along cables. Gaussian and the first order non-Gaussian closure solutions are deduced with the cumulant closure scheme. A numerical case of the cable A20 with a length about 330\,m of No.2 Nanjing Bridge over Yangtze River is carried out to obtain the cable vibration response. Monte-Carlo method is applied to verify the theoretical solutions in the present work. Moreover, the effects of excitation frequency on the vibration response of the cable are investigated when the ratio value of the central excitation frequency to natural frequency of the cable is 1 or 2. Some new conclusions are summarized in the present study.