斜拉索面内参数振动的理论和试验研究

研究斜拉索在弦向位移激励下的面内非线性振动方程,该振动方程考虑拉索垂度、倾斜角、大位移、激励幅值、阻尼等影响因素,并应用龙格-库塔数值积分法求解该微分方程。在试验室建立了斜拉索模型,开展斜拉索受弦向位移激励的面内参数振动的试验研究,实现了斜拉索的参数振动。试验研究和数值计算表明斜拉索的参数振动与系统频率比、激励幅值、阻尼等因素有关,参数振动发生在一定的频率比范围内,斜拉索振幅与频率比关系曲线体现出非线性特性,系统阻尼使得斜拉索参数振动的激励幅值要超过一定的阀值。

Theoretical and experimental study on planar parametric oscillations in a stayed-cable

An in-plane nonlinear vibration equation of a stayed-cable under axial displacement excitation was intro-duced. Influencing factors including sag of cable, inclination angle, large displacement, excitation amplitude, damping coefficient and etc were taken into the equation. The equation was solved numerically using Runge-Kutta method. An Experimental model of a stayed-cable was established and tested in lab. Parametric oscillation of the cable was observed.The results of numerical calculation and experimental data showed that parametric oscillations appear in a special range of frequency ratio, amplitude-frequency curve of the cable was nonlinear, damping of the cable enables the excitation ampli-tude of its parametric oscillations should exceed a certain threshold.