安装肋条斜拉索的涡激振动和气动力特性研究OA北大核心CSTPCD

Hence,further investigation is needed.Taking the stay cables with ribs installed as the object,a series of wind tunnel tests were conducted to systematically study the effects of the installation methods(through-length installation and intermittent staggered installation),sizes and numbers of ribs on the VIV,and aerodynamic force.Additionally,the suppression mechanism of vortex-induced vibration(VIV)was analyzed.Results show that stay cables with ribs can effectively suppress VIV compared with standard stay cables.The intermittent staggered installation exhibits a better vibration suppression effect than the through-length installation.The control effect was better for 8 ribs than for 6 and 12 ribs.Increasing rib width and thickness can reduce the amplitude of VIV.The fluctuating lift coefficients of the stay cables with ribs are remarkably smaller than those of the standard stay cables.Moreover,the amplitudes of the power spectrum peaks are significantly reduced,or the peaks are even vanished.This suggests that intermittent staggered rib can weaken the strength of Karman vortex shedding or even control it completely.For aerodynamic forces,the Reynolds number effect on the mean aerodynamic coefficient is significantly weakened by the ribs.Compared to standard stay cables,the installation of ribs throughout the entire length increases the mean drag coefficient of the stay cables.When the installation is intermitte staggered,the increase and decrease in the drag varies with the number and size of ribs and the wind attack angle.When the ribs with the size of 20mm×15mm and the number of 8 are intermittently staggered,good vibration suppression effects can be obtained at all wind attack angles.The maximum reduction of VIV amplitude can reach 96.79%,the mean drag coefficient is near 1.13,and the mean lift coefficient is near 0.