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斜拉索被广泛应用于索承结构,如大跨度桥梁或屋盖结构等.由于极低的内在阻尼,斜拉索易发生因其支承的运动或天气状况影响而引起的大幅值的振动.这些振动可以危及斜拉索本身以及整个索承结构的安全与寿命,甚至引起人们对该类结构信心的降低.在斜拉索减振的诸多方法中,采用磁流变阻尼器的智能阻尼技术近来引起了人们的研究兴趣.该阻尼器的阻尼特性可以通过调节(控制)磁场的输入电流/电压而改变,从而实现在不同振动(频率及幅值)情况下的最优或次优减振效果.本文发展了一个数学模型用于评价在开环控制状态下斜拉索-阻尼器系统的阻尼比.该模型考虑了阻尼器的安装高度、阻尼系数、刚度、质量、支撑刚度、磁变阻尼力以及斜拉索的垂度与倾角等因素,推导出了一个‘广义的通用公式’用于阻尼器参数的设计与优化,即寻求可提供系统最大阻尼比的最佳阻尼器参数.本文以目前世界最长斜拉桥——苏通大桥的最长斜拉索为例,确定了能够提供足够的阻尼以抑制风雨振的阻尼器安装高度以及相应的阻尼器参数.
Cable stayed cables are widely used in cable-stayed structures such as long-span bridges or roof structures, etc. Due to the extremely low internal damping, cable stays susceptible to large amplitude vibrations due to their supporting motion or weather conditions. These vibrations can endanger the safety and life span of the stay cables and the entire cable bearing structure, and even lead to the decrease of people's confidence in such structures.In many methods of cable stay vibration damping, the intelligent damping technology using magnetorheological damper Recently, there has been aroused much interest in research, and the damping characteristic of the damper can be changed by adjusting (controlling) the input current / voltage of the magnetic field so as to realize the optimal or suboptimal damping under different vibration (frequency and amplitude) Effect. In this paper, a mathematical model was developed to evaluate the damping ratio of the cable-damper system under open-loop control. This model considers the damper mounting height, damping coefficient, stiffness, mass, support stiffness, Damping force and the dip and dip angle of the stay cable, a generalized generalized formula is derived for the design and optimization of the damper parameters, namely, to seek to provide the maximum system damping Ratio of the best damper parameters.In this paper, the longest cable stayed bridge in the world - Sutong Bridge, the longest cable as an example, to determine sufficient damping can be provided to suppress the wind and rain damper installation height and the corresponding Damper parameters.