【摘要】 以杭州之江大桥为例,研究斜拉桥拱形钢塔动力特性及多重调谐质量阻尼器MTMD风振控制方法。运用ANSYS软件,分析拱形钢塔施工及成塔状态的动力特性,确定钢塔MTMD风振控制振型及频率。采用改进谐波合成法模拟随机性良好的脉动风场,以拱形钢塔顶部位移及加速度风振响应减振率为优化目标,对MTMD系统的参数进行优化分析,设计可控制拱形钢塔面内与面外振动的调谐质量阻尼器TMD结构及其参数。研究结果表明:MTMD系统的控制效率与其参数有很大关系,MTMD系统存在最优参数组合,对于拱形钢塔施工未合拢阶段(风振最不利状态),MTMD系统应选择质量比为0.01,TMD个数为12,阻尼比为0.05,带宽为0.1的参数组合。MTMD系统中各参数对结构位移和加速度减振效果的影响较为一致,一般加速度的减振率大于位移减振率。更多还原

【Abstract】 Based on Zhijiang Bridge in Hangzhou,the dynamic characteristics and Multiple T uned Mass Dampers(MTMD) control method of wind-induced vibration for the arch steel tower of cable-stayed bridge were studied.Using software ANSYS, the dynamic characteristics of arch steel tower under construction and service status were analyzed.The control objectives of the vibration modes and frequenc y of the arch steel tower were suggested.Perfect stochastic fluctuating wind fi eld processes were generated by improved WAWS.With the wind vibration response reduction ratios of the displacement and acceleration at the top of arch steel t ower as optimization objectives,the parameters of MTMD system were optimized an d the Tuned Mass Damper(TMD) devices and parameters which could control the pla ne vibration and out-of-plane vibration for arch steel tower were designed.Th e results show that the control efficiency of MTMD system has much to do wit h its parameters,and MTMD system has optimum parameter combinations.Wh en the arch steel tower is under construction,especially at non-closure stage, (the most disadvantageous state of wind vibration),the parameter combinations for MTMD system are suggested: the mass ratio is 0.01,the number of TMD is 12, the damping ratio is 0.05 and the bandwidth is 0.1.The parameters in MTMD sy stem have a consistent vibration reduction effect on structural displacement and acceleration.In general,the vibration reduction ratio of acceleration is grea ter than that of displacement.更多还原