磁流变阻尼器对高速列车通过简支箱梁桥时的振动控制研究

【作者】 王典斌；

【导师】 郭文华；

【作者基本信息】 中南大学 ， 桥梁与隧道工程， 2009， 硕士

【摘要】 桥梁在我国高速铁路占有很大比重,高速列车过桥时动力响应的课题研究已逐步提上日程。桥梁振动控制作为一种智能主动(或半主动)的方法,基于控制系统和被控结构的联合作用来抵御外部的动力输入,从而有效地减小桥梁的动力响应,进而提高行车的安全稳定性。近年来随着智能材料的快速发展,磁流变阻尼器(MRD)作为一种新型的阻尼器受到广泛的关注。它是一种通过实时改变磁流变阀中的磁场强度,来智能调节阻尼出力目的的智能装置.与传统的机械可调阻尼器相比减少了阀门部分的机械装置,其系统更加可靠.本文主要工作如下:1)磁流变阻尼器的工作原理及其力学模型。系统的阐述了磁流变阻尼器几种经典的力学模型,本文采用其中能较准确反映其力学性能的修正的现象模型。2)车-桥-MRD耦合系统的建立。在选取了MRD的力学模型,并建立了桥梁有限元模型和具有两个转向架四个轮对的列车振动分析模型、轨道不平顺模型的基础上,根据虚功原理推导出车桥系统的动力方程,此方程适用于作匀速运动的车辆与具有任意轨道不平顺函数、各种不同边界条件的桥梁的耦合系统。3)车-桥-MRD耦合系统的求解与程序实现。本文基于Fortran95编制了较为通用的车-桥-MRD竖向振动分析程序和轨道不平顺计算程序,该程序可进行车-桥-MRD系统的动力分析,适用于能够用梁单元、桁架单元和索单元模拟的桥梁模型,适用于移动荷载和可简化为弹簧、阻尼器相连的多刚体模型的车辆模型,能够实现匀速车辆作用下的车桥系统的竖向响应分析,也可考虑轨道不平顺的影响,并在MRD作用下分析其及其对车-桥系统的动力响应的影响。4)磁流变阻尼器最优控制力的求解。首先利用瞬时最优主动控制求解出结构在外界激励作用下的最优控制力,然后利用本文探讨的双限值半主动控制算法对最优控制力进行过滤,最终得出阻尼器当前最优出力。双限值半主动控制算法是建立在主动控制理论基础之上,再结合阻尼器的当前状态,在参数限值范围内计算出阻尼器的当前最优出力。5)MRD对桥梁的减振效果分析。本文采用了一种新的MRD与锚索组成的减振系统,研究了磁流变阻尼器减振系统对高速列车通过简支梁桥时列车、桥梁动力响应的减振效果,计算分析了磁流变阻尼器减振系统对40m和32m简支梁桥动力响应的影响,尤其在共振车速下对桥梁的动力响应有更好的控制效果,可在工程实践中推广应用。同时分析了磁流变阻尼器减振系统对车辆运行平稳性的影响,通过分析MRD对桥梁在不同荷载下的控制效果,验证了磁流变阻尼器在控制桥梁振动方面的可行性。更多还原

【Abstract】 Among of the high-speed railway constructions of China, bridges are in a large proportion. Dynamic performances of train-bridge interaction system under the loads of high-speed trains and have been put on the agenda. The vibration problem of bridge as a kind of intelligent and active or semi-active strategy, basing on the teamwork of the control system and structure to withstand external power input, in order to decrease the dynamic response of train-bridge, and increase the safety and stability of travelling.As the development of smart materials in recent years, as a new type of damper, magneto rheological damper (MRD) attracts widespread attention. It can generate variable and real-time damping force by adjusting the magnetic filed strength. It is more reliable comparing with the traditional mechanical adjustable damper for it takes out the mechanic valve. The major work has been done as follows:Firstly,the working-principle and mechanical models of magneto rheological damper. Several classic mechanical models of MRD have been elaborated systemly, and adopted the amended phenomenon-mod- el which which can response the performance of the model correctly.Secondly, the train-bridge-MRD interaction system. After choose the model of MRD and simulating the model of the train vehicle on the bridge, the model with two bogies and four wheels, was established for vertical analysis. As the same time, the finite element model of the bridge and the surface roughness model were also built. Then based on the virtual work principle, the dynamical equations of the coupled train-bridge system were deduced. The equations are applicable to the system composed by vehicles with uniformed speeds and bridges with arbitrary surface roughness functions and different constraints.Thirdly, the solving and the analysis program of the train-bridge-MRD interaction system. An all-purpose program for vertical dynamic analysis of train-bridge-MRD interaction system and a program for the simulation of surface roughness were developed using FORTRAN 95. Using the dynamic analysis program of train-bridge-MRD interaction system, the dynamic properties analysis of train-bridge-MRD interaction system can be done. It is applicable to the bridge models which can be simulated by beam, truss and cable elements, and moving load and the vehicle models which can be predigested into mass-spring-damper systems. The responses of train-bridge interaction system under high-speed trains with uniformed speeds can be analyzed. Moreover it can take surface roughness and MRD into consideration.Fourthly, the solving of the opimal control force of MRD. First,the optimal control of structure under external loads is calculated by instantaneous optimal control, and the dual-threshold control algorithm of the semi-active control strategy of MR damper is built on the basis of the theory of active control, and then combined with the current state of damper; the damping force of model which will be used in the bridge to control structural vibration is calculated by control algorithm limits (semi-active control algorithm).Finally, the analysis of the vibration-reducing of the MRD to the bridge. This paper maded a new vibration-reducing model which was made of MRD and anchor. The effects of MRD were studied on vibration suppression of simply supported bridges and vehicles when high-speed trains were moving on the beam. A case study using 40-metre and 32-metre simply supported PC box beam bridges was conducted. The results show that the MRD has better effects on reducing the resonant responses of the bridge. Therefore it is suggested to apply into practice. Besides, the effect of MRD on smooth performance for railway vehicles was discussed. Through the analysis shows, MR dampers for vibration control of bridges are feasible.更多还原