变频减振器—梁桥耦合系统的动力学行为和功率流特性

发布时间：2018-03-29 04:19

本文选题：车桥耦合系统　切入点：移动弹簧质量　出处：《石家庄铁道大学》2015年硕士论文

【摘要】：近年来,车桥耦合系统在交通、土木、机械工程领域始终是热点课题之一。当车辆的振动频率和桥梁的固有频率相等或接近时,会产生共振,直接影响车辆和梁桥的使用寿命和工作状态。因此,车桥耦合系统的减振问题具有重要地位。事实上,移动载荷的不同会导致车桥耦合系统的频率也随之发生变化。因此,构建一种新型的变频非线性减振器成为科学与工程研究亟待解决的课题。SD(光滑不连续)振子的频率依赖于光滑参数的变化而变化。本文在SD(光滑不连续)振子的基础上构建变频减振器,研究变频减振器(SD振子)—梁桥耦合系统的动力学行为和功率流特性。本文具体内容如下:第一章,介绍文章选题的背景与意义,综述国内外动力减振装置、SD振子和功率流理论及应用的相关研究和存在的问题。第二章,研究由减振器和轴向载荷作用下的梁桥组成的两自由度耦合系统。首先,建立了系统的运动方程,并利用伽辽金离散得到无量纲化方程。然后,利用谐波平衡法得到振动系统功率流的表达式。最后,通过数值模拟研究了各参数对减振效果的影响规律。结果显示SD减振器可以时而充当线性减振器时而充当非线性减振器,通过调节光滑参数来达到理想的减振效果。第三章,研究由移动弹簧质量、减振器和轴向载荷作用梁桥组成的三自由度耦合系统。首先,利用可以表示出系统无限长时间内运动状态的函数建立系统运动方程,并得到系统运动的无量纲方程。然后,用多自由度系统的平均法得到系统稳态运动时的幅频响应函数,并给出系统功率流的表达式。最后,通过数值模拟发现:裸梁具有复杂的动力学行为,有周期、概周期和混沌运动,出现了分岔现象,而车桥—SD减振器耦合系统的功率流曲线平滑,达到了抑制混沌的目的,并且调节SD减振器参数具有减振效果。第四章,研究等间隔的载荷作用下梁桥的SD减振两自由度系统。首先建立系统的振动方程。然后用Melnikov方法得到系统发生混沌的条件,运用平均法得到系统的幅频响应函数,并给出系统功率流的表达式。最后,利用Matlab进行数值模拟,发现裸梁有丰富的动力学现象,而车桥—SD减振器耦合系统的功率流曲线平滑,具有抑制混沌的作用,并且调节SD减振器参数达到了减振效果。第五章,总结全文的主要成果和创新点,指出研究车桥耦合系统存在的问题及今后的研究方向。
[Abstract]:In recent years, the vehicle-bridge coupling system has always been one of the hot topics in the field of traffic, civil engineering and mechanical engineering. When the vibration frequency of the vehicle is equal to or close to the natural frequency of the bridge, it will produce resonance. Therefore, the vibration reduction problem of vehicle-bridge coupling system plays an important role. In fact, the difference of moving load will cause the frequency of vehicle-bridge coupling system to change. Constructing a new type of frequency conversion nonlinear vibration absorber has become an urgent task for scientific and engineering research. The frequency of SD-oscillator depends on the variation of smooth parameters. In this paper, the frequency of SD-discontinuous oscillator is studied. Based on the construction of frequency conversion absorber, The dynamic behavior and power flow characteristics of the coupling system of SD vibrator and beam bridge are studied. The main contents of this paper are as follows: chapter 1, the background and significance of the selected topic are introduced. This paper summarizes the relevant research and existing problems in the theory and application of SD vibrator and power flow of dynamic vibration absorber at home and abroad. Chapter 2, the coupling system of two degrees of freedom composed of shock absorber and beam bridge under axial load is studied. The equations of motion of the system are established, and the dimensionless equations are obtained by Galerkin discretization. Then, the expressions of the power flow of the vibration system are obtained by using the harmonic balance method. The results show that SD absorber can act as linear shock absorber and nonlinear shock absorber at the same time, and achieve ideal damping effect by adjusting smooth parameters. A three degree of freedom coupling system consisting of moving spring mass, shock absorber and axial load acting beam bridge is studied. Firstly, the system motion equation is established by using the function which can express the motion state of the system for an infinite time. The dimensionless equation of the system motion is obtained. Then, the amplitude-frequency response function of the system is obtained by using the averaging method of the multi-degree-of-freedom system, and the expression of the power flow of the system is given. By numerical simulation, it is found that the bare beam has complex dynamic behavior, periodic, almost periodic and chaotic motion, and the bifurcation occurs, while the power flow curve of the vehicle-bridge / SD damper coupling system is smooth, and the purpose of suppressing chaos is achieved. And adjusting the parameters of SD absorber has the effect of damping vibration. In chapter 4, the two-degree-of-freedom system of beam bridge under the action of equal interval load is studied. First, the vibration equation of the system is established, and then the condition of chaos in the system is obtained by using Melnikov method. The amplitude-frequency response function of the system is obtained by using the averaging method, and the expression of the power flow of the system is given. Finally, numerical simulation with Matlab is carried out, and it is found that there are abundant dynamic phenomena in the bare beam, while the power flow curve of the vehicle-bridge / SD damper coupling system is smooth. It has the function of suppressing chaos and adjusting the parameters of SD absorber to achieve the effect of vibration reduction. Chapter 5 summarizes the main achievements and innovations of this paper and points out the problems existing in the study of vehicle-bridge coupling system and the future research direction.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.3

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