基于磁流变弹性体的动力吸振器设计及性能研究

发布时间：2018-08-31 10:04

【摘要】：动力吸振器由于结构简单、性能稳定、经济性好，在机械系统、工程结构、桥梁及建筑等振动控制领域中得到了一定应用。然而传统动力吸振器只有当固有频率等于激振频率时，减振效果才明显，不适用于宽频减振。针对上述问题，近年来许多学者对自适应动力吸振器进行了广泛研究。自适应动力吸振器通过调整自身结构参数改变固有频率以追踪外界激振频率，可以有效拓宽吸振器减振频带，克服了传统动力吸振器的缺点。磁流变弹性体（MRE）是一种新型智能材料，，其典型特征是剪切模量可控。本论文研究了一种基于磁流变弹性体的自适应动力吸振器，通过调节磁场强度来改变其刚度，可以在较宽频带内抑制主系统振动。本论文研究内容如下：（1）通过对吸振器主系统构成的二自由度系统进行动力学建模及分析，研究了动力吸振器工作原理。利用MATLAB/Simulink分析了结构参数对吸振器减振效果的影响，并研究了吸振器设计理论和结构参数优化理论。（2）介绍了MRE研究现状、组成原料、制备过程和结构特征等。讨论了基体材料、磁性颗粒和添加剂等对弹性体磁流变效应的影响，并分析了磁流变弹性体的剪切模量和应力应变之间的关系。（3）依据磁流变弹性体各向同性、各向异性以及工作模式的特点，确定本论文采用流体状态制备工艺制备各向异性磁流变弹性体，并以磁流变弹性的剪切模式完成了自适应动力吸振器的设计。（4）基于MATLAB/Simulink建立了动力吸振器仿真模型，分别在频域和时域对吸振器减振性能进行了分析。利用设计的MRE自适应动力吸振器，搭建实验台进行实验研究。实验中，通过控制电流以改变磁场大小，进而改变吸振器刚度，实现对吸振器固有频率的调节。做出了在不同电流下主系统振动的频域和时域响应。通过对响应的分析，证明了所设计的吸振器拓宽了减振频带，达到了预期设计的目的。
[Abstract]:Because of its simple structure, stable performance and good economy, the dynamic vibration absorber has been applied in mechanical systems, engineering structures, bridges and buildings. However, the traditional dynamic vibration absorber only when the natural frequency is equal to the exciting frequency, the effect of vibration absorption is obvious, so it is not suitable for broadband vibration reduction. In view of the above problems, many scholars have carried out extensive research on adaptive dynamic vibration absorbers in recent years. The adaptive dynamic vibration absorber can effectively widen the frequency band of vibration absorber by adjusting its structural parameters to change the natural frequency to track the external excitation frequency and overcome the shortcomings of the traditional dynamic vibration absorber. Magnetorheological elastomer (MRE) is a new type of smart material, which is characterized by controllable shear modulus. In this paper, an adaptive dynamic vibration absorber based on magnetorheological elastomer is studied. By adjusting the intensity of magnetic field to change its stiffness, the vibration of the main system can be restrained in a wide band. The main contents of this thesis are as follows: (1) the working principle of the dynamic vibration absorber is studied by dynamic modeling and analysis of the two-degree-of-freedom system composed of the main system of the vibration absorber. The influence of structure parameters on vibration absorber is analyzed by MATLAB/Simulink, and the design theory and optimization theory of structure parameters are studied. (2) the research status of MRE, composition of raw materials, preparation process and structural characteristics are introduced. The effects of matrix materials, magnetic particles and additives on the magneto-rheological effect of elastomer are discussed, and the relationship between shear modulus and stress strain of magneto-rheological elastomer is analyzed. (3) according to the isotropy of magneto-rheological elastomer, The anisotropy and the characteristics of the working mode are determined in this paper to prepare the anisotropic magneto-rheological elastomer by using the fluid state preparation process. The design of adaptive dynamic vibration absorber is completed with the shear mode of magnetorheological elasticity. (4) the simulation model of dynamic vibration absorber based on MATLAB/Simulink is established, and the performance of vibration absorber is analyzed in frequency domain and time domain respectively. Using the designed MRE adaptive dynamic vibration absorber, the experimental platform is built for experimental research. In the experiment, the natural frequency of the absorber can be adjusted by controlling the current to change the magnetic field and then changing the stiffness of the absorber. The frequency and time domain responses of the main system vibration at different currents are obtained. Through the analysis of the response, it is proved that the designed vibration absorber widens the frequency band of vibration absorption and achieves the purpose of expected design.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB535.1

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