自反馈控制摩擦阻尼器耗能性能研究

发布时间：2018-06-02 19:42

本文选题：振动控制 + 摩擦耗能器　；参考：《济南大学》2014年硕士论文

【摘要】：无论是机械装备还是建筑结构，在其使用或工作过程中，振动现象是不可避免的。剧烈的振动会造成结构性能下降甚至会严重破坏机械结构，造成不可挽回的重大损失。为了实现振动控制，通常是在机械设备或建筑结构中安装相应的减振耗能装置。本课题在前期研究中，结合库伦摩擦理论和控制理论设计了一种自反馈控制摩擦阻尼器。新阻尼器可以实现阻尼力的半主动控制，克服了一般摩擦阻尼器输出恒定阻尼力的缺点，不仅实现了阻尼力的可变、可调，还能根据振源信号进行阻尼力大小的控制，使得这种新型的阻尼器能够更好的发挥耗能减振作用。前期研究虽然完成了对该类新型阻尼器关键零部件的刚度和强度分析，阐述了其耗能机理。但是，这种阻尼器在实际工作过程中会产生热量，热量积存在阻尼器中就会使阻尼器的一些参数发生变化，，致使阻尼器耗能性能发生波动，产生“温移现象”。其中温度对影响阻尼器耗能性能最关键因素-初始压力-的影响最为突出。而这种影响在前期研究中没有充分考虑。因此，本文研究的重点就是对阻尼器温移现象的产生及其对阻尼器耗能性能的影响进行分析；在此基础上，对原有的阻尼器进一步改进，增设调整装置来消除温移对阻尼器耗能性能的影响。同时，为该类阻尼器应用于主动控制奠定结构基础。本文的研究内容如下：第一、基于温度影响的阻尼器结构改进设计和耗能性能机理分析。根据前期研究得到的阻尼器阻尼力理论计算公式，通过Matlab编写相应的程序进行数值模拟，为研究外载荷（载荷的振幅和频率）以及温度对阻尼器耗能性能的影响奠定基础。并且绘制出在特定载荷条件下的滞回曲线，进行分析。第二、对在温升影响下的阻尼器耗能性能进行理论研究。分析温移产生的机理、对阻尼器增压气室压力的影响，得到温度与油液压力关系的理论公式。建立阻尼器的简化模型，根据热平衡方程，对阻尼器稳定状态耗能性能进行理论分析。首次定量计算了该阻尼器的生热功率，通过计算模型各种散热功率，进而得到平衡时的温度，并对影响平衡温度的因素进行分析。利用编写的Matlab程序，修改相应的参数，计算出不同温度下阻尼器的滞回特性。第三、阻尼器耗能性能有限元仿真分析。首先对油液和增压气室系统进行仿真分析，得到增压气室作用下阻尼器内部油液压力，为后续的流固热耦合分析提供边界条件；二是对阻尼器结构工作过程中温度变化仿真分析，得到阻尼器工作过程温度变化规律和不同时刻的温度；三是将时间—温度变化结果作为边界条件加载到油液气室流体模型中，对在温度的影响下油液压力进行仿真分析，得到温度作用下油液压力的变化规律；最后是把油液压力输出结果作为阻尼器的边界条件，分析温度变化对阻尼器耗能性能的影响。第四、阻尼器耗能性能的仿真试验分析。对影响阻尼器耗能性能的因素设计正交表，用正交试验的方法分析各因素影响的显著性。进行单因素的试验分析，找到最显著因素影响的趋势，为今后的参数优化提供依据。
[Abstract]:The vibration phenomenon is inevitable in the process of use and work, whether mechanical equipment or building structure. Severe vibration can cause structural performance decline or even serious damage to mechanical structure, causing irreparable major loss. In order to realize vibration control, it is usually installed in mechanical equipment or construction structure. In the previous study, a self feedback control friction damper is designed in the previous study, which combines the friction theory and the control theory of Kulun. The new damper can realize the semi-active control of the damping force and overcome the disadvantages of the ordinary friction damper to output constant damping force. It not only realizes the variable damping force, but also can adjust the damping force, and can also base on the vibration. The source signal is controlled by the size of the damping force, which makes this new type of damper can play a better role in energy dissipation and vibration reduction. In the previous study, the stiffness and strength of the key parts of the new type dampers were analyzed, and the energy dissipation mechanism was expounded. However, this kind of damper will produce heat and heat product in the actual working process. In the presence of the damper, some parameters of the damper will change, which causes the energy dissipation of the damper to fluctuate and produce a "temperature shift phenomenon". The temperature has the most prominent effect on the influence of the initial pressure on the energy dissipation performance of the damper. The point is to analyze the temperature shift of the damper and its influence on the energy dissipation of the damper. On this basis, the original damper is further improved and the adjustment device is set up to eliminate the influence of temperature shift on the energy dissipation performance of the damper. At the same time, this kind of damper is applied to the active control to lay the foundation of the structure. The following is as follows:
First, the structure improvement design and the energy dissipation mechanism analysis based on the temperature influence are made. According to the theoretical formula of damping force of the dampers obtained in the previous study, the corresponding program is compiled by Matlab to simulate the effect of the external load (amplitude and frequency of load) and the influence of temperature on the energy dissipation performance of the damper. The hysteretic curve under specific load conditions is plotted and analyzed.
Second, the energy dissipation performance of the damper under the influence of temperature rise is theoretically studied. The mechanism of the temperature shift and the influence of the pressure on the pressure of the damper chamber are analyzed. The theoretical formula of the relationship between the temperature and the oil pressure is obtained. The simplified model of the damper is established and the energy dissipation performance of the damper is theoretically analyzed according to the heat balance equation. The heat generating power of the damper is calculated, and the temperature of the balance is obtained by calculating the heat dissipation of the model, and the factors that affect the balance temperature are analyzed. The Matlab program is used to modify the corresponding parameters and calculate the hysteresis characteristics of the damper at different temperatures.
Third, the finite element simulation analysis of dampers energy dissipation performance. First, the fluid and pressurized gas chamber system are simulated and analyzed. The fluid pressure inside the damper under the action of the pressurized gas chamber is obtained, and the boundary conditions are provided for the subsequent fluid solid thermal coupling analysis. The two is the simulation analysis of the temperature change in the work process of the damper, and the damper work is obtained. The change rule of process temperature and the temperature at different time; three is to load the time and temperature change as boundary condition into the fluid model of oil and gas chamber, to simulate the oil pressure under the influence of temperature, and get the change law of oil pressure under the effect of temperature; the most later is the output of oil pressure as the damper. The influence of temperature variation on the energy dissipation performance of dampers is analyzed.
Fourth, the simulation test and analysis of the energy dissipation performance of the damper. The orthogonal table is designed for the factors affecting the energy dissipation of the damper. The significance of the influence of each factor is analyzed by the orthogonal test method. The test analysis of the single factor is carried out to find the most significant factor influence trend and provide the basis for the optimization of the future parameters.
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB535.1

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