基于半主动模糊控制的MR阻尼器结构减振数值模拟

发布时间：2018-12-24 16:25

【摘要】：建筑结构在地震状态下的抗震设计不应仅局限在研究材料来提高抗震性能上,还应以更主动的手段进行抗震设计。但地震激励的精确值以及建筑结构的精确模型在目前的科技手段下尚无法求得,因此需要建立一个不依赖于精确模型的控制手段以削弱结构的地震响应。模糊控制是解决此种问题的有效途径,它能模拟人类大脑的思维方式,仅对事先以专家经验为基础的输入和输出变量进行控制。因而模糊控制不需要受控结构的精确模型,只需要结合适当的作动器便能发挥较好的控制效果。在地震时将阻尼器作为一种作动器输出控制力改变原结构的刚度和阻尼是一种切实有效且相对低成本的积极抗震方法。磁流变液(MRF)作为发展了几十年的智能材料,由此衍生的磁流变液(MR)阻尼器因其具有快响应功耗低、连续可调的大阻尼力等优点广泛应用于结构的减振的各领域中。但MR阻尼器的动力学模型有很强的非线性,建立合适的MR阻尼器本构模型以及有效的控制策略是一项关键技术。本文采用的半主动控制法兼具了主动控制控制效果强和被动控制造价低廉、设置简单的优点,结合MR阻尼器以及模糊控制便能显著的降低建筑结构的地震响应。因此本文主要研究的内容如下:1、分析了半主动控制与其他控制方法的利弊,阐述MR阻尼器的本构关系选取的原则、模糊控制器的设计时的关键原则、算例的建模仿真流程。2、在MATLAB软件中Simulink平台设计并编写了一个基于Bouc-Wen型的普通剪阀式MR阻尼器程序并用于第五章的仿真算例中。3、在MATLAB软件中的原始界面下(m文件)和Simulink平台分别设计了含有梯形隶属函数和高斯型隶属函数的模糊控制器、编制了半主动控制下的模糊减振规则库并用于第五章的仿真算例中。由受控结果可知,当内积相近时,不同隶属函数对模糊控制的控制效果影响不大。4、为了仿真算例,文中建立了一个三层钢框架的状态方程,并将其输入至Simulink平台内的算例仿真模型状态空间中,结合所设计的不同种模糊控制器,采用Wilson-θ时程分析法在天然地震波的激励下,对比受控结构的各项动力参数峰值及峰值控制率。结论是该半主动控制系统的减振效果良好,能实时而高效的控制结构振动响应,具有一定的工程实践意义和参考价值。
[Abstract]:The seismic design of building structures under earthquake should not only be limited to the study of materials to improve seismic performance, but also should be carried out by more active means. However, the exact value of earthquake excitation and the exact model of building structure can not be obtained under the present scientific and technological means, so it is necessary to establish a control method independent of the exact model to weaken the seismic response of the structure. Fuzzy control is an effective way to solve this problem. It can simulate the thinking mode of human brain and only control the input and output variables based on expert experience in advance. Therefore, fuzzy control does not need the precise model of controlled structure, but only needs a proper actuator to play a better control effect. It is an effective and relatively low cost active seismic method to change the stiffness and damping of the original structure by using the damper as an actuator output control force to change the stiffness and damping of the original structure during the earthquake. Magnetorheological fluid (MRF) has been developed as a smart material for decades. The derived MRF (MR) damper has been widely used in various fields of structural vibration reduction due to its advantages of fast response low power consumption and continuous adjustable large damping force. However, the dynamic model of MR damper has strong nonlinearity. It is a key technology to establish an appropriate constitutive model of MR damper and effective control strategy. The semi-active control method adopted in this paper has the advantages of strong active control effect, low cost of passive control and simple setting. Combined with MR damper and fuzzy control, the seismic response of building structure can be significantly reduced. Therefore, the main contents of this paper are as follows: 1. The advantages and disadvantages of semi-active control and other control methods are analyzed, and the principle of selecting constitutive relation of MR damper and the key principle of fuzzy controller design are expounded. 2. The flow of modeling and simulation. 2. In the MATLAB software, the Simulink platform has designed and written a general shearing valve MR damper program based on Bouc-Wen and used in the fifth chapter of the simulation example. 3. A fuzzy controller with trapezoid membership function and Gao Si membership function is designed under the original interface (m file) and Simulink platform of MATLAB software. A fuzzy vibration reduction rule base under semi-active control is developed and applied to the simulation example in chapter 5. According to the controlled results, when the inner product is close, different membership functions have little effect on the control effect of fuzzy control. In order to simulate an example, a state equation of a three-layer steel frame is established in this paper. It is inputted into the state space of the simulation model of Simulink platform, combined with the different fuzzy controllers designed, and the Wilson- 胃 time-history analysis method is used under the excitation of natural seismic wave. The peak value and peak control rate of each dynamic parameter of the controlled structure are compared. The conclusion is that the semi-active control system has good damping effect and can control the vibration response of the structure in real time and efficiently. It has certain engineering practical significance and reference value.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU352.1

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