【作者】 杨杨；

【导师】 徐赵东； Quek Ser Tong；

【作者基本信息】 东南大学 ， 防灾减灾工程及防护工程， 2022， 博士

【摘要】 为了满足现代建筑功能多样性与外观美学的需求,建筑结构往往呈现不对称的平面布局和不规则的立面布置,从而在地震作用下产生复杂的空间扭转振动。空间扭转振动在某些情况下会成为导致建筑物倒塌的主要因素,因此有必要对地震作用下结构的空间扭转振动进行研究和控制。磁流变减震技术作为一种半主动控制技术,兼具了被动控制的可靠性和主动控制的精密性,为结构振动尤其是空间扭转振动的有效抑制提供了一个新的思路。目前,磁流变减震技术在控制结构扭转振动中的有效性已得到初步的理论与试验验证。但是磁流变智能减震技术是一个涉及多领域的交叉学科,在磁流变阻尼器的磁场特性、力学性能和力学模型等方面仍然存在诸多问题尚未解决,其在扭转不规则结构的空间扭转振动控制领域的研究与应用也不够深入。因此,本文针对磁流变减震技术及其在扭转不规则结构振动控制领域应用的关键问题,结合试验研究、理论分析和数值模拟,从磁流变阻尼器的磁场特性与力学性能、磁流变减震结构的动力分析与扭转振动控制、磁流变减震系统的控制策略与优化设计等方面展开系统研究,主要研究工作如下:(1)多段线圈磁流变阻尼器的磁场试验与分析首先,基于磁路分析和结构设计,制作了一个内置霍尔传感器的三段线圈磁流变阻尼器,得到磁流变阻尼器在不同控制电流和通电工况下内部磁感应强度的实测数据。然后,利用有限元分析得到三段线圈磁流变阻尼器的内部磁感应强度模拟值,并与磁场试验数据进行对比,验证了磁场有限元分析的准确性。最后,利用有限元分析数据,分析了三段线圈磁流变阻尼器在不同控制电流和通电工况下的磁场耦合情况,引入耦合系数考虑相邻线圈产生磁场的耦合效应,提出了描述多段线圈磁流变阻尼器内部磁场耦合效应的磁场耦合模型。(2)多段线圈磁流变阻尼器的力学性能试验首先,在磁流变阻尼器内部存在不同体积分数滞留空气的情况下进行了力学性能试验,分析了滞留空气体积以及激励特性对磁流变阻尼器“力滞”现象的影响。然后,对三段线圈磁流变阻尼器进行了不同通电工况和激励特性下的恒定电流试验,比较了不同通电工况和激励特性下磁流变阻尼器的力学性能、耗能能力与滞回特性。最后,利用研制的磁流变一体化智能控制系统,对磁流变阻尼器施加随着位移幅值变化的控制电流,研究了时变电流下磁流变阻尼器的力学性能,分析了“磁滞”现象对磁流变阻尼器力学性能的影响。(3)磁流变阻尼器的多影响因素力学模型首先,在磁场耦合模型的基础上,结合磁流变液修正微观力学模型与磁流变阻尼器的力学性能试验数据,提出了可以综合考虑磁流变液微观参数、阻尼器尺寸、激励特性和磁饱和效应的多影响因素力学模型。然后,将力学模型计算值与力学性能试验结果对比,验证了该力学模型的有效性和准确性。最后,基于提出的多影响因素力学模型,分析了磁流变液微观结构参数对磁流变阻尼器宏观力学性能的影响。(4)考虑空间扭转的磁流变减震结构协同控制首先,基于空间杆系模型,建立了同时考虑平面不对称和立面不规则的十层框架结构的数值模型。利用OpenSEES自定义新材料的功能,引入了本文提出的磁流变阻尼器的多影响因素力学模型。然后,对磁流变减震结构进行弹塑性动力分析,研究了扭转不规则结构的扭转振动特性和磁流变减震系统对空间扭转振动的控制效果。最后,基于蚁群算法,通过蚂蚁在行进过程中的路径选择和信息交换行为模拟不同磁流变阻尼器之间的协同工作,提出适用于磁流变减震系统中众多磁流变阻尼器的协同控制策略。对比了不同控制策略下磁流变减震结构的地震响应,验证了协同控制策略的有效性和优越性。(5)考虑空间扭转的磁流变减震结构综合优化分析首先,基于OpenSEES-Matlab联合仿真,考虑扭转不规则结构平动振动与扭转振动的协同控制,利用本文提出的磁流变阻尼器多影响因素力学模型和磁流变减震结构的弹塑性动力分析方法,提出了基于遗传算法对磁流变减震结构中磁流变液微观结构参数、磁流变阻尼器尺寸参数以及安装位置和数量的综合优化方法。然后,对比了优化前后磁流变减震结构的地震响应,验证了本文提出的综合优化方法的可行性。本文的主要创新点如下:(1)引入耦合系数考虑相邻线圈产生磁场的耦合效应,提出了准确描述多段线圈磁流变阻尼器内部磁场分布的磁场耦合模型。将其与磁流变液修正微观力学模型相结合,建立了能够综合考虑磁流变液微观结构参数、激励特性和磁饱和效应的多影响因素力学模型。(2)通过蚁群算法中蚂蚁的路径选择和信息交换行为模拟不同磁流变阻尼器之间的相互作用与协同工作,提出了适用于磁流变减震系统中众多磁流变阻尼器的协同控制策略。(3)以扭转不规则结构平动振动和扭转振动的协同控制为优化目标,基于遗传算法对磁流变液微观结构参数、磁流变阻尼器尺寸参数以及安装位置与数目进行优化,构建了磁流变减震结构的综合优化方法。更多还原

【Abstract】 In order to meet the requirements of functional diversity,appearance aesthetics and urban planning of modern structures,the building structures often presents asymmetric plane layout and irregular facade layout,resulting in complex spatial torsion vibrations under the action of earthquakes.Spatial torsional vibrations will even become the main factor leading to building collapse in some cases.Therefore,it is necessary to study and control the structural torsional vibrations due to seismic excitations.As a typical representative of semi-active control technology,the magnetorheological(MR)damping technology combines the effectiveness of active control and the reliability of passive control,and provides a new idea for the control of structural seismic response.The effectiveness of MR damping technology in structural torsional vibration control has also been preliminarily verified theoretically and experimentally.However,MR intelligent damping technology is an interdisciplinary subject.There are still many unresolved problems in the magnetic field characteristics,mechanical properties and mathematical models of MR dampers,and its application in the field of spatial torsional vibration control of complex structures is not enough.Therefore,aiming at the key problems of MR intelligent damping technology and its application in structural spatial torsional vibration control,combined with experimental research,theoretical analysis and numerical simulation,this study systematically studies the magnetic field distribution and mechanical properties of MR dampers,dynamic analysis and torsional vibration control of MR damped structures,cooperative control algorithm and optimization design of MR control systems.The main contents of the present work are listed as follows:(1)Internal magnetic field tests and analysis for multi-coil MR damperFirstly,a three-coil MR damper with a built-in hall sensor is fabricated based on magnetic circuit analysis and structure design,and the measured data of internal magnetic induction intensities under different excitation currents and electrify conditions are obtained.Then,the simulation value of the internal magnetic induction distribution of the three-coil MR damper is obtained by finite element analysis,and compared with the internal magnetic field test data to verify the accuracy of the magnetic field finite element analysis.Finally,using the finite element analysis data,the magnetic field coupling of the three coil MR damper under different excitation currents and electrify conditions is analyzed,and a magnetic field coupling model describing the internal magnetic field coupling effect of multi-coil MR dampers is proposed.(2)Mechanical performance tests of multi-coil MR damperFirstly,the mechanical properties of MR damper with different volume fraction of trapped air are tested,and the effects of internal air volume and excitation properties on the ‘force hysteresis’ phenomenon of MR damper are analyzed.Then,the constant current test of the three coil MR damper is carried out,and the mechanical properties of the MR damper under different power on condition combinations and different excitation properties are mainly analyzed,and then the energy dissipation capacity and hysteretic characteristics of the MR damper under different working conditions are compared.Finally,using the developed MR integrated intelligent control system,the excitation current varying with the displacement amplitude is applied to the MR damper,the mechanical properties of the MR damper under time-varying current are studied,and the influence of ‘magnetic hysteresis’ phenomenon on the mechanical properties of the MR damper is analyzed.(3)A multi-factor mathematical model of MR dampersFirstly,based on the magnetic field coupling model,combining the modified micromechanical model of MR fluid considering the uneven distribution of magnetic particles and mechanical property test data,a refined mathematical model is proposed,which can comprehensively consider the influencing factors such as micro parameters of MR fluid,damper dimensions,control current,excitation properties and magnetic saturation effect.Then,the effectiveness and accuracy of the proposed model is verified by comparisons with performance test results.Finally,based on the proposed multi-factor refined mathematical model,the influence of micro parameters of MR fluid on the macro mechanical properties of MR damper is analyzed.(4)Cooperative control of the MR damped structure considering the spatial torsional vibrationFirstly,based on the spatial member model,a 10-story complex spatial eccentric structure model considering plane asymmetry and facade irregularity is established in OPENSEES.Using the function of self-defined materials in OPENSEES,the nonlinear dynamic properties of MR damper are introduced to the structure model.Then,the elastic-plastic time history analysis of the uncontrolled structure and the structure with MR dampers under earthquake is carried out,and the torsional vibration characteristics of spatial eccentric structures and the control effect of MR dampers on torsional vibrations is analyzed.Finally,based on the ant colony algorithm that considers the interaction between different MR dampers through ant path selection and information update,a control algorithm for cooperative control of multiple MR dampers is proposed.The effectiveness and superiority of the cooperative control strategy is verified by comparing the seismic responses of the MR damped structure model with different control strategies.(5)Comprehensive optimization analysis of the MR damped structure considering the spatial torsional vibrationFirstly,considering the control of translational vibration and torsional vibration of the structure at the same time,using the multi-factor refined mathematical model proposed in this paper and the elastic-plastic time history analysis program of MR damped structures,a comprehensive optimization analysis method based on genetic algorithm for the micro-structure parameters of MR fluid,the size,installation position and number of MR dampers in the control system with multiple MR dampers is proposed.Then,the control effect of the MR control system on the structural vibration response before and after optimization is compared,and the feasibility of the comprehensive optimization design method proposed in this paper is verified.The main innovations of the present work are listed below:(1)By introducing a coupling coefficient to consider the coupling effect of magnetic field generated by adjacent coils,a magnetic field coupling model which can accurately describe the internal magnetic field distribution of multi-coil MR dampers is proposed.Combining the magnetic field coupling model with the modified micro-model of MR fluid,a mechanical model considering the micro parameters of MR fluid,excitation properties and magnetic saturation effect is proposed.(2)The path selection and information exchange behavior of ants in the ant colony algorithm are used to simulate the interaction and synergy between different MR dampers,and a cooperative control strategy of many MR dampers in the MR control system is proposed.(3)Taking the cooperative control of translational and torsional vibrations of torsional irregular structure as the optimization goal,the microstructure parameters of MR fluid,the size,installation position and number of MR dampers are optimized based on the genetic algorithm,and a comprehensive optimization design method of MR damping structure is constructed.更多还原