【作者】 翁光远；

【导师】 王社良；

【作者基本信息】 西安建筑科技大学 ， 结构工程， 2011， 博士

【摘要】 大跨空间网壳结构具有造型美观、自重轻、布置灵活等优点,从而在大型公共建筑中得到了越来越广泛的应用。然而,由于这类结构是振动周期大、阻尼小的柔性结构,对动力作用比较敏感,在地震时往往会发生较大的振动,产生较大的变形,并且随着网壳结构跨度的增大,地震动的行波效应会导致各支承点的地震激励出现较明显的差异。因此,研究大跨空间网壳结构考虑地震动多点输入下的地震响应和控制方法是十分必要的。本文分析了一大跨空间网壳结构在一致输入和多点输入下的地震响应,探讨了一致输入和多点输入下这类结构地震响应的变化规律,同时利用磁控形状记忆合金（Magnetic Shape Memory Alloy-MSMA）特殊的物理力学性能,自主研发了2种MSMA作动器以及相应的主动控制系统,设计制作了2个空间网壳模型结构并对其进行了模拟地震振动台试验,论文的主要研究工作如下:（1）以一平面直径为80m的单层球面网壳结构为算例,分析了单层球面网壳结构在一致输入下的水平、竖向运动方程及反应谱求解方法,采用ANSYS有限元软件,建立了该单层球面网壳结构的有限元分析模型,同时利用一致输入反应谱的二次组合法（CQC）,研究了该结构在水平和竖向地震作用下的杆件内力和节点位移,探讨了主要影响因素,总结了一致输入下网壳结构的地震响应规律。（2）在一致输入分析的基础上,研究了上述算例网壳结构考虑多点输入时的运动方程和多点输入反应谱分析方法,推导了基于虚拟激励原理的加速度反应谱计算公式,并对该网壳结构进行了水平和竖向多点输入下的地震响应分析,同时将一致输入和多点输入的分析结果进行比较,对比分析了水平、竖向多点输入下该网壳结构杆件内力响应和节点位移响应的变化规律,探讨了行波效应和视波速等对网壳结构地震响应的影响,为球面网壳结构考虑多点输入时的抗震设计提供了参考依据。（3）采用新型材料制备和实验力学方法,选用Ni-Mn-Ga为MSMA的主要材料成分,经过多次材料制备和材性试验,考虑磁场、温度、预加压力等多种因素的影响和相互耦合作用,分析了Ni-Mn-Ga合金不同化学成分含量对材料物理力学性能的影响,制备了物理力学性能较好的Ni₅₃Mn₂₅Ga₂₂合金材料,并对其进行了相应的磁力学性能试验,建立了Ni₅₃Mn₂₅Ga₂₂合金材料的预加压力-磁场-应变等磁力学本构模型。（4）以自主制备的Ni₅₃Mn₂₅Ga₂₂合金材料为核心元件,从磁场、磁路、预压力装置、温控装置等方面系统地分析了MSMA作动器的工作原理和构造方法,重点进行了磁路的优化与分析,经过合理构造和优化设计,自主研发了2种新型MSMA作动器,并进行了相应的磁场-作动性能试验,分析了主要影响因素和一般规律,建立了MSMA作动器的静/动力本构模型。结果表明,文中研发的MSMA作动器的动力响应频率可达200Hz以上,出力较大,能够满足结构地震响应主动控制的需要。（5）在自主研发的2种MSMA作动器的基础上,研究了主动控制系统的组成、控制原理和实现方法,设计了合理的控制策略,确定和优化了控制算法,制作了相应的控制器,集成和开发了2种MSMA主动控制系统并进行了相应的控制性能试验。结果表明,文中研发的MSMA作动器及主动控制系统均具有较好的适应性,应用其可进行网壳结构地震响应的主动控制。（6）采用不同长细比的杆件,设计制作了1个凯威特型空间网壳结构的试验模型,并利用遗传算法优化了MSMA作动器的位置和数量,进行了未设置MSMA主动控制系统和设置MSMA主动控制系统模型结构的模拟地震振动台试验,试验时分别输入正弦波、EL-Centro地震波和Taft地震波等,试验工况共20余种。结果表明,文中研发的2种MSMA作动器及主动控制系统均能很好地控制模型结构的地震响应,一般情况下其控制效果可达30%左右,说明文中研发的MSMA主动控制系统是可行有效的,具有较好的研究和应用前景。更多还原

【Abstract】 Large-span space latticed shell structures are used more and more in people’s lives for they are aesthetically appealing with layout flexibility and can satisfy the requirement of large space. However, long-span space structure is very sensitive to seismic response for they belong to the flexible structure, their vibration period is long and damping is small, they sometimes will lead to greater vibration and generate larger deformation, the structures with larger planar size are different from each fulcrum ground motion, the spatial changes of ground motion will have an important influence to seismic responses of structures, so, considering the multi-point ground motion input is very necessary.The seismic responses of large-span space latticed shell structures are calculated respectively in consensus input and multi-point input, the changing regularity of seismic responses was obtained. At the same time, with the special physical and mechanical performance, Magnetic Shape Memory Alloy （MSMA） is used to make two kinds of actuators independently, accordingly, the active control systems are exploited, two model structures is designed and made, the simulated seismic shaking table tests are carried on the two model structures. The main research works of the paper are as follows:（1） A single-layer reticulated spherical shell structure with planar diameter 80m is as an example, under vertical and horizontal consistent input; equations of motion and response spectrum are analyzed. The finite element analysis model of the single-layer reticulated spherical shell structure is established with ANSYS finite element analysis software, the rods internal force and nodal displacements of model structure under vertical and horizontal consistent input are studied by CQC of consistent input response spectrum, the major effect factors are discussed, the laws of consistent input seismic response are summarized.（2） Based on the analysis of the consensus input, equations of motion and response spectrum of multi-point input are studied, the acceleration response spectrum calculation formula is derived based on pseudo excitation method. The horizontal and the vertical seismic response of the model structure under multi-point input is conducted, at the same time, the analysis results of consistent input and multi-point input are compared, The contrastive analysis of horizontal and vertical multi-point input are conducted to reveal the changing rules of the rods internal force response and node displacement response. The influence of the traveling wave effects are discussed, it provides the reference for large-span space latticed shell structures design.（3） Using new materials preparation and experimental mechanics methods, Ni-Mn-Ga is selected as the main ingredients of MSMA material. After several times materials preparation and material performance tests, considering coupling of magnetic field, temperature and prestressing etc. factors, Ni-Mn-Ga chemical composition contents influence physical and mechanical properties of MSMA, and the influence law is analyzed. The good performance alloy materials of Ni₅₃Mn₂₅Ga₂₂ is prepared, the magnetics performance tests are done, and the magnetics constitutive models of Ni₅₃Mn₂₅Ga₂₂ alloys are established in different conditions of magnetic field, prestressing and deformation etc.（4） As the self-designed MSMA materials are core elements, the working principle and structural method of the MSMA actuators are systematically analyzed from magnetic field and magnetic circuit, prestressing device, temperature control device, etc. it put the emphasis on the magnetic circuit optimization and analysis. Through the reasonable idea and optimization design, two types of new MSMA actuators are independently researched and produced, and the corresponding field-actuator performance tests are done, the main influence factors and general rules are analyzed, the static/dynamic constitutive models of the MSMA actuators are established. The results show that the dynamic response frequency of the MSMA actuators can reach 200Hz above, and the output force is larger, it can satisfy active control needs of the earthquake response. （5） On the basis of two types of new MSMA actuators researched and developmented independently, the compositions of the active control system, control principles and realization methods are studied, the reasonable control strategy is designed, the control algorithm is planed and optimized, then, the corresponding controller is made,the two kinds of MSMA active control system is integrated and exploited, and the corresponding control performance tests are done. The results show that the MSMA actuators and active control system developed in this paper have better adaptabilities, they can actively control seismic response of shell structure.（6） Using different slenderness ratios of the rods, two experiment models of Kiah witter space reticulated shell structure are designed and made, the MSMA actuators position and number are optimized by genetic algorithm, the earthquake simulating shaking table tests of the experiment models with the MSMA active control systems and no MSMA active control systems are done, in the tests, the sine waves, EL-centro seismic waves and Taft seismic waves are respectively input, more than 20 kinds of experimental conditions are completed. The results indicate that the two MSMA actuators and active control systems can well control seismic responses of the model structures, usually the control effects can reach 30%, it is shows that the MSMA active control systems are feasible and efficient, they have good researching value and application prospect.更多还原