变摩擦TMD机理及其减震控制研究

Recently,earthquakes occur frequently at home and abroad.It is impressive to research and development cheap and effective devices for seismic control. The excellent control effectiveness of TMD for wind-induced vibration is unanimous recognized. As for seismic control of TMD, there is no coincident conclusion theoretically. There is no report on buildings using TMD for seismic control. To reduce the cost of TMD, some researchers have proposed to use friction dampers in TMD instead of traditional oil dampers. Nevertheless, invariable friction dampers is nonlinear and has a hysteretic curve of approximately rectangular, which makes it difficult to design TMD. In addition, previous study showed that the control effectiveness of invariable friction TMD is influenced by the level of excitation. In this project, a new type of variable friction damper is proposed and used in TMD (refered as variable friction TMD). Variable friction damper can provide pseudo-viscous damping, which not only make the design of TMD becomes easy but also makes the control effectiveness of TMD independent of the excitation level.Together with the low cost, variable friction TMD is advantageous in popularization. The structural design of variable friction damper will be studied firstly. Based on harmonic balance theory and performance test, the performance and parameter setting of damper and variable friction TMD will be studied. The simple design method of variable friction TMD will be proposed. The seismic control law and effectiveness of variable friction TMD for SDOF structures will be studied based on the concept of response spectrum. Shaking Table Test will be carried out to verify the theoretical results.The problems of closely spaced models and modal contamination in MTMD-structure systems will be studied based on complex mode theory. Simple and suit design method of MTMD will be proposed. The seismic control of TMD/MTMD for actual structure will be studied by virture of ANSYS. The anticipated results of this project is hopeful to promote the popularization and application of tuned mass dampers.

近年来国内外地震频发，价廉高效之减震装置亟待研究。TMD风振控制得到一致认可，关于其地震控制，尚无一致结论，更无应用报道。为降低TMD造价,有学者提出用摩擦阻尼器代替油阻尼器。但常摩擦阻尼器的滞回特性使TMD设计困难，且有研究表明常摩擦TMD的控制效果受荷载大小影响。本项目提出变摩擦系数式变摩擦阻尼器，将其用于TMD（称为变摩擦TMD）。变摩擦TMD设计简单，效果稳定，加之造价低廉, 极具推广应用优势。本项目拟先研制变摩擦阻尼器，基于谐波理论和性能试验,研究阻尼器和TMD性能与参数设置,给出变摩擦TMD简化设计方法。借助反应谱概念研究变摩擦TMD对单自由度结构的地震控制规律与效果，并通过实验验证。基于复模态理论研究MTMD-结构体系模态污染问题，探讨实用的MTMD设计方法。借助ANSYS软件，研究TMD/MTMD对实际结构的地震控制效果。预期研究成果有望推进TMD的普及应用。

常规油阻尼TMD造价高，维护困难。采用摩擦阻尼器代替油阻尼器，能大大降低TMD的造价和维护成本，但常摩擦TMD采用摩擦力不可变的常摩擦阻尼器，控制效果受外激励大小的影响，设计时摩擦力的选择也较为困难。本项目针对常规油阻尼TMD和常摩擦TMD的上述问题，研究了一种采用变摩擦阻尼器的TMD，称为变摩擦TMD。变摩擦阻尼器采用变摩擦系数的方式实现了摩擦力随阻尼器位移的增大而线性增大，变摩擦TMD在结构受到较小激励时即可启动发挥减振作用，当结构遭遇罕见大荷载时，也能保持较好的控制效果，加之设计简单，造价低廉，具有推广应用的优势。本项目研究主要取得了以下成果：1）给出了变摩擦系数式变摩擦阻尼器的理论模型，即摩擦力大小与阻尼器位移绝对值成正比，摩擦力方向与速度方向相反，基于谐波理论研究了变摩擦阻尼器的滞回特性，给出了变摩擦阻尼器的等效线性化模型；2）设计了变摩擦系数式变摩擦阻尼器，通过性能试验研究了变摩擦阻尼器的滞回性能，通过与理论模型的对比，修正了理论模型，改进了阻尼器的设计；3）基于谐波理论，通过非线性数值分析研究了变摩擦TMD系统的动力特性，参数设计。基于变摩擦阻尼器的等效线性化模型，给出了变摩擦TMD的简化设计方法；4）采用非线性数值分析方法研究了变摩擦TMD对单自由度结构的地震控制规律与效果；5）通过振动台实验，研究了变摩擦TMD对单自由度结构的控制效果；6）提出了采用带质量块的悬臂结构对多自由度的高层建筑进行振动控制，并建议将压电获能技术与TMD集合，达到收集、转化并利用结构振动能量的目的。本项目的研究成果有望推进TMD的普及应用。