单面碰撞式调谐质量阻尼器结构减振理论与试验研究

Recently, the pounding damping mechanism employing viscoelastic materials, which can enhance the energy dissipation efficiency of the conventional impact damping mechanism, becomes a novel and promising energy dissipation method in vibration control of civil engineering structures. The applicant has proposed a novel single side pounding tuned mass damper (SS-PTMD) based on pounding damping from viscoelastic materials to mitigate excessive vibrations. The SS-PTMD consists of a mass block, a spring and a pounding boundary covered by viscoelastic materials. The SS-PTMD can absorb the vibration energy from the primary structure utilizing the tuning effect, and efficiently dissipate the energy from viscoelastic poundings when the maximum relative velocity between the mass block and the primary structure is achieved. The following studies on the SS-PTMD will be covered in this project: The trends on the energy dissipation respectively from viscous damping and residual deformation under various pounding conditions will be summarized, and the energy dissipation mechanism will be explored. An accurate pounding force model, which can precisely describe the pounding force, the pounding duration and the residual deformation, will be proposed. The dynamic properties of the SS-PTMD will be studied, and the accurate expressions of frequency and equivalent damping ratio of the SS-PTMD will be obtained. Considering the spectral characteristics of external loadings, the optimization objective and high-efficient optimization algorithm will be determined. Moreover, the deign formulas, which are easily applicable to engineering practices, will be proposed. The numerical simulations and experimental studies to evaluate the control performance of the SS-PTMD will be conducted under free vibration, harmonic loadings and the broadband loadings. The structural control theory and technology of the SS-PTMD will be proposed and enhanced based on the research results of the project, which may have a promising future in controlling of civil structures under wind-induced, human-induced and seismically-excited vibrations.

粘弹性碰撞耗能是近年土木工程领域兴起的新型耗能减振方式，能有效提升传统碰撞耗能效率。申请人提出了一种单面碰撞式调谐质量阻尼器（SS-PTMD），该阻尼器由质量块、弹簧和覆盖有粘弹性材料的碰撞挡板组成，其减振机理为：通过调谐效应将主结构振动能量转移给SS-PTMD，在SS-PTMD质量块与主结构相对速度最大时进行碰撞耗能并实现结构减振。本项目研究包括：总结粘弹性材料碰撞中粘滞阻尼耗能和残余变形耗能变化规律，探究其碰撞耗能机理，提出准确描述碰撞时间及残余变形的碰撞力精细化模型；研究SS-PTMD动力特性，提出其精确固有频率和等效阻尼比表达式；考虑外荷载频谱特征，确定参数优化目标和高效优化算法，提出简化设计公式；开展仿真与试验研究，评估在自由振动、简谐激励及宽频荷载激励下的SS-PTMD减振性能。研究成果将形成SS-PTMD结构减振理论与技术，对风振、人致振动及地震等的控制均具有广阔应用前景。

大幅的结构振动危及自身结构安全，并降低其使用舒适性。研究结构振动控制技术对于确保结构在重大自然动力灾害下的安全与服役功能具有重要意义。摆式调谐质量阻尼器（PTMD）是目前常用于高耸结构的振动控制手段，然而其存在控制频带窄，对设计参数敏感等不足之处，且在实际工程中，其在摆质底部连接阻尼的工艺，使PTMD的安装尤为困难。本项目提出一种摆式碰撞型双重调谐质量阻尼器（PPDTMD），其将PTMD与碰撞阻尼机制相结合，将碰撞耗能装置设计于摆质内部，不仅简化了PTMD的设计与安装，取消了传统PTMD中在摆质底部外接阻尼器的设计，且由于碰撞耗能系统中第二重调谐机制的存在，使该新式阻尼器的减振性能拥有大幅提升，此外，与碰撞型调谐质量阻尼器相比，PPDTMD因碰撞元素仅存于摆质中，受控结构运动过程中并未因碰撞而产生加速度突变响应。为验证PPDTMD的减振性能，本项目通过理论推导、数值分析与减振试验多方面对其进行研究，主要内容包括：（1）对当前常用碰撞力模型进行了分析比较，针对本项目研究性质与要求，选择其中适用于本文研究的模型，并将其运用于滚动碰撞体系中，最终与PTMD结构相结合，形成PPDTMD系统；开展了自由碰撞试验对碰撞耗能机理进行研究，并验证了碰撞力模型的适用性；（2）推导多自由结构与PPDTMD耦合系统运动方程，通过单自由度-PPDTMD系统，基于H∞优化准则对PPDTMD的参数进行优化设计，以某自立桥塔为研究背景，通过简谐、地震、风等荷载多方面对PPDTMD的实际工程减振性能进行数值分析；（3）制作了三层框架结构与PPDTMD样机，通过PPDTMD减振测试以及鲁棒性测试试验，对PPDTMD的减振性能进行试验验证。研究结果表明，PPDTMD能有效减小结构的动力响应，且加装PPDTMD后结构的耗能能力有了显著提升，为柔性结构大幅振动提供了一种先进、经济、简洁的控制手段。研究成果共发表高水平论文9篇，授权发明专利5项，形成了PPDTMD结构减振理论与技术，在柔性结构振动控制领域具有广阔应用前景。