表观质量阻尼器的被动负刚度阻尼特性及其提升连续梁减震性能的研究

Apparent mass damper is a new type of passive damper that can produce effects of damping and appended mass being thousands times of its original mass level, which has been given great attentions in Japan. In the project the characteristics of negative stiffness and high damping of the apparent mass damper and its performance improvement for seismic control of continuous bridges will be studied by theory analysis, numerical simulations and model experiments. The main contents will be as follows: 1) By investigating the coupling effect between apparent mass, spring and damping of the apparent mass damper, production mechanism and evolvement rules of its effects of negative stiffness and high damping will be revealed; 2) Developing the simplified model of the seismic control system of regular continuous bridge, relation expressions between the structural equivalent damping ratio, objective norms of key response values and model parameters will be resolved, and the mechanisms to control the internal force and displacement of the bridge seismic responses simultaneously and substantially by using the apparent mass damper will be uncovered; 3) The two-stage optimization method based on the active control force and global optimization theory based on the performance objective function will be studied, by which the passive control theory using the apparent mass dampers will be developed for the seismic control of complicated continuous bridges, then great performance and robustness for the seismic control of the continuous bridges by using the apparent mass dampers will be investigated by considering various dynamical characteristics of the bridges and bearings, and characteristics of earthquake ground motions. The research achievements will provide promotion and demonstration role for the studies and engineering applications of seismic control systems using the apparent mass damper in our country.

表观质量阻尼器是一种新型的被动式阻尼器，它可对受控结构产生比阻尼器本身质量大上千倍的附加质量和阻尼效应，近年来在日本得到高度重视。本项目将结合理论分析、仿真计算和模型试验，开展表观质量阻尼器的负刚度和高阻尼特性,及其提升连续梁桥减震性能的研究。主要内容包括：（1）探究联合弹簧作用的表观质量阻尼器元件的耦合作用，揭示其负刚度和高阻尼效应的产生机理和演化规律；（2）建立规则连续梁桥减震体系的简化模型，求解结构等效阻尼比和关键响应值目标范数与模型参数的关系式，揭示表观质量阻尼器对梁桥内力和位移的同步大幅减震机制；（3）研究基于主动控制力的二阶段优化法，和基于性能目标函数的整体优化法，建立表观质量阻尼器对复杂连续梁桥减震的被动控制理论，探求在不同桥梁与支座动力特性以及地震动特征时，表观质量阻尼器对连续梁桥减震的强健性。研究成果对我国表观质量阻尼器减震体系的研究和应用具有推动和示范作用。

调谐惯质类阻尼器（TIBD）能有效利用调谐效应和放大上千倍的惯质质量，来实现结构减震，近来备受关注。目前，对安装在单自由度结构上的TIBD的参数优化和减振效果进行了较多研究，但对TIBD实现结构减振的机制尚未较好地阐述；对多个TIBD应用于多自由度结构减震时的参数优化和减震分析仍有待深入开展。本项目就TIBD实现多自由度结构（特别是连续梁桥）的减震问题，建立TIBD单体力学模型，推导了其为结构提供等效刚度与和等效阻尼比的解析表达式，通过分析对结构阻尼贡献和刚度的影响阐明了高效减震的机制；建立了规则梁桥的双自由度简化模型，实现TIBD的参数优化并验证了TIBD减震机理，揭示了TIBD参数与模型参数变化对减震效果的影响；用复特征值方法实现了TIBD的优化设计，阐明了安装TIBD后减震系统特征参数的演变，指出优化后的减震结构的模态阻尼比近乎达到TID阻尼元件阻尼比的一半——这一评价减震效果的重要结论；以H2范数与模态分析的有机结合，提出了包括外激励影响的TIBD位置优化配置的H2范数指标，评估和确立TIBD的优化位置和数量； 推导了以H2范数为目标的优化梯度，高效实现了安装多个位置且对多阶模态调谐的用于多自由度结构减震的TIBD的优化设计；建立了多自由度结构受随机地震动激励时实现多TID减震时的整体优化设计方法，实现了对TIDs的频率、阻尼比和惯质质量的三元参数的整体优化，给出了其进一步提升TIDs减震效果的机理；建立不规则连续梁桥的精细模型建模，针对不规则连续梁桥纵、横向减震时的典型状态，采用H2控制理论实现了TVMD的安装位置、控制模型和多模态控制的参数同步优化，就连续梁桥的稳态谐振响应以及不同谱特性的地震波输入时的地震响应开展减震分析，阐明了TVMD的高效性能；完成了不同惯质质量的电涡流阻尼器试制，对不同装置参数设计及不同激振状态下的性能进行了测试，并对安装弹簧后的调谐惯质阻尼器进行试制和调试，初步进行了单体性能和模型试验。以上相关成果将为TIBD在土木结构上的应用起到推动作用。