【作者】 閤东东；

【导师】 朱宏平；

【作者基本信息】 华中科技大学 ， 防灾减灾工程及防护工程， 2010， 博士

【摘要】 由于人口密集、土地有限,现代城市中相邻建筑结构之间的间距可能过小,些高层建筑也可能因使用功能要求设计成多个子结构组成的主从结构。在大地震作用下,相邻建筑结构间发生碰撞的可能性很大。采用耗能减震装置来连接相邻结构,利用结构间的相互作用耗能,这样既能吸收一部分地震能量,又可以避免结构间的碰撞,因此,开展相邻结构振动控制研究具有重要的意义。本文综合应用理论分析、数值模拟验证等手段在如下几个方面进行了研究,取得了一些有价值的成果：(1)基于双体单自由度体系间Kelvin型和Maxwell型阻尼器优化参数的理论表达式,通过理论推导得出相邻多自由度结构间Kelvin型和Maxwell型阻尼器优化参数与相邻结构的第一阶自振圆频率以及总质量有关的推论。以一个过滤白噪声激励下的不同高度相邻多自由度结构模型为例,通过大量的数值分析得出了结构间Kelvin型和Maxwell型阻尼器优化参数取值,并将参数化研究结果与基于理论表达式求得的结果进行比较,发现二者吻合良好。(2)将相邻结构振动控制体系运用于带裙房双塔楼结构中。对过滤白噪声激励下大底盘双塔楼结构间阻尼器优化参数的参数化结果和理论结果进行了比较,结果表明可取两塔楼结构的第一阶自振圆频率和塔楼总重计算得到阻尼器优化参数。对相邻结构控制体系与共享调谐质量阻尼器控制体系进行了比较,结果表明前者比后者更实用。以某一实际双塔楼结构为例,通过比较确定性地震波作用下阻尼器优化参数与理论结果的差别,证明了双体单自由度体系间Kelvin型和Maxwell型阻尼器优化参数表达式的实用性。(3)对考虑结构参数和阻尼器参数变异性的相邻结构振动控制体系进行了分析。结合某利用阻尼器连接的相邻随机结构,分析了其在确定性地震波激励以及随机演变地震激励下的响应,结果证明相邻结构振动控制体系具有鲁棒性,能够有效削弱地震作用下结构的随机响应。(4)采用改进遗传算法程序包对相邻结构间阻尼器位置进行了优化设计。基于相邻多自由度结构的第一阶自振圆频率和总质量,求得了Kelvin型和Maxwell型阻尼器优化参数。对采用二进制编码的遗传算法交叉算子和变异算子进行改进,解决了确定性数目的阻尼器在相邻结构间位置优化问题。将位置优化设计后的相邻多自由度结构响应与等效的双体单自由度体系响应进行了比较,研究结果表明,对于高度相同或者不同的相邻结构,基于等效双体单自由度体系求相邻多自由度结构间Kelvin型和Maxwell型阻尼器的优化参数是可行的。(5)对近断层地震激励下相邻结构间连接的粘滞流体阻尼器性能进行了研究。采用Bouc-Wen模型模拟结构的滞回特性,并采用常规地震波(底波)与模拟近断层特性的等效速度脉冲进行叠加生成若干条近断层地震波。通过大量的参数化研究得到了合适的粘滞流体阻尼器阻尼系数。基于阻尼器的滞回曲线、最大冲程以及最大输出力,对阻尼器的特性进行了评价。数值分析结果表明,安装阻尼器后的相邻结构动力反应大大减小；在加速度峰值相同的不同近断层地震波激励下,粘滞流体阻尼器的优化阻尼系数相差不大；以目前的技术条件可以制造出满足工程要求的流体阻尼器。更多还原

【Abstract】 Buildings in a crowded city are often built closely to each other because of the limited availability of land. Some of high-rise building structures are designed to be composed of several substructures because of functional application. It is considerably possible that pounding between adjacent structures may occur. Coupled building control strategy has been shown to be an effective method of protection for adjacent structures. This application takes advantages of the interaction between neighboring structures which is expected not only to prevent the pounding problem of the adjacent structures but also to reduce seismic response of the adjacent structures. Therefore, it has great significance to study on this subject. In this dissertation, the following aspects are studied through theoretical and numerical analysis, some important results and conclusions have been achieved as follows:(1) On the basis of theoretical expressions of Kelvin model defined or Maxwell model defined damper between two single degree of freedom system. Through theoretical derivation, the results showed that the optimum parameters of Kelvin model defined and Maxwell model defined dampers between two multi degree of freedoms structures are closely relate to the first circle natural frequencies and the sum of mass of adjacent structures. A pair of parallel structures with different heights subjected to filtered white noise excitation is taken as an example. The optimal values of Kelvin model defined and Maxwell model defined damper between adjacent structures are sought by means of extensive parametric analysis. Through comparative study, it can be found that the numerical results and theory results are consistent with each other well.(2) Coupled building control strategy is applied to the twin-tower structure with large podium. Through the comparisons of theory results and numerical results for optimum parameters between twin-tower structures with large podium under filtered white noise excitation, the results show that the appropriate parameters of dampers can be computed by the first circle natural frequencies and the sum of mass of twin towers. Then, the coupled building control strategy is compared with the shared tuned mass damper (STMD) method, it can be discovered that the former is better than the latter obviously. Based on a practical twin-tower structure under actual earthquake records, the differences of optimal parameters of dampers between parametric study and theory results are evaluated, the results proved that the applicability of analytical expressions of Kelvin model defined and Maxwell model defined damper between two single degree of freedom systems.(3) Dynamic analysis is carried out to the coupled building control strategy with the consideration of the variability of structural parameters and damper parameters. On the basis of adjacent stochastic structures connected by dampers, the dynamic responses of adjacent structures subjected to actual earthquake records and non-uniformly modulated evolutionary excitation are analyzed. The results show the robustness of coupled building control strategy, and the random responses of adjacent structures are mitigated effectively.(4) An improved genetic algorithm is used to deal with the optimal design of positions of dampers between two adjacent structures. The optimal parameters of Kelvin model defined element or Maxwell model defined element between adjacent high-rise structures is obtained based on the equivalent single degree of freedom system, the first circle natural frequencies and the sum of mass of adjacent structures are taken as parameters. Crossover operator and mutation operator in the binary-coded genetic algorithm are improved, in order to solve the optimal distribution problem of damper while the number of dampers is determined. Then, the dynamic responses of two multi degree of freedom structures are compared with thoes of two equivalent single degree of freedom system, the results show that the optimum parameters of Kelvin model defined element or Maxwell model defined element between adjacent multi degree of freedom structures can be achieved based on the two equivalent single degree of freedom system.(5) The behavior of viscous fluid damper applied in coupling structures subjected to near source earthquake is studied. The structural nonlinearity is characterized by Bouc-Wen model and several near fault ground motions are simulated by the combination of a recorded earthquake (background ground motion) with equivalent velocity pulses that posses near fault features. Extensive parametric studies are carried out to find the appropriate damping coefficient. Performances of viscous fluid dampers are demonstrated by the relation between the force and displacement, the maximal damper force and stroke. The control performances are demonstrated in terms of the response reductions of adjacent structures. Results show that the dynamic responses of adjacent structures are mitigated greatly. Proper damping coefficients of connecting fluid dampers have a little difference, while adjacent structures under different near fault ground motions with the same peak acceleration. Satisfied viscous fluid dampers can be produced according to the current manufacturing skills.更多还原