【作者】 张挣鑫；

【导师】 黄方林；

【作者基本信息】 中南大学 ， 土木工程， 2013， 博士

【摘要】 斜拉索作为斜拉桥的主要受力构件,具有小质量、低阻尼、大柔度等特点,极易在风、风雨、桥面振动等外部激励下发生大幅振动,如涡激共振、尾流驰振、参数共振和风雨振等。拉索的大幅振动一方面会引起拉索的疲劳破坏,对拉索的使用寿命和桥梁安全运营构成很大威胁；另一方面,拉索大幅振动会引起人对桥梁安全性的怀疑。因此,准确分析拉索振动机理及特性,特别是对振幅可达数米的拉索参数振动,寻求其有效振动控制措施具有重要学术意义和工程应用价值。本文以在设计阶段的贵州红水河混合梁特大斜拉桥(213+508+185m)为工程背景,对基于MR阻尼器的斜拉桥拉索参数振动的半主动控制、MR阻尼器优化布置等问题进行了深入研究,主要研究内容和取得的研究成果如下：1.总结了已有MR阻尼器力学模型,依据RD-1097型MR阻尼器的实验数据,提出了一种新的MR阻尼器力学模型——非线性Bingham滞回模型,该模型能从物理意义上反映MR阻尼器阻尼与速度的滞回特性,并能很好地反映低速时MR阻尼器阻尼力与速度之间的关系。对提出的新模型在ANSYS中的数值分析进行了研究,采用大型通用有限元软件ANSYS中的COMBIN37单元实现了对非线性Bingham滞回模型的模拟；2.从理论计算和ANSYS数值模拟两方面分析了考虑垂度效应的斜拉索振动特性和端部轴向简谐激励下的拉索非线性参数振动特性。采用ANSYS对拉索在端部轴向简谐位移激励下振动进行了瞬态动力学分析,并与理论计算结果进行了分析对比,为斜拉索-MR阻尼器系统在端部轴向简谐位移激励下斜拉索主共振和参数共振振动控制的研究奠定了基础；3.采用ANSYS对斜拉索-MR阻尼器系统端部轴向周期激励下引起的拉索主共振和参数共振下的被动控制进行了研究,编制了斜拉索-MR阻尼器系统振动控制的APDL程序,分析了Passive-off(OV)和Passive-on(2.5V)、不同激励幅值、阻尼器安装位置、阻尼器间安装角度对斜拉索主共振和参数共振振动控制的影响；4.基于模糊逻辑理论,提出了斜拉索-MR阻尼器系统主共振与参数共振振动控制的一般模糊半主动控制策略,编制了斜拉索-MR阻尼器系统一般模糊半主动控制的APDL程序,并与被动控制进行了对比分析,所提出的模糊半主动控制策略控制效果优于被动控制效果,且采用模糊控制器控制MR阻尼器的输入电压,简单实用；5.基于一般模糊半主动控制策略,提出了改进的半主动控制策略。引入量化因子模糊控制器,根据拉索振动状态自适应调整量化因子,大大简化了模糊半主动控制中通过大量尝试以确定输入、输出变量的基本论域以及相应的量化因子的过程。与一般模糊半主动控制对比分析结果表明：改进的模糊半主动控制策略的效果稍优于一般模糊控制策略效果,且更简便和智能,提高了控制效率；6.对八种不同工况下斜拉索参数共振的振动控制进行MR阻尼器的优化布置研究,提出了斜拉索-MR阻尼器系统MR阻尼器优化布置方法。建立多目标函数,基于MATLAB平台和ANSYS软件编制了MR阻尼器优化布置程序,采用遗传算法进行优化求解。结果表明,提出的MR阻尼器优化布置的方法可行、有效。研究结果为红水河混合梁特大斜拉桥拉索抑振提供了依据。更多还原

【Abstract】 As main supporting components of cable-stayed bridges, cables with small mass, low damping and large flexibility are easy to induce large amplitude vibration in wind, rain and excitation vibration of deck and other external excitations etc., such as vortex-excited resonance, wake galloping, parametric resonance and rain-wind induced vibration. On one hand, large amplitude vibration can cause fatigue failure of cables which threats service life of cables and safe operation of a bridge; on the other hand, large amplitude vibration induces the suspicion of the safety of a bridge. Therefore, the accurate analysis of cable vibration mechanism and characteristics, especially for cable parameter vibration with amplitude of several meters, has important academic significance and engineering application value to seek the effective vibration control measures.Taking the Guizhou Hongshuihe hybrid girder supermajor cable-stayed bridge with213+508+185meters spans in design stage as the engineering background, the issues of semi-active parameter vibration control of cables based on MR damper (MRD) and the optimized placement of MRD are investigated deeply. The main research contents and results are summarized as follows:1. The present MRD dynamic models were summarized. Based on the experimental data of the RD-1097MRD and analysis, a new dynamic model, nonlinear Bingham hysteresis model, which can not only reflect the hysteretic characteristics between the damper and velocity of MRD physically, but also can better reflect the new mechanical model in low speed, was proposed. The new model in the ANSYS numeric analysis was studied and the simulation of nonlinear Bingham hysteresis model was realized by using COMBIN37element in the finite element software ANSYS.2. The natural vibration characteristics of the stay cables including sag effect and the non-linear parameter vibration characteristics of the stay cables under the end axial periodic excitation were analyzed through theoretical calculation and numerical simulation by ANSYS. Transient dynamic analysis was carried out on the vibration of the stay cables under the end axial periodic excitation by ANSYS, and results of ANSYS analysis were compared with those theoretical results, which laid a foundation for study on the primary resonance and the parameter resonance control of the stay cables under the end axial periodic excitation.3. The study on the passive control of cable-MRD system under the primary and parameter resonance induced by the end axial periodic excitation was carried out by ANSYS software. The APDL programs of vibration control of cable-MRD system were compiled. Meanwhile, the effects on vibration control with primary and parametric resonance of stay cables at different conditions, including passive-off (OV) and Passive-on (2.5V), excitation amplitudes, the installation position and the installation angles, were investigated.4. Based on fuzzy logic theory, a fuzzy semi-active control strategy of vibration control of cable-MRD system under primary and parametric resonance was proposed. The APDL fuzzy semi-active control programs of cable-MR damper system were compiled. The effects of fuzzy semi-active control were compared with the effects of passive control. The control effect of the proposed fuzzy semi-active control strategy was better than that of passive control. The fuzzy control strategy presented in this paper which adopted the fuzzy controller to control input voltage of MRD was simple and practical.5. Based on the fuzzy semi-active control strategy, the improved fuzzy semi-active control strategy was proposed. By introducing the quantitative factor fuzzy controller, the quantitative factor can be adjusted adaptively according to the different cable vibration conditions. The process of the fuzzy semi-active control through a large number of attempts to determine the basic domain of input, output variables and quantification factor corresponding was greatly simplified. In comparison with the fuzzy semi-active control strategy, the effect of the improved strategy was slightly better than that of the fuzzy semi-active control strategy. In addition, the improved strategy was more convenient and intelligent and had a high control efficiency. 6. Study on the optimized placement of MRD in vibration control of cable parametric resonance under eight different working conditions was carried out. The optimized placement method of MRD in cable-MRD system was proposed. To establish a multi-objective function, the optimized placement of MRD was programmed based on MATLAB and ANSYS, and the optimized calculation was complishied by the genetic algorithm. The result showed that the presented method of MRD optimized placement was feasible and effective.The research results will provide basis for the cable vibration suppression of the Guizhou Hongshuihe hybrid girder supermajor cable-stayed bridge.更多还原