人行荷载作用下结构的竖向振动分析与控制

发布时间：2018-11-25 19:48

【摘要】：随着轻质和高强建筑材料的运用、结构分析和设计技术的进步、建筑使用功能的需要以及施工技术的发展，许多大跨度结构在大型公共建筑中广泛应用。大跨结构如大跨人行天桥，具有跨度大、质量轻、阻尼低等特点，尽管在结构设计中能够保证此类结构的承载力和变形满足规范的要求。但在大量的人员通行时，大跨轻质结构会产生显著的动力响应，这种振动达到一定程度时，常常会使居住者或使用者感觉不舒服甚至恐慌，极大地降低了结构的适用性。所以，基于人体舒适度的大跨度结构在人行荷载作用下的减振控制尤为必要。本论文以某室内人行桥为工程背景，较系统的研究了大跨结构人致振动舒适度问题和减振控制。主要分析了箱型截面人行桥在人行荷载作用下的动力响应，评价了该人行桥在人行荷载作用下的舒适度问题，同时布置调频质量阻尼器系统（TMD），以减小它们的竖向振动响应，保证结构的使用安全和人员的舒适感，主要研究内容如下： 1、阐述了常见人行荷载的特点和模型，综合分析了国内外楼板结构振动的研究概况以及楼板振动规范，结合本工程的实际情况，，总结出了大跨结构在人行荷载激励下的振动舒适度评价方法和分析方法； 2、介绍了竖向减振装置TMD的理论和参数设计方法，利用等效线性化方法将有阻尼的单自由度体系等效为无阻尼的单自由度体系，在此基础上利用无阻尼主结构TMD参数优化的结果推导了有阻尼主结构TMD最优参数； 3、针对既有室内人行桥结构特点，确定该人行桥的边界条件，单独建立该结构的有限元模型，并进行动力特性分析。根据自振频率和振型初步判断竖向振动最不利的区域，并考虑在不同人行荷载工况下计算人行荷载作用下的动力响应，最后根据规范评价了结构竖向振动的舒适度性； 4、根据竖向TMD理论，在竖向振动最不利区域布置了调频质量阻尼器系统，并计算了TMD的减振效果，减振后的加速度响应满足现有规范的要求。最后，总结了全文所做的工作，得出相应的结论并提出下一步要做的工作。
[Abstract]:With the application of lightweight and high-strength building materials, the progress of structural analysis and design technology, the need of building function and the development of construction technology, many long-span structures are widely used in large public buildings. Large span structures, such as long span footbridges, are characterized by large span, light weight and low damping, although in structural design, the bearing capacity and deformation of such structures can meet the requirements of the code. However, when a large number of people pass through, the long-span lightweight structure will produce a significant dynamic response. When the vibration reaches a certain level, it often makes the occupant or the user feel uncomfortable or even panic, which greatly reduces the applicability of the structure. Therefore, it is necessary to control the vibration of long-span structure based on human comfort under the action of pedestrian load. In this paper, based on the engineering background of an indoor footbridge, the problem of human induced vibration comfort and vibration control of long span structures are studied systematically. This paper mainly analyzes the dynamic response of the box section footbridge under the action of pedestrian load, evaluates the comfort degree of the footbridge under the action of pedestrian load, and arranges the FM mass damper system (TMD), at the same time. In order to reduce their vertical vibration response and ensure the safety of the structure and the comfort of the personnel, the main research contents are as follows: 1. The characteristics and models of common pedestrian loads are described. The general situation of the research on the vibration of floor structure at home and abroad and the criterion of floor vibration are analyzed synthetically. Combined with the actual situation of this project, the evaluation method and analysis method of vibration comfort of long-span structure under the excitation of pedestrian load are summarized. 2. The theory and parameter design method of vertical vibration absorber TMD are introduced. The damping single degree of freedom system is equivalent to the undamped one degree of freedom system by using the equivalent linearization method. On the basis of this, the optimal parameters of TMD for damped main structure are derived by using the results of TMD parameter optimization of undamped main structure. 3. According to the structural characteristics of the existing indoor footbridge, the boundary conditions of the footbridge are determined, the finite element model of the structure is established separately, and the dynamic characteristics are analyzed. According to the natural vibration frequency and vibration mode, the most unfavorable region of vertical vibration is preliminarily judged, and the dynamic response under different conditions of pedestrian load is considered. Finally, the comfort degree of vertical vibration of structure is evaluated according to the code. 4. According to the vertical TMD theory, the FM mass damper system is arranged in the most unfavorable area of vertical vibration, and the damping effect of TMD is calculated. The acceleration response after damping meets the requirements of the existing specifications. Finally, the paper summarizes the work done in this paper, draws the corresponding conclusions and puts forward the next step.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3;U448.11

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