高耸板式塔的风振响应分析

发布时间：2018-03-03 21:56

本文选题：高耸板式塔　切入点：数值模拟　出处：《燕山大学》2015年硕士论文　论文类型：学位论文

【摘要】：近些年,我国多地的石化企业多次发生高耸塔器的振动事故。持续的剧烈振动不单让生产难以正常运行、塔器变形严重,甚至使塔体产生破坏。因此研究高耸塔器在风载荷作用下的动态响应规律,已变为一个迫切的要求。然而,目前国内外标准中把风载荷等效成静力载荷的计算方法,并不能对高耸塔器进行动态响应分析。本文以某石化项目中高耸板式塔作为研究对象,对其进行风振响应分析,旨在为高耸塔器的正常运行、结构改进、抗振研究提供参考。本文具体工作和成果如下:(1)建立了高耸板式塔的有限元模型,对其进行了模态分析,求出了板式塔的前四阶振型,分析了高径比对塔器自振周期的影响。(2)不同于传统的分段风载荷法,本文在FLUENT软件中通过自编程序代码模拟了塔器在指数风速分布下的卡曼涡街流场。本文采用沿高度呈指数分布的风载荷更接近塔设备受到的真实风载荷,能更准确研究塔器的风振响应。通过模拟真实再现了风绕塔体的流动过程;求出了塔器在不同风速下的表面风压分布;对比分析了同一风速不同塔高和不同风速同一塔高处的风压、卡曼涡街流场、横向力、顺向力的变化规律。(3)通过流固耦合的方法将FLUENT计算得到的时变风载荷导入到ANSYS Workbench瞬态动力学模块,模拟了塔器在不同风速下的动态响应。通过模拟:得出了塔器的横风向和顺风向位移时程曲线;对比分析了塔器处于共振和非共振状态的振动规律;将模拟结果和传统卢曼法计算结果进行了对比,即验证了模拟的准确性,又弥补了传统法只能对塔器横风向振动振幅进行分析,无法对振动过程和顺风向振动分析的缺点。(4)根据瞬态动力学模块计算出来的横风向应力时程曲线,对高耸板式塔进行了疲劳寿命分析。
[Abstract]:In recent years, vibration accidents of towering towers have occurred many times in petrochemical enterprises in many places in China. The continuous and intense vibration not only makes it difficult for production to operate normally, but also deforms the towers seriously. Therefore, it has become an urgent requirement to study the dynamic response of towering tower under the action of wind load. However, the calculation method of equivalent wind load to static load in domestic and foreign standards at present has become an urgent requirement. It is not possible to analyze the dynamic response of the towering tower. In this paper, the tall slab tower in a petrochemical project is taken as the research object, and its wind-induced vibration response is analyzed in order to improve the structure for the normal operation of the towering tower. The concrete work and results of this paper are as follows: 1) the finite element model of the towering plate tower is established, and the modal analysis is carried out, and the first four vibration modes of the plate tower are obtained. The influence of height to diameter ratio on the natural vibration period of tower is analyzed, which is different from the traditional subsection wind load method. In this paper, the flow field of Kaman vortex street under exponential wind velocity distribution is simulated in FLUENT software. The wind load with exponential distribution along the height is closer to the real wind load on tower equipment. The wind vibration response of the tower can be studied more accurately. The flow process around the tower body is reproduced by simulation, and the wind pressure distribution on the surface of the tower under different wind speeds is obtained. The wind pressure of the same wind speed, different tower height and different wind speed and the same tower height, the flow field of Kaman vortex street, and the transverse force are compared and analyzed. The variation of forward force. (3) the time-varying wind load calculated by FLUENT is imported into the transient dynamic module of ANSYS Workbench by the method of fluid-solid coupling. The dynamic response of the tower under different wind speeds is simulated. The transverse wind direction and the downwind displacement time history curves of the tower are obtained, and the vibration laws of the tower in the resonant and non-resonant states are compared and analyzed. The simulation results are compared with those calculated by the traditional Loman method, which verify the accuracy of the simulation and make up for the fact that the traditional method can only analyze the vibration amplitude of the traverse wind direction of the tower. It is impossible to analyze the vibration process and downwind vibration. (4) based on the time-history curve of transverse wind stress calculated by transient dynamic module, the fatigue life of towering slab tower is analyzed.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ053.5

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