基于POD和SPT分解的大型钢储罐风压分布机制分析

发布时间：2018-04-28 14:09

本文选题：钢储罐 + 风荷载　；参考：《北京交通大学》2017年硕士论文

【摘要】：钢储罐是存贮石油的主要设施,随着土地资源的日益缺乏,钢储罐的容积越来越大,大型钢储罐的建设也越来越普遍。另一方面,大型钢储罐是典型的风敏感结构,容易发生风致屈曲破坏,近年来该类破坏屡见不鲜。大型钢储罐抗风性能是重大工程实践中需要解决的关键科学问题之一。本文在已有研究的基础上,利用POD(Proper Orthogonal Decomposition)和SPT(Spectral Proper Transformation)分解方法,对大型钢储罐的风压作用机制进行了分析。完成的主要工作包括以下几个方面:1)为了更好的分析雷诺数效应,通过重新定义的折算湍流度来表示风场湍流特征,从新的角度分析了4种湍流风场下,高径比分别为0.875、0.323的大型钢储罐风压随雷诺数的变化规律,在此基础上,对比了高径比分别为0.556、0.323的敞口与平顶大型钢储罐风荷载。2)从随机场分解的角度,介绍了POD、SPT分解的基本原理及其在风工程中的应用,并以方形截面超高层建筑为例,利用POD和SPT方法对0.6H(H为建筑高度)高度处建筑表面风压场进行分解,结果表明,利用POD与SPT分解相结合的方法,能够有效识别风压作用机制。3)利用POD和SPT分解技术,对高径比分别为0.556、0.323的平顶大型钢储罐表面风压场进行分解,对其风压作用机制进行识别,并与二维圆柱的特征模态进行对比。结果表明,二维圆柱的风荷载以横风向涡激激励为主导,随着高径比的减小,顺风向湍流激励的影响越来越大,并成为主导机制。4)利用POD和SPT分解技术,对高径比分别为0.556、0.323的敞口大型钢储罐表面风压场进行分解,对其风压作用机制进行识别,与平顶储罐的分解结果进行对比分析。结果表明,在高径比相同的情况下,敞口储罐顺风向湍流激励的影响逐渐减小。
[Abstract]:Steel storage tanks are the main facilities for oil storage. With the increasingly lack of land resources, the volume of steel storage tanks is becoming larger and larger, and the construction of large steel storage tanks is becoming more and more common. On the other hand large steel storage tanks are typical wind-sensitive structures which are prone to wind-induced buckling failure and are not uncommon in recent years. Wind resistance of large steel storage tanks is one of the key scientific problems to be solved in important engineering practice. Based on the previous research, the mechanism of wind pressure in large steel storage tanks is analyzed by using POD(Proper Orthogonal decomposition and SPT(Spectral Proper transformation methods. The main work accomplished includes the following aspects: 1) in order to better analyze the Reynolds number effect, the turbulent characteristics of the wind field are expressed by redefining the converted turbulence degree, and the four turbulent wind fields are analyzed from a new perspective. Based on the variation of wind pressure with Reynolds number in large steel storage tanks with height to diameter ratio of 0.875 and 0.323, the wind load of large steel storage tanks with height to diameter ratio of 0.556 to 0.323 is compared with wind load of flat-top large steel storage tanks from the angle of random field decomposition. This paper introduces the basic principle of PODS-SPT decomposition and its application in wind engineering. Taking the super-tall building with square section as an example, the wind pressure field on the building surface at the height of 0.6H(H is decomposed by using POD and SPT methods. The results show that, By combining POD with SPT decomposition, the wind pressure mechanism can be effectively identified. 3) using POD and SPT decomposition techniques, the wind pressure field on the surface of large steel storage tank with height to diameter ratio of 0.556 ~ 0.323 is decomposed, and the mechanism of wind pressure action is identified. And compared with the characteristic mode of two-dimensional cylinder. The results show that the wind load of a two-dimensional cylinder is dominated by cross-wind vortex-induced excitation. With the decrease of the ratio of height to diameter, the downstream wind turbulence excitation becomes more and more important, and becomes the dominant mechanism. 4) POD and SPT decomposition techniques are used. The wind pressure field on the surface of large steel storage tank with height to diameter ratio of 0.556 ~ 0.323 is decomposed, and the mechanism of wind pressure action is identified, and the results are compared with those of flat-top storage tank. The results show that under the same ratio of height to diameter, the effect of downwind turbulence on the open storage tank decreases gradually.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU312.1

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