大型钢储罐结构的风荷载和风致屈曲

发布时间：2018-07-01 10:28

本文选题：大型钢储罐 + 风荷载　；参考：《浙江大学》2014年博士论文

【摘要】：储罐结构是一类典型的薄壳结构,广泛应用于工农业生产中,如石油、液化天然气、粮食、水泥等各类液体和固体的储存,其中,石油化工业中的钢制储油罐最为常见。近年来,随着国民经济的发展和国家能源战略的实施,以大型储油罐为代表的大型钢储罐结构的建造方兴未艾。大型钢储罐结构的特点是径厚比大、高径比低,属风敏感结构,在强风甚至是长时间和风作用下容易失稳破坏,特别是在空罐或储液、储料不多的情况下。在过去几十年中,世界各国和地区已先后发生过多起钢储罐的风毁事故。由于钢储罐的风毁造成巨大的经济损失和严重的环境污染,其风力稳定问题长期以来受到众多学者的广泛关注和重视,然而已有的文献主要关注中小型储罐及筒仓结构,对大型变壁厚钢储罐结构鲜有涉及。因此,开展大型钢储罐风荷载和风力稳定的研究有着迫切的现实意义与广泛的应用前景。本文主要通过风洞试验和有限元分析对以十万方立式圆柱形钢油罐为代表的大型钢储罐结构的风荷载和风致屈曲进行系统的研究,力求揭示这类结构的风致屈曲机理及行为,为大型钢储罐结构的合理抗风设计提供参考和建议。全文主要内容如下：第1章介绍本文研究的背景,回顾钢储罐及金属圆柱壳结构风荷载和风致屈曲的研究历史,总结现行规范的设计规定,指出本文工作的出发点和思路。第2章简要介绍流体动力学原理及其数值解法——计算流体动力学(CFD)的基本理论,采用CFD商用软件Fluent对十万立方大型钢储罐进行数值风洞分析,初步了解这类结构的风场绕流特点和风荷载分布特征,并为后文大型钢储罐的风洞试验设计提供参考。第3章针对十万立方大型钢储罐单体条件下的风荷载进行风洞试验,考察三种不同的储罐形式：敞口储罐、平顶储罐和穹顶储罐；获得上述三种储罐的基本风荷载数据,包括平均风压和脉动风压、偏度和峰度,对风压脉动的概率分布进行分析并与高斯分布比较；讨论顶盖形式对钢储罐罐壁部分风荷载的影响、平均风压和脉动风压的相关性,将获得的风荷载数据和以往相关研究成果和规范进行对比,拟合圆柱壳罐壁平均风荷载体型系数的傅里叶公式,以供设计应用参考。第4章以敞口储罐为例,通过519种工况试验,考察群体效应对储罐表面风荷载的影响。试验包括三种典型的排列：两相邻储罐包括串列、并列和错列、三角形三罐排列和正方形四罐排列；重点研究来流风向角和罐群间距对钢储罐风荷载分布的影响。第5章简述薄壳结构的力学特点、稳定问题的基本概念和薄壳结构非线性稳定理论的发展历程；简单介绍圆柱薄壳结构稳定问题的有限元求解方法；概括圆柱薄壳结构稳定问题的分类并提出侧压稳定的概念；以实际工程中常用的五种圆柱钢储罐(容量为2000-50000m3)为例,建立有限元模型,对其风致屈曲的一般行为进行分析,讨论焊缝缺陷和特征值模态缺陷对风致屈曲性能的影响。第6章以十万方钢油罐为研究对象,建立有限元模型,进行大型钢储罐结构在平均风荷载下的稳定分析,包括线性特征值屈曲分析和几何非线性分析,研究初始几何缺陷对钢储罐稳定性能的影响；讨论壁厚腐蚀和储液高度等基本参数对钢储罐风致屈曲性能的影响；研究群体条件下钢储罐风致屈曲承载力的变化特点。第7章简述结构动力稳定性原理和结构动力稳定性的实用判定准则；采用非线性动力时程分析方法对大型钢储罐结构的风振屈曲行为进行研究,考察初始缺陷对大型钢储罐结构风振屈曲性能的影响。第8章结合现行规范和工程设计方法,从包边角钢、抗风圈和加强圈三方面对大型钢储罐抗风结构的加强机理和破坏特点进行剖析,讨论不同国家规范所采用设计方法的差异,研究采取抗风设计后钢储罐的风致屈曲性能和破坏特点,提出大型钢储罐结构的抗风设计建议。第9章总结全文,概括全文主要结论,并提出进一步研究工作的建议。
[Abstract]:Storage tank structure is a typical kind of thin shell structure, which is widely used in industrial and agricultural production, such as oil, liquefied natural gas, grain, cement and other liquids and solids. In the petroleum industry, steel tanks are the most common. In recent years, with the development of national economy and the implementation of national energy strategy, large oil storage tanks are replaced. The structure of large steel storage tank is in the ascendant. The structure of large steel storage tank is characterized by large diameter thickness ratio, low height to diameter ratio, wind sensitive structure, easy to lose stability under strong wind and even long time and wind, especially in the case of empty tank or liquid storage. In the past several decades, the countries and regions of the world have happened successively. The wind destruction of steel tanks has been caused by huge economic losses and serious environmental pollution caused by the destruction of steel tanks. The problem of wind stability has long been paid attention and paid attention to by many scholars. However, the existing literature focuses on small and medium storage tanks and silo structures, which are rarely involved in the structure of large wall thick steel tanks. Therefore, the study of wind load and wind stability of large steel storage tanks is of urgent practical significance and wide application prospects.
In this paper, wind tunnel test and finite element analysis are used to systematically study the wind and wind buckling of the large steel tank structure represented by one hundred thousand square vertical cylindrical steel tanks, and try to reveal the wind induced buckling mechanism and behavior of this kind of structure, and provide reference and suggestion for the rational wind resistance design of large steel storage tank structure.
The main contents of the full text are as follows:
The first chapter introduces the background of this study, reviews the history of wind load and wind induced buckling of steel storage tanks and metal cylindrical shells, summarizes the design regulations of current norms, and points out the starting points and ideas of this work.
The second chapter briefly introduces the principle of hydrodynamics and its numerical solution - the basic theory of computational fluid dynamics (CFD). The CFD commercial software Fluent is used to carry out numerical wind tunnel analysis on one hundred thousand cubic large steel tanks. The characteristics of wind flow around the wind field and the distribution characteristics of wind load are preliminarily understood, and the wind tunnel test for the later large steel tanks is tested. The design provides reference.
The third chapter conducts wind tunnel tests on the wind load of one hundred thousand cubic large steel tanks under single condition, and investigates three different types of storage tanks: open storage tanks, flat top storage tanks and dome tanks. The basic wind load data of the three kinds of tanks are obtained, including the average wind pressure and fluctuating wind pressure, deflection and kurtosis, and the probability distribution of the wind pressure pulsation. A row analysis is made and compared with the Gauss distribution; the influence of the roof form on the partial wind load on the wall of the steel tank, the correlation of the average wind pressure and the pulsating wind pressure is discussed, and the obtained wind load data is compared with the previous relevant research results and specifications, and the Fourier formula of the average wind load body coefficient of the cylindrical shell wall is fitted for the design and application. Reference resources.
The fourth chapter, taking open storage tanks as an example, investigates the effect of group effect on the surface wind load on the tank surface through 519 test conditions. The test includes three typical arrangements: two adjacent tanks including tandem, parallel and wrong columns, triangular three cans and square four cans, focusing on wind direction angle and tank group spacing to the wind load of steel tanks. The influence of distribution.
The fifth chapter briefly describes the mechanical characteristics of thin shell structure, the basic concept of stability problem and the development course of the theory of nonlinear stability of thin shell structure, briefly introduces the finite element solution method of the stability problem of thin cylindrical shell structure, generalizes the classification of the stability problem of the thin cylindrical shell structure and puts forward the concept of lateral pressure stability, which is used in the practical engineering. A cylindrical steel tank (capacity 2000-50000m3) is used as an example to establish a finite element model. The general behavior of its wind induced buckling is analyzed, and the effect of weld defects and eigenvalue modal defects on the wind induced buckling performance is discussed.
The sixth chapter takes the one hundred thousand square steel tank as the research object, establishes the finite element model, carries out the stability analysis of the large steel storage tank structure under the average wind load, including the linear eigenvalue buckling analysis and geometric nonlinear analysis, and studies the influence of the initial geometric imperfections on the stability of the steel storage tank, and discusses the basic parameters of the wall thickness corrosion and the height of the storage liquid. The influence of wind load on buckling behavior of steel storage tanks is studied.
In the seventh chapter, the principle of structural dynamic stability and the practical criterion for structural dynamic stability are described briefly. The wind vibration buckling behavior of large steel tank structure is studied by using nonlinear dynamic time history analysis method, and the effect of initial defects on the wind vibration buckling performance of large steel storage tank structure is investigated.
The eighth chapter, based on the current norms and engineering design methods, analyzes the strengthening mechanism and failure characteristics of the wind resistant structure of large steel tanks from the three aspects of the corner steel, the anti wind ring and the reinforcing ring, and discusses the differences in the design methods adopted by different national standards. The wind buckling performance and damage characteristics of the steel tanks after wind resistance design are studied. A proposal for wind resistance design for large steel tank structures.
The ninth chapter summarizes the full text, summarizes the main conclusions of the full text, and puts forward suggestions for further research.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU391;TU312.1;TE972

【参考文献】