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水电站蜗壳结构非线性分析与设计优化

Nonlinear Structural Analysis and Improved Design for Scroll Case in Hydropower Station

【作者】 肖阳

【导师】 马震岳;

【作者基本信息】 大连理工大学 , 水利水电, 2004, 硕士

【摘要】 钢衬钢筋混凝土压力管道早在二十世纪六、七十年代就被应用在水电站工程中。蜗壳结构被称之为水电站厂房的心脏,是一个复杂的具有独特优点的钢衬钢筋混凝土压力管道。现在在水电站设计中,这种钢衬钢筋混凝土蜗壳结构被广泛地应用。 但是,随着钢衬钢筋混凝土压力管道的广泛应用,一些问题也随之产生:①由于蜗壳结构是由线性材料和非线性材料共同构成,因此很难准确描述结构各部分的应力情况;②结构中各构成部分不能充分发挥作用:③不能清楚地了解各构成部分对结构裂缝的产生、发展和分布的影响情况。 因此,本文针对上述问题进行研究。为了使计算研究的结果具有实际意义,本文以几个实际水电站结构作为蜗壳结构优化设计方面的研究对象,进行了以下研究: 1)采用有限元法对蜗壳结构进行研究。采用著名的ANSYS软件对蜗壳结构进行仿真模拟与结构计算分析。模型中主要模拟实际结构中三种不同的构成部分(钢蜗壳、钢筋混凝土结构和素混凝土结构)以及它们之间的连接关系,为结构分析奠定基础;结合现有裂缝间距和宽度的计算公式,根据蜗壳结构的自身特点,提出蜗壳结构的最大裂缝宽度公式,为蜗壳限裂设计提供理论基础; 2)通过所建立的仿真模型对实际水电站蜗壳结构进行分析。根据各构成部分的应力分布情况确定了各部分在蜗壳整体结构中的作用;分析各荷载对蜗壳结构的作用,得出结构所受的主要荷载以及此荷载对结构的作用情况,为蜗壳结构的优化设计提供参考; 3)蜗壳结构的优化设计。参考计算结果,总结出配筋率、钢筋布置对结构受力以及结构中的裂缝分布的影响,选择最优的配筋率和钢筋布置方案,从而使结构各构成部分可以充分地发挥作用。根据结构的动力计算结果,选择出合理的蜗壳结构埋置方案。结合不同保压水头对结构的影响作用,提出保压浇筑方式中保压水头的选取方法。从各主要方面对水电站中蜗壳结构的设计进行研究,其结论对蜗壳结构的优化设计具有实际指导意义。 本文的结论已经应用在许多实际工程的设计中,已被证明是正确可靠的。本文同时也简化了蜗壳结构的设计方法并有益于促进相关理论的发展。

【Abstract】 Steel Lined Reinforced Concrete Penstock (SLRCP) was firstly applied to hydroelectric power stations in 1960s. The structure of scroll case, the heart of a power station, is a complex structure of SLRCP which has specific advantages. Now this kind of scroll case is adopted in most of power stations.However, some problems are brought out. (1) It is difficult to determine the complex stress state of this kind of scroll case structure due to the coexistence of the nonlinear constitutive and elastic linear constitutive material in the scroll case structure; (2) The constitutive material do not act fully; (3) It is not clear how the components affect the formation, development and distribution of cracks.Therefore, this paper is focused on the above questions. To make the research results more practical, finite element models for the scroll case structure of several real hydroelectric power stations are created. The following aspects are studied:1). The study of the method of scroll case structure by finite element method. A scroll case structure simulating model is accomplished by ANSYS. This model including: three different components (steel scroll case, reinforced concrete structure and concrete structure) and the interaction between them; according the formulas for crack and the characteristic of scroll case structure, the formula for scroll case’s crack is achieved. These lay the academic foundation for optimal design of scroll case structure;2). The analyses of some real scroll case structures through the simulating models. The distributing drawings of stresses of different components in the scroll case structures are achieved and their effects to the whole structure are known; the loads applying the structure are analyzed and the crucial loads are found out. These supply references to optimal design of scroll case structure;3). The optimal design of scroll case structures. Considering the calculation results, the relations between the rebar and the crack development are concluded, the best way to lay the rebar is chosen which make the components play a full role. All kinds of structural styles are analyzed by dynamical method, and the reasonable style is forward out. According the effect of different pre-cast water head, the conclusion is drawn on the choice of pre-cast water head. The scroll case structure is studied from these aspects, which are used in the optimal design project.The research results of this paper are used in some practical projects and are proved correct and reliable. Thus the work simplifies the design methods of the scroll case structures and promotes the development of the corresponding theory. On the other hand, it also promote the corresponding theory.

【关键词】 蜗壳有限元方法优化设计线性非线性裂缝
【Key words】 scroll casefinite element methodoptimal designlinearnonlinearcrack
  • 【分类号】TV33
  • 【被引频次】13
  • 【下载频次】291
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