拱坝结构设计应力控制标准研究
发布时间：2018-10-05 19:42
【摘要】：拱坝结构设计应力控制标准的研究是拱坝设计领域一个复杂而又重要的课题,应力控制标准的合理性将直接关系着拱坝的经济性和安全性。当前,在拱坝结构设计中主要的应力分析方法有拱梁分载法和有限单元法。相对于拱梁分载法,有限单元法拥有较强的适用性,能够解决许多拱梁分载法不能解决的复杂问题。但其计算结果受计算网格影响较大,同时在建基面附近易出现应力集中,给有限元应力控制标准的制定带来困难。为解决上述提到的问题,现行拱坝设计规范采用的方法是有限元等效应力法,并制定了相应的应力设计标准。但有限元等效应力法中关于应力分量的线性化假定与拱坝真实的应力分布规律不相符合。本文在分析拱、梁向应力分布规律的基础上,提出了拱坝有限元三次等效应力法。并依托小湾、二滩、杨房沟、周公宅四座拱坝工程,开展三次等效应力控制标准的研究,并给出相应的应力控制指标的建议值。主要研究内容如下:(1)总结了关于国内外拱坝主要的应力分析方法及其相应的应力控制标准的基本内容和进展,分析比较不同应力分析的优缺点及其应力控制指标的制定方式,为三次等效应力法的应力控制指标的提出作铺垫。(2)介绍了拱坝有限元分析的基本理论,着重讲述了有限元分析过程。在此基础上,简要概况了 ANSYS的有限元求解。(3)分析了拱坝梁、拱应力分布规律,基于最小二乘法拟合多项式提出拱坝有限元三次等效应力分析方法及其计算步骤。结合小湾拱坝工程,研究了三次等效应力对有限元模型网格的敏感性,结果显示三次等效应力法可消除网格效应影响。(4)利用ANSYS软件对四座拱坝建立有限元分析模型并进行基本荷载组合下的三维线弹性有限元分析,并分别计算了有限元三次等效应力和设计规范中的有限元等效应力。通过分析对比两种等效应力的最大拉压应力,提出了有限元三次等效应力设计标准的确定方法,并结合DL/T5346-2006规范和SL282-2003规范给出了相应的控制指标。
[Abstract]:The research of stress control standard for arch dam structure design is a complex and important subject in the field of arch dam design. The rationality of stress control standard will directly affect the economy and safety of arch dam. At present, the main stress analysis methods in arch dam structure design include arch beam load sharing method and finite element method. Compared with the arch beam load sharing method, the finite element method has a strong applicability and can solve many complex problems which can not be solved by the arch beam load separation method. However, the calculation results are greatly affected by the calculation grid, and stress concentration is easy to occur near the foundation plane, which makes it difficult to formulate the finite element stress control standard. In order to solve the problems mentioned above, the current design code for arch dams adopts the method of finite element equal effect force method, and formulates the corresponding stress design standard. But the linearization assumption of the stress component in the finite element equal effect force method does not accord with the true stress distribution of the arch dam. Based on the analysis of the stress distribution of arch and beam, the third order effect force method of arch dam is presented in this paper. Based on the four arch dams of Xiaowan, Ertan, Yangfanggou and Zhougongzhai, the research on three equivalent stress control standards is carried out, and the corresponding suggested stress control index is given. The main research contents are as follows: (1) the main stress analysis methods and their corresponding stress control standards at home and abroad are summarized, and the advantages and disadvantages of different stress analysis and the formulation of stress control indexes are analyzed and compared. The basic theory of finite element analysis of arch dam is introduced, and the process of finite element analysis is emphasized. On this basis, the finite element solution of ANSYS is briefly introduced. (3) the stress distribution of arch dam beam and arch is analyzed. Based on the least square fitting polynomial, the cubic equivalent stress analysis method of arch dam and its calculation steps are proposed. Combined with Xiaowan arch dam project, the sensitivity of cubic equivalent stress to finite element model mesh is studied. The results show that the third order effect force method can eliminate the influence of grid effect. (4) the finite element analysis model of four arch dams is established by using ANSYS software and the three-dimensional linear elastic finite element analysis under the basic load combination is carried out. The cubic equivalent stress of the finite element and the equivalent stress of the finite element in the design code are calculated respectively. By analyzing and comparing the maximum tensile and compressive stresses of two kinds of equivalent stresses, a method of determining the design standard of the cubic equivalent stress of finite element is put forward, and the corresponding control indexes are given in combination with the DL/T5346-2006 Code and the SL282-2003 Code.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV642.4;TV31
，
本文编号：2254633
[Abstract]:The research of stress control standard for arch dam structure design is a complex and important subject in the field of arch dam design. The rationality of stress control standard will directly affect the economy and safety of arch dam. At present, the main stress analysis methods in arch dam structure design include arch beam load sharing method and finite element method. Compared with the arch beam load sharing method, the finite element method has a strong applicability and can solve many complex problems which can not be solved by the arch beam load separation method. However, the calculation results are greatly affected by the calculation grid, and stress concentration is easy to occur near the foundation plane, which makes it difficult to formulate the finite element stress control standard. In order to solve the problems mentioned above, the current design code for arch dams adopts the method of finite element equal effect force method, and formulates the corresponding stress design standard. But the linearization assumption of the stress component in the finite element equal effect force method does not accord with the true stress distribution of the arch dam. Based on the analysis of the stress distribution of arch and beam, the third order effect force method of arch dam is presented in this paper. Based on the four arch dams of Xiaowan, Ertan, Yangfanggou and Zhougongzhai, the research on three equivalent stress control standards is carried out, and the corresponding suggested stress control index is given. The main research contents are as follows: (1) the main stress analysis methods and their corresponding stress control standards at home and abroad are summarized, and the advantages and disadvantages of different stress analysis and the formulation of stress control indexes are analyzed and compared. The basic theory of finite element analysis of arch dam is introduced, and the process of finite element analysis is emphasized. On this basis, the finite element solution of ANSYS is briefly introduced. (3) the stress distribution of arch dam beam and arch is analyzed. Based on the least square fitting polynomial, the cubic equivalent stress analysis method of arch dam and its calculation steps are proposed. Combined with Xiaowan arch dam project, the sensitivity of cubic equivalent stress to finite element model mesh is studied. The results show that the third order effect force method can eliminate the influence of grid effect. (4) the finite element analysis model of four arch dams is established by using ANSYS software and the three-dimensional linear elastic finite element analysis under the basic load combination is carried out. The cubic equivalent stress of the finite element and the equivalent stress of the finite element in the design code are calculated respectively. By analyzing and comparing the maximum tensile and compressive stresses of two kinds of equivalent stresses, a method of determining the design standard of the cubic equivalent stress of finite element is put forward, and the corresponding control indexes are given in combination with the DL/T5346-2006 Code and the SL282-2003 Code.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV642.4;TV31
，
本文编号：2254633
本文链接：https://www.wllwen.com/kejilunwen/shuiwenshuili/2254633.html
