基于ANSYS的曲线重力坝坝形优化设计

发布时间：2018-04-19 19:42

本文选题：混凝土重力坝 + 曲线　；参考：《兰州交通大学》2014年硕士论文

【摘要】：重力坝作为坝工设计中广为应用的一种坝形，它的优化设计已成为人们关注和研究的焦点。对重力坝进行优化设计，是重力坝设计的关键步骤。重力坝断面优化设计的目的是在特定的荷载作用下寻找最优的设计方案，通过一系列的分析计算，能够获得一个既安全稳定又经济合理的设计方案。目前在重力坝设计中，断面都采用基本三角形断面，该断面形式能有效的简化计算，较易得出坝体的几何尺寸，但它并非是理论上最优的断面形式。传统的基本三角形断面能恰巧满足坝体建基面上的各项控制条件，但在坝体较高的截面上材料的强度不能充分发挥，，常有所富余，且由于坝体上下游折坡点的存在，坝体在折点处容易产生应力集中现象，所以可以考虑将上下游坝面做成曲面形式，通过数学规划法求解一个能恰巧满足坝体各截面处控制条件的最优断面。本文首先阐述了重力坝进行优化设计的基本理论和方法，以及重力坝应力、稳定计算应遵循的计算方法和控制标准；然后采用数学规划法，以曲线坝面的上下游方程系数为设计变量，以几何约束、抗滑稳定和应力约束为控制条件，以单位坝段断面面积作为目标函数建立重力坝的数学模型；最后通过ANSYS有限元分析软件进行坝体的优化计算模拟，其研究的主要内容分述如下： 1.采用ANSYS的参数化语言建立了重力坝曲线断面模型，并用ANSYS自带的优化分析程序对坝体进行优化分析。整个计算分析过程由于是参数化输入，所以无论是几何模型建立、网格划分、几何边界条件以及荷载(坝体自重、静水压力、扬压力和地震作用)施加，还是计算求解、判断收敛条件是否满足以及进行相应的优化计算，这所有的工作都依靠计算机来完成，其求解效率高，结果较为可靠。 2.进行传统断面和曲线断面的对比分析。本文不仅建立了曲线断面的有限元模型，而且还建立了传统的基本三角形断面模型，通过对坝高为30m，材料属性、坝顶宽度以及荷载全部相同的两种断面进行分析研究，发现曲线断面既能满足强度和稳定要求，又能使目标函数更小，满足我们经济性的要求，这便增加了这种断面形式的可使用性。 3.根据重力坝的分类标准，对高、中、低坝三种坝形分别进行了优化设计，在几何约束、稳定、应力都满足规范规定的要求下，通过对比分析结果可知，随着坝体坝高的增加，曲线形断面的面积减少率逐渐减小，这也表明曲线形重力坝设计更加适合于低坝设计。通过本文的分析研究，发现曲线形重力坝在实际工程中有一定的可行性，这为以后的重力坝设计提供了一定的方案参考。
[Abstract]:Gravity dam is widely used in dam design, its optimization design has become the focus of attention and research. The optimization design of gravity dam is the key step of gravity dam design. The purpose of optimization design of gravity dam section is to find the optimal design scheme under specific load. Through a series of analysis and calculation, a safe, stable and economical design scheme can be obtained. At present, in the design of gravity dams, basic triangular sections are used in the design of gravity dams. This section form can simplify the calculation effectively and get the geometric size of the dam body more easily, but it is not the optimal section form in theory. The traditional basic triangular section can meet the control conditions on the foundation surface of the dam body, but the strength of the material on the higher section of the dam body can not be brought into full play, which is often surplus, and due to the existence of the upstream and downstream slope points of the dam body, It is easy to produce stress concentration phenomenon at the break point of the dam, so we can consider making the upstream and downstream dam surface into a curved surface form, and solve an optimal section by mathematical programming method, which can just meet the control conditions of each section of the dam body. In this paper, the basic theory and method for optimum design of gravity dam, the calculation method and control standard for stress and stability calculation of gravity dam, and the mathematical programming method are introduced in this paper. The mathematical model of gravity dam is established with the coefficient of upstream and downstream equation as design variable, geometric constraint, anti-slip stability and stress constraint as control conditions, and the cross-section area of unit dam segment as objective function. Finally, the optimization calculation and simulation of the dam body are carried out by ANSYS finite element analysis software. The main contents of its research are described as follows: 1. The curve section model of gravity dam is established by using the parametric language of ANSYS, and the optimization analysis program of ANSYS is used to optimize the dam body. The whole calculation and analysis process is parameterized input, so whether it is geometric modeling, meshing, geometric boundary conditions and loads (dam body weight, hydrostatic pressure, uplift pressure and seismic action) or computational solution, To judge whether the convergence condition is satisfied or not and to carry on the corresponding optimization calculation, all the work depends on the computer to complete, its solution efficiency is high, the result is more reliable. 2. The traditional section and curve section are compared and analyzed. In this paper, not only the finite element model of curve section is established, but also the traditional triangular section model is established. Through the analysis of two sections whose dam height is 30 m, material attribute, dam top width and load are all the same. It is found that the curve section can not only meet the requirements of strength and stability, but also make the objective function smaller and meet our economic requirements, which increases the usability of this type of section. 3. According to the classification standard of gravity dam, the optimum design of three types of dams are carried out separately. Under geometric constraints, stability and stress, the results of comparison and analysis show that the height of dam body increases with the increase of dam height. The area reduction rate of curved section gradually decreases, which also indicates that the design of curved gravity dam is more suitable for the design of low dam. Through the analysis and research in this paper, it is found that the curved gravity dam is feasible in practical engineering, which provides a certain scheme reference for the design of gravity dam in the future.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV642.3

【引证文献】