基于ANSYS和遗传算法的重力坝剖面优化设计

发布时间：2018-06-22 09:10

本文选题：重力坝 + 优化设计　；参考：《西北农林科技大学》2017年硕士论文

【摘要】：重力坝是一种常见的坝型,包括溢流坝段和非溢流坝段,其作用主要是挡水和泄水。实际工程中重力坝存在剖面尺寸大,所需混凝土方量多,坝体与坝基接触面积大,使坝底面受到的扬压力较大,不利于坝体稳定等问题,这将导致施工工程量以及工程投资增加,故对重力坝的剖面进行优化设计显得尤为重要。对重力坝的剖面进行优化设计对有效减少整个工程的工程量、降低工程投资具有很好的实用价值。本文采用MATLAB遗传算法和ANSYS的一阶优化方法分别对某典型重力坝的溢流坝段和非溢流坝段剖面进行优化设计分析,以剖面面积最小为目标函数,主要研究内容和结果如下:(1)采用ANSYS一阶优化方法对溢流坝段和非溢流坝段正常工况进行了优化,用校核工况验算了最优剖面是否合理。用APDL语言参数化建立了坝体剖面有限元模型,对有限元模型施加边界约束并求解计算;后处理提取了优化变量用于优化分析,并分别查看了两个断面的应力云图和位移云图,判断是否满足优化设计要求;采用一阶优化方法对两个断面进行正常工况优化,优化结果为溢流坝段剖面面积减小了86.62m2,优化率达到了14.43%,非溢流坝段剖面面积减小了75.27m2,优化率达到12.34%;校核工况验算坝体最优剖面符合设计规范要求。(2)采用MATLAB遗传算法对溢流坝段和非溢流坝段正常工况进行了优化,用校核工况验算了最优剖面是否合理。根据几何约束条件产生初始种群,将初始种群作为设计变量值;把初始种群代入ANSYS分析文件,MATLAB调用ANSYS计算优化变量;把计算结果返回MATLAB进行遗传算法优化,当达到迭代次数时优化终止,否则对初始种群进行选择、交叉、变异形成新一代种群,MATLAB继续调用ANSYS重新计算。采用遗传算法对正常工况优化结果为溢流坝段剖面面积减小了77.92m2,优化率达到了12.80%;非溢流坝段剖面面积减小了39.08m2,优化率达到6.05%。校核工况验算坝体最优剖面符合设计规范要求。在重力坝优化过程中将两个坝段分开优化,这容易导致优化结果中溢流坝段和非溢流坝段坝底宽度不一致,故在未来研究中,应严格控制坝底宽度并将溢流坝段和非溢流坝段合为一体优化。
[Abstract]:Gravity dam is a common dam type, which includes overflow dam section and non-overflow dam section. In actual engineering, the gravity dam has problems such as large profile size, large concrete quantity, large contact area between dam body and dam foundation, which makes the uplift pressure on the bottom face of the dam greater, which is not conducive to the stability of the dam body, and so on. This will lead to the increase of construction quantity and project investment, so it is very important to optimize the design of gravity dam profile. The optimum design of gravity dam section is of great practical value in reducing the engineering quantity and investment of the whole project. In this paper, MATLAB genetic algorithm and ANSYS first-order optimization method are used to optimize the section of overflow dam and non-overflow dam of a typical gravity dam, and the minimum area of section is taken as the objective function. The main research contents and results are as follows: (1) the normal working conditions of overflow dam section and non-overflow dam section are optimized by ANSYS first-order optimization method. The finite element model of dam profile is set up by using APDL language parameterized, the finite element model is subjected to boundary constraints and the calculation is solved. After processing, optimization variables are extracted for optimization analysis, and the stress cloud map and displacement cloud map of two sections are inspected respectively. The first order optimization method is used to optimize the normal working conditions of two sections. The optimization results are as follows: the section area of overflow dam section is reduced by 86.62m2, the optimization rate is 14.43 and the section area of non-spillage dam section is reduced by 75.27m2, and the optimization rate is 12.34.The optimum section of the dam body is checked and calculated under the condition of checking the working condition. (2) the genetic calculation of MATLAB is used to calculate the optimum section of the dam body. The normal working conditions of spillway section and non-spillway dam section are optimized by this method. The optimum profile is calculated by checking the working condition. The initial population is produced according to the geometric constraint condition, the initial population is taken as the value of the design variable, the initial population is replaced in the ANSYS analysis file and the ANSYS calculation optimization variable is called by MATLAB, and the calculation result is returned to MATLAB for genetic algorithm optimization. When the number of iterations is reached, the optimization terminates, otherwise, the initial population is selected, crossed and mutated to form a new generation of population. MATLAB continues to call ANSYS to recalculate. The results of optimization under normal working conditions by genetic algorithm are as follows: the section area of overflow dam section is reduced by 77.92 m2, the optimization rate is 12.80%, and the section area of non-overflow dam section is reduced by 39.08 m2, and the optimization rate reaches 6.05%. Checking and calculating the optimum section of dam body accords with the requirements of design code. In the process of gravity dam optimization, the two segments are optimized separately, which easily leads to the inconsistency of the dam bottom width between the overflow section and the non-spillway section in the optimization results, so in the future research, The width of the bottom should be strictly controlled and the spillway section and the non-spillway section should be optimized.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV642.3

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