变分技术在重力坝优化设计中的应用

在Ansys中,传统的重力坝断面优化方法通常是一阶或者零阶优化,用时较长.而变分优化方法作为一种新型的优化方法,能快速的进行优化计算,降低计算成本,提高计算精度,但是这种方法还未在水工结构优化中广泛应用.本文是基于大型有限元计算软件ANSYS,将变分技术DesignXplorer VT模块与网格随移修改工具ParaMesh相结合,以上游坡面、下游坡面的坡比和上游起坡点为设计变量,以坝体断面面积最小为优化目标,以坝踵点不出现拉应力和坝体满足抗滑稳定为条件变量,对变分技术在重力坝优化设计的应用进行了详细研究.进行优化之后,坝体断面面积减少了27％,满足抗滑稳定和应力要求,且用时不到传统优化方法的1/10.研究结果表明:变分技术在水工结构优化设计中是可行的,不仅计算精度高,操作方便,且计算成本大大降低,在水工结构方面的优化设计有很大前景.

Application of variational technology in optimal design of gravity dam

In Ansys the traditional gravity dam section optimization method is usually a first-order or zero-order optimization and takes a long time.Variational optimization method as a new optimization method can quickly optimize computing and reduce computing costs and improve the calculation accuracy, but this approach has not been widely used in the hydraulic structure optimization. Through the grid with the move tool in ParaMesh the gravity dam downstream slope and the upstream slope point set to geometric design variables, the dam heel point don't appear tensile stress and satisfy the stability against sliding for condition variables, the paper studied the application of variational technology in the gravity dam shape optimization research.After optimizing, the cross-sectional area of dam reduced by 27% to meet sliding stability and stress requirements, and the spending time of the method is less than one tenth of that of a traditional optimization methods. The results show that the variational technology in hydraulic structure optimization design is feasible, not only high precision, easy to operate, and the computation cost greatly reduced, the technology has great prospects in hydraulic structure optimization design .