基于模糊理论的高拱坝体型多目标优化设计

Multi-objective shape optimization design of high arch dams based on fuzzy theory

综合考虑静力荷载作用下双曲拱坝的经济性与安全性,采用坝体体积作为经济目标函数,坝体最大主拉应力作为拱坝局部区域的安全目标函数,整体应变能作为拱坝整体安全目标函数,建立高拱坝体型的三目标优化设计模型.根据模糊数学理论,计算海明距离、贴近度和关联度,对这些指标进行加权建立模糊评价函数.以某拟建拱坝为例进行了优化设计,结果表明,模糊优化体型在多个目标函数上改善效果较明显:体积方量减少了25.03万m3,占总体积量的3.63%;最大主拉应力小了0.70MPa,降低6.05%;应变能下降了0.082 GJ,下降2.20%.

The economy and safety of double curvature arch dams under the static load were comprehensively considered. The dam volume, the maximum principle tensile stress, and the integral strain energy were regarded as the economic objective function, the local safety objective function, and the integral safety objective function, respectively. On such a basis, a tri-objective optimization design model for high arch dams was established. According to the theories of the fuzzy mathematics, the hamming distance, closeness degree and correlation degree were calculated, and the fuzzy evaluation function was established according to the weight of those indices. An arch dam was considered for its optimization design. The results show that the after the shape optimization design, the dam volume is reduced by 25.03 × 104 m＆3, 3.63% of the total volume; the maximum principle tensile stress is reduced by 0.70 MPa, 6.05 % of the total stress; and the strain energy of the dam is reduced by 0.082 GJ, 2.20% of the total energy. The improvement efficiency of multi-objective functions is obvious.