弦支穹顶结构的预应力优化设计

Optimal prestress design of suspen-domes

采用遗传算法对弦支穹顶结构进行了预应力优化设计.从随机产生的初始种群出发,通过选择、杂交及变异等遗传算子,使种群一代一代地进化到最优解.本文采用二级优化的步骤对水平径向约束反力和上部杆件轴力两个优化目标同时进行了预应力优化,并编制了相应的程序对联方型弦支穹顶结构进行了预应力优化设计.结果表明,采用遗传算法收敛速度快,而且所需迭代次数少;最外圈索杆的预应力对水平径向约束反力的影响最大,而内部几圈索杆的预应力对上部单层网壳杆件的轴力影响较大.

Genetic algorithm method is applied into the optimal prestress design of suspen-domes. By using the operators such as selection, crossover and mutation, the randomized initial population can converge upon the global optimum solution.Two-level algorithm is developed to deal with the two objective function optimal design where the horizontal radial constraint force and the axial force of the upper structure are taken as two optimal objects. Corresponding program has been developed to optimize the prestress of Lamella's suspen-domes. The numerical results indicate that the genetic algorithm method have a good convergence and ability to get the best solution. The prestress of the most outer loop has the greater effect on its horizontal radial constraint force, and the prestress of the other loops has the greater effect on its axial force of the upper structure.