目前复杂结构的抗风优化研究大多集中于高层建筑,很少针对风敏感的大跨屋盖结构.考虑强度、刚度和几何尺寸等多重约束,基于虚功原理和Lagrange乘子将抗风优化转化为无约束问题,编制数值程序整合有限元计算和优化分析两部分,然后对杆件数为10 080的实际双层柱面网壳进行优化设计,讨论了设计变量可行域、初始值和调整步选择等对优化结果的影响.研究表明,采用本文方法可实现对空间桁架结构进行多重约束下的高效抗风优化设计,网壳总重降低约37%,风致响应分布不均使得有必要设定可行域下限,而设计变量初值和调整步选择不影响最后的优化结果.
The existing wind resistant optimization research on wind-sensitive structures mostly focused on high-rise buildings,and large span roof structures were seldom involved.The wind resistant optimization problem under multi-constraints like strength,stiffness and geometric dimensions,was converted to an unconstrained problem based on the principle of virtual work and Lagrange multiplier.A numerical program including finite element computation and optimization analysis was then developed to optimize a real double-layer cylindrical reticulated shell with 10 080 bars,followed by discussion of the influences of design variable feasible regions,design variable initial values and adjusting steps on the optimum results.Studies show that wind resistant performance of spatial truss structures under multi-constraints can be efficiently optimized by the proposed approach,and total weight of the shell is decreased by 37%.Lower limits of the design variables are necessary owing to non-uniform distribution of wind-induced responses,and different choices of initial design variables and adjusting steps could hardly influence the final optimum results.