拉索预应力球面巨型网格结构静力性能优化分析

针对拉索预应力球面巨型网格结构的静力优化问题,提出对拉索预应力、立体桁架梁高度、杆件截面的三级优化法,对各变量分别采用不同的目标和方法进行逐级优化.对杆件截面优化以结构自重为目标函数并采用满应力法;立体桁架梁高度通过结构内力峰值和挠度比两项指标予以确定;优化拉索预应力时,采用结构杆件内力的平方和最小为目标函数建立数学模型,并运用影响矩阵线性优化法和复形法求解.文中对一个180 m跨度的结构,提出了5种不同的布索方案,并基于以上理论,进行了优化分析.结果表明,实际工程采用沿周边布索方案为佳.同时优化分析结果也证明了本文采用的优化分析方法和编制的程序是高效可行的.

Optimizing Analysis of the Static Behaviors of Pretensioned Spherical Reticulated Mega-structure

To optimize the static behaviors of prestressed spherical reticulated mega-structure, a three-grade optimization method was presented, in which the member cross section, the height of 3D-trussed beam, and the cable prestress were all considered. Different objects and methods were applied in the process of optimization. The full-stress method was adopted to optimize the member cross section for the minimum structural self-weight. The optimal height of 3D-trussed beam was determined with both the peak value of internal forces and the structural deflection. As to the optimization of prestress, the minimum sum of internal forces squared was taken as the objective function, and the influence matrix and complex methods were adopted. For the structure with a span of 180 m, five arrangement styles of cables were presented, and optimization analysis was carried out on the basis of the above-mentioned method. The results have shown that the cables should be arranged along the perimeter of the structure. In addition, the effectiveness and the feasibility of the theories and programs have also been validated.