基于复形法的大跨屋盖结构抗风优化

Wind resistant optimization of long span roof structures by the complex method

文章以广州国际会展中心E区张弦梁屋盖为研究对象,根据测压风洞试验确定最不利风荷载时程作为主要环境荷载,建立动力优化数学模型,以钢管厚度为设计变量,以构件内力和变形作为约束条件,以结构总体积为目标函数,采用复形法进行抗风优化,得到E区屋盖的抗风设计最优方案.研究表明:抗风优化大大减小了结构总体积,节约了用钢量,并使杆件受力得到较好协调,有效利用了材料性能.结构最大竖向挠度明显降低,因此提高了结构安全性.

Structural wind resistant optimization is confined to tall buildings by equivalent static wind loads, and studies on long span roof structures and optimization algorithms are rare. The wind resistant optimization of the long span roof of E area of Guangzhou International Convention ＆ Exibition Center is studied in the paper. The most unfavorable wind pressure time histories from wind tunnel tests are set as the environmental loads. Then the mathematical model of dynamic optimization for the complex method is built to obtain the optimum structure for wind resistance. In the model, the thickness of steel pipe is design variable, the internal forces and deforma- tion are the constraint conditions, and the total volume of structural members is the object function. The results show that the total volume is greatly decreased by the optimization, so the steel consumption is saved. Mean- while, the internal forces are well coordinated, and the materials are efficiently used. The maximum vertical displacement is obviously lowered, enhancing the structural safety.