预应力对柱支承扁网壳静力性能的影响

沿柱支承钢扁网壳的拉力环域施加适当预应力能降低结构在使用阶段的变形。以预应力三阶段设计为例分析预应力施加对柱支承扁网壳静力性能的影响。结果发现,预应力可以降低支座水平推力,提高结构刚度,但同时增大了结构在负风压作用时的变形,加大了支座附近杆件的轴力。预应力不能有效提高结构的临界荷载。与其他布索方案相比,折线形索-桁方案对网壳变形控制更有效。

Effect of Prestressing on Static Performance of Column-supported Shallow Steel Lattice Shell Roofs

It can efficiently control the structural deformation at serve period by suitably prestressing a shallow steel lattice shell along its tension stress trajectories.The effect of practical prestressing on the static specialties of a kind of column-supported lattice shallow spherical shells is studied through the example of three-phase prestressing design.Analysis results show that: 1) suitably prestressing a column-supported shallow shell can well control the deformation of the shell and can lower its bend moment at edge regions,but the internal force of many bars close to the shell supports are significantly enlarged; 2) prestressing cannot efficiently increase the critical load and significantly change the relationship curve of load-displacement;3) it can control the deformation of the shell effectively by employing zigzag-string truss.