网壳结构施工过程易引发杆件弯曲关键因素研究

Research on key factors of bar bending in construction process of reticulated shell structure

为合理评估杆件弯曲对网壳结构力学性能的影响,并对存在杆件弯曲缺陷的网壳结构进行有效的加固设计方案,有必要对杆件弯曲机理进行研究。通过对某双层螺栓球节点网壳结构进行施工全过程精细化模拟,分别从施工方法、温度效应以及支座节点性能对结构的静力性能影响进行了分析。结果表明:考虑内扩悬挑施工方案的影响后,杆件最大应力增大29%,结构最大位移增大11%;下部网壳对温度效应较为敏感,随着环境温度的升高,温度应力相比合拢时增大3.7倍;当支座构造高度过大,考虑支座节点影响后,支座位移变化明显,与支座相连的杆件迅速屈服。因此,设计和施工此类网壳结构时,应合理考虑上述因素的影响。

In order to evaluate the effect of bar bending on the mechanical properties of the reticulated shell structure and to carry out effective reinforcement design for the reticular shell structure with bar bending defects, it is necessary to study the bending mechanism of bar. The effect of construction method, temperature effect and bearing node performance on the static performance of a double-layer bolted ball node mesh shell structure was analyzed through the fine simulation of the whole construction process. The results show that the maximum stress of the bar increases by 29% and the maximum displacement of the structure increases by 11% after considering the influence of the overhanging construction scheme. The lower reticulated shell is sensitive to the temperature effect. With the increase of ambient temperature, the temperature stress increases by 3.7 times compared with that of closing. When the bearing structure height is too high, the bearing displacement changes obviously after considering the influence of bearing nodes, and the bar connected with the bearing rapidly yields. Therefore, the influence of the above factors should be considered reasonably when designing and constructing this kind of reticulated shell structure.