风雪荷载作用下柱面网壳结构的动力倒塌分析

Dynamic collapse analysis of single-layer cylindrical reticulated shells under the combination of wind and snow loads

动力倒塌分析是空间结构研究的重要课题之一。动力失效破坏临界风速是网壳结构抗风雪设计的重要依据。本研究基于非线性有限元理论和弹塑性动力响应时程分析理论,模拟了具有时空相关性的随机风速时程曲线,考虑了均布雪荷载在网壳表面的不同分布,建立了三向网格单层柱面网壳结构有限元模型。对比分析了在不同均布风雪荷载组合作用下网壳结构整体稳定性的影响,结果显示,单层柱面网壳在迎风面有雪荷载作用时的失效破坏临界风速最小,而在背风面有雪荷载作用时的失效破坏临界风速最大。

Dynamic collapse analysis is one of the important research topics in space structures. Critical wind velocity of dynamic failure is a vital factor for the wind and snow resistance de- sign of reticulated shell structures. In this paper, based on the nonlinear finite element meth- od and the theory of elastic-plastic dynamic response time history analysis, the random velocity-time curve correlated with space was simulated. With the consideration of different distri- butions of uniform snow load on the surface of the reticulated shell, a finite element model was therefore established for three-way single-layer cylindrical reticulated shells. The influ- ence of different wind and snow load combinations to the overall stability of single-layer lat-ticed structure was compared and analyzed. Comparison of the ultimate bearing capacity showed that, for single-layer cylindrical reticulated shells, the critical wind velocity of dynam- ic failure on windward side with snow loads was much lower than that on leeward side with snow loads.