某锥形穹顶半刚接单层网壳分析与设计

Analysis and design of the semi-rigid single-lager reticulated shell of a conical vault

以某图书馆的锥形穹顶单层网壳为研究对象,分析其受力变形性能和整体稳定性能。对比研究了不同截面方案和节点假定对网壳构件承载力、屈曲特性和极限承载力的影响。采用多尺度有限元分析方法,真实模拟节点性能,与节点刚接、铰接模型的计算结果进行了对比。结果表明:采用钢管非加劲相贯焊连接的单层网壳为典型的半刚接网壳,合理的杆件截面设计可使其整体稳定性能接近于节点刚接模型;节点铰接会改变单层网壳的屈曲形态,使结构整体协同性能严重弱化或丧失;多尺度有限元分析方法是判别节点刚度和承载力的有效方法,可真实反映节点性能对整体结构性能的影响。

Taking the conical vault of a library as the example,which fabricated by single-layer reticulated shell,its mechanical deformation and overall stability were analyzed.The effects of different section schemes and joint assumptions on the member bearing capacity,buckling characteristics and ultimate bearing capacity of reticulated shells were studied.The multi-scale finite element analysis method was used to simulate the real performance of the joints,the results from which were compared with the ones from the rigid model and pinned model.The results show that the single-layer reticulated shell connected by directed welded tubular joints is a typical semi-rigid reticulated shell,and its overall stability can close to that of the rigid model through reasonable section design.The hinged joints will change the buckling mode of the single-layer reticulated shell and make the overall coordination performance of the structure seriously weaken or lost.Multi-scale finite element analysis method is an effective method to identify the stiffness and bearing capacity of joints,and it can truly reflect the influence on the performance of the whole structure due to the real behavior of joints.