节点轴向刚度对圆柱面巨型网格结构静力性能的影响研究

Static Performance Research on Cylindrical Reticulated Mega-structure with Semi-rigid Joints

分别利用弹簧单元和大面积梁单元模拟节点轴向刚度和节点域,建立轴向半刚性节点结构的数值分析模型,考虑几何非线性和初始缺陷的影响,进行承载全过程跟踪分析,研究节点轴向刚度对结构静力稳定性、内力和位移的影响。结果表明:轴向刚度对结构影响较大,随着轴向刚度增大,稳定承载力随之增大,杆件内力分布趋于均匀,结构位移减小。进而研究了常用焊接球轴向半刚性节点结构的静力性能。结果显示:考虑实际节点轴向刚度后,稳定极限承载力比节点轴向刚性最大降低30.4%,最大挠度增大16.9%,可见节点刚接或是铰接则过高估计了结构的性能,但经计算发现轴向半刚性节点结构仍然满足设计要求。

Using the spring and large section beam elements respectively to simulate the axial connection stiffness and panel zone, numerical model with semi-rigid joints is established. Considering the geometric nonlinearity and initial defects, the entire bearing process is analyzed and the static performance is studied based on the axial stiffness. The results show that the stability capacity improves, internal force distribution tends to he uniform and structural displacement decreases with the increase of axial stiffness. The performance of the common axial semi- rigid welded hollow spherical joint structure is discussed. Results display that, if the real axial stiffness is considered, the stable capacity decreases by 30.4% and the maximum displacement improves by 16.9%. So if the connections are regarded as perfectly rigid or frictionless pinned, it will improperly estimate the structural performance, however, by calculating, the semi-rigid node structure is still found to meet the design requirements.