网壳结构考虑杆件失稳过程的整体稳定分析

Stability analysis method for lattice shells accounting for buckling of members

通过引入杆件初始缺陷的方法对杆件失稳过程及其对网壳结构整体稳定性能的影响进行分析。首先研究杆件的单元划分数量和缺陷幅值对杆件稳定承载力的影响,提出合理的缺陷幅值。进而计算分析了世博轴阳光谷网壳结构杆件失稳过程中的内力变化及对结构整体稳定性能的影响。结果表明,结构非对称、杆件截面有强弱轴的网壳结构易引起杆件失稳,网壳结构整体稳定分析中可通过对杆件施加初始缺陷有效地考虑杆件失稳对整体稳定性能的影响;对整体失稳之前存在杆件失稳的网壳结构,有必要引入杆件初始缺陷考虑杆件连续失稳的影响。最后提出了网壳结构稳定分析的合理计算流程。

The process of member buckling and its effect on overall stability of lattice shells was investigated by introducing initial imperfection in members. The determination of element mesh and imperfection amplitude was firstly discussed,and the rational imperfection amplitude was then investigated. The analysis of Sun-valley revealed the internal force variation during the process of member buckling and the influence of member buckling on overall stability of lattice shells. The results indicate that,members of asymmetric structures and members with major and minor axis are apt to buckle before overall buckling. In overall stability analysis of lattice shells,the effect of member buckling can be accounted for efficiently by introducing initial imperfection in members; for lattice shells where members buckle before overall buckling,it is necessary to introduce member imperfection to consider buckling of members. Finally,a reasonable calculation procedure for stability analysis of lattice shells was proposed.