基于多尺度模拟的铁路客站异形分叉柱稳定性分析OA

[Objective]Y-shaped forked columns,as a kind of tree-like load-bearing component,are increasingly applied in large-span railway passenger station structures.Ensuring their out-of-plane stability is particularly important for the overall structural safety.Existing research on the stability of forked columns mainly focuses on either the global structural model or local component analysis.The former fails to adequately consider the local mechanical characteristics and complex cross-sectional information of the components,whereas the latter cannot effectively simulate load transfer and the influence of global stiffness,which may lead to problems such as inaccurate analysis results.[Methods]Judging from the previous drawbacks,based on Rhino Grasshopper,for the special-shaped and variable cross-section forked columns in long-span railway passenger stations,a total of twelve forked columns with four variable cross-section forms were constructed.MIDAS Gen and MIDAS FEA were used to establish a multi-scale finite element model of the station building with special-shaped forked columns,and the stability performance of the forked columns was then analyzed.[Results]The results showed that the mode direction factor of Z-rotation in the first mode of the station building was 21.50%,indicating that the torsional coupling effect caused by the irregular plane layout was significant,and the adverse effects induced by eccentricity should be carefully considered in structural design.The large-span roof truss structure and steel pipe columns exhibited good deformation compatibility,and the load transfer mechanism of the whole structure was clear,indicating that the established multi-scale structure model was reasonable.The linear buckling eigenvalue of the forked column was 19.88,and the vertical ultimate bearing capacity was 51 220.62 kN.After considering the influence of initial defects,the ultimate stability bearing capacity of the most unfavorable forked column decreased by 33.5%.After considering geometric nonlinearity,the ultimate stability bearing capacity of the most unfavorable forked column decreased by 22.48%,but it still featured enough safety reserves,which demonstrated that the design of the forked columns met the specification requirements and the design method was reasonable.[Conclusion]The research findings provide guidance for the calculation of special components in complex long-span structures.