基于激光扫描的轻型模块柱初始缺陷分析及轴压稳定性能研究OA

Lightweight modular steel structures commonly use asymmetric cold-formed thin-walled steel columns,of which the axial compression bearing performance is significantly influenced by initial geometric imperfections.In this paper,full-scale axial compression tests are conducted on commonly used asymmetric cold-formed thin-walled single columns in lightweight modular steel structures,as well as on assembled columns combining long-limb and short-limb sections with practical end bolted connections,and the influence of initial geometric imperfection is also analyzed.Before testing,high-precision 3D laser scanning technology was utilized to measure the geometric morphology of modular columns before and after installation,to extract initial imperfection characteristics and obtain geometric elevation deviations.Reverse reconstruction modeling,which transforms scanned point cloud models into finite element models,was applied to introduce actual initial imperfections.An improved modal method was also proposed,and the results were compared with models using traditional imperfection involvement method.The results indicate that the initial imperfections of open-section cold-formed thin-walled modular columns can be categorized into three distinct types.The axial compression failure modes under practical installation boundary primarily involve global flexural-torsional buckling triggered by bending deformation of the long-limb plates.Comparative analysis demonstrates that the reverse reconstruction modeling method effectively predicts both the failure modes and bearing capacity of modular columns.Furthermore,the improved modal method exhibits higher accuracy in bearing capacity prediction compared to traditional approaches.