腹板开孔冷弯卷边槽钢轴压构件受力性能及设计方法

Mechanical Behavior and Load-carrying Capacity Analysis on Cold-formed Thin-walled Steel Lipped Channel Columns with Slotted Holes under Axial Compression

对26根腹板开长圆孔和未开孔冷弯薄壁型钢截面轴压构件进行承载力实验研究,分析构件的屈曲模式和极限承载力.利用我国现行国家规范《冷弯薄壁型钢结构技术规范》GB50018—2002、北美冷弯钢结构构件设计规范AISI S100—2012计算构件承载力并与非线性有限元数值模拟结果及实验结果进行分析比较.在此基础上,对腹板开长圆孔冷弯薄壁型钢截面轴压构件的承载力合理计算模式进行研究.结果表明:对于中等长度腹板开孔,冷弯薄壁型钢截面轴压构件主要出现局部、畸变和整体屈曲的相关作用;腹板开孔对构件畸变屈曲稳定承载力有一定的降低作用;采用折减构件有效截面面积的修正方法可计算开长圆孔构件的畸变屈曲稳定承载力;非线性有限元可用于腹板开孔冷弯薄壁型钢构件的屈曲模式和极限承载力的分析.

The objective of this paper is to research load-carrying capacity of cold-formed thin-walled steel members with slotted holes.Compression tests are conducted on 26 intermediate length columns with and without web slotted holes.For each specimens,a shell finite element eigen buckling analysis and nonlinear analysis is also conducted such that the influence of the hole on local,distortional,and global elastic buckling response can also be captured.The comparison on ultimate strength between test results and calculated results using Chinese code Technical code of cold-formed thin-wall steel structures GB 50018—2002,North American specification for the design of cold-formed steel structural members AISI S100—2012and nonlinear Finite Element method is made.The calculated method for cold-formed thin-walled steel columns with web slotted holes is proposed.The results show that the interaction of local buckling,distortional buckling,and overall buckling usually will occur for the intermediate length axial compression;the web holes have a litter influence on the distortional buckling ultimate strength of columns;the ultimate strength can be predicted using a reduced effective area,and the nonlinear Finite Element method can be used to analysis the buckling mode and ultimate strength of cold-formed steel members with holes in web.