开孔冷弯薄壁C型钢压弯构件的数值分析和设计方法

Numerical Analysis and Design Method of Cold-Formed Thin-Walled C-Section Steel Perforated Member

冷弯薄壁型钢结构因自重轻、强度高、便于施工等优点在国内外应用广泛,腹板开孔的C型截面构件常作为其承重构件.为了研究局部、畸变、整体屈曲以及各屈曲间相关作用对冷弯薄壁型钢压弯构件的影响,基于数值模拟方法,针对开孔冷弯薄壁C型压弯构件进行弹性和弹塑性分析,研究开孔形式、大小、位置对其性能的影响.根据数值分析结果,对无孔冷弯薄壁型钢轴压构件的直接强度法(DSM)公式进行了修正.结果表明:数值模拟结果与试验结果较为一致,验证了数值模型的准确性;开孔会对构件的临界荷载产生一定影响,并且会降低构件的承载力.本研究得到了开孔冷弯薄壁C型钢压弯构件的DSM设计公式,并揭示了其畸变-整体屈曲相关作用机制.

Cold-formed thin-walled steel structure is widely used because of its light weight,high strength,and easy construction.C-section member with web perforate is commonly used as a load-bearing member in cold-formed thin-walled steel structures.To investigate the influence of various buckling modes,i.e.,local,distortional,global buckling and their interactions,on the behaviour of cold-formed steel beam-columns,a numerical study was undertaken to analyze the elasticity and elastoplasticity of cold-formed thin-walled C-section steel perforated member and investigate the influences of hole size,position and form on the member performance.Based on the numerical study,the direct strength method(DSM)curve for the compression member without holes was modified.The results show that the numerical model is verified by the existing test data.The holes will have a certain impact on the critical load of the member,and will reduce the bearing capacity.This study proposes the associated DSM design curve in cold-formed thin-walled C-section steel perforated member,and reveals the associated distortional and global buckling mode interactions.