冷弯薄壁卷边槽钢轴压构件畸变与局部相关屈曲试验研究

对卷边尺寸不同的两类腹板中间设置加劲卷边槽形截面，共18个冷弯薄壁型钢固支轴压试件进行畸变屈曲与局部屈曲相关作用的静力试验研究。得到试件的屈曲模式、相关屈曲行为、破坏模式以及极限荷载。试验结果表明：畸变屈曲与局部屈曲的耦合相关对试件的变形和极限荷载有不利作用；畸变屈曲与局部屈曲的耦合相关作用存有较大的屈曲后承载力；畸变屈曲与局部屈曲的耦合相关顺序，即畸变屈曲 局部屈曲耦合相关、局部屈曲 畸变屈曲耦合相关，对试件的变形、非线性平衡路径、破坏模式以及极限荷载的影响有所不同。采用ABAQUS有限元软件对试件进行模拟分析，计算结果与试验结果吻合良好。

Experimental investigation of cold-formed thin-walled lipped channel steel columns experiencing local-distortional interactive buckling under axial compression

This paper describes a series of compression tests conducted on lipped channels with stiffened-web fabricated from mild steel plate of thickness 1.5 mm with nominal strength Grade Q345. A total of 18 channel specimens including two cross-section dimensions with three different column lengths were tested to failure with both ends of the column fixed, in order to determine the structural behavior and ultimate strength of cold-formed thin-walled steel columns experiencing post-buckling mode interaction between local and distortional buckling, due to the closeness of the critical buckling stresses. Test results consist of the column geometries, material properties, initial geometrical imperfections, non-linear equilibrium paths, deformed configuration, collapse modes and ultimate strength values. The results indicate that the column specimens undergoing interaction between local buckling and distortional displayed a significant post-buckling strength reserve. Moreover, the adverse interaction of local and distortional buckling reduced significantly the ultimate strength of the column specimen. Most of all, the post-local buckling interaction with distortional buckling (L+D) and the post-distortional buckling interaction with local buckling (D+L) have different effects on structural behavior, collapse mechanism, and failure load. Besides, the tested specimens were simulated by means of finite element program ABAQUS. Results from the analysis agree well with the experimental data.