高强冷弯薄壁型钢卷边槽形截面轴压构件畸变屈曲控制试验研究

针对屈服强度550MPa高强冷弯薄壁型钢轴压构件提出了一种控制畸变屈曲的构造措施--在卷边间设缀板，并通过试验对其有效性进行了验证。试验结果表明：屈服强度550MPa高强冷弯薄壁型钢卷边槽形截面轴压构件易发生畸变屈曲，通过构造措施能有效地阻止翼缘的转动，试件的畸变屈曲荷载和极限承载力都有很大的提高；随着缀板布置间距的不同，构件承载力的提高幅度也不同；缀板间距越小，试件承载力提高越多，但当缀板间距大于畸变屈曲半波长时，缀板不能起到提高承载力的作用。最后，在此基础上提出了构件不考虑畸变屈曲影响的若干条件，供实际设计参考。

Experimental study on distortional buckling control for high-strength cold-formed thin-walled steel lipped channel columns subject to axial compression

In this paper, a countermeasure to restrain the occurrence of distortional buckling of 550 MPa high-strength cold-formed thin-walled steel columns by setting batten sheets between two lips is presented, and a series of tests was carried out to investigate its validity. Results show that, distortional buckling is a common buckling mode for 550 MPa high-strength cold-formed thin-walled steel columns, the suggested countermeasure can be valid to prevent the rotation of flanges, which lets the elastic distortional buckling load and the ultimate bearing capacity of axially-compressed members increase evidently; With the intervals of batten sheets adjusted, the corresponding load-carrying capacity improvement is obviously different; Generally, the load-carrying capacity improvement is higher as the interval decreases, but when the interval exceeds the half-wave length of distortional buckling of the sections, the batten sheets may have very limited, even no effect on the ultimate bearing capacity of axially-compressed members. Finally, based on above study, some conditions that the effect of distortional buckling can be ignored were presented for giving further reference to practical design.