Compression tests and numerical analysis of web-stiffened channels with complex edge stiffeners

The paper describes a series of pin-ended compression tests and numerical analysis of channels with complex edge stiffeners and two different types of web stiffeners. In the tests, axial compression and eccentric compression loading were imposed respectively on 18 and 12 specimens. The stability capacity, buckling mode and deformation behavior of these specimens were studied. It was found that the longitudinal intermediate stiffeners could reduce the web width-to-thickness ratio effectively and enhance the stability capacity of members subjected to axial loading or eccentric loading with the eccentricity close to the web side. Compared with channels with complex edge stiffeners under the same condition, the ultimate load-carrying capacity of Σ shape section members and members with V type web stiffeners was increased by 65% and 50%, respectively. But distortional buckling of the complex section member was the governing failure modes of the specimens. Tests were then simulated by finite element analysis. The numerical analysis results show good agreement with experimental results. Furthermore, parametric study on a total of 144 samples was conducted to obtain the optimal web sub-element proportion for Σ cross-section columns. •Complex section shape made distortional buckling control the failure modes.•The ultimate load of C2 members is about 65% higher than that of C1 members.•The ultimate load of C3 members is about 50% higher than that of C1 members.•Tests were simulated by finite element analysis.•The optimal web sub-element proportion of Σ section was determined.