Investigation of the behavior of C-section cold-formed steelprofiles under axial and eccentric loading

In this thesis, the buckling behavior of cold-formed steel (CFS) beam-column members with lipped channel sections under the combined effect of axial load and biaxial bending moment (P-Mx-My) is investigated. A total of 30 members, each 1500 mm in length, were experimentally tested under monotonic and cyclic loading. The local, distortional and global buckling modes that determine the bearing capacity of the section and the length of the lipped channel member in which all these buckling modes can be seen were determined. Finite element analysis (FEA) was performed with Abaqus software, and the numerical results were verified with the experimental results. Using the validated finite element model, a comprehensive parametric study was carried out by performing 345 FEA on sigma and lipped channel section members with various cross-sectional dimensions and lengths. The experimental results show that significant differences in load bearing capacity, energy absorption capacity and buckling modes occur even for the smallest eccentricity variation. At the end of the parametric study, monotonic and cyclic experimental and numerical studies generally show that the energy dissipation capacity of P members is higher than that of N members. As a result of the studies, the buckling properties of cold-formed steel beamcolumn members have been determined to a large scale. Keywords: CFS, lipped channel section, monotonic loading, cyclic loading, finite element analysis