Novel Imperfection Method for Post-Buckling Strength of C-Sectioned CFS Members

The overall behavior of cold-formed steel (CFS) members is significantly affected from existing geometric imperfections. In this work, a mode shape-based imperfection coefficient computation method is developed to investigate the effects of initial geometric imperfections on member behavior. The point clouds of CFS members are collected and used to extract imperfection distributions and coefficients. The computed coefficients are integrated into the numerical model for analysis. Finally, axial loading tests are conducted to compare the numerical and experimental results. The results obtained using mode shape-based imperfection coefficients are generally closer to the experimental results than the common method used in practice.