ABSTRACT
It is a well known fact that cold-formed steel members subjected to compression are sensitive to geometrical imperfections, due to their often slender cross-sectional proportions. In both research and design such geometrical imperfections are most commonly introduced as eigenmodes obtained from linear buckling analyses. However, the reason for introducing imperfections as eigenmodes are grounded in practical reasons rather than the actual physics of imperfections. This can lead to incorrect or conservative representations of the actual distribution of imperfections. A more accurate way to include geometrical imperfections in simulations is to generate a point-cloud, representing the true geometry of the member, with a 3D laser scanner. In this paper a lipped C-channel cold-formed from high strength steel is scanned using a hand-held 3D laser scanner. The scans are used to create a true geometry mesh, to be used in non-linear finite element analysis using the finite element software Abaqus. Using a 3D laser scanner to generate a true geometry mesh of the member, is proved to be an efficient and accurate way to represent a true geometry model in numerical simulations. The channel with high strength steel poses a large post-critical reserve, due to the increased yield stress. Additionally, models with HFMI treated corners are presented and simulated as well. A significant increase in collapse capacity, is shown for models with HFMI treated corners.
