Numerical Modelling and Validation of Built‐up Cold‐formed Steel Members Assembled by Laser Welding

The paper presents recent experimental tests and numerical simulations on built‐up cold‐formed steel elements assembled by laser welding, developed within the CEMSIG Research Centre of the Politehnica University Timisoara. The study focuses on numerical simulations on beams, columns, and joints, aiming to extend the application of cold‐formed steel from traditional secondary uses (facades, racks, and non‐structural walls) to primary structural systems such as portal frames. The main objective is to develop and validate the preliminary finite element models for laser‐welded built‐up cold‐formed steel members, and to investigate the influence of key parameters on failure modes, load‐bearing capacity, and system deformability. The experimental and numerical results demonstrate improved material efficiency, enhanced joint stiffness, and favourable cyclic behaviour compared to conventional assembly techniques. The findings highlight the advantages of laser welding as an innovative assembly technology for cold‐formed steel structures and confirm the feasibility of laser‐welded systems as a competitive alternative for primary structural applications, including portal frames.