Experimental and Numerical Methodology for Assessing the Bending Behaviour of Thin-Walled Steel Angle Members: A Representative Case Study

This study investigates the bending response of a thin-walled asymmetric cold-formed steel angle using a combined experimental and numerical approach. Full-scale four-point bending tests were carried out on an L180 × 130 × 3 cold-formed steel angle and compared with numerical simulations using shell finite element models developed in ANSYS 2025 R2 and simplified beam-based models implemented in ARSAP. The experimental results showed that the load-carrying capacity, reaching approximately 25–27 kN, is governed by the interaction of global bending and local buckling of the compressed walls, leading to a pronounced post-peak softening response. The ANSYS shell finite element models accurately reproduced both the initial stiffness and nonlinear deformation mechanisms. The best agreement with the experimental force–displacement response was obtained for an effective load eccentricity in the range of 15 to 18.5 mm, which reflects realistic load transfer and contact conditions and results in errors below 10% in terms of stiffness and peak load. In contrast, the beam-based models captured the elastic behaviour but showed limited capability in reproducing local instability effects and post-peak response. The study is intentionally limited to a single geometry and loading configuration and should be interpreted as an experimentally calibrated case study. The obtained results allow the applicability limits of simplified beam models to be identified and confirm the necessity of shell finite element modelling for the analysis of thin-walled asymmetric steel angle members subjected to bending.