Experimental and numerical studies on the axial compression behaviour of stub cold-formed steel lipped channels experiencing simulated web corrosion damage

Through a series of tests and numerical analyses, this study examines the axial compression behaviour of stub cold-formed steel (CFS) lipped channels subjected to simulated local web corrosion. In the tests, the random nature of local corrosion is simplified as a circumscribed rectangular defect with a constant corrosion depth. Corrosion degradation alters the load transfer path, causing stress concentration in the plate and promoting the early onset of local buckling, thereby reducing the ultimate resistance. As corrosion spreads increase, the ultimate resistance decreases significantly. A numerical study was conducted to assess the randomness of corrosion spread and location for subsequent parametric analysis. Finally, an equivalent thickness was introduced to account for the impact of local corrosion on the local buckling stress. The modified calculation method, validated by both experimental and numerical results, provides a practical, adaptable tool for predicting the ultimate resistance of stub CFS-lipped channels with simulated local web corrosion. This approach offers engineering implications by enabling corrosion-aware design and assessment of CFS members under service-degradation conditions.