Case study: Impact of flame straightening on performances of preset beam ends in a steel corridor

Abstract Flame straightening corrects deviations in steel structures but induces residual stresses and microstructural alterations, potentially affecting safety. This study evaluates its impact on preset beam ends for a steel corridor connection. Deviations resulted from differential building settlement and thermal torsional deformation. A cyclic vein heating process (up to 800 °C) was simulated on a Q355B steel beam end using Abaqus coupled temperature–displacement analysis to generate the residual stress field, which was then used as an initial condition in mechanical analysis. The bearing capacity, energy dissipation under cyclic loading, and fatigue life under wind loads were compared before and after straightening. Results indicate that flame straightening has negligible effects on ultimate bearing capacity and displacement ability. It may slightly enhance energy dissipation at small displacements due to earlier localized yielding. Importantly, while fatigue life remains adequate for designed wind loads, it degrades significantly under high‐stress fatigue conditions. Thus, flame straightening is a viable correction method under moderate service loads but is not recommended for members experiencing high‐stress dynamic or fatigue loading.