Numerical and Experimental Analysis of Residual Stresses in S235 Structural Steel Elements Cut Using Fiber Laser and Different Assist Gas

Abstract

Laser cutting is widely employed in the fabrication of structural‐steel components, yet the extreme thermal gradients generated during processing can induce tensile residual stresses that threaten dimensional stability and fatigue resistance. Although numerous studies have evaluated thermal behavior, surface morphology, or stress formation independently, there remains a lack of integrated assessments capable of linking transient heat input to the resulting mechanical response under realistic industrial conditions. To address this, the present work combines coupled thermo‐mechanical finite‐element simulations with in‐situ infrared thermography and X‐ray diffraction measurements on S235 steel, establishing a framework for examining how assist‐gas, power, and cutting speed influence temperature evolution and near‐edge stress development. This approach enables a more complete understanding of the thermo‐mechanical mechanisms governing residual‐stress formation and provides information of laser‐cutting parameters to reduce them.