Friction stir welding induced residual stresses in thick steel plates from experimental and numerical analysis

Friction stir welding induces a relatively low level of deflection, and residual stresses and recent advances in the welding technology has shown that friction stir welding may now be broadly used in steel welding leading to significant improvement of the welding quality for new constructions and repairs. In the present study experimental and numerical analyses of friction stir welding in thick steel plates are performed. A finite element model is developed, based on a new heat input source mathematical formulation, accounting for the welding transient thermo-mechanical process of the friction stir welding-induced residual stresses. The welding-induced residual stresses, estimated by the new developed finite element model, are compared with the experiment. The present study shows that the newly developed heat source finite element model demonstrates an acceptable agreement between the numerical and experimental results. A sensitivity analysis concerning the essential governing parameters predicting the friction stir welding - induced residual stresses is also addressed.

Automated summary

Friction stir welding has shown significant improvement in steel welding, with experimental and numerical analyses confirming the accuracy of the welding-induced residual stress model, and a sensitivity analysis being conducted on essential governing parameters.