A Sensitivity Analysis on the Effect of Laser Power on Residual Stresses When Laser-assisted Machining AISI 4340

The current study investigates the effects of laser power on machining-induced residual stresses (RS), when laser-assisted machining AISI-4340. Finite element modelling was used, where different levels of laser power were simulated. First, the laser preheating effects were modelled, using DFLUX subroutine, followed by orthogonal cutting simulations, using ABAQUS/Explicit. Experimental RS measurements were used for model validation. A non-monotonic effect was found for the laser power on RS. Lower powers induced higher surface tensile RS compared to conventional machining; however, such stresses dropped with further increase in power. The RS results were explained in terms of plastic strain and temperature distributions.