Machining-induced residual stress: Experimentation and modeling

Controlled orthogonal and controlled oblique machining of annealed AISI 4340 have been undertaken in a design of experiments framework to investigate the machininginduced residual stresses resulting from these processes. The experimentation demonstrates significant simplifications in the machining-induced residual stress problem when the stresses are expressed in a coordinate system fixed in the tool and also indicates that the directions along the cutting edge and normal to the cutting edge of the tool are principal directions of the machining-induced residual stresses. Based on the experimental results, a plane strain thermoelastoplastic model of metal flow under the flank of a cutting tool is developed to predict the full in-plane biaxial residual stress profiles existing at and beneath the newly created surface. Calibrated results show favorable agreement with the experimental machining-induced residual stresses in annealed AISI 4340.