Analytical modelling of residual stresses in machining

Abstract

An analytical model is developed for prediction of residual stresses in machining. In the thermo-mechanical model of residual stresses both the thermal field of the workpiece and mechanical cutting forces are coupled. The shear energy created in the primary shear zone, the friction energy produced at the rake face-chip contact zone, the heat balance between the chip, tool and workpiece are considered based on the first law of thermodynamics. The temperature distributions on the workpiece, tool and chip are solved by using finite difference method. The calculated workpiece temperature field is used in thermal load calculations. Stresses resulting from thermal and mechanical loading are computed using an analytical elasto-plastic model and a relaxation procedure. The model is verified with experimental measurements of residual stresses on bearing steel 100Cr6 (JIS SUJ2) in the literature. With the analytical model presented here, substantial reduction in computational time is achieved in the predictions of residual stresses.