Strain, strain rate and velocity fields determination at very high cutting speed

High speed imaging is used for the purpose of examining the strain and strain rate variations in the primary shear zone at cutting speed of 1020 m/min. Experimental investigation focused on flow pattern describing the severe plastic deformation zone where a general streamline model is employed to investigate the distribution of velocity. Strain and strain rate distribution are directly deduced from the experimental observation of a cross-section of chip obtained through a high-speed camera system. The strain and strain rate gradients were analyzed along several streamlines. A finite element method model based on a Lagrangian formulation has been used to corroborate the conclusion of the streamline model. It has been found that the simulation results are similar to the experimental observations with regards to the magnitude of the equivalent strain rate and cumulative plastic strain but slightly differ in the geometry of flow pattern.