Orthogonal cutting to develop a damage law for severe plastic deformation processes: application to friction stir welding

Damage laws built for numerical simulation are developed from mechanical testing, even if not consistently representative of extreme manufacturing conditions. A better representation of material plastic behavior may be withdrawn from orthogonal cutting, characterized by tool compressive and shearing actions on the workpiece during material removal and by an accessible tool-workpiece interaction zone. Thus, orthogonal cutting is used to develop the virtual frictional resistance (VFR) damage evolution law for an accurate description of chip generation mechanisms and extended to friction stir welding within the coupled Eulerian-Lagrangian framework. It considers the frictional resistance within an Eulerian material after full damage to substitute the mesh, explicitly describing the newly born interface interaction in a Lagrangian material. The damage law is inversely calibrated on orthogonal cutting tests allowing accurate chip generation mechanism predictions. The approach is then extended to a 3D friction stir welding model, improving the material flow simulation.