Towards material flow prediction in friction stir welding accounting for mechanisms governing chip formation in orthogonal cutting

Abstract

A new approach to integrate the damage in a 3D friction stir welding model within the coupled Eulerian–Lagrangian (CEL) framework is proposed. The novelty is represented by the employed damage criteria accounting for the mechanisms governing chip formation in orthogonal cutting. Material flow is correctly predicted with the new approach avoiding the problems encountered when neglecting damage or when including it through the traditional approach (Johnson–Cook failure criterion for initiation and energy criterion for evolution). The model can simulate in-plane forces and nugget zone width according to the experiments. The maximum equivalent plastic strain is estimated in the flow arm zone, due to the simultaneous action of pin and shoulder. Additionally, it is demonstrated the importance in mesh element size if material flow is investigated through CEL models. The elements in the interaction zone must be sufficiently small for describing the cyclical layer deposition at each tool rotation.