Philippe Bussetta

3D numerical models of FSW processes with non-cylindrical pin

Abstract Friction stir welding (FSW) process is a relatively recent welding process (patented in 1991). FSW is a solid-state joining process during which materials to be joined are not melted. During the FSW process, the behaviour of the material is at the interface between solid mechanics and fluid mechanics. In this paper, a 3D numerical model of the FSW process with a non-cylindrical tool based on a solid formulation is compared to another one based on a fluid formulation. Both models use advanced numerical techniques such as the arbitrary Lagrangian–Eulerian formulation, remeshing or the orthogonal sub-grid scale method. It is shown that these two formulations essentially deliver the same results.

3D numerical models using a fluid or a solid formulation of FSW processes with a non-cylindrical pin

Friction stir welding process is a relatively recent welding process (patented in 1991). FSW is a solid-state joining process during which materials to be joined are not melted. During the FSW process, the behaviour of the material is at the interface between solid mechanics and fluid mechanics. In this paper, a 3D numerical model of the FSW process with a non-cylindrical tool based on a solid formulation is compared to another one based on a fluid formulation. Both models use advanced numerical techniques such as the Arbitrary Lagrangian Eulerian formulation, remeshing or the Orthogonal Sub-Grid Scale method. It is shown that these two formulations essentially deliver the same results.

Numerical Simulation and Visualization of Material Flow in Friction Stir Welding via Particle Tracing

This work deals with the numerical simulation and material flow visualization of Friction Stir Welding (FSW) processes. The fourth order Runge- Kutta (RK4) integration method is used for the computation of particle trajectories. The particle tracing method is used to study the effect of input process parameters and pin shapes on the weld quality. The results show that the proposed method is suitable for the optimization of the FSW process.

Two 3D thermomechanical numerical models of friction stir welding processes with a trigonal pin

ABSTRACT During the friction stir welding (FSW) process, the behavior of the material is at the interface between solid mechanics and fluid mechanics. This article deals with a comparison of two 3D numerical models of FSW processes with a trigonal pin. The first model is based on a solid formulation and the second one is based on a fluid formulation. Both models use a Norton–Hoff constitutive model with the high temperature sensitivity of the parameters’ value and advanced numerical techniques such as the Arbitrary Lagrangian Eulerian (ALE) formalism. It can be concluded that, basically, these two formulations lead to the same results.

Modeling Thixoforming Process Using the eXtended Finite Element Method and the Arbitrary Lagrangian Eulerian Formulation

This contribution proposes to model thixoforming processes using the eXtended Finite Element Method (X-FEM). The X-FEM is very suitable for modeling forming processes with complex tool geometries as the mesh does not need to conform with the boundary of the structure. Even if the use of the X-FEM helps to describe the boundary position, the mesh still deforms when the structure is stressed. To avoid mesh distortions that appear in large deformation analysis, an Arbitrary Lagrangian Eulerian formulation is used (ALE) [3].