Formulation to control mesh distortion in finite element simulation of 3D metal-forming problems

Finite element method simulation of large deformation processes as metal forming has to deal with the problem of high mesh distortion during the analysis. This distortion damages the quality of results or even makes the simulation impossible. The Arbitrary Lagrangian Eulerian (ALE) Formulation proposed in this work consists of relocating mesh nodes at each time step during the simulation. Mesh motion is performed by new nodal relocation methods, developed for eight-node hexahedral elements, that take into account geometric aspects and plastic strain results to avoid distortion. These relocation methods can move internal and boundary nodes improving and concentrating the mesh in critical zones. They are also applied for contact problems. The work presents the technique proposed and results of 3D problems that show the method efficiency.