3D simulation of adiabatic shear bands in high speed machining

Fabien Delalondre (1) , Simon Guerdoux (1) , Lionel Fourment (1)

1 CEMEF - Centre de Mise en Forme des Matériaux

A finite element model of three-dimensional high speed machining is developed. In order to catch Adiabatic Shear Band (ASB), which is about few microns wide, the simulation uses mesh adaptation triggered by an isotropic error estimator. An enhanced version of the Zienkiewicz and Booromand REP in Patches technique is used. As ASB is a much localized phenomenon, the adaptive procedure provides highly refined meshes with strong gradients of the element size, which makes it quite difficult to produce satisfactory 3D meshes. Furthermore, high speed machining leads to very important values of strain rate, deformation and possibly to extreme mesh distortion. So, an Arbitrary Lagrangian Eulerian (ALE) method is employed. With the utilized splitting method and linear finite element interpolation, the transport of nodal variables is based on the gradient calculated in the upwind element. For variables stored at the integration points, a remapping procedure using patch recovery techniques is preferred. Finally, because of the very strong thermo-mechanical coupling taking place in ASB, several thermo-mechanical coupling schemes are studied. Explicit and fully implicit schemes are compared, showing that the second one offers a stabilizing effect and a better accuracy. All of these ingredients provide a fully automatic and process independent procedure which allows detecting and following the formation of Adiabatic Shear Band in High Speed Machining. The creation of 3D segmented chip is observed and compared to 2D reference results obtained by Baker in [1]. The influence of numerical coefficients like the mesh size is investigated. Other application to actual 3D high speed machining such as blanking is also presented.

Mots clés: 3D meshing; Adaptive remeshing; Adiabatic shear band; ALE formulation; Error estimation; High speed machining; Implicit thermomechanical coupling; Segmented chip

Domaines: Matériaux

Fabien Delalondre, Simon Guerdoux, Lionel Fourment. 3D simulation of adiabatic shear bands in high speed machining. Materials Processing and Design, Modeling, Simulation and Applications, NUMIFORM '07: 9th International Conference on Numerical Methods in Industrial Forming Processes, Jun 2007, Porto, Portugal. pp.Pages 1137-1142, ⟨10.1063/1.2740963⟩. ⟨hal-00510568⟩