Length changes and texture prediction during free end torsion test of copper bars with FEM and remeshing techniques

FEM numerical simulations of the experimental free end torsion tests [Toth, L.S., Jonas, J.J., Daniel, D., Bailey, J.A., 1992. Texture development and length changes in copper bars subjected to free end torsion. Textures Microstruct. 19, 245–262] of copper cylindrical bars were analysed in the present study. The self-made Finite Element (FE) code LAGAMINE was used to compute numerical prediction of the Swift effect, i.e. the lengthening of the cylinder during the torsion. The material behaviour was represented by an interpolation law [Habraken, A.M., Duchêne, L., 2004. Anisotropic elasto-plastic finite element analysis using a stress–strain interpolation method based on a polycrystalline model. Int. J. Plasticity 20 (8–9), 1525–1560] linked with a Taylor polycrystal plasticity model either based on a strain rate insensitive or a visco-plastic crystal plasticity model. The influence of texture evolution was analysed. A torsion dedicated remeshing technique was developed to allow very large strain simulations. Predicted axial lengthening and predicted textures were compared to experimental measurements. A good agreement was obtained for shear strain up to 2.0. The Swift effect related angular shift of the pole figure maxima from symmetrical orientations was reproduced correctly.