Influence of Spatial Grain Orientation Distribution on Sheet Metal Necking

Necking under in-plane plane strain tension along the transverse direction (TD) is numerically simulated for two sheets: one with very high Cube (HC) and the other with low Cube (LC). To do so, the EBSD measurement is performed in the TD-ND (normal direction) section for the sheets. The EBSD map (grain orientations and their spatial distributions) is directly implemented into the crystal plasticity based finite element code. More specifically, the measured orientations are assigned to elements in the mesh according to their positions. The values of the material parameters in the crystal plasticity model are determined by curve-fitting numerical simulations of uniaxial tension in the rolling direction (RD) to corresponding experimental data. The effect of spatial grain orientation distribution on necking is emphasized. It is found that both the global averaged texture and its spatial distribution are important to the onset of necking. The predicted results are in good agreement with experimental observations.