Possibilities of application of the multi scale strain localization CAFE model

Complex information about material behavior during deformation can be achieved by using finite element numerical simulations based on a realistic rheological model. However, when more complicated deformation process is being modeled, several phenomena, which are not accounted for in the reological model, can occur inside the sample. It is the reason why on going research in several laboratories focus on development of advanced rheological models, which are capable of including stochastic and discontinuous processes occurring in materials under thermo mechanical conditions. One of the solutions may be the rheological model based on the combination of the Cellular Automata (CA) technique and the Finite Element (FE) method [

1

]. Developed multi scale CAFE model for prediction of initiation and propagation of micro shear bands and shear bands in metallic materials subjected to plastic deformation is presented in this work. Such model was applied to real industrial processes, such as extrusion and rolling, and has proved its good predictive capabilities (Figure 1). As it is seen in the figure, in the CAFE approach a material flow in the area of high strain localization is higher than in the conventional FE approach. It is due to the simultaneous development of micro shear and shear bands in the material. It agrees well with the experimental observatios.

Figure 1.

Strain distribution obtained from the FE (right) and CAFE (left) approach in the extrusion process.