Determination of constitutive equation at the deformation of materials using the compression test

Numerical simulation is a modern method to optimize cold plastic deformation processes in order to provide product quality, reduction of time and costs of execution. One of the important problems of numerical simulation is the mode of characterizing the plastic behaviour of the material which undergoes deformation. The results obtained through simulation are closer to real ones as the description of material behaviour of the piece is done as accurately as possible. The simulation results depend on the stress-strain relationship which is obtained experimentally by compression tests. The paper presents the mode of determining the constitutive equation starting from the results of the compression test. This test was used because it allows achieving high strain and the stress distribution is similar to other corresponding plastic deformation processes.