Constitutive equations for finite element simulation

The necessity to simulate extrusion processes requires the knowledge of the material in terms of the constitutive equations. The present investigation deals with the development of a methodology based on the multivariable regression analysis in order to predict the flow behaviour of a ZEK200 Mg alloy in the interval of temperature varying between 150 and 450°C. The proposed models relate the flow curve levels with temperature, strain rate and deformation with the variables selected using the statistical method. It has been found that the proposed methodology allows the modeling of the flow behaviour of the Mg alloy under investigation from the beginning of the plastic deformation down to the softening phase taking into account the peak value. In addition, it is comparable, in terms of the temperature intervals considered in the modeling, with the Sellars and Tegart-based models.