Abstract
Proposition of a new material model accounting for twinning and slip is described in the paper. The model was developed on the basis of physical and numerical simulations of hot deformation of magnesium alloy. Slip is base deformation mechanism in a majority of alloys but twinning occurs for example in some special steels or in the investigated in the present work magnesium alloys. The model is based on the internal variable method. This method is well researched for slip. In the proposed model twinning is treated as pseudo-slip with the twins volume fraction being a dependent variable. Experimental tests for the AZ31 alloy were performed and inverse analysis was applied for identification of the models parameters. The results obtained for the closed form equations and for the internal variable model are compared in the paper. It is shown that the latter model accounts for accommodation of strains by twinning and better reproduces behaviour of the alloy at the beginning of deformation.