6. Summary of results

The results obtained are in perfect agreement between*Code_Aster* -Umat and*Code_Aster.*

The two models of large deformations (SIMO_MIEHE and GDEF_LOG give different results (8 to \(\text{9\%}\) difference) which is explained by the difference in elasticity formulation (one being hyper-elastic and the other hypo-elastic). This test actually shows the possibility of using UMAT in large deformations.