The Vegter Lite material model: simplifying advanced material modelling

The need for cost reduction and increased fuel efficiency in the automotive industry has lead to an increased importance of accurate simulations and the need for more advanced material models to achieve highly reliable forming and springback predictions. Conventional material models implemented in FE-codes are in general not capable of describing the plastic material behaviour during monotonic strain paths with sufficient accuracy. This applies to the strain hardening model, the influence of strain rate and the description of the yield locus in these models. This led to the development of the Vegter yield criterion. For the determination of parameters, mechanical tests at different strain paths (uniaxial, plane strain, equibiaxial and shear) are required. Until now the high accuracy of the Vegter yield criterion was only available if all parameters were determined. However, due to the limited availability of the large number of tests methods needed for this material model not all parameters are always determined. For maintaining high accuracy with a reduced set of parameters, the Vegter Lite model was developed.