Mechanical behavior analysis of metallic materials using a Finite Element modeling of the SHPB test, a numerical calibration of the bar’s elastic strains and an inverse analysis method

For non-conventional or rapid forming processes important gradients of the plastic strain and strain rate can be reached, especially for severe loadings or complex deformation paths applied to the material. It is then required to improve the accuracy of the experimental data generally obtained from high speed mechanical tests as the Split Hopkinson Pressure Bar ones (SHPB). In the same time it is necessary to define quantitatively reliable rheological constitutive equations and adequate values of corresponding material coefficients. This paper proposes to use a Finite Element model for the simulation of the entire SHPB experiment based on a new calibration method of the raw measurements, together with some applications concerning the use of special specimen shapes in order to obtain large ranges variation of plastic strains and strain rate values. A description of an inverse analysis strategy, applied in order to identify the thermo-mechanical behavior laws of the materials and the computation of the corresponding rheological parameters, is also presented.