Analysis of the dynamic SHPB test using the finite element simulation

摘要

This paper deals with a behaviour analysis of a steel starting from the dynamic SHPB test. The standard analysis is given with the corresponding analytical analysis of the strain waves measurements in the elastic bars as well as the different relations that are needed in order to deduce flow stress data, particularly for large plastic deformation. Using an identification method based on the analytical computation of the Von-Mises stress values we obtain the rheological parameters corresponding to different formulations of the constitutive equation. The principal problems are linked to the feasibility of the classical analysis because several approximations are used, as for example, the homogeneity of the strain and stress in the specimen or the influence of the friction between the specimen and the bars. It is the reason why this work proposes to use a finite element simulation. The constitutive model, obtained by classical analysis, is introduced into a numerical simulation of the experimental test developed with the implicit package FORGE2. A comparison is made between the experimental and the computed values of the strain waves. To identify more correctly the constitutive model, an inverse analysis is proposed.