Wrinkling and necking instabilities for tube hydroforming

摘要

In this paper, a numerical simulation and experimental results for the hydroforming limit of isotropic tubes are presented. Swift '5 criterion is often used in this case for the prediction of diffuse plastic instability. We have already highlighted the existence of two different Swift's criteria (for sheets and for tubes). We have also recalled that these types of approaches do not take into account buckling induced by axial loading. A numerical simulation is presented here to confirm these points and to analyze both the buckling and necking phenomena together. An experimental setup and the first results are then presented. They are in good agreement with the numerical simulation and contribute to the elaboration of a Hydroforming Limit Diagram.