PNNL

Abstract

An inverse approach to tube hydroforming developed in our previous work is used in this paper for the analysis of Aluminum 6061-T4 tubes hydroformed within a conical die. This approach, which extended the flat sheet forming analysis by Guo et al. to tube hydroforming problems, considers two configurations: the as-formed conical tube coaxial with the initial round tube. The analysis uses a membrane finite element formation within the framework of the deformation theory and Hill?s criterion to describe the plastic flow. Furthermore, a fracture criterion based on the material forming limit diagram (FLD) is employed to predict the onset of necking. Hydroforming experiments on Aluminum tubes using a conical die were also conducted to validate the model. Good agreements of results have been found for the deformed configurations in which the bending effect is small.