A simple experiment to characterize material formability in tube hydroforming

Abstract In tube hydroforming processes an internal fluid pressure is utilized to form the material on a properly shaped die; during the process the material axial movement is favoured by the axial feeding of an active punch. In the paper a simple experiment is presented aimed to investigate the influence of the main process variables on material formability. This equipment has enabled an extensive experimental investigation; furthermore a numerical analysis based on the finite element technique has been performed and a ductile fracture criterion has been implemented to predict the insurgence of bursting defects.