Error evaluation on experimental stress–strain curve obtained from tube bulging test

To get precise material data for advanced numerical modelling of tube hydroforming process, the tube bulging test is recommended. Stresses and strains in the tube cannot be evaluated easily and several approaches have been proposed. A review is proposed and points out their advantages and drawbacks.A semi-analytical model is presented and experimental measures done on an original tube show the thickness scattering along a generating line of the tube. These observations justify the processing of a linear sensitivity analysis which reveals the most influencing parameters on the accuracy of the hardening curve and gives information to perform relevant experiments.

► Tube bulging test permits to get adequate material data for tube hydroforming simulation. ► This test is source of several inaccuracies: tube and tool geometry, measures. ► A linear sensitivity analysis is conducted on a semi-analytical model developed by the authors. ► It reveals influencing parameters and provides information to perform relevant experiments.