Tensile destabilization of tube hydroforming

Aimed at the deficiency of tube hydro plasticity technology, effect of stress ratio on tension destabilization was analyzed by plasticity mechanic. It was shown, during tube hydro bulging, the total stress was generated by internal pressure. During tube hydroforming, with the increasing of stress ratio, Mises strain, axial strain and circle strain increased correspondingly, Hill destabilization strain increased more rapidly than Swift destabilization strain, burst trend decreased. However, thick strain was not sensitive to the variation of stress ratio, the Hill utmost strain was double of that of Swift.