An approach to improve thickness uniformity within tailor-welded tube hydroforming

Abstract

Both experimental and simulation studies were run to investigate the effects of deformation sequence on stress and strain states and thickness distribution during tailor-welded tube hydroforming. The effects of geometrical boundary condition were also studied. Then, an approach to improve thickness uniformity was put forward. Both stress and strain histories indicate that the deformation states of thinner and thicker tubes were obviously different duo to the difference in thickness during tailor-welded tube hydroforming. These induce tensile strain concentrates to happen near weld seam on thinner tube, but compressive strain on thicker tube, which lead to strain mutation around weld seam on tailor-welded tube components. As result, bigger thinning takes place on thinner tube. The difference in thinning ratio between thinner and thicker tubes reaches about 6.6%. By deformation sequence optimization, thickness distribution uniformity can be improved obviously. When deformation sequence altered from thicker tube to thinner tube, the difference in thinning ratio between two segments can be decreased to 1.5%. At last, the effects of geometrical parameters of preform component were analyzed and the suitable parameters were given.