Effects of thickness ratio and length ratio on deformation uniformity of tailor-welded tube hydroforming

Abstract

Both experimental and simulation studies were run to investigate the deformation uniformity of tailor-welded tube hydroforming with dissimilar thickness. The effects of weld-seam location and difference in thickness were analysed in detail. There are indications that obvious differences in deformation states appear between thinner and thicker tubes owing to poor deformation uniformity, which induces fluctuation in axial strain distribution, especially in the weld-seam zone nearby. Consequently, excessive thinning takes place on the thinner tube. Deformation uniformity improves as the length ratio increases or the thickness ratio decreases. However, it is more sensitive to the thickness ratio, and hence more effective for improving deformation uniformity by optimizing structure design.