Effect of axial displacement on non-circular tube shaping in hydroforging

Tube hydroforging with non-circular shaping has been conducted to show the deformation mechanics of an AHSS tube. In this paper, the tube was hydroforged in a multistage FEA simulation to show the effects of axial forging distance on noncircular cross-sections during hydroforging. The tube will be allowed to expand with a ramped internal pressure, then be shaped to a certain expansion ratio by the axial compression in the forging step and finally be shaped into either a square or an equilateral triangle shaped cross-section. It was observed that triangular shaped models have a greater resistance to thickness loss than the square shaped models. The forging die distance for both square and triangular shaping models each influence the maximum amount of shaping die distance for the process. The simulations show that as the forging die distance increases, the lateral radius increases for both the square and triangular shaped models. For the square shaped models, there is an uncorrelated relationship between the vertical and horizontal longitudinal radii but is correlated in the equilateral triangle configurations. The thickness distributions for the triangular shaped configurations show greater stability in the deformed wall portion than the square shaped configurations. All the model setups failed due to wrinkling, except the triangular shaped model with 20 mm of axial displacement, which failed due to bursting.