Finite Element Simulation of Stretch Bending Springback of Aluminum Alloy Vehicle Bumper

The springback during stretch bending process of the 6061-T6 aluminum alloy vehicle bumper was simulated based on the LS-DYNA software platform.The effects of pretension,post-tension and friction coefficient on the springback were investigated.The stretch bending mold profile was modified to compensate for springback,the verification experiments were performed.The results show that change of the pretension influenced the stress distribution in the cross section of the profile.When the pretension increased to the product (A·σs)of the profile cross section area and the material yield strength of the stretch bending parts,the springback decreased.With the gradually increasing post-tension from A·σs in a extent,it was benefited to decrease the springback of the stretch bending parts.The larger the friction coefficient,the larger the springback.The springback could be compensated through modifing the mold globoidal size.The simulated results were in agreement with the experimental results.The established finite element model could accurately predict the stretch bending springback of the vehicle bumper.