Constitutive modeling and springback prediction of stress relaxation age forming of pre-deformed 2219 aluminum alloy

Abstract

Abstract Stress relaxation ageing behavior of pre-deformed AA2219 is studied through stress relaxation age experiments and finite element (FE) simulation. The results show that the stress can promote the process of ageing precipitation, and shorten the time to reach the peak strength. Meanwhile, the residual stress and yield strength increase along with the increase in the initial stress. Based on microstructure evolution and ageing strengthening theory, a unified constitutive model is established and incorporated into the FE simulation model through a user subroutine. It is found that the relative error of the radius is 3.6% compared with the experimental result and the springback is 16.8%. This indicates that the proposed stress relaxation ageing constitutive model provides a good prediction on the springback of such stiffened panel during its ageing process.