Numerical simulation for creep age forming of aluminium alloy 7050 saddle-shaped part

Unified creep-ageing constitutive equations for aluminium alloy 7050 (AA7050) determined from experimental data were implemented into the finite element (FE) code, ABAQUS, through the user-defined subroutine, CREEP, for creep age forming (CAF) process modelling. The outer contour and yield strength of a saddle-shaped component were predicted, and the accuracy of FE prediction was analysed with experimental results. The research results show that, stress relaxation and creep deformation occur mainly in the early stage of the CAF process. A close agreement has been achieved between the simulation results and measurement data for the formed shape. More than 90% of the area has a surface gap less than 0.5 mm, and the relative error of the yield strength is between -1.18% and +7.22%, which prove the validity of the numerical computation.