Abstract
In tube free bending forming technology, the springback behavior affects the bent tubes' forming accuracy and quality. Thus, in this investigation, the springback behaviors of T2-Cu and AA6061-T6 tubes manufactured by free bending technology were studied experimentally and using finite element modeling. The bending radius of the formed tubes was measured in ABAQUS combined with the geometric calculation. After investigating the different A-values (sufficient length of deformation zone) of Cu and Al tubes, it was found that the higher the A-value, the higher the bending angle, the lower the bending radius, and the larger the springback angle. The changes of both bending and material properties affect the springback to specific values. The tube forming's stress peak occurred in the forming segment, where the springback angle is the highest, and the outer springback is higher than the inner side at the same A-value and position. Under the same forming parameters, each section's strain variation and springback angle in the bending process of T2-Cu tubes is higher than that of AA6061-T6 tubes. The simulation results were in remarkable agreement with those obtained from experimentation, proving the simulation's reliability and accuracy.