Abstract:

Stress and strain analysis of flange deformation region are the basis of studying wrinkling, instability and forming limit of sheet metal in axisymmetrical drawing process. Two different kinds of analytical methods, the slab method and the method based on generalized Hooke’s law and deformation compatibility equations, are established for the stress and strain analysis of the flange deformation. Comparisons are made between experimental and numerical simulation results and calculated results for two proposed analytical methods respectively. The results show that, in slab method, the calculated radial strain are different from experimental and simulation results greatly for the thickness variation of flange is ignored; the calculated tangential stress has large deviation, while the calculated radial stress has a small deviation as compared to simulation with the average hardening model expressed by tangential strain. Thus the calculated results through slab method can meet engineering requirement for estimating drawing deformation force. In the method of generalized Hooke's law, the defects of slab method solution can be avoided, the calculated values of stress and strain are in good agreement with experimental and simulation results, and the relative deviation is less than 5%. The method based on generalized Hooke’s law is a relatively accurate theory analysis method for axisymmetrical drawing process.

Key words: flange deformation region, strain, stress, theoretical models, drawing