Expansion of pipe blanks

The development of new shaping technologies for pipe blanks requires simulation of the stress and strain fields, which permits assessment of the limiting stress and strain values. The stress–strain state of a pipe blank in expansion (including nonuniform expansion) is analyzed in the present work. Joint solution of the equilibrium equations and plasticity condition is employed here; that is the traditional approach. Analytical dependences of the stress in the wall of the pipe blank on the technological parameters are obtained; the basic formulas for estimating the strain are also presented. Experiments confirm the results.