Thin-walled pipe expansion by a punch with a curvilinear profile

A model is developed for the nonstationary process of thin-walled pipe expansion by a punch with a curvilinear profile generator by taking into account hardening, normal anisotropy, wall thickness measurement, and contact friction according to the membrane theory of rigid-plastic shells with a quadratic plasticity condition. The computational program of the model determines the distributions of thickness, meridian stress, contact pressure, and hardened material yield load along the generating line of the deformed tube and the expansion force variation from the punch displacement.