Numerical improvement of thin tubes hydroforming with respect to ductile damage

Fully coupled constitutive equations, formulated in the framework of the thermodynamics of irreversible processes with state variables, accounting for isotropic hardening as well as the isotropic ductile damage are used to simulate numerically, by the finite element analysis, 3D metal hydroforming processes with damage occurence. An implicit integration scheme for local time integration of the constitutive equations and a dynamic explicit resolution scheme to solve the associated dynamic equilibrium problem are used. The effects of friction coefficient, material ductility and hydro bulging condition, on the hydroformability of various thin tubes are discussed.