Some computational aspects of large deformation,rate-dependent plasticity problems

The governing equations for a finite element formulation of boundary value problems for large deformation metal forming processes are derived using a principle of virtual work formulated in a Lagrangian reference system. The updated Lagrangian method is used to simplify the equations. The resulting nonlinear equilibrium equations are solved using Newton's method.A constitutive model for large deformation, rate-dependent plasticity is developed. The model incorporates a one parameter, implicit integration operator for stability and accuracy. The stressrate/strain-rate relation is written in terms of the Jaumann rate of stress.Numerous example problems are solved to demonstrate the effectiveness of the numerical algorithms.