PLASTIC AND VISCOPLASTIC DAMAGE MODELS WITH NUMERICAL TREATMENT FOR METAL-FORMING PROCESSES

Metal forming processes are problems with a multiplicity of non linear ities. There are physical non linearities (plasticity, viscoplasticity , damage), geometrical non linearities (large displacements, large def ormations), contact and friction non linearities. Therefore, numerical simulations of metal forming processes lead to choosing appropriate c onstitutive equations and a suitable algorithm to solve these problems . The work presented here treats these difficulties. Firstly, we propo sed a stable elasto-plastic damage model and a stable elasto-viscoplas tic (visco) damage model for large transformations. Secondly, we use t he large time increment method in a version adapted to solve non linea r geometrical problems with contact and friction. (C) 1998 Elsevier Sc ience S.A. All rights reserved.