Numerical Modeling of Ductile Plastic Damage in Tensile Test

Material behaviour description frequently used in commercial codes may not be adequate to simulate real forming processes. One of the reasons is the fact that they rarely include the modeling of internal damage of material. This is a decisive feature in order to be able to predict defective parts in processes like forging or to describe processes in which fracture is a part of the process itself as in sheet blanking or metal cutting. In large deformation of metals, when plastic deformation reaches a threshold level, which may depend on the loading, the fatigue limit and the ultimate stress, a ductile damage process may occur concomitantly with the plastic deformation due to the nucleation, growth and coalescence of micro-voids. Although damage and plastic deformation are two distinct dissipative processes, they influence each other. In this paper a numerical benchmark of the uniaxial tensile tests, for aluminium alloy, has been performed using LS-Dyna and Deform 2D without damage. Then, a numerical uniaxial tensile tests has been studied using a coupled model of elasto-plasticity and ductile damage implemented in LS-Dyna. Experimental material property present in literature has been used.