Cyclic Plasticity and Damage of Metals by a Gradient-Enhanced CDM Model

In the present work a thermodynamically consistent mechanical model for damageable elasto-plastic materials is proposed. The governing equations are obtained within the framework of a microstructure theory since a scalar damage variable is introduced as an additional cinematic variable. The constitutive equations are developed within a thermodinamic framework taking the damage variable and also its gradient as stte variables. This model leads to an adequate description o f the softening behavior due to the degradation of the microstructure. The main features of the proposed thory are discussed through the simulation and the comparison with results of low cycle fatigue tests performed on a structural alloy.