Failure of Porous Metals Based on Strain Energy Density Criterion

Porosity in metals is well known to influence the mechanical behavior, namely, the elastic response, the plastic behavior, and the material loading capacity. The main focus of the current work is to investigate the failure of porous metals. Extensive literature search was conducted to identify failure mechanisms associated with the increase of porosity for up to 15% by volume. Consequently, micromechanical modeling is utilized to investigate the damage process at microlengths. Finally, a complete macromechanical modeling approach is proposed for specimen-sized models. The approach utilizes the extended Ramberg-Osgood relationship for the elastoplastic behavior, while the failure is predicted using a strain energy-based failure criterion capturing the effect of porosity. The proposed approach is validated against several testing results for different metals at various porosity levels.