Yield criterion and finite strain behavior of random porous isotropic materials

The mechanical response of isotropic elastoplastic materials containing random distributions initially spherical voids is investigated computationally based on Fast Fourier Transform simulations. Numerical limit-analysis simulations at constant stress triaxiality allow to determine the yield surfaces, leading in particular determination a Representative Volume Element size for onset coalescence / inhomogeneous yielding. Moreover, two different regimes are observed that differ by presence shearing. surfaces found be consistent with combination models proposed literature, GTN-type model calibrated homogeneous yielding porous and an accounting both or without shear. Finite strain performed hardening moduli triaxialities under axisymmetric loading conditions confirm existence RVE up Coalescence strains significantly smaller than periodic distribution voids. A homogenized finally reproduces quantitatively behavior finite strains.