Fourier-based spectral method solution to finite strain crystal plasticity with free surfaces

Abstract A plastically dilatational material model is proposed that enables to simulate the mechanical response of non-compact geometries (containing free surfaces) by means of established spectral methods without any particular adaptations, i.e. in combination with arbitrary constitutive laws describing the remainder of the simulated geometry and under mixed boundary conditions. The versatility of this material model and more accurate representation of empty space in comparison to an isotropic elastic model employing low stiffness is demonstrated for the cases of void growth under biaxial extension and grain-scale deformation behavior of an oligocrystalline dogbone-shaped aluminum sample under uniaxial tension.