Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Full isotropic yield surfaces for porous ductile materials by computational homogenization
Submission Author:
Wanderson Ferreira dos Santos , GO , Brazil
Co-Authors:
Wanderson Ferreira dos Santos, Ayrton Ribeiro Ferreira, Sergio Persival Proenca
Presenter: Wanderson Ferreira dos Santos
doi://10.26678/ABCM.COBEM2023.COB2023-0105
Abstract
The formulation of realistic macroscopic constitutive models for porous elasto-plastic solids requires consideration of the effects of voids on the distribution of stresses and strains at the microscale. In this context, a computational homogenization procedure is explored herein to investigate yield criteria for porous ductile media. The microscale of the porous solid is modeled using the concept of Representative Volume Element (RVE). The microscopic fields of the RVE are computed by three-dimensional (3D) simulations using the Finite Element Method with the hypothesis of small strains. Macroscopic strain and stress fields are then obtained based on the volume averaging of the microscopic strain and stress fields over the RVE. Different stress states are imposed on the RVEs, encompassing low, intermediate, and high triaxilities. In particular, the sensitivity of the yield criterion to the Lode angle is investigated by combining shear states with low and intermediate triaxialities. The influence of the RVE void morphology is assessed on the yield surfaces, considering the uniform strain boundary condition and the periodic boundary condition imposed on the RVEs. Spherical and cubic voids are investigated for a cubic RVE, and the results provide reference limits for voids with similar morphology. The RVE matrix behavior is adopted as an isotropic perfect elasto-plastic material following the von Mises yield criterion. In general, the yield surfaces have different geometries, resulting in different constitutive behaviors for the same load situations. The responses provided by the periodic boundary condition show significant differences when compared to the uniform strain boundary condition. Moreover, the stress Lode angle has a strong influence on the yield surface geometry.
Keywords
porous ductile solids, full yield surfaces, computational homogenization, void morphology, boundary conditions
