A Variational Full-Network Constitutive Model with Anisotropic Damage and Viscoelasticity Induced by Deformation for Biological Tissues

Resumo

Rubberlike materials, such as soft biological tissues, may exhibit high nonlinear inelastic responses
when subject to large strains. Also, anisotropic inelastic behaviors induced by deformation are observed in the
literature. The anisotropic behavior associated with coupled inelastic effects has been a major challenge in the
constitutive modeling of materials. Then, this paper presents a variational full-network model capable of
representing coupled anisotropic damage and viscoelasticity responses induced by deformation. The proposed
model combines the advantages of the full-network and variational frameworks, resulting naturally in a set of
scalar minimization problems. The inelastic scalar variables at each material point are related to the quadrature
points directions used in the full-network integration scheme, and their evolution is assessed graphically in a very
intuitive way. A numerical inflation test of a plate is presented to explore the ability of the proposed model to
represent anisotropic damage and viscoelasticity and maintain accuracy for large deformations and increments.