# UM ESTUDO DE MODELOS MATEMATICOS BIFÁSICOS PARA TECIDOS BIOLÓGICOS MOLES SOB GRANDES DEFORMAÇÕES

## Palavras-chave:

Biphasic theory, Finite Element, Soft hydrated tissues## Resumo

Several biological tissues present a considerable percentage of their weight constituted by

fluid, which directly impacts on its mechanical behavior, mainly due to viscous effects. An appropriate

approach for the description of this material is the biphasic theory, in which the intrinsic mechanical

properties of each phase, as well as their interactions, are taken into account. Therefore, this work has

the objective of evaluating if biphasic models found in the literature are capable of representing the

mechanical behavior of soft biological tissues in large deformations. The biphasic theory was used to

describe the tissue as a continuous mixture of two incompressible phases: a hyperelastic solid phase,

and an inviscid fluid. Finite element formulations, based on mixed elements and penalty technique, were

implemented. The computational cost and accuracy of results were evaluated for an isotropic tissue in

the case of a confined compression. An anisotropic constitutive relation for the solid phase was also

studied under traction for fiber-reinforced biological tissues. The results for the confined compression

shown good agreement with the literature. The traction case allowed to evaluate the ability of the model

to represent the dissipative and anisotropic behavior expected for hydrated fiber-reinforced biological

tissues, which would allow its use for the characterization of tissues under physiological conditions.