A poro-hyper-viscoelastic rate-dependent constitutive modeling for the analysis of brain tissues.

A poro-hyper-viscoelastic rate-dependent constitutive modeling for the analysis of brain tissues. J Mech Behav Biomed Mater. 2019 Oct 11;102:103475 Authors: Hosseini-Farid M, Ramzanpour M, McLean J, Ziejewski M, Karami G Abstract In this paper, the dynamic behavior of bovine brain tissue, measured from in-vitro unconfined compression tests, is examined and represented through a viscoelastic biphasic model. The experiments have been carried out under three compression speeds of 10, 100, and 1000 mm/s. The results exhibited significant rate-dependent behavior. The brain tissue is modeled as a biphasic continuum consisting of a compressible solid matrix, fully saturated with an incompressible interstitial fluid. The governing equations based on conservation of mass and momentum are used to describe the solid-fluid interactions. An inverse scheme is employed in which a finite element model runs iteratively to optimize constitutive constants. The obtained material parameters of the proposed biphasic model show relatively good agreement (R2 ≥ 0.96) with the experimental tissue mechanical responses at different rates. The model can successfully capture the key aspects of the rate-dependency for both solid and fluid phases under large strain deformation. This poro-hyper viscoelastic model can effectively estimate the global and local rate-dependent tissue deformations, the spatial variations in pore spaces, hydrostatic pressure as we...
Source: Journal of the Mechanical Behavior of Biomedical Materials - Category: Materials Science Authors: Tags: J Mech Behav Biomed Mater Source Type: research