Poroelastic Models for Biological Structures

Abstract

Many biological structures are composed of tissues which have a fluid phase that can move relative to a deformable solid phase in the material. A number of experimental, analytical and numerical studies have been carried out using a two-phase material law to allow structural analysis of components of the spine (Simon et al., 1985), synovial joints (Mow et al., 1980) and arteries (Kenyon, 1976). A two-phase poroelastic view of the material (e.g. see Biot, 1962) is useful in quantifying the material response where the material model includes a perfect fluid phase that saturates and flows through a deforming porous solid material skeleton. Here we describe a finite element procedure that includes such a nonlinear elastic porous solid skeleton and fluid that undergoes finite straining. This finite element procedure should find application in predicting the structural response of soft biological tissues where material behaviour, geometry, and applied loading are complicated.