oa Remodeling Of Collagen-Fibers In Deformed Tissues

One goal in the field of soft tissue biomechanics is to understand and to model the properties of collagen-fibers in biological tissues such as blood vessels, brain tissues, and skin which undergo growth and remodeling processes. Experimental studies of Bhole et al.\ [1] suggest that the mechanical properties of fibers in biological tissues depend not only on the current state of the deformation but also on the deformation history. Demirkoparan et al.\ [2] developed a hyperelasticity based framework taking this effect into account. The framework developed in [2] uses an additive hyperelastic material model for the strain energy density, $W = W_m + W_f$. The matrix contribution $W_m$ does not take time-dependent changes of the material properties into account yet the fiber contribution $W_f$ changes over time as it is modeled in terms of a constant creation rate and a deformation dependent dissolution rate of the fibers. Then Topol et al.\ [3] have investigated the predictions of such a model by studying the effect of fiber deformation state at the time of their creation on the overall mechanical properties of the material. This research investigates the relation between the change in the fiber density, the Cauchy stress development, and the deformation of the material.