engleski

The modelling of fibre reorientation in soft tissue

In this paper, a hyperelastic and thermodynamically consistent model for soft tissue is developed that is able to describe the change of the initial orientation of the collagen fi bres. Full numerical implementation is considered as well. The collagen architecture is assumed to reorient driven by a specifi c thermodynamical force. The anisotropy is described by a strain energy function, which is decomposed into a part related to the matrix and a part related to the fi bres. The initial fi bre orientation is defi ned by a structural tensor, while the current orientation is described by a time-dependent structural tensor, which results from the initial one by a rotational transformation. The rotation tensor is obtained via an integration process of a rate tensor, which depends on an adequately defi ned thermodynamical force. The integration is achieved via an exponential map algorithm, where it is shown that the rotation is necessarily a two-parametric one. Effi ciency of the proposed formulation is demonstrated using some numerical examples.

soft tissue; collagen; reorientation; elastin; remodelling

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