Strain-dependent internal parameters in hyperelastic biological materials

TL;DR

This paper investigates how internal parameters in hyperelastic models, especially in skeletal muscle tissue, depend on strain and how their derivatives influence accurate stress-strain predictions.

Contribution

It introduces strain-dependent internal parameters in hyperelastic models and emphasizes the importance of their derivatives for realistic stress-strain behavior in biological tissues.

Findings

Activation parameter depends on strain

Derivative of the parameter affects stress-strain relations

Models improve understanding of muscle tissue mechanics

Abstract

The behavior of hyperelastic energies depending on an internal parameter, which is a function of the deformation gradient, is discussed. As an example, the analysis of two models where the parameter describes the activation of a tetanized skeletal muscle tissue is presented. In those models, the activation parameter depends on the strain and it is shown the importance of considering the derivative of the parameter with respect to the strain in order to capture the proper stress-strain relations.