Kinetic model description of dissipation and recovery in collagen fibrils under cyclic loading

TL;DR

This paper presents a kinetic model for collagen fibrils that captures their cyclic loading behaviour, including hysteresis, energy dissipation, and recovery, aligning well with experimental observations.

Contribution

A novel kinetic model incorporating hidden loops and stochastic bond dynamics to explain collagen fibril behaviour under cyclic loading.

Findings

Model reproduces experimental hysteresis and residual strains.

Recovery dynamics match observed experimental data.

Steady state approached after a characteristic cycle number.

Abstract

Collagen fibrils, when subjected to cyclic loading, are known to exhibit hysteretic behaviour with energy dissipation that is partially recovered on relaxation. In this paper, we develop a kinetic model for a collagen fibril incorporating presence of hidden loops and stochastic fragmentation as well as reformation of sacrificial bonds. We show that the model reproduces well the characteristic features of reported experimental data on cyclic response of collagen fibrils, such as moving hysteresis loops, time evolution of residual strains and energy dissipation, recovery on relaxation, etc. We show that the approach to the steady state is controlled by a characteristic cycle number for both residual strain as well as energy dissipation, and is in good agreement with reported existing experimental data.