# A predictive model for protein materials: from macromolecules to macroscopic fibers

## TL;DR

This paper introduces a predictive model for the mechanical behavior of protein materials, specifically keratin fibers and spider silks, using limited experimental parameters to accurately simulate their cyclic and damage behaviors.

## Contribution

It presents a novel macroscopic model derived from molecular parameters that captures damage, residual strains, and dissipation in protein-based materials.

## Key findings

- Model accurately reproduces cyclic behavior of keratin fibers
- Capable of describing dissipation and permanent strains in spider silks
- Robust model with high quantitative accuracy

## Abstract

We propose a model for the mechanical behavior of protein materials. Based on a limited number of experimental macromolecular parameters (persistence and contour lengths, rate of unfolding dissipation) we obtain the macroscopic behavior of keratin fibers (human, cow, and rabbit hair), taking into account the damage and residual stretches effects which are fundamental in many functions of life. We support our theoretical results by showing that our model is robust and able to reproduce with high quantitive accuracy the cyclic experimental behavior of different keratinous protein materials we tested. We also show the capability of describing, even if with lower precision, the dissipation and permanent strain effects in spider silks.