# A Multiscale Multisurface Constitutive Model for The Thermo-Plastic Behavior of Polyethylene

## TL;DR

This paper develops a multiscale model that predicts the thermo-plastic behavior of polyethylene by integrating molecular dynamics simulations with continuum mechanics, enabling accurate yield predictions across different strain rates and temperatures.

## Contribution

The paper introduces a novel hierarchical multiscale modeling approach that links molecular simulations to continuum predictions for polyethylene's yield behavior.

## Key findings

- Multisurface yield functions for polyethylene identified.
- High strain rate MD simulations scaled to quasi-static conditions.
- Temperature and strain rate dependent yield strength predicted.

## Abstract

We present a multiscale model bridging length and time scales from molecular to continuum levels with the objective of predicting the yield behavior of amorphous glassy polyethylene (PE). Constitutive parameters are obtained from molecular dynamics (MD) simulations, decreasing the requirement for ad-hoc experiments. Consequently, we achieve: (1) the identification of multisurface yield functions; (2) the high strain rate involved in MD simulations is upscaled to continuum via quasi-static simulations. Validation demonstrates that the entire multisurface yield functions can be scaled to quasi-static rates where the yield stresses are possibly predicted by a proposed scaling law; (3) a hierarchical multiscale model is constructed to predict temperature and strain rate dependent yield strength of the PE.