A polyurethane-urea elastomer at low to extreme strain rates

TL;DR

This paper introduces a comprehensive nonlinear constitutive model for polyurethane-urea elastomers that accurately predicts their behavior across a wide range of strain rates, from slow to ultrafast impacts, validated by experiments and simulations.

Contribution

The study develops a micromechanically- and thermodynamically-based model capturing extreme strain rate behavior of polyurethane-urea, validated by laser impact tests and numerical simulations.

Findings

Model accurately predicts behavior over 9 orders of magnitude in strain rates.

Experimental data confirms the model's validity at ultrafast strain rates.

Numerical simulations align well with laser impact test results.

Abstract

A finite strain nonlinear constitutive model is presented to study the extreme mechanical behavior of a polyurethane-urea well suited for many engineering applications. The micromechanically- and thermodynamically based constitutive model captures salient features in resilience and dissipation in the material at low to high strain rate. The extreme deformation features are further elucidated by laser-induced micro-particle impact tests for the material, where an ultrafast strain rate ($>10^6$ s$^{-1}$) incurs. Numerical simulations for the strongly inhomogeneous deformation events are in good agreement with the experimental data, supporting the predictive capabilities of the constitutive model for the extreme deformation features of the PUU material over at least 9 orders of magnitude in strain rates ($10^{-3}$ to $10^{6}$ s$^{-1}$).