Dynamic compression and energy absorption of nanofluidic solid-fluid composites

Abstract

This study presents a comprehensive investigation on the dynamic energy absorption mechanisms of nanofluidic solid-fluid composites (NSFCs) through an integrated approach combining dynamic compressive experiments and molecular dynamics (MD) simulations analysis. The interrelationship between microscale nanofluidic behavior and macroscale mechanical response is extensively elucidated by examining the effects of strain rate (1000–3000 s^-1) and aspect ratio. Based on the dynamic stress equilibrium analysis, the increase in critical infiltration stress under dynamic loading may be attributed to nanoparticle clustering. The result reveals a 250 % enhancement in strain rate-dependent peak infiltration stress with increasing loading rates, attributed to the diminished loading duration that suppresses secondary elastic stage shown in quasi-static conditions. MD simulations confirm the rate-dependent infiltration characteristics while demonstrating strain rate-insensitive exfiltration initiation and duration. The loading intensity determines the number of infiltrating water molecules, and the peak infiltration stress can be efficient decreased by increasing the aspect ratio. A dual-phase energy absorption mechanism differentiating active and inactive nanofluidic behaviors is proposed to explain the effect of strain rate and aspect ratio. These findings establish a tunable design framework for NSFCs, providing fundamental insights into rate-dependent energy dissipation mechanisms for advanced impact protection applications.