Fracture Properties of Green Nano Fibrous Network with Random and Aligned Fibre Distribution: A Hierarchical Molecular Dynamics and Peridynamics Approach

TL;DR

This paper develops a hierarchical modeling approach combining molecular dynamics and peridynamics to predict fracture behavior in PLA nanofibrous networks with different fiber orientations, aiding design of durable eco-friendly materials.

Contribution

It introduces a novel nano-to-micro coupling method for transferring data between molecular dynamics and peridynamics, enabling accurate fracture analysis of nanofibrous networks.

Findings

Determined mechanical properties of PLA nanofibres via molecular dynamics.

Analyzed fracture toughness and crack propagation in nanofibrous networks.

Showed effects of fiber alignment and surface coating on mechanical performance.

Abstract

Polylactic acid (PLA) nanofibrous networks have gained substantial interest across various engineering and scientific disciplines, such as tissue engineering, drug delivery, and filtration, due to their unique and multifunctional attributes, including biodegradability, tunable mechanical properties, and surface functionality. However, predicting their mechanical behaviour remains challenging due to their structural complexity, multiscale features, and variability in material properties. This study presents a hierarchical approach to investigate fracture phenomena in both aligned and randomly oriented nanofibrous networks by integrating atomistic modelling and nonlocal continuum mechanics, namely peridynamics. At the nanoscale, all-atom molecular dynamics simulations are employed to apply tensile loads to freestanding pristine and silver-doped PLA nanofibres, where key mechanical properties such as Young's modulus, Poisson's ratio, and critical energy release rate are determined. A new method is introduced to transfer data from molecular dynamics to peridynamics by ensuring convergence of the tensile response of a single fiber in both frameworks. This nano-to-micro coupling technique is then used to examine the Young's modulus, fracture toughness in modes I and II, and crack propagation in PLA nanofibrous networks. The proposed framework can also incorporate the effects of surface coating and fiber arrangements on the measured properties. This research paves the way for the development of stronger and more durable eco-friendly nanofibrous networks with optimised performance.