Electromechanical phase-field fracture modelling of piezoresistive CNT-based composites

TL;DR

This paper introduces a new computational framework combining phase-field fracture modeling with electromechanical analysis to simulate the fracture and sensing response of CNT-based composites, validated through various case studies.

Contribution

The novel framework integrates electrical, mechanical, and fracture modeling for CNT composites, enabling detailed simulation of damage and sensing behavior.

Findings

Efficient and robust simulation of crack evolution in CNT composites.

Accurate prediction of electromechanical response during fracture.

Framework validated against experimental data and complex crack scenarios.

Abstract

We present a novel computational framework to simulate the electromechanical response of self-sensing carbon nanotube (CNT)-based composites experiencing fracture. The computational framework combines electrical-deformation-fracture finite element modelling with a mixed micromechanics formulation. The latter is used to estimate the constitutive properties of CNT-based composites, including the elastic tensor, fracture energy, electrical conductivity, and linear piezoresistive coefficients. These properties are inputted into a coupled electro-structural finite element model, which simulates the evolution of cracks based upon phase-field fracture. The coupled physical problem is solved in a monolithic manner, exploiting the robustness and efficiency of a quasi-Newton algorithm. 2D and 3D boundary value problems are simulated to illustrate the potential of the modelling framework in assessing the influence of defects on the electromechanical response of meso- and macro-scale smart structures. Case studies aim at shedding light into the interplay between fracture and the electromechanical material response and include parametric analyses, validation against experiments and the simulation of complex cracking conditions (multiple defects, crack merging). The presented numerical results showcase the efficiency and robustness of the computational framework, as well as its ability to model a large variety of structural configurations and damage patterns. The deformation-electrical-fracture finite element code developed is made freely available to download.