Dependence of the electrical conductivity of graphene reinforced epoxy resin on the stress level

Wentzel, Daniel; Miller, Sandi G.; Sevostianov, Igor

doi:10.1016/j.ijengsci.2017.06.013

Cited by 31 publications

(6 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…MFH approaches have also been applied to estimate the electrical conductivity and the strain self-sensing properties of CNT-based composites. Experiments have shown that CNT-based composites exhibit two main conduction mechanisms as a result of their percolation-like nature [20,21]: conductive networking and electron hopping (or quantum tunnelling) [22,23]. Below a critical volume fraction known as the percolation threshold, the conductive fillers are distant from each other and electrons can only be transferred by trespassing the potential barrier of the matrix through a quantum tunnelling mechanism.…”

Section: Introductionmentioning

confidence: 99%

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

Quinteros¹,

García-Macías²,

Martínez-Pañeda³

2023

Preprint

View full text Add to dashboard Cite

We present a novel computational framework to simulate the electromechanical response of selfsensing 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.

show abstract

Section: Introductionmentioning

confidence: 99%

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

Quinteros¹,

García-Macías²,

Martínez-Pañeda³

2023

Preprint

View full text Add to dashboard Cite

show abstract

“…In a COMSOL microwave heating simulation within the same work, activated carbon particles were 217°C hotter than the 340°C bulk media. In addition, these materials are often used as fillers in thermoset‐based formulations to increase hardness, modulus of elasticity, tensile strength, thermal conductivity, and electrical conductivity 53–58 . They can also improve thermoset microwave absorption after curing for use in radar applications 59,60 …”

Section: Introductionmentioning

confidence: 99%

“…In addition, these materials are often used as fillers in thermoset-based formulations to increase hardness, modulus of elasticity, tensile strength, thermal conductivity, and electrical conductivity. [53][54][55][56][57][58] They can also improve thermoset microwave absorption after curing for use in radar applications. 59,60 The scope of this paper is to investigate the feasibility and the effects of curing Lonza PT-30 cyanate ester resin and EPON 826 bisphenol-A diglycidyl ether via microwave heating in the presence of r-GO, a microwave absorbing catalytic filler.…”

Section: Introductionmentioning

confidence: 99%

Reduced graphene oxide catalytically enhances the rate of cyanate ester curing under variable frequency microwave heating

Warner

Jeng

Ayar

et al. 2023

J of Applied Polymer Sci

View full text Add to dashboard Cite

The curing of Lonza Primaset PT-30 novolac cyanate ester resin and EPON 826 bisphenol-A diglycidyl ether were investigated using convective thermal heating and variable frequency microwave (VFM) heating. The addition of 1 part per hundred reduced graphene oxide (r-GO) to PT-30 novolac cyanate ester increased the VFM cure rate compared to thermal heating. Curing it at 160 C for 240 min with VFM heating resulted in a 55% degree of cure compared to a 26% degree of cure with thermal heating. This observed VFM rate enhancement is due to selective microwave heating of the r-GO particles in the resin resulting in increased r-GO catalytic activity toward cyanate ester curing. It is both a thermal and catalytic effect, the latter of which is absent when r-GO is added to a bisphenol-A diglycidyl ether resin with ophenylenediamine hardener. Impurities present in the PT-30 matrix do not appear to contribute to its overall cure kinetics, nor do they participate in the observed VFM rate enhancement.

show abstract

“…References (Brandrup and Immergut, 1999; Rohsenow et al ., 1985) provide information on the dependence of diffusivity on temperature, pressure and material characteristics which certainly change over time. Similarly, the conductivity of a material can depend on time due to several reasons including temperature (see, for example (Abdallah et al ., 2017)), moisture (see, for example (Gorbachuk et al ., 2001)), exposure to radiation (see, for example (Tsuchiya et al ., 2011)), aging (see, for example (Ahmad et al ., 2012)), mechanical stress (see, for example (Wentzel et al ., 2017)), doping (see, for example (Lu et al ., 2021)) which surely change over time. Therefore, it is relevant to include the aspect of time-dependency of the material's properties in a study of modeling.…”

Section: Introductionmentioning

confidence: 99%

A combined BEM and Laplace transform for unsteady modified-Helmholtz equation of time–space variable coefficients for anisotropic media

Azis

2023

View full text Add to dashboard Cite

PurposeTwo-dimensional (2D) problems are governed by unsteady anisotropic modified-Helmholtz equation of time–space dependent coefficients are considered. The problems are transformed into a boundary-only integral equation which can be solved numerically using a standard boundary element method (BEM). Some examples are solved to show the validity of the analysis and examine the accuracy of the numerical method.Design/methodology/approach The 2D problems which are governed by unsteady anisotropic modified-Helmholtz equation of time–space dependent coefficients are solved using a combined BEM and Laplace transform. The time–space dependent coefficient equation is reduced to a time-dependent coefficient equation using an analytical transformation. Then, the time-dependent coefficient equation is Laplace transformed to get a constant coefficient equation, which can be written as a boundary-only integral equation. By utilizing a BEM, this integral equation is solved to find numerical solutions to the problems in the frame of the Laplace transform. These solutions are then inversely transformed numerically to obtain solutions in the original time–space frame.FindingsThe main finding of this research is the derivation of a boundary-only integral equation for the solutions of initial-boundary value problems governed by a modified-Helmholtz equation of time–space dependent coefficients for anisotropic functionally graded materials with time-dependent properties.Originality/valueThe originality of the research lies on the time dependency of properties of the functionally graded material under consideration.

show abstract

Dependence of the electrical conductivity of graphene reinforced epoxy resin on the stress level

Cited by 31 publications

References 23 publications

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

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

Reduced graphene oxide catalytically enhances the rate of cyanate ester curing under variable frequency microwave heating

A combined BEM and Laplace transform for unsteady modified-Helmholtz equation of time–space variable coefficients for anisotropic media

Contact Info

Product

Resources

About