Effective permittivity of compacted granular materials: Effects of interfacial polarization and pore-filling fluids

Interfacial polarization dominates the permittivity spectra of heterogeneous granular materials for the intermediate frequency range (i.e., from kHz to MHz). In this study, we examine the corresponding dielectric responses of compacted glass sphere packings saturated with pore-filling fluids under v...

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Main Authors: Xu Wang, Chongpu Zhai, Yixiang Gan
Format: Article
Language:English
Published: Elsevier 2024-11-01
Series:Theoretical and Applied Mechanics Letters
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Online Access:http://www.sciencedirect.com/science/article/pii/S2095034924000369
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author Xu Wang
Chongpu Zhai
Yixiang Gan
author_facet Xu Wang
Chongpu Zhai
Yixiang Gan
author_sort Xu Wang
collection DOAJ
description Interfacial polarization dominates the permittivity spectra of heterogeneous granular materials for the intermediate frequency range (i.e., from kHz to MHz). In this study, we examine the corresponding dielectric responses of compacted glass sphere packings saturated with pore-filling fluids under various compressive stresses. The effective permittivity spectra are observed to exhibit consistently a plateau-to-plateau drop, described by low-frequency permittivity, characteristic frequency, and high-frequency permittivity. The permittivity spectra under different compressive levels are found to be influenced by the packing structure, compressive stress, and electrical property contrasts between solid and fluid (specifically permittivity and conductivity). For considered measurement conditions, the variation of packing structure and its associated porosity is found to be more significant than the stress evolution in controlling the interfacial polarization, thus the permittivity spectra, as supported by analytical and numerical results for unit cells. Furthermore, to gain a general rule for dielectric responses for saturated granular materials, we train multi-layer artificial neural network (ANN) models based on a series of simulations for unit cells with various structures, stresses, and electrical and dielectric properties. The predictions with two-layer ANN agree well with experimental measurements, presenting errors smaller than 5% for both low-frequency and high-frequency permittivity. This study offers an effective predicting approach for the dielectric behaviour of heterogeneous and multiphase materials.
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spelling doaj-art-a9ffbb14769a49e48db631b98b70c1fa2024-12-26T08:53:02ZengElsevierTheoretical and Applied Mechanics Letters2095-03492024-11-01146100525Effective permittivity of compacted granular materials: Effects of interfacial polarization and pore-filling fluidsXu Wang0Chongpu Zhai1Yixiang Gan2School of Civil Engineering, The University of Sydney, Sydney NSW 2006, AustraliaState Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China; Corresponding authors.School of Civil Engineering, The University of Sydney, Sydney NSW 2006, Australia; The University of Sydney Nano Institute (Sydney Nano), The University of Sydney, Sydney NSW 2006, Australia; Corresponding authors.Interfacial polarization dominates the permittivity spectra of heterogeneous granular materials for the intermediate frequency range (i.e., from kHz to MHz). In this study, we examine the corresponding dielectric responses of compacted glass sphere packings saturated with pore-filling fluids under various compressive stresses. The effective permittivity spectra are observed to exhibit consistently a plateau-to-plateau drop, described by low-frequency permittivity, characteristic frequency, and high-frequency permittivity. The permittivity spectra under different compressive levels are found to be influenced by the packing structure, compressive stress, and electrical property contrasts between solid and fluid (specifically permittivity and conductivity). For considered measurement conditions, the variation of packing structure and its associated porosity is found to be more significant than the stress evolution in controlling the interfacial polarization, thus the permittivity spectra, as supported by analytical and numerical results for unit cells. Furthermore, to gain a general rule for dielectric responses for saturated granular materials, we train multi-layer artificial neural network (ANN) models based on a series of simulations for unit cells with various structures, stresses, and electrical and dielectric properties. The predictions with two-layer ANN agree well with experimental measurements, presenting errors smaller than 5% for both low-frequency and high-frequency permittivity. This study offers an effective predicting approach for the dielectric behaviour of heterogeneous and multiphase materials.http://www.sciencedirect.com/science/article/pii/S2095034924000369Interfacial polarizationVolumetric compressionPacking structurePore deformationArtificial neuron network
spellingShingle Xu Wang
Chongpu Zhai
Yixiang Gan
Effective permittivity of compacted granular materials: Effects of interfacial polarization and pore-filling fluids
Theoretical and Applied Mechanics Letters
Interfacial polarization
Volumetric compression
Packing structure
Pore deformation
Artificial neuron network
title Effective permittivity of compacted granular materials: Effects of interfacial polarization and pore-filling fluids
title_full Effective permittivity of compacted granular materials: Effects of interfacial polarization and pore-filling fluids
title_fullStr Effective permittivity of compacted granular materials: Effects of interfacial polarization and pore-filling fluids
title_full_unstemmed Effective permittivity of compacted granular materials: Effects of interfacial polarization and pore-filling fluids
title_short Effective permittivity of compacted granular materials: Effects of interfacial polarization and pore-filling fluids
title_sort effective permittivity of compacted granular materials effects of interfacial polarization and pore filling fluids
topic Interfacial polarization
Volumetric compression
Packing structure
Pore deformation
Artificial neuron network
url http://www.sciencedirect.com/science/article/pii/S2095034924000369
work_keys_str_mv AT xuwang effectivepermittivityofcompactedgranularmaterialseffectsofinterfacialpolarizationandporefillingfluids
AT chongpuzhai effectivepermittivityofcompactedgranularmaterialseffectsofinterfacialpolarizationandporefillingfluids
AT yixianggan effectivepermittivityofcompactedgranularmaterialseffectsofinterfacialpolarizationandporefillingfluids