Special Issue "Multiscale Innovative Materials and Structures"

A special issue of Nanomaterials (ISSN 2079-4991). This special issue belongs to the section "Nanocomposite Materials".

Deadline for manuscript submissions: 31 August 2021.

Special Issue Editors

Prof. Dr. Raffaele Barretta
E-Mail Website
Guest Editor
Department of Structures for Engineering and Architecture, University of Naples Federico II, 80125 Naples, Italy
Interests: continuum mechanics; non-local elasticity; beam theories; plate theories; fracture mechanics
Special Issues and Collections in MDPI journals
Prof. Dr. Domenico De Tommasi
E-Mail Website
Guest Editor
Politecnico di Bari, Bari, Italy
Interests: Finite elasticity; Linear and nonlinear kinematics; Membrane tensile structures; Fibre reinforced composite material mechanics; Masonry structure mechanics; Multilayer solids; Elastic bodies with non-convex energies; Biological material and metamaterials; Electroactive Polymers (EAP) devices
Prof. Dr. Fernando Fraternali
E-Mail Website
Guest Editor
Department of Civil Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy
Interests: multiscale modeling and simulation of solids and structures; nonlinear dynamics of materials and structures; design and engineering of sustainable materials at multiple scales
Special Issues and Collections in MDPI journals

Special Issue Information

Dear Colleagues,

Nanomaterials are currently essential constituents of ground-breaking nano-electromechanical systems (NEMS). There is increasing attention in multiscale metamaterials and a rising demand for exploring the potential of such novel systems in real-life engineering applications, including: smart buildings, antiseismic engineering, and structural health monitoring. Investigation of the size-dependent response of advanced materials and structures has gained intensive interest in literature due to the vast application of NEMS in a broad spectrum of modern nanoengineering systems. Local approaches of continuum mechanics are not able to effectively describe the size-dependent behavior of nanomedia, and thus, development of suitable analytical and numerical models is of major significance in design and optimization of materials and devices in the small-scale range.

This Special Issue on Multiscale Innovative Materials and Structures is aimed at extending the fundamental understanding of the mechanics of multiscale materials, ranging from multifunctional lattices to nanocomposites, and its application to the design of unconventional materials and structures. This Special Issue intends to publish original research papers and review articles addressing innovative theoretical approaches and novel numerical proposals aimed at amending the current state of the art on size-dependent modeling of nanomaterials and -structures. Authors are invited to submit both theoretical and experimental contributions.

Potential topics include but are not limited to the following:

  • Nanosized and nanostructured materials;
  • Periodic lattices and multiscale composites;
  • Preparation, characterization, and application of nanomaterials;
  • Nanocomposites, nanosystems, and nanodevices;
  • Nonlinear lattices, hierarchical lattices;
  • Nonlocal and generalized continua;
  • Experimental and computational techniques in nanoscience;
  • Design of ultralight structures and seismic devices for smart buildings.

Prof. Dr. Raffaele Barretta
Prof. Dr. Domenico De Tommasi
Prof. Dr. Fernando Fraternali
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Nanomaterials is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2200 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • nanomaterials
  • metamaterials
  • tensegrity structures
  • multifunctional lattices
  • nanocomposites
  • carbon nanotubes
  • size effects
  • nanobeams
  • nanoplates
  • nanoshells
  • nano-actuators
  • nanosensors
  • nanoengineering
  • NEMS

Published Papers (8 papers)

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Research

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Open AccessArticle
Development of a Novel Multifunctional Cementitious-Based Geocomposite by the Contribution of CNT and GNP
Nanomaterials 2021, 11(4), 961; https://doi.org/10.3390/nano11040961 - 09 Apr 2021
Viewed by 295
Abstract
In this study, a self-sensing cementitious stabilized sand (CSS) was developed by the incorporation of hybrid carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) based on the piezoresistivity principle. For this purpose, different concentrations of CNTs and GNPs (1:1) were dispersed into the CSS, [...] Read more.
In this study, a self-sensing cementitious stabilized sand (CSS) was developed by the incorporation of hybrid carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) based on the piezoresistivity principle. For this purpose, different concentrations of CNTs and GNPs (1:1) were dispersed into the CSS, and specimens were fabricated using the standard compaction method with optimum moisture. The mechanical and microstructural, durability, and piezoresistivity performances, of CSS were investigated by various tests after 28 days of hydration. The results showed that the incorporation of 0.1%, 0.17%, and 0.24% CNT/GNP into the stabilized sand with 10% cement caused an increase in UCS of about 65%, 31%, and 14%, respectively, compared to plain CSS. An excessive increase in the CNM concentration beyond 0.24% to 0.34% reduced the UCS by around 13%. The addition of 0.1% CNMs as the optimum concentration increased the maximum dry density of the CSS as well as leading to optimum moisture reduction. Reinforcing CSS with the optimum concentration of CNT/GNP improved the hydration rate and durability of the specimens against severe climatic cycles, including freeze–thaw and wetting–drying. The addition of 0.1%, 0.17%, 0.24%, and 0.34% CNMs into the CSS resulted in gauge factors of about 123, 139, 151, and 173, respectively. However, the Raman and X-ray analysis showed the negative impacts of harsh climatic cycles on the electrical properties of the CNT/GNP and sensitivity of nano intruded CSS. Full article
(This article belongs to the Special Issue Multiscale Innovative Materials and Structures)
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Open AccessEditor’s ChoiceArticle
Elastostatics of Bernoulli–Euler Beams Resting on Displacement-Driven Nonlocal Foundation
Nanomaterials 2021, 11(3), 573; https://doi.org/10.3390/nano11030573 - 25 Feb 2021
Viewed by 334
Abstract
The simplest elasticity model of the foundation underlying a slender beam under flexure was conceived by Winkler, requiring local proportionality between soil reactions and beam deflection. Such an approach leads to well-posed elastostatic and elastodynamic problems, but as highlighted by Wieghardt, it provides [...] Read more.
The simplest elasticity model of the foundation underlying a slender beam under flexure was conceived by Winkler, requiring local proportionality between soil reactions and beam deflection. Such an approach leads to well-posed elastostatic and elastodynamic problems, but as highlighted by Wieghardt, it provides elastic responses that are not technically significant for a wide variety of engineering applications. Thus, Winkler’s model was replaced by Wieghardt himself by assuming that the beam deflection is the convolution integral between soil reaction field and an averaging kernel. Due to conflict between constitutive and kinematic compatibility requirements, the corresponding elastic problem of an inflected beam resting on a Wieghardt foundation is ill-posed. Modifications of the original Wieghardt model were proposed by introducing fictitious boundary concentrated forces of constitutive type, which are physically questionable, being significantly influenced on prescribed kinematic boundary conditions. Inherent difficulties and issues are overcome in the present research using a displacement-driven nonlocal integral strategy obtained by swapping the input and output fields involved in Wieghardt’s original formulation. That is, nonlocal soil reaction fields are the output of integral convolutions of beam deflection fields with an averaging kernel. Equipping the displacement-driven nonlocal integral law with the bi-exponential averaging kernel, an equivalent nonlocal differential problem, supplemented with non-standard constitutive boundary conditions involving nonlocal soil reactions, is established. As a key implication, the integrodifferential equations governing the elastostatic problem of an inflected elastic slender beam resting on a displacement-driven nonlocal integral foundation are replaced with much simpler differential equations supplemented with kinematic, static, and new constitutive boundary conditions. The proposed nonlocal approach is illustrated by examining and analytically solving exemplar problems of structural engineering. Benchmark solutions for numerical analyses are also detected. Full article
(This article belongs to the Special Issue Multiscale Innovative Materials and Structures)
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Open AccessFeature PaperEditor’s ChoiceArticle
Capsules Rheology in Carreau–Yasuda Fluids
Nanomaterials 2020, 10(11), 2190; https://doi.org/10.3390/nano10112190 - 03 Nov 2020
Cited by 1 | Viewed by 544
Abstract
In this paper, a Multi Relaxation Time Lattice Boltzmann scheme is used to describe the evolution of a non-Newtonian fluid. Such method is coupled with an Immersed-Boundary technique for the transport of arbitrarily shaped objects navigating the flow. The no-slip boundary conditions on [...] Read more.
In this paper, a Multi Relaxation Time Lattice Boltzmann scheme is used to describe the evolution of a non-Newtonian fluid. Such method is coupled with an Immersed-Boundary technique for the transport of arbitrarily shaped objects navigating the flow. The no-slip boundary conditions on immersed bodies are imposed through a convenient forcing term accounting for the hydrodynamic force generated by the presence of immersed geometries added to momentum equation. Moreover, such forcing term accounts also for the force induced by the shear-dependent viscosity model characterizing the non-Newtonian behavior of the considered fluid. Firstly, the present model is validated against well-known benchmarks, namely the parabolic velocity profile obtained for the flow within two infinite laminae for five values of the viscosity model exponent, n = 0.25, 0.50, 0.75, 1.0, and 1.5. Then, the flow within a squared lid-driven cavity for Re = 1000 and 5000 (being Re the Reynolds number) is computed as a function of n for a shear-thinning (n < 1) fluid. Indeed, the local decrements in the viscosity field achieved in high-shear zones implies the increment in the local Reynolds number, thus moving the position of near-walls minima towards lateral walls. Moreover, the revolution under shear of neutrally buoyant plain elliptical capsules with different Aspect Ratio (AR = 2 and 3) is analyzed for shear-thinning (n < 1), Newtonian (n = 1), and shear-thickening (n > 1) surrounding fluids. Interestingly, the power law by Huang et al. describing the revolution period of such capsules as a function of the Reynolds number and the existence of a critical value, Rec, after which the tumbling is inhibited in confirmed also for non-Newtonian fluids. Analogously, the equilibrium lateral position yeq of such neutrally buoyant capsules when transported in a plane-Couette flow is studied detailing the variation of yeq as a function of the Reynolds number as well as of the exponent n. Full article
(This article belongs to the Special Issue Multiscale Innovative Materials and Structures)
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Open AccessArticle
Failure Analysis of Ultra High-Performance Fiber-Reinforced Concrete Structures Enhanced with Nanomaterials by Using a Diffuse Cohesive Interface Approach
Nanomaterials 2020, 10(9), 1792; https://doi.org/10.3390/nano10091792 - 09 Sep 2020
Cited by 2 | Viewed by 647
Abstract
Recent progresses in nanotechnology have clearly shown that the incorporation of nanomaterials within concrete elements leads to a sensible increase in strength and toughness, especially if used in combination with randomly distributed short fiber reinforcements, as for ultra high-performance fiber-reinforced concrete (UHPFRC). Current [...] Read more.
Recent progresses in nanotechnology have clearly shown that the incorporation of nanomaterials within concrete elements leads to a sensible increase in strength and toughness, especially if used in combination with randomly distributed short fiber reinforcements, as for ultra high-performance fiber-reinforced concrete (UHPFRC). Current damage models often are not able to accurately predict the development of diffuse micro/macro-crack patterns which are typical for such concrete structures. In this work, a diffuse cohesive interface approach is proposed to predict the structural response of UHPFRC structures enhanced with embedded nanomaterials. According to this approach, all the internal mesh boundaries are regarded as potential crack segments, modeled as cohesive interfaces equipped with a mixed-mode traction-separation law suitably calibrated to account for the toughening effect of nano-reinforcements. The proposed fracture model has been firstly validated by comparing the failure simulation results of UHPFRC specimens containing different fractions of graphite nanoplatelets with the available experimental data. Subsequently, such a model, combined with an embedded truss model to simulate the concrete/steel rebars interaction, has been used for predicting the load-carrying capacity of steel bar-reinforced UHPFRC elements enhanced with nanoplatelets. The numerical outcomes have shown the reliability of the proposed model, also highlighting the role of the nano-reinforcement in the crack width control. Full article
(This article belongs to the Special Issue Multiscale Innovative Materials and Structures)
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Open AccessArticle
Tensegrity Modelling and the High Toughness of Spider Dragline Silk
Nanomaterials 2020, 10(8), 1510; https://doi.org/10.3390/nano10081510 - 31 Jul 2020
Viewed by 1554
Abstract
This work establishes a tensegrity model of spider dragline silk. Tensegrity systems are ubiquitous in nature, being able to capture the mechanics of biological shapes through simple and effective modes of deformation via extension and contraction. Guided by quantitative microstructural characterization via air [...] Read more.
This work establishes a tensegrity model of spider dragline silk. Tensegrity systems are ubiquitous in nature, being able to capture the mechanics of biological shapes through simple and effective modes of deformation via extension and contraction. Guided by quantitative microstructural characterization via air plasma etching and low voltage scanning electron microscopy, we report that this model is able to capture experimentally observed phenomena such as the Poisson effect, tensile stress-strain response, and fibre toughness. This is achieved by accounting for spider silks’ hierarchical organization into microfibrils with radially variable properties. Each fibril is described as a chain of polypeptide tensegrity units formed by crystalline granules operating under compression, which are connected to each other by amorphous links acting under tension. Our results demonstrate, for the first time, that a radial variability in the ductility of tensegrity chains is responsible for high fibre toughness, a defining and desirable feature of spider silk. Based on this model, a discussion about the use of graded tensegrity structures for the optimal design of next-generation biomimetic fibres is presented. Full article
(This article belongs to the Special Issue Multiscale Innovative Materials and Structures)
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Open AccessArticle
Remarkable Physical and Thermal Properties of Hydrothermal Carbonized Nanoscale Cellulose Observed from Citric Acid Catalysis and Acetone Rinsing
Nanomaterials 2020, 10(6), 1049; https://doi.org/10.3390/nano10061049 - 29 May 2020
Cited by 4 | Viewed by 724
Abstract
Citric acid (CA) was used for the hydrothermal carbonization (HTC) of cellulose nanofiber and found to exert remarkable effects on the chemistry and physical aspects of the product distribution. More specifically, the morphology, yield, elemental and proximate composition, chemical functional groups, thermal properties [...] Read more.
Citric acid (CA) was used for the hydrothermal carbonization (HTC) of cellulose nanofiber and found to exert remarkable effects on the chemistry and physical aspects of the product distribution. More specifically, the morphology, yield, elemental and proximate composition, chemical functional groups, thermal properties and surface properties of the resultant hydrochars were studied extensively. The morphological properties of the final char were the singularly most surprising and unique finding of this study. The cellulose nanofiber hydrochars were contrasted to hydrochars from bleached softwood pulp, having a similar composition with the former, to pinpoint the role of nano-dimensions. Without the presence of CA, the pulp hydrochar lacked several of the spherical dimensions shown in the nanocellulose; however, and unexpectedly, the presence of CA caused a homogenization of the final product distribution for both samples. Finally, thermally stable and high surface area hydrochars were obtained when the hydrochar was rinsed with acetone. Full article
(This article belongs to the Special Issue Multiscale Innovative Materials and Structures)
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Open AccessArticle
Design and Testing of Bistable Lattices with Tensegrity Architecture and Nanoscale Features Fabricated by Multiphoton Lithography
Nanomaterials 2020, 10(4), 652; https://doi.org/10.3390/nano10040652 - 31 Mar 2020
Cited by 5 | Viewed by 1663
Abstract
A bistable response is an innate feature of tensegrity metamaterials, which is a conundrum to attain in other metamaterials, since it ushers unconventional static and dynamical mechanical behaviors. This paper investigates the design, modeling, fabrication and testing of bistable lattices with tensegrity architecture [...] Read more.
A bistable response is an innate feature of tensegrity metamaterials, which is a conundrum to attain in other metamaterials, since it ushers unconventional static and dynamical mechanical behaviors. This paper investigates the design, modeling, fabrication and testing of bistable lattices with tensegrity architecture and nanoscale features. First, a method to design bistable lattices tessellating tensegrity units is formulated. The additive manufacturing of these structures is performed through multiphoton lithography, which enables the fabrication of microscale structures with nanoscale features and extremely high resolution. Different modular lattices, comprised of struts with 250 nm minimum radius, are tested under loading-unloading uniaxial compression nanoindentation tests. The compression tests confirmed the activation of the designed bistable twisting mechanism in the examined lattices, combined with a moderate viscoelastic response. The force-displacement plots of the 3D assemblies of bistable tensegrity prisms reveal a softening behavior during the loading from the primary stable configuration and a subsequent snapping event that drives the structure into a secondary stable configuration. The twisting mechanism that characterizes such a transition is preserved after unloading and during repeated loading-unloading cycles. The results of the present study elucidate that fabrication of multistable tensegrity lattices is highly feasible via multiphoton lithography and promulgates the fabrication of multi-cell tensegrity metamaterials with unprecedented static and dynamic responses. Full article
(This article belongs to the Special Issue Multiscale Innovative Materials and Structures)
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Review

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Open AccessReview
Nanocrystalline Soft Magnetic Iron-Based Materials from Liquid State to Ready Product
Nanomaterials 2021, 11(1), 108; https://doi.org/10.3390/nano11010108 - 05 Jan 2021
Cited by 1 | Viewed by 562
Abstract
The review is devoted to the analysis of physical processes occurring at different stages of production and application of nanocrystalline soft magnetic materials based on Fe–Si–B doped with various chemical elements. The temperature dependences of the kinematic viscosity showed that above a critical [...] Read more.
The review is devoted to the analysis of physical processes occurring at different stages of production and application of nanocrystalline soft magnetic materials based on Fe–Si–B doped with various chemical elements. The temperature dependences of the kinematic viscosity showed that above a critical temperature, the viscosity of multicomponent melts at the cooling stage does not coincide with the viscosity at the heating stage. Above the critical temperature, the structure of the melt is more homogeneous, the amorphous precursor from such a melt has greater plasticity and enthalpy of crystallization and, after nanocrystallization, the material has a higher permeability. The most effective inhibitor elements are insoluble in α-Fe and form a smoothed peak of heat release during crystallization. On the other hand, the finest nanograins and the highest permeability are achieved at a narrow high-temperature peak of heat release. The cluster magnetic structure of a nanocrystalline material is the cause of magnetic inhomogeneity, which affects the shape of the magnetic hysteresis loop and core losses. Full article
(This article belongs to the Special Issue Multiscale Innovative Materials and Structures)
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Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title: Design and testing of bistable lattices with nanoscale features fabricated by multiphoton lithography
Authors: Zacharias Vangelatos 1, Andrea Micheletti 2, Costas Grigoropoulos 1,*, and Fernando Fraternali 3
Affiliation: 1 Department of Mechanical Engineering, University of California, Berkeley, CA, USA; [email protected], [email protected] 2 Department of Civil and Computer Science Engineering, University of Rome Tor Vergata, Italy; [email protected] 3 Department of Civil Engineering, University of Salerno, Italy; [email protected] * Correspondence: [email protected]; Tel.: +1-510-642-2525
Abstract: Bistable response is a peculiar feature of tensegrity metamaterials, which is not easily found in other lattice metamaterials. It reflects into unconventional mechanical behaviors both in statics and dynamics. This paper explores the design, modeling, fabrication and testing of bistable lattices with tensegrity architecture and nanoscale features. First, a method to design bistable lattices starting from mono-stable tensegrity structures is formulated. Such a process leads to the design of lattices based on triangular tensegrity prism units with bistable response. The additive manufacturing of these structures is performed through multiphoton lithography, which enables the fabrication of microscale structures with nanoscale features and extremely high resolution. Different modular lattices are fabricated with 250 nm strut radius and subsequently tested under loading-unloading uniaxial compression cycles. Compression test results confirm the activation of the bistable twisting mechanism in the examined lattices, combined with a moderate viscoelastic response. The force-displacement plots of 3D assemblies of bistable tensegrity prisms reveal a softening behavior during loading form the first stable configuration, up to a snapping event that drives the structure into a second stable configuration. The twisting mechanism that characterizes such a transition is preserved after unloading and during repeated loading-unloading cycles. The results of the present study demonstrate that fabrication of multistable tensegrity lattices is highly feasible via multiphoton lithography, and pave the way to the fabrication of multi-cell tensegrity metamaterials with unconventional static and dynamic responses.

Title: A tensegrity model of the spider dragline silk that paves the way to the design of next-generation biomimetic fibres
Authors: Fernando Fraternali1, Nicola Stehling2, Ada Amendola1, Chris Holland2, Cornelia Rodenburg 2,*
Affiliation: 1 Department of Civil Engineering, University of Salerno (Italy); [email protected], [email protected] 2 Department of Materials Science & Engineering, University of Sheffield (UK); [email protected] * Correspondence: [email protected];
Abstract: This work presents a tensegrity modelling of the spider silk that captures the microstructural characterization of the Nephila dragline silk through plasma etching and low-voltage scanning electron microscopy. The proposed model reproduces the region-dependent hierarchical organization of the spider dragline silk in microfibrils, which are formed by crystalline granules of -sheet crystals (crystalline domains) linked each other by polypeptide (amorphous) tendons (noncrystalline domains). The crystalline granules endow the fibrils with transverse stiffness and produce transverse contraction under longitudinal stretching (Poisson’s effect). The variability of the regional properties of the fibrils across the radial depth explains the enhanced toughness and energy absorption capacity of the spider silk. The proposed modelling paves the way to the optimal design of novel biomimetic fibres with unprecedented mechanical properties. Keywords: spider silk; scanning electron microscopy; mechanical modelling; tensegrity systems; biomimetic fibres.

Title: Optimal Shapes and Junctions of Spider Webs: from Nanostructure to Macro Response
Authors: D. De Tommasi1, G. Puglisi1, N.M. Pugno2
Affiliation: 1 Dipartimento di Scienze dell’Ingegneria Civile e dell’Architettura, Politecnico di Bari, Bari, Italy; [email protected]; [email protected] 2 Laboratory of Bio-Inspired and Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento; Ket Lab, Edoardo Amaldi Foundation, Italian Space Agency; School of Engineering and Materials Science, Queen Mary University of London, U.K.; [email protected]
Abstract: Spider silks represent biological materials with incredible dissipative, strength and healing properties that descend from their complex nanostructure. The recent progress in the experimental techniques revealed that these extraordinary properties result by a ‘smart’ combination of materials, junctions and web geometric properties. These aspects are of great interest not only from an evolutionary and biological point of view, but also in the perspective of the design of innovative bioinspired materials and structures. Here, based on a multiscale model that we previously proposed, relating the macro response of the silk wires to their nanostructure, we analyze some important optimality properties of spider webs, taking care also of the fundamental role of silk junctions.

Title: Nonlocal thermo-viscoelastic responses analysis of viscoelastic laminated sandwich nanocomposites under non-uniform temperature
Authors: Huili Guoa, Tianhu Heb, Chenlin Li a,c
Affiliations: a School of Civil Engineering, Lanzhou Jiaotong University, Lanzhou, Gansu 730070, China
b School of Science, Lanzhou University of Technology, Lanzhou 730050, Gansu, P.R. China;
c State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, P. R. China
Abstract: Viscoelastic laminated sandwich nanocomposite structure stands as a new class of smart nano-structure which is widely used as high-efficient shock absorbers in nanoengineering due to its excellent performance in vibration isolation and control. Especially under extreme non-isothermal conditions (e.g., high heat-flux, drastic change of temperature, etc.), how to improve the heat isolation and avoid unwanted vibrations appears to be particularly important for its safety working, and therefore a thorough and comprehensive study on such problems imperatively needed. This work aims to investigate the nonlocal thermo-viscoelastic responses of viscoelastic laminated sandwich nanocomposites under non-uniform temperature. It is assumed that the structure considered is subjected to symmetrical thermal loadings at its upper and lower bounding surfaces. The thermal contact resistance and elastic wave impedance at the interface are assumed to be zero with ideal adhesion. For each homogeneous isotropic layer, the governing equations are the first to be systematically formulated and solved by Laplace transformation techniques. The effects of size-dependent characteristic lengths and material constants ratio on structural responses are also evaluated and discussed. The strategy adopted in this work is expected to provide new insights on the vibration control and thermal management of viscoelastic laminated sandwich nanocomposites.

Title: Failure analysis of ultra high-performance fiber-reinforced concrete structures enhanced with nanomaterials by using a diffuse cohesive interface approach
Authors: Umberto De Maio1, Nicholas Fantuzzi2, Fabrizio Greco1*, Lorenzo Leonetti1, Andrea Pranno1
Affiliation: 1 Department of Civil Engineering, University of Calabria, Rende, 87036, Italy 2 Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, Bologna, 40136, Italy
Abstract: Recent progresses in nanotechnology have clearly shown that the incorporation of nanomaterials within concrete elements leads to a sensible increase in strength and toughness, especially if used in combination with randomly distributed short fiber reinforcements, as for ultra high-performance fiber-reinforced concrete (UHPFRC). Current damage models often are not able to accurately predict the development of diffuse micro/macro-crack patterns which are typical for such concrete structures. In this work, a diffuse cohesive interface approach is proposed to predict the structural response of UHPFRC structures enhanced with embedded nanomaterials. According to this approach, all the internal mesh boundaries are regarded as potential crack segments, modeled as cohesive interfaces equipped with a mixed-mode traction-separation law suitably calibrated to account for the toughening effect of nano-reinforcements. The proposed fracture model has been firstly validated by comparing the failure simulation results of UHPFRC specimens containing different fractions of graphite nanoplatelets with the available experimental data. Subsequently, such a model, combined with an embedded truss model to simulate the concrete/steel rebars interaction, has been used for predicting the load-carrying capacity of steel-bar reinforced UHPFRC elements enhanced with nanoplatelets. The numerical outcomes have shown the reliability of the proposed model, also highlighting the role of the nanoreinforcement in the crack width control.

Title: Nanocapsules Rotating under Shear in A Yasuda-Carreau Non-Newtonian Fluid
Authors: A. COCLITE1*, G. M. COCLITE2, D. DE TOMMASI3
Affiliation: 1. Scuola di Ingegneria, Università degli Studi della Basilicata, Potenza, Italy. 2. Dipartimento di Meccanica, Matematica e Management, Bari, Italy. 3. Dipartimento dell’Ingegneria e dell’Architettura, Bari, Italy.
Abstract: Micro- and nano-particles have been proven as efficient carriers of therapeutics for the specific treatment of diseases such as cancer or cardiovascular disorders. For the target specific delivery of drugs, two major steps are required: the accumulation of these small constructs into capillary peripheries (margination) and the firm adhesion to the diseased tissue capillary walls. Specifically, soft nanomedicines should release their cargo mostly when firmly adhering such walls. In order to rationally design such carriers shape, is fundamental to understand their rotational behavior in non-Newtonian fluid so as to tailor their shape and let them be as prone as possible to marginate and stick diseased vascular walls. In this work a multi relaxation time Lattice Boltzmann method is used to describe the evolution of a non-Newtonian fluid. Such method is coupled with an Immersed-Boundary technique for the transport of arbitrarily shaped objects navigating the flow. In order to enforce the no-slip boundary conditions on immersed bodies a convenient forcing term is added to the discrete Boltzmann’s equation accounting for the hydrodynamic force generated by the presence immersed geometries. Moreover, such forcing term accounts also for the force induced by the shear-dependent viscosity characterizing the non-Newtonian behaviour of the fluid.

Title: Nanocrystalline Soft Magnetic Materials from Liquid State to Ready Product
Authors: Vladimir S. Tsepelev 1,*, Yuri N. Starodubtsev 1,2
Affiliation: 1 Ural Federal University, Research Center for Physics of Metal Liquids, Mira str.19, Ekaterinburg, 620002, Russia; [email protected] 2 Gammamet Research and Production Enterprise, Tatishchev str. 92, Ekaterinburg, 620028, Russia; [email protected]
Abstract: The place of nanocrystalline soft magnetic materials among other magnetic materials and methods of production. Physical principles of obtaining high permeability in nanocrystalline materials. The structure of liquid multicomponent alloys and its effect on magnetic properties. Nanocrystallization process and structure of nanocrystalline materials. Nanograin growth inhibitors. The influence of chemical composition on the structure and magnetic properties of nanocrystalline materials. Nanocrystalline soft magnetic materials with high magnetic flux density. Heat treatment in a magnetic field and thermal stability of nanocrystalline materials. Magnetic hysteresis, frequency dependences of core losses and permeability. Dependence of core losses on the amplitude of induction. Magnetic cores, transformers and inductive elements made of nanocrystalline materials and their application.

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