Pub Date : 2024-09-01DOI: 10.1016/j.ijengsci.2024.104137
The incorporation of ceramics into polymers, forming solid composite electrolytes (SCEs) leads to enhanced electrical performance of all-solid-state lithium metal batteries. This is because the dispersed ceramics particles increase the ionic conductivity, while the polymer matrix leads to better contact performance between the electrolyte and the electrode. In this study, we present a model, based on Hybrid Elements Methods, for the time-dependent Li metal and SCE rough interface mechanics, taking into account for the oxide (ceramics) inclusions (using the Equivalent Inclusion method), and the viscoelasticity of the matrix. We study the effect of LLTO particle size, weight concentration, and spatial distribution on the interface mechanical and electrical response. Moreover, considering the viscoelastic spectrum of a real PEO matrix, under a given stack pressure, we investigate the evolution over time of the mechanical and electrical performance of the interface. The presented theoretical/numerical model might be pivotal in tailoring the development of advanced solid state batteries with superior performance; indeed, we found that conditions in the SCE mixture which optimize both the contact resistivity and the interface stability in time.
{"title":"Interfacial performance evolution of ceramics-in-polymer composite electrolyte in solid-state lithium metal batteries","authors":"","doi":"10.1016/j.ijengsci.2024.104137","DOIUrl":"10.1016/j.ijengsci.2024.104137","url":null,"abstract":"<div><p>The incorporation of ceramics into polymers, forming solid composite electrolytes (SCEs) leads to enhanced electrical performance of all-solid-state lithium metal batteries. This is because the dispersed ceramics particles increase the ionic conductivity, while the polymer matrix leads to better contact performance between the electrolyte and the electrode. In this study, we present a model, based on Hybrid Elements Methods, for the time-dependent Li metal and SCE rough interface mechanics, taking into account for the oxide (ceramics) inclusions (using the Equivalent Inclusion method), and the viscoelasticity of the matrix. We study the effect of LLTO particle size, weight concentration, and spatial distribution on the interface mechanical and electrical response. Moreover, considering the viscoelastic spectrum of a real PEO matrix, under a given stack pressure, we investigate the evolution over time of the mechanical and electrical performance of the interface. The presented theoretical/numerical model might be pivotal in tailoring the development of advanced solid state batteries with superior performance; indeed, we found that conditions in the SCE mixture which optimize both the contact resistivity and the interface stability in time.</p></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142117495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-30DOI: 10.1016/j.ijengsci.2024.104135
The determination of surface elastic moduli is discussed in the context of a recently proposed strongly anisotropic surface elasticity model. The aim of the model was to describe deformations of solids with thin elastic coatings associated with so-called hyperbolic metasurfaces. These metasurfaces can exhibit a quite unusual behaviour and concurrently a very promising wave propagation behaviour. In the model of strongly anisotropic surface elasticity, strain energy as a function of the first and second deformation gradients has been introduced in addition to the constitutive relations in the bulk. In order to obtain values of surface elastic moduli, we compare dispersion relations for anti-plane surface waves obtained using the two-dimensional (2D) model and three-dimensional (3D) straightforward calculations for microstructured coatings of finite thickness. We show that with derived effective surface moduli, the 2D model can correctly describe the wave propagation.
{"title":"On effective surface elastic moduli for microstructured strongly anisotropic coatings","authors":"","doi":"10.1016/j.ijengsci.2024.104135","DOIUrl":"10.1016/j.ijengsci.2024.104135","url":null,"abstract":"<div><p>The determination of surface elastic moduli is discussed in the context of a recently proposed strongly anisotropic surface elasticity model. The aim of the model was to describe deformations of solids with thin elastic coatings associated with so-called hyperbolic metasurfaces. These metasurfaces can exhibit a quite unusual behaviour and concurrently a very promising wave propagation behaviour. In the model of strongly anisotropic surface elasticity, strain energy as a function of the first and second deformation gradients has been introduced in addition to the constitutive relations in the bulk. In order to obtain values of surface elastic moduli, we compare dispersion relations for anti-plane surface waves obtained using the two-dimensional (2D) model and three-dimensional (3D) straightforward calculations for microstructured coatings of finite thickness. We show that with derived effective surface moduli, the 2D model can correctly describe the wave propagation.</p></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020722524001198/pdfft?md5=c2416474a1bd2e434072802677d6c807&pid=1-s2.0-S0020722524001198-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142097190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-24DOI: 10.1016/j.ijengsci.2024.104136
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, tuneable 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 the fracture phenomena in both aligned and randomly oriented nanofibrous networks by integrating atomistic modelling and non-local continuum mechanics, 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 using innovative approaches. A new method is introduced to seamlessly transfer data from molecular dynamics to peridynamics by ensuring the convergence of the tensile response of a single fiber in both frameworks. This nano to micro coupling technique is then utilised to examine the Young's modulus, fracture toughness of mode 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. The current research paves the way for the development of stronger and more durable eco-friendly nanofibrous networks with optimised performance.
聚乳酸(PLA)纳米纤维网络因其独特的多功能属性,包括生物可降解性、可调节的机械性能和表面功能性,在组织工程、药物输送和过滤等多个工程和科学领域引起了广泛关注。然而,由于其结构的复杂性、多尺度特征以及材料属性的可变性,预测其机械行为仍然具有挑战性。本研究提出了一种分层方法,通过整合原子模型和非局部连续介质力学(周动力学)来研究排列和随机取向纳米纤维网络的断裂现象。在纳米尺度上,采用全原子分子动力学模拟对独立的原始聚乳酸纳米纤维和掺银聚乳酸纳米纤维施加拉伸载荷,利用创新方法确定关键力学性能,如杨氏模量、泊松比和临界能量释放率。该研究引入了一种新方法,通过确保单根纤维的拉伸响应在两个框架中的趋同性,将数据从分子动力学无缝传输到周动力学。然后利用这种纳米到微观的耦合技术来研究聚乳酸纳米纤维网络的杨氏模量、模式 I 和模式 II 的断裂韧性以及裂纹扩展。所提出的框架还包括表面涂层和纤维排列对测量特性的影响。目前的研究为开发性能更强、更耐用的生态友好型纳米纤维网络铺平了道路。
{"title":"Fracture properties of green nano fibrous network with random and aligned fiber distribution: A hierarchical molecular dynamics and peridynamics approach","authors":"","doi":"10.1016/j.ijengsci.2024.104136","DOIUrl":"10.1016/j.ijengsci.2024.104136","url":null,"abstract":"<div><p>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, tuneable mechanical properties, and surface functionality. However, predicting their mechanical behaviour remains challenging due to their structural complexity, multiscale features, and variability in material properties.</p><p>This study presents a hierarchical approach to investigate the fracture phenomena in both aligned and randomly oriented nanofibrous networks by integrating atomistic modelling and non-local continuum mechanics, 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 using innovative approaches. A new method is introduced to seamlessly transfer data from molecular dynamics to peridynamics by ensuring the convergence of the tensile response of a single fiber in both frameworks. This nano to micro coupling technique is then utilised to examine the Young's modulus, fracture toughness of mode 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. The current research paves the way for the development of stronger and more durable eco-friendly nanofibrous networks with optimised performance.</p></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020722524001204/pdfft?md5=5a2924a0737229ad53086f87723b9ce9&pid=1-s2.0-S0020722524001204-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142048518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-16DOI: 10.1016/j.ijengsci.2024.104126
The macroscopic behaviors of materials are determined by interactions that occur at multiple lengths and time scales. Depending on the application, describing, predicting, and understanding these behaviors may require models that rely on insights from atomic and electronic scales. In such cases, classical simplified approximations at those scales are insufficient, and quantum-based modeling is required. In this paper, we study how quantum effects can modify the mechanical properties of systems relevant to materials engineering. We base our study on a high-fidelity modeling framework that combines two computationally efficient models rooted in quantum first principles: Density Functional Tight Binding (DFTB) and many-body dispersion (MBD). The MBD model is applied to accurately describe non-covalent van der Waals interactions. Through various benchmark applications, we demonstrate the capabilities of this framework and the limitations of simplified modeling. We provide an open-source repository containing all codes, datasets, and examples presented in this work. This repository serves as a practical toolkit that we hope will support the development of future research in effective large-scale and multiscale modeling with quantum-mechanical fidelity.
{"title":"Quantum-informed simulations for mechanics of materials: DFTB+MBD framework","authors":"","doi":"10.1016/j.ijengsci.2024.104126","DOIUrl":"10.1016/j.ijengsci.2024.104126","url":null,"abstract":"<div><p>The macroscopic behaviors of materials are determined by interactions that occur at multiple lengths and time scales. Depending on the application, describing, predicting, and understanding these behaviors may require models that rely on insights from atomic and electronic scales. In such cases, classical simplified approximations at those scales are insufficient, and quantum-based modeling is required. In this paper, we study how quantum effects can modify the mechanical properties of systems relevant to materials engineering. We base our study on a high-fidelity modeling framework that combines two computationally efficient models rooted in quantum first principles: Density Functional Tight Binding (DFTB) and many-body dispersion (MBD). The MBD model is applied to accurately describe non-covalent van der Waals interactions. Through various benchmark applications, we demonstrate the capabilities of this framework and the limitations of simplified modeling. We provide an open-source repository containing all codes, datasets, and examples presented in this work. This repository serves as a practical toolkit that we hope will support the development of future research in effective large-scale and multiscale modeling with quantum-mechanical fidelity.</p></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020722524001101/pdfft?md5=2101857dffb97909280e02ce601f2c8c&pid=1-s2.0-S0020722524001101-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141992768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-14DOI: 10.1016/j.ijengsci.2024.104127
Structural schemes of applicative interests in Engineering Science frequently encounter the intricate phenomenon of discontinuity. The present study intends to address the discontinuity in the flexure of elastic nanobeam by adopting an abstract variational scheme. The mixture unified gradient theory of elasticity is invoked to realize the size-effects at the ultra-small scale. The consistent form of the interface conditions, stemming from the established stationary variational principle, is meticulously set forth. The boundary-value problem of equilibrium is properly closed and the analytical solution of the transverse displacement field of the elastic nanobeam is addressed. As an alternative approach, the eigenfunction expansion method is also utilized to scrutinize the efficacy of the presented variational formulation in tackling the flexure of elastic nanobeams with discontinuity. The flexural characteristic of mixture unified gradient beams with diverse kinematic constraints is numerically illustrated and thoroughly discussed. The anticipated nanoscopic features of the characteristic length-scale parameters are confirmed. The demonstrated numerical results can advantageously serve as a benchmark for the analysis and design of pioneering ultra-sensitive nano-sensors. The established variationally consistent size-dependent framework paves the way ahead in nanomechanics and inspires further research contributing to fracture mechanics of ultra-small scale elastic beams.
{"title":"Non-standard interface conditions in flexure of mixture unified gradient Nanobeams","authors":"","doi":"10.1016/j.ijengsci.2024.104127","DOIUrl":"10.1016/j.ijengsci.2024.104127","url":null,"abstract":"<div><p>Structural schemes of applicative interests in Engineering Science frequently encounter the intricate phenomenon of discontinuity. The present study intends to address the discontinuity in the flexure of elastic nanobeam by adopting an abstract variational scheme. The mixture unified gradient theory of elasticity is invoked to realize the size-effects at the ultra-small scale. The consistent form of the interface conditions, stemming from the established stationary variational principle, is meticulously set forth. The boundary-value problem of equilibrium is properly closed and the analytical solution of the transverse displacement field of the elastic nanobeam is addressed. As an alternative approach, the eigenfunction expansion method is also utilized to scrutinize the efficacy of the presented variational formulation in tackling the flexure of elastic nanobeams with discontinuity. The flexural characteristic of mixture unified gradient beams with diverse kinematic constraints is numerically illustrated and thoroughly discussed. The anticipated nanoscopic features of the characteristic length-scale parameters are confirmed. The demonstrated numerical results can advantageously serve as a benchmark for the analysis and design of pioneering ultra-sensitive nano-sensors. The established variationally consistent size-dependent framework paves the way ahead in nanomechanics and inspires further research contributing to fracture mechanics of ultra-small scale elastic beams.</p></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020722524001113/pdfft?md5=a656c71a5c74865742beba0627bbd601&pid=1-s2.0-S0020722524001113-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141985498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1016/j.ijengsci.2024.104120
There has been tremendous recent interest in Direct Air Capture (DAC) systems. A key part of any DAC system are the multiple air intake units. In particular, the arrangement of such units for optimal capture and sequestration is critical. Accordingly, this work develops an easy to use model for a modular unit system, where an approximate flow field is computed for each unit and the aggregate flow field is developed by summing the fields from each unit. This allows for a modular framework that can be used for rapid simulation and design of an overall DAC system. The rapid rate at which these simulations can be completed enables the ability to explore inverse problems seeking to determine which parameter combinations can deliver the maximum sequestration of tracer plume particles for the minimum amount of energy input. In order to cast the objective mathematically, we set up an inverse as a Machine Learning Algorithm (MLA); specifically a Genetic MLA (G-MLA) variant, which is well-suited for nonconvex optimization. Numerical examples are provided to illustrate the framework.
{"title":"A digital-twin for rapid simulation modular Direct Air Capture systems","authors":"","doi":"10.1016/j.ijengsci.2024.104120","DOIUrl":"10.1016/j.ijengsci.2024.104120","url":null,"abstract":"<div><p>There has been tremendous recent interest in Direct Air Capture (DAC) systems. A key part of any DAC system are the multiple air intake units. In particular, the arrangement of such units for optimal capture and sequestration is critical. Accordingly, this work develops an easy to use model for a modular unit system, where an approximate flow field is computed for each unit and the aggregate flow field is developed by summing the fields from each unit. This allows for a modular framework that can be used for rapid simulation and design of an overall DAC system. The rapid rate at which these simulations can be completed enables the ability to explore inverse problems seeking to determine which parameter combinations can deliver the maximum sequestration of tracer plume particles for the minimum amount of energy input. In order to cast the objective mathematically, we set up an inverse as a Machine Learning Algorithm (MLA); specifically a Genetic MLA (G-MLA) variant, which is well-suited for nonconvex optimization. Numerical examples are provided to illustrate the framework.</p></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141939788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.1016/j.ijengsci.2024.104125
Nanocomposites can show different properties according to the type of reinforcements they have. In this article, a model for the study of nanocomposites is examined, which is able to examine all nanocomposites with elliptical, cylindrical, spherical and rectangular reinforcements. Also, in this model, unlike some other models, the effects of interphase section are included. The results obtained from this model are compared with the results of experimental tests. Also, in present research, instead of classical continuum theories, generalized continuum mechanics is used and combined with above model to present more accurate model for studying nanocomposites. After estimating the material properties of nanocomposites, the static and dynamics behaviors of them are also studied and the influences of various parameters such as volume fraction of interphase section, geometrical shapes of reinforcements, volume fraction of fibers, gradient parameter, nonlocality and magnetic field are investigated on the results.
{"title":"Nanocomposites with cylindrical/rectangular/spherical/ellipsoidal reinforcements: Generalized continuum mechanics","authors":"","doi":"10.1016/j.ijengsci.2024.104125","DOIUrl":"10.1016/j.ijengsci.2024.104125","url":null,"abstract":"<div><p>Nanocomposites can show different properties according to the type of reinforcements they have. In this article, a model for the study of nanocomposites is examined, which is able to examine all nanocomposites with elliptical, cylindrical, spherical and rectangular reinforcements. Also, in this model, unlike some other models, the effects of interphase section are included. The results obtained from this model are compared with the results of experimental tests. Also, in present research, instead of classical continuum theories, generalized continuum mechanics is used and combined with above model to present more accurate model for studying nanocomposites. After estimating the material properties of nanocomposites, the static and dynamics behaviors of them are also studied and the influences of various parameters such as volume fraction of interphase section, geometrical shapes of reinforcements, volume fraction of fibers, gradient parameter, nonlocality and magnetic field are investigated on the results.</p></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141939789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-03DOI: 10.1016/j.ijengsci.2024.104119
The drying phenomenon in soils involves complex interactions between thermal, hydrological, and mechanical effects within a multiphase system. While several researches (both mechanics and mixture theory approach) has been applied to study various thermo-hydro-mechanical (THM) coupled processes in porous media, incorporating both multiphase flow and phase change in soil drying remains limited. This work addresses this research gap by deriving new governing equations for a two-phase flow model suitable for soil drying by extending the mixture coupling approach. The derived model is implemented in COMSOL Multiphysics and validated against experimental data, demonstrating good agreement between the model predictions and the ob- served results. A sensitivity analysis is performed to investigate the impact of critical parameters on the drying process. The findings reveal that volumetric strain is most sensitive to Young’s modulus, while the saturation of liquid water is most affected by intrinsic permeability. Additionally, preliminary results for a kaolinite clay sample during the drying process are presented, extending the applicability of the derived model to specific soil types. This research provides a comprehensive framework for fully THM coupled modelling of soil drying, which can serve as a basis for future investigations.
{"title":"Multiphase thermo-hydro-mechanical coupled soil drying model with phase-exchange based on mixture coupling theory","authors":"","doi":"10.1016/j.ijengsci.2024.104119","DOIUrl":"10.1016/j.ijengsci.2024.104119","url":null,"abstract":"<div><p>The drying phenomenon in soils involves complex interactions between thermal, hydrological, and mechanical effects within a multiphase system. While several researches (both mechanics and mixture theory approach) has been applied to study various thermo-hydro-mechanical (THM) coupled processes in porous media, incorporating both multiphase flow and phase change in soil drying remains limited. This work addresses this research gap by deriving new governing equations for a two-phase flow model suitable for soil drying by extending the mixture coupling approach. The derived model is implemented in COMSOL Multiphysics and validated against experimental data, demonstrating good agreement between the model predictions and the ob- served results. A sensitivity analysis is performed to investigate the impact of critical parameters on the drying process. The findings reveal that volumetric strain is most sensitive to Young’s modulus, while the saturation of liquid water is most affected by intrinsic permeability. Additionally, preliminary results for a kaolinite clay sample during the drying process are presented, extending the applicability of the derived model to specific soil types. This research provides a comprehensive framework for fully THM coupled modelling of soil drying, which can serve as a basis for future investigations.</p></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0020722524001034/pdfft?md5=7b9579150cd6c77652885e8ef3a57b3f&pid=1-s2.0-S0020722524001034-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141895799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-02DOI: 10.1016/j.ijengsci.2024.104124
The paper proposes a transparent and compact form of constitutive and equilibrium relations for the plane thermoelasticity of quasicrystal solids. The symmetry and positive definiteness of the obtained extended tensors of material constants are studied. An extension of the Stroh formalism is proposed for solving plane problems of thermoelasticity for quasicrystals. It is proved that the eigenvalues of the Stroh eigenvalue problem in the most general case of 3D quasicrystal materials do are purely complex. The relations between the matrices and vectors of phonon–phason elastic and thermoelastic coefficients of the proposed extended Stroh formalism are obtained. A fundamental solution to the plane problem of thermoelasticity of a quasicrystal medium is derived. The asymptotic behavior of physical and mechanical fields near the vertices of objects whose geometry can be modeled by a discontinuity line (cracks, thin inclusions) is studied, and the concepts of the corresponding generalized field (heat flux and phonon–phason stress) intensity factors are introduced. Examples of the influence of heat sources and sinks on an infinite quasicrystal medium containing a rectilinear heated crack are considered.
{"title":"Extended Stroh formalism for plane problems of thermoelasticity of quasicrystals with applications to Green’s functions and fracture mechanics","authors":"","doi":"10.1016/j.ijengsci.2024.104124","DOIUrl":"10.1016/j.ijengsci.2024.104124","url":null,"abstract":"<div><p>The paper proposes a transparent and compact form of constitutive and equilibrium relations for the plane thermoelasticity of quasicrystal solids. The symmetry and positive definiteness of the obtained extended tensors of material constants are studied. An extension of the Stroh formalism is proposed for solving plane problems of thermoelasticity for quasicrystals. It is proved that the eigenvalues of the Stroh eigenvalue problem in the most general case of 3D quasicrystal materials do are purely complex. The relations between the matrices and vectors of phonon–phason elastic and thermoelastic coefficients of the proposed extended Stroh formalism are obtained. A fundamental solution to the plane problem of thermoelasticity of a quasicrystal medium is derived. The asymptotic behavior of physical and mechanical fields near the vertices of objects whose geometry can be modeled by a discontinuity line (cracks, thin inclusions) is studied, and the concepts of the corresponding generalized field (heat flux and phonon–phason stress) intensity factors are introduced. Examples of the influence of heat sources and sinks on an infinite quasicrystal medium containing a rectilinear heated crack are considered.</p></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141951309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-02DOI: 10.1016/j.ijengsci.2024.104118
Estimation of macroscopic properties of heterogeneous materials has always posed significant problems. Procedures based on numerical homogenization, although very flexible, consume a lot of time and computing power. Thus, many attempts have been made to develop analytical models that could provide robust and computationally efficient tools for this purpose. The goal of this paper is to develop a reliable analytical approach to finding the effective elastic–plastic response of metal matrix composites (MMC) and porous metals (PM) with a predefined particle or void distribution, as well as to examine the anisotropy induced by regular inhomogeneity arrangements. The proposed framework is based on the idea of Molinari & El Mouden (1996) to improve classical mean-field models of thermoelastic media by taking into account the interactions between each pair of inhomogeneities within the material volume, known as a cluster model. Both elastic and elasto-plastic regimes are examined. A new extension of the original formulation, aimed to account for the non-linear plastic regime, is performed with the use of the modified tangent linearization of the metal matrix constitutive law. The model uses the second stress moment to track the accumulated plastic strain in the matrix. In the examples, arrangements of spherical inhomogeneities in three Bravais lattices of cubic symmetry (Regular Cubic, Body-Centered Cubic and Face-Centered Cubic) are considered for two basic material scenarios: “hard-in-soft” (MMC) and “soft-in-hard” (PM). As a means of verification, the results of micromechanical mean-field modeling are compared with those of numerical homogenization performed using the Finite Element Method (FEM). In the elastic regime, a comparison is also made with several other micromechanical models dedicated to periodic composites. Within both regimes, the results obtained by the cluster model are qualitatively and quantitatively consistent with FEM calculations, especially for volume fractions of inclusions up to 40%.
异质材料宏观特性的估算一直是个大问题。基于数值均质化的程序虽然非常灵活,但却耗费大量时间和计算能力。因此,人们多次尝试开发分析模型,以便为此提供稳健且计算效率高的工具。本文的目标是开发一种可靠的分析方法,以找到具有预定颗粒或空隙分布的金属基复合材料(MMC)和多孔金属(PM)的有效弹塑性响应,并研究规则不均匀排列引起的各向异性。所提出的框架基于 Molinari & El Mouden(1996 年)的想法,即通过考虑材料体积内每对非均质物之间的相互作用(即群集模型)来改进热弹性介质的经典均场模型。对弹性和弹塑性状态都进行了研究。为了考虑非线性塑性状态,对原始公式进行了新的扩展,使用了金属基体构成定律的修正切线线性化。该模型使用第二应力矩来跟踪基体中的累积塑性应变。在示例中,考虑了三种立方对称布拉维晶格(常规立方、体心立方和面心立方)中球形非均质体的排列,以及两种基本材料情况:"软中硬"(MMC)和 "硬中软"(PM)。作为验证手段,将微机械平均场建模结果与使用有限元法(FEM)进行数值均质化的结果进行了比较。在弹性状态下,还与其他几种专门用于周期性复合材料的微机械模型进行了比较。在这两种情况下,群集模型得到的结果在质量和数量上都与有限元法的计算结果一致,尤其是当夹杂物的体积分数达到 40% 时。
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