Pub Date : 2024-11-17DOI: 10.1016/j.ijengsci.2024.104170
Ivan I. Argatov , Federico J. Sabina
An active composite material is assumed to be composed of a passive isotropic elastic matrix with spherical voids containing active rod-like elements, each of which being in diametrical contact with the void’s surface. A ball-bearing fixation between the rod and the contact pads is assumed, and thereby the normal contact becomes a primary mode through which the rod-like elements transfer active loading to the surrounding elastic matrix. Under the assumption that the radius of contact pads is small compared to the void radius, an asymptotic solution to the corresponding elasticity polarization matrix has been derived by the method of matched asymptotic expansions. The obtained explicit analytical results for the matrix/inclusion contact problem and a non-interaction approximation scheme are utilized for constructing an asymptotic model of the dilute elastic active microstructure.
{"title":"Elastic active matter — A composite mechanics approach via non-interaction approximation","authors":"Ivan I. Argatov , Federico J. Sabina","doi":"10.1016/j.ijengsci.2024.104170","DOIUrl":"10.1016/j.ijengsci.2024.104170","url":null,"abstract":"<div><div>An active composite material is assumed to be composed of a passive isotropic elastic matrix with spherical voids containing active rod-like elements, each of which being in diametrical contact with the void’s surface. A ball-bearing fixation between the rod and the contact pads is assumed, and thereby the normal contact becomes a primary mode through which the rod-like elements transfer active loading to the surrounding elastic matrix. Under the assumption that the radius of contact pads is small compared to the void radius, an asymptotic solution to the corresponding elasticity polarization matrix has been derived by the method of matched asymptotic expansions. The obtained explicit analytical results for the matrix/inclusion contact problem and a non-interaction approximation scheme are utilized for constructing an asymptotic model of the dilute elastic active microstructure.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"206 ","pages":"Article 104170"},"PeriodicalIF":5.7,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651672","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 : 2024-11-15DOI: 10.1016/j.ijengsci.2024.104164
Xiao-Jian Xu , Bo Wang
The recent advances of solid mechanics of polymer networks are that they can be well-modelled by a physically-based size-dependent constitutive relation via a simplified strain gradient elasticity theory. However, boundary value problems of plate models composed of polymer networks have not been reported, which limit wide applications of the models in the engineering science. In this paper, we systematically established a variationally consistent boundary value problems of Mindlin plate models for polymer networks leading to the framework of a simplified strain gradient elasticity. This study considers the strain energy produced by the strain gradient in the thickness direction and proposes a well-posed boundary value problem for a Mindlin plate with arbitrary boundaries, discussing possible boundary conditions, especially higher-order nonconventional ones. The senses of stress resultants and double stresses acting on the face of a volume element are firstly explained. Surprisingly, it is found that unexpected corner condition related to normal derivatives of shear force, bending moment, and twisting moment exists for plates with irregular boundaries—contradicting conventional mechanics notions of plates. For illustrative purpose, static bending analyses of a simply supported rectangular plate subjected to a uniformly distributed loading and a concentrated loading are provided. The effective Young's modulus predicted by this approach agrees well with reported result in the open literature. This work may be helpful in developing efficient numerical methods and offers new insights into the existence of corner condition in Mindlin plates within the context of a simplified strain gradient elasticity theory.
{"title":"On size-dependent mechanics of Mindlin plates made of polymer networks","authors":"Xiao-Jian Xu , Bo Wang","doi":"10.1016/j.ijengsci.2024.104164","DOIUrl":"10.1016/j.ijengsci.2024.104164","url":null,"abstract":"<div><div>The recent advances of solid mechanics of polymer networks are that they can be well-modelled by a physically-based size-dependent constitutive relation via a simplified strain gradient elasticity theory. However, boundary value problems of plate models composed of polymer networks have not been reported, which limit wide applications of the models in the engineering science. In this paper, we systematically established a variationally consistent boundary value problems of Mindlin plate models for polymer networks leading to the framework of a simplified strain gradient elasticity. This study considers the strain energy produced by the strain gradient in the thickness direction and proposes a well-posed boundary value problem for a Mindlin plate with arbitrary boundaries, discussing possible boundary conditions, especially higher-order nonconventional ones. The senses of stress resultants and double stresses acting on the face of a volume element are firstly explained. Surprisingly, it is found that unexpected corner condition related to normal derivatives of shear force, bending moment, and twisting moment exists for plates with irregular boundaries—contradicting conventional mechanics notions of plates. For illustrative purpose, static bending analyses of a simply supported rectangular plate subjected to a uniformly distributed loading and a concentrated loading are provided. The effective Young's modulus predicted by this approach agrees well with reported result in the open literature. This work may be helpful in developing efficient numerical methods and offers new insights into the existence of corner condition in Mindlin plates within the context of a simplified strain gradient elasticity theory.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"206 ","pages":"Article 104164"},"PeriodicalIF":5.7,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651561","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 : 2024-11-13DOI: 10.1016/j.ijengsci.2024.104167
Koami P. DADABO, Napo BONFOH, Hafid SABAR, Rodrigue MATADI-BOUMBIMBA
Eshelby's inhomogeneity problem is solved within the second form of Mindlin's first strain gradient elasticity theory for the prediction of the effective elastic properties of composites. Considering Green's function technique, an integral equation is established for an ellipsoidal inhomogeneity embedded in a homogeneous elastic medium and subjected to non-uniform boundary conditions. Within isotropic elasticity, the mean strain inside a spherical inhomogeneity is detailed to provide analytical results. In addition to the elastic properties of the inhomogeneity and the matrix, the strain localization depends on five gradient elastic constants, introduced by the first strain gradient elasticity theory. The effective bulk and shear moduli of a two-phase composite are predicted through Mori-Tanaka's scheme. The strain localization and the effective elastic moduli are then expressed within some simplified gradient elasticity theories. To test the relevance of the developed model, its predictions are compared with those of some investigations and the effective elastic properties are analyzed for a metal matrix composite. Finally, some comparisons with experimental data are performed to estimate the characteristic length scale parameters and gradient elastic constants of local phases.
{"title":"Eshelby's inhomogeneity model within Mindlin's first strain gradient elasticity theory and its applications in composite materials","authors":"Koami P. DADABO, Napo BONFOH, Hafid SABAR, Rodrigue MATADI-BOUMBIMBA","doi":"10.1016/j.ijengsci.2024.104167","DOIUrl":"10.1016/j.ijengsci.2024.104167","url":null,"abstract":"<div><div>Eshelby's inhomogeneity problem is solved within the second form of Mindlin's first strain gradient elasticity theory for the prediction of the effective elastic properties of composites. Considering Green's function technique, an integral equation is established for an ellipsoidal inhomogeneity embedded in a homogeneous elastic medium and subjected to non-uniform boundary conditions. Within isotropic elasticity, the mean strain inside a spherical inhomogeneity is detailed to provide analytical results. In addition to the elastic properties of the inhomogeneity and the matrix, the strain localization depends on five gradient elastic constants, introduced by the first strain gradient elasticity theory. The effective bulk and shear moduli of a two-phase composite are predicted through Mori-Tanaka's scheme. The strain localization and the effective elastic moduli are then expressed within some simplified gradient elasticity theories. To test the relevance of the developed model, its predictions are compared with those of some investigations and the effective elastic properties are analyzed for a metal matrix composite. Finally, some comparisons with experimental data are performed to estimate the characteristic length scale parameters and gradient elastic constants of local phases.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"206 ","pages":"Article 104167"},"PeriodicalIF":5.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651562","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 : 2024-11-08DOI: 10.1016/j.ijengsci.2024.104173
Meral Tuna , Patrizia Trovalusci , Nicholas Fantuzzi
The present study provides closed-form expressions of propagation (kinking) angles by generalizing maximum energy release rate criterion in linear elastic fracture mechanics (LEFM) within micropolar theory of elasticity to address the in-plane, brittle crack propagation phenomenon in size-dependent materials with the presence of particle rotations.
The accuracy and limitations of the derived formulation is checked by manually detecting the peak point of the energy release rate (ERR) through repetitive numerical simulations performed for arbitrary orientations of infinitesimal branch crack, modelled via magnifying the corresponding region with proper boundary conditions. In both approaches (analytical and numerical), the basic fracture parameters (i.e. stress and couple-stress intensity factors at the main or infinitesimal branch tip) are attained with the aid of micropolar/extended-FEM (micropolar/XFEM) model.
Through the parametric study, performed for numerous material properties and loading conditions, it is revealed that, as non-locality increases, the variation of propagation angle with the mode mixity ratio substantially diverges from that in Cauchy continuum. It is manifested as a change in the trend of angle-mode mixity ratio curve, and dominated by the stress related intensity factors in the absence of non-singular terms for the considered example. Having a branch orientation approaching to crack’s axis with increased non-locality indicates the practical importance of resorting to non-classical theories for materials with scale effects such as particulate composites, masonry walls, rock-like assemblages, etc. following their disposition to fracture type failure. Moreover, the proposed fracture criterion enables crack propagation simulations within the framework of LEFM by integrating the formulation into a numerical method.
{"title":"An energy-based fracture criterion for quasi-brittle crack propagation in micropolar continuum: Analytical and numerical study","authors":"Meral Tuna , Patrizia Trovalusci , Nicholas Fantuzzi","doi":"10.1016/j.ijengsci.2024.104173","DOIUrl":"10.1016/j.ijengsci.2024.104173","url":null,"abstract":"<div><div>The present study provides closed-form expressions of propagation (kinking) angles by generalizing maximum energy release rate criterion in linear elastic fracture mechanics (LEFM) within micropolar theory of elasticity to address the in-plane, brittle crack propagation phenomenon in size-dependent materials with the presence of particle rotations.</div><div>The accuracy and limitations of the derived formulation is checked by manually detecting the peak point of the energy release rate (ERR) through repetitive numerical simulations performed for arbitrary orientations of infinitesimal branch crack, modelled via magnifying the corresponding region with proper boundary conditions. In both approaches (analytical and numerical), the basic fracture parameters (i.e. stress and couple-stress intensity factors at the main or infinitesimal branch tip) are attained with the aid of micropolar/extended-FEM (micropolar/XFEM) model.</div><div>Through the parametric study, performed for numerous material properties and loading conditions, it is revealed that, as non-locality increases, the variation of propagation angle with the mode mixity ratio substantially diverges from that in Cauchy continuum. It is manifested as a change in the trend of angle-mode mixity ratio curve, and dominated by the stress related intensity factors in the absence of non-singular terms for the considered example. Having a branch orientation approaching to crack’s axis with increased non-locality indicates the practical importance of resorting to non-classical theories for materials with scale effects such as particulate composites, masonry walls, rock-like assemblages, etc. following their disposition to fracture type failure. Moreover, the proposed fracture criterion enables crack propagation simulations within the framework of LEFM by integrating the formulation into a numerical method.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"206 ","pages":"Article 104173"},"PeriodicalIF":5.7,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651671","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 : 2024-11-06DOI: 10.1016/j.ijengsci.2024.104175
Anatoly Markov , Mikhail Markov , Valery Levin
In this paper, we propose a self-consistent scheme for the calculation of the components of the effective electrical conductivity tensor. The calculations were fulfilled for a microinhomogeneous material, the components of which have the Hall effect. The presence of the Hall effect leads to appearance of asymmetry of the components of the conductivity tensor and to dependence of these components on the magnitude of the magnetic field applied to the material. Our approach is based on the Generalized Differential Effective Medium (GDEM) method. This method generalizes the classical differential scheme (DEM) for the case of several inclusion types instead of one. In this case, the GDEM scheme leads to a system of matrix differential equations that were solved numerically. This solution was obtained for materials containing spherical or cylindrical inclusions (3D and 2D-problems). In the case of cylindrical inclusions, the results were obtained for inclusions with the symmetry axes orthogonal to the magnetic field. The application of the GDEM method allows us to consider the percolation effect for 2D and 3D-microheterogeneous materials. The results obtained are compared to the experimental data and the calculation results obtained by other self-consistent schemes.
{"title":"A generalized differential scheme for the effective conductivity of percolating microinhomogeneous materials with the Hall effect","authors":"Anatoly Markov , Mikhail Markov , Valery Levin","doi":"10.1016/j.ijengsci.2024.104175","DOIUrl":"10.1016/j.ijengsci.2024.104175","url":null,"abstract":"<div><div>In this paper, we propose a self-consistent scheme for the calculation of the components of the effective electrical conductivity tensor. The calculations were fulfilled for a microinhomogeneous material, the components of which have the Hall effect. The presence of the Hall effect leads to appearance of asymmetry of the components of the conductivity tensor and to dependence of these components on the magnitude of the magnetic field applied to the material. Our approach is based on the Generalized Differential Effective Medium (GDEM) method. This method generalizes the classical differential scheme (DEM) for the case of several inclusion types instead of one. In this case, the GDEM scheme leads to a system of matrix differential equations that were solved numerically. This solution was obtained for materials containing spherical or cylindrical inclusions (3D and 2D-problems). In the case of cylindrical inclusions, the results were obtained for inclusions with the symmetry axes orthogonal to the magnetic field. The application of the GDEM method allows us to consider the percolation effect for 2D and 3D-microheterogeneous materials. The results obtained are compared to the experimental data and the calculation results obtained by other self-consistent schemes.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"206 ","pages":"Article 104175"},"PeriodicalIF":5.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593376","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 : 2024-11-05DOI: 10.1016/j.ijengsci.2024.104169
Anna L. Kolesnikova , Nguyen Van Tuyen , Mikhail Yu. Gutkin , Alexey E. Romanov
For the first time, strict analytical solutions for the elastic fields and the strain energies of an infinitely thin dilatational disk (DD) and a dilatational cylindrical inclusion (CyI) of finite length coaxially embedded in an infinite elastically isotropic cylinder with free surface are given and analyzed in detail. The solutions are represented in an integral form that is suitable for further analytical use and numerical study. The screening effect of the cylinder free surface on the elastic fields and the strain energies of the DD and the CyI is discussed. It is shown that this effect is significant for both the axial displacement and stress fields when the DD and CyI radii are comparable with the cylinder radius, however it is rather weak for the DD strain energy (the energy release does not exceed ∼10%). In contrast, for the CyI strain energy, the screening effect can be very strong. It is also shown that the hydrostatic stress is inhomogeneous and exists not only inside the CyI, as is the case with this stress for inclusions in an infinite medium, but also outside it. This stress is concentrated on the free surface at the points that are closest to the CyI boundary. Inside the CyI, the hydrostatic stress is much higher in magnitude than outside it.
{"title":"Dilatational disk and finite cylindrical inclusion in elastic nanowire","authors":"Anna L. Kolesnikova , Nguyen Van Tuyen , Mikhail Yu. Gutkin , Alexey E. Romanov","doi":"10.1016/j.ijengsci.2024.104169","DOIUrl":"10.1016/j.ijengsci.2024.104169","url":null,"abstract":"<div><div>For the first time, strict analytical solutions for the elastic fields and the strain energies of an infinitely thin dilatational disk (DD) and a dilatational cylindrical inclusion (CyI) of finite length coaxially embedded in an infinite elastically isotropic cylinder with free surface are given and analyzed in detail. The solutions are represented in an integral form that is suitable for further analytical use and numerical study. The screening effect of the cylinder free surface on the elastic fields and the strain energies of the DD and the CyI is discussed. It is shown that this effect is significant for both the axial displacement and stress fields when the DD and CyI radii are comparable with the cylinder radius, however it is rather weak for the DD strain energy (the energy release does not exceed ∼10%). In contrast, for the CyI strain energy, the screening effect can be very strong. It is also shown that the hydrostatic stress is inhomogeneous and exists not only inside the CyI, as is the case with this stress for inclusions in an infinite medium, but also outside it. This stress is concentrated on the free surface at the points that are closest to the CyI boundary. Inside the CyI, the hydrostatic stress is much higher in magnitude than outside it.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"206 ","pages":"Article 104169"},"PeriodicalIF":5.7,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586751","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 : 2024-11-04DOI: 10.1016/j.ijengsci.2024.104168
Meral Tuna , Patrizia Trovalusci , Nicholas Fantuzzi
The main objective of this study is to implement extended finite element method (XFEM) to two-dimensional (2D) micropolar structures in order to extract basic fracture parameters required in linear elastic fracture mechanics (LEFM) in a computationally efficient manner, and thus to provide basis to explore the crack propagation phenomenon within this framework. The stress and couple-stress intensity factors (SIF and CSIF) are detected with the aid of interaction integral, I-integral, and compared with the ones in the literature for validation purposes while an engineering problem of practical importance; plate with an oblique edge crack, is investigated to demonstrate the applicability of the developed methodology. The approach presents considerable simplification in modeling process owing to ability of XFEM to treat discontinuities and singularities appeared in the cracked domains, and offers a new, and different perspective to available methods (e.g. phase field method and peridynamics), each with their own advantages and limitations, extended to deal with crack and its growth in micropolar structures.
{"title":"On quasi-brittle static fracture analysis of micropolar plates via XFEM model","authors":"Meral Tuna , Patrizia Trovalusci , Nicholas Fantuzzi","doi":"10.1016/j.ijengsci.2024.104168","DOIUrl":"10.1016/j.ijengsci.2024.104168","url":null,"abstract":"<div><div>The main objective of this study is to implement extended finite element method (XFEM) to two-dimensional (2D) micropolar structures in order to extract basic fracture parameters required in linear elastic fracture mechanics (LEFM) in a computationally efficient manner, and thus to provide basis to explore the crack propagation phenomenon within this framework. The stress and couple-stress intensity factors (SIF and CSIF) are detected with the aid of interaction integral, <em>I-integral</em>, and compared with the ones in the literature for validation purposes while an engineering problem of practical importance; plate with an oblique edge crack, is investigated to demonstrate the applicability of the developed methodology. The approach presents considerable simplification in modeling process owing to ability of XFEM to treat discontinuities and singularities appeared in the cracked domains, and offers a new, and different perspective to available methods (e.g. phase field method and peridynamics), each with their own advantages and limitations, extended to deal with crack and its growth in micropolar structures.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"206 ","pages":"Article 104168"},"PeriodicalIF":5.7,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586743","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 : 2024-11-04DOI: 10.1016/j.ijengsci.2024.104163
Amit Ashkenazi, Dana Solav
Estimating model parameters from experimental data is a common practice across various research fields. For nonlinear models, the parameters are estimated using an optimization algorithm that minimizes an objective function. Assessing the certainty of these parameter estimates is crucial to address questions such as “what is the probability the estimation error is smaller than 5%?”, “is our experiment sensitive enough to estimate all parameters?”, and “how much can we change each parameter while still fitting the data accurately?”. Typically, the certainty levels are quantified using a linear approximation of the model. However, we show that in models that are highly nonlinear in their parameters or in the presence of large experimental errors, this method fails to capture the certainty levels accurately. To address these limitations, we present an alternative method based on the Hessian approximation of the objective function. We show that this method captures the certainty levels more accurately and can be derived geometrically. We demonstrate the efficacy of our approach through a case study involving a nonlinear hyperelastic material constitutive model and an application on a nonlinear model for the conductivity of electrolyte solutions. Despite its higher computational cost, we recommend adopting the Hessian approximation when accurate certainty levels are required in highly nonlinear models.
{"title":"Parameter certainty quantification in nonlinear models","authors":"Amit Ashkenazi, Dana Solav","doi":"10.1016/j.ijengsci.2024.104163","DOIUrl":"10.1016/j.ijengsci.2024.104163","url":null,"abstract":"<div><div>Estimating model parameters from experimental data is a common practice across various research fields. For nonlinear models, the parameters are estimated using an optimization algorithm that minimizes an objective function. Assessing the certainty of these parameter estimates is crucial to address questions such as “what is the probability the estimation error is smaller than 5%?”, “is our experiment sensitive enough to estimate all parameters?”, and “how much can we change each parameter while still fitting the data accurately?”. Typically, the certainty levels are quantified using a linear approximation of the model. However, we show that in models that are highly nonlinear in their parameters or in the presence of large experimental errors, this method fails to capture the certainty levels accurately. To address these limitations, we present an alternative method based on the Hessian approximation of the objective function. We show that this method captures the certainty levels more accurately and can be derived geometrically. We demonstrate the efficacy of our approach through a case study involving a nonlinear hyperelastic material constitutive model and an application on a nonlinear model for the conductivity of electrolyte solutions. Despite its higher computational cost, we recommend adopting the Hessian approximation when accurate certainty levels are required in highly nonlinear models.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"206 ","pages":"Article 104163"},"PeriodicalIF":5.7,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586744","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 : 2024-11-01DOI: 10.1016/j.ijengsci.2024.104171
Iskander S. Akmanov, Stepan V. Lomov, Mikhail Y. Spasennykh, Sergey G. Abaimov
Engineering interleaves of composite laminates with carbon nanotubes (CNTs) improves interlaminar fracture toughness, creating also conductivity, which can be employed for damage identification. The paper explores machine learning (ML) solution of the inverse problem of the defect identification for interleaves with anisotropic conductivity (aligned CNTs). The electrical and geometrical properties of the interleave are assigned based on the synchrotron X-ray computer tomography of glass fibre / epoxy laminates with nanostitch. Several machine learning (ML) models are applied (XGBoost, fully connected (FCNN) and convolution neural (CNN) networks). XGBoost and FCNN algorithms performed poorly, failing to detect smaller defects and giving significant errors for larger ones. CNN algorithm detects defects well: It predicts the geometric characteristics of the defect with error below 16 %.
使用碳纳米管（CNTs）对复合材料层压板的交错层进行工程设计，不仅能提高层间断裂韧性，还能提高导电性，可用于损伤识别。本文探讨了各向异性导电性（排列的碳纳米管）交错层缺陷识别逆问题的机器学习（ML）解决方案。交错层的电气和几何特性是根据具有纳米缝隙的玻璃纤维/环氧树脂层压板的同步辐射 X 射线计算机断层扫描来确定的。应用了多种机器学习（ML）模型（XGBoost、全连接（FCNN）和卷积神经（CNN）网络）。XGBoost 和 FCNN 算法表现不佳，无法检测到较小的缺陷，而对较大的缺陷则误差很大。CNN 算法能很好地检测出缺陷：它能预测缺陷的几何特征，误差低于 16%。
{"title":"Machine learning for crack detection in an anisotropic electrically conductive nano-engineered composite interleave with realistic geometry","authors":"Iskander S. Akmanov, Stepan V. Lomov, Mikhail Y. Spasennykh, Sergey G. Abaimov","doi":"10.1016/j.ijengsci.2024.104171","DOIUrl":"10.1016/j.ijengsci.2024.104171","url":null,"abstract":"<div><div>Engineering interleaves of composite laminates with carbon nanotubes (CNTs) improves interlaminar fracture toughness, creating also conductivity, which can be employed for damage identification. The paper explores machine learning (ML) solution of the inverse problem of the defect identification for interleaves with anisotropic conductivity (aligned CNTs). The electrical and geometrical properties of the interleave are assigned based on the synchrotron X-ray computer tomography of glass fibre / epoxy laminates with nanostitch. Several machine learning (ML) models are applied (XGBoost, fully connected (FCNN) and convolution neural (CNN) networks). XGBoost and FCNN algorithms performed poorly, failing to detect smaller defects and giving significant errors for larger ones. CNN algorithm detects defects well: It predicts the geometric characteristics of the defect with error below 16 %.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"205 ","pages":"Article 104171"},"PeriodicalIF":5.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572961","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 : 2024-10-30DOI: 10.1016/j.ijengsci.2024.104161
Andrey S. Vasiliev, Sergei S. Volkov, Andrey L. Nikolaev, Sergei M. Aizikovich
Indentation of the coated piezoelectric transversely isotropic half-space by a conical conductive punch is modeled. The coating is assumed to be functionally-graded (continuously inhomogeneous in depth) with all group of electromechanical properties varying independently in depth according to arbitrary continuous functions or piecewise homogeneous. The problem is described mathematically in terms of linear electroelasticity and reduced to solution of a system of dual integral equations using the Hankel’s integral transformations. Closed-form approximated analytical solution of this system is obtained using the bilateral asymptotic method taking into account asymptotic properties of the kernel transforms. Expressions for the contact pressure, electric induction are obtained in an analytical form suitable for engineering analysis as well as the relations for the indentation force, total electric charge, indentation depth, contact radius and electric potential. Analytical form of results clearly demonstrates the contribution of mechanical and electric loading to the total solution and influence of the coating’s thickness and its properties on contact characteristics. Numerical results for homogeneous and two types of functionally-graded coatings illustrate features of the theoretical results in a wide range of values of relative coatings thickness.
{"title":"Indentation of a piezoelectric FGM-coated half-space by a conical conductive punch: Approximated analytical solution","authors":"Andrey S. Vasiliev, Sergei S. Volkov, Andrey L. Nikolaev, Sergei M. Aizikovich","doi":"10.1016/j.ijengsci.2024.104161","DOIUrl":"10.1016/j.ijengsci.2024.104161","url":null,"abstract":"<div><div>Indentation of the coated piezoelectric transversely isotropic half-space by a conical conductive punch is modeled. The coating is assumed to be functionally-graded (continuously inhomogeneous in depth) with all group of electromechanical properties varying independently in depth according to arbitrary continuous functions or piecewise homogeneous. The problem is described mathematically in terms of linear electroelasticity and reduced to solution of a system of dual integral equations using the Hankel’s integral transformations. Closed-form approximated analytical solution of this system is obtained using the bilateral asymptotic method taking into account asymptotic properties of the kernel transforms. Expressions for the contact pressure, electric induction are obtained in an analytical form suitable for engineering analysis as well as the relations for the indentation force, total electric charge, indentation depth, contact radius and electric potential. Analytical form of results clearly demonstrates the contribution of mechanical and electric loading to the total solution and influence of the coating’s thickness and its properties on contact characteristics. Numerical results for homogeneous and two types of functionally-graded coatings illustrate features of the theoretical results in a wide range of values of relative coatings thickness.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"205 ","pages":"Article 104161"},"PeriodicalIF":5.7,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553424","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号