International Journal of Engineering Science最新文献

{"title":"Machine learning for crack detection in an anisotropic electrically conductive nano-engineered composite interleave with realistic geometry","authors":"","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":null,"pages":null},"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}

{"title":"Indentation of a piezoelectric FGM-coated half-space by a conical conductive punch: Approximated analytical solution","authors":"","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":null,"pages":null},"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}

{"title":"Initially stressed strain gradient elasticity: A constitutive model incorporates size effects and initial stresses","authors":"","doi":"10.1016/j.ijengsci.2024.104166","DOIUrl":"10.1016/j.ijengsci.2024.104166","url":null,"abstract":"<div><div>Unlike ordinary solid materials, underground nano-materials such as kerogen, have relatively small dimensions and suffer from unavoidable in-situ stresses. The coexistence of size effects and initial stresses poses a great challenge to the constitutive modeling of deeply buried nano-inclusions. Despite the theories of strain gradient elasticity (SGE) and initially stressed elasticity (ISE) have been separately developed, the phenomenological model that fully considers the impact of the two ingredients remains unexplored. This paper proposes a strain gradient elasticity constitutive model for kerogen with size effects and in-situ stresses. Based on the decomposition of strains and strain gradients, the initially stressed strain gradient elasticity (ISSGE) framework is established. Then, a new form of the volumetric response function for kerogen is derived utilizing the density and porosity independence of the Poisson ratio. On this basis, we construct the corresponding hyperelastic and higher-order strain energy densities embedded with the given initial stress. The new constitutive model is applied to investigate the spherical pore contraction problem. Theoretical analysis and experimental results indicate that combining the in-situ stress and the size effect strengthens the elastic stiffness. Such enhancement cannot be comprehensively described by the existing theories. The model presented here provides the first constitutive relation of initially stressed strain gradient elasticity and lays the foundation for further incorporating more mechanical behaviors of underground nano-materials.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553425","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}

{"title":"On the effective properties of matrix composites: The role of geometric factors in relation to property contrast","authors":"","doi":"10.1016/j.ijengsci.2024.104156","DOIUrl":"10.1016/j.ijengsci.2024.104156","url":null,"abstract":"<div><div>The effective elastic and conductive properties of matrix composites depend on two geometric factors – inhomogeneity shapes and orientation distribution – and on the property contrast between the matrix and inhomogeneities. The roles of the two geometric factors are strongly coupled; both are also coupled with the role of the property contrast. These issues are examined, with particular attention paid to the case of preferential orientation with random scatter.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531177","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}

{"title":"Nonlinear resonance of fractional order viscoelastic PET films under temperature loading","authors":"","doi":"10.1016/j.ijengsci.2024.104153","DOIUrl":"10.1016/j.ijengsci.2024.104153","url":null,"abstract":"<div><div>The effects of oven temperature during printing on nonlinear vibration for fractional-order PET films are considered in this paper. The effect of temperature, fractional order modelling and some other parameters are analysed with respect to the response of the resonance. Fractional order kelvin-Voigt ontological relationship is used to describe the characteristics of viscoelastic materials. The differential equations for nonlinear vibrations are inferred according to the second law of Newton and the theory of von Karman. Discretization for nonlinear equations on locomotion using the Bubnov–Galerkin method. Forced co-oscillatory amplitude-frequency response equations for thin-films systems under temperature loading were calculated using the multiple scales method. Results of numeral results show that temperature, and fractional-order visco-elastic modelling influence the membrane's response to resonance. These results provide a basis for studying fractional-order visco-elastic films vibrations and identifying regions of stable operation in moving systems to prevent divergent instabilities for flexible electronic device manufacturing.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531184","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}

{"title":"Hemodynamics past a dysfunctional bileaflet mechanical heart valve","authors":"","doi":"10.1016/j.ijengsci.2024.104154","DOIUrl":"10.1016/j.ijengsci.2024.104154","url":null,"abstract":"<div><div>A mechanical heart valve, an essential prosthetic for managing valvular heart disease, consists of a metal frame housing two or three leaflets (depending on the design) that control blood flow within the heart. However, leaflet dysfunction can impede their movement, leading to valve defects. This study extensively investigates the hemodynamics of such a bileaflet mechanical heart valve with dysfunctions of various extents with the help of direct numerical simulations (DNS) under both steady inflow and pulsatile flow conditions. The results are presented and discussed in terms of spatial variations of velocity magnitude, Reynolds stresses, and surface and time-averaged clinically important parameters such as wall shear stress (WSS), pressure drop, and blood damage. Under steady inflow conditions, the flow field becomes unsteady and turbulent even at a modest Reynolds number of 750 when the valve has 50% defective conditions, in contrast to a steady and laminar flow for a fully functional heart valve with 0% defect condition. The values of WSS also increase by around 50%, and net pressure drops by more than 200% with these defective conditions, which further increase as the defective condition increases. On the other hand, the same trend is also seen under pulsatile flow conditions, with maximum values of wall shear stress and blood damage seen during the peak systolic stage of the cardiac cycle, increasing by more than 200% as the defect condition increases from 0% to 50% for the latter parameter. Furthermore, the present study also investigates the effect of blood rheological behaviors such as shear-thinning and yield stress on hemodynamics past this dysfunctional heart valve. It is seen that blood rheological behavior has a substantial influence on hemodynamics at low Reynolds numbers, diminishing as the Reynolds number increases. Under pulsatile flow conditions, blood exhibiting non-Newtonian characteristics such as shear-thinning shows higher values of wall shear stress and blood damage values compared to Newtonian ones. Therefore, the present study highlights the importance of accounting for blood rheology in clinical assessments. However, this study simulates the cases where both valve leaflets are fixed in position, thereby excluding fluid–structure interaction (FSI) from the present simulations. Such conditions are representative of common occurrences in dysfunctional heart valves. All in all, the in-depth analysis and information obtained from this study are expected to facilitate early detection of valve leaflet dysfunction, thereby contributing to improved clinical management of patients with valvular heart disease.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418657","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}

{"title":"On elastic wave propagation in piezoelectric semiconductors with coupled piezoelectric and semiconductor properties","authors":"","doi":"10.1016/j.ijengsci.2024.104160","DOIUrl":"10.1016/j.ijengsci.2024.104160","url":null,"abstract":"<div><div>Coupling of piezoelectric and semiconducting properties can stimulate a field-particle coupling wave (FPCW) between electric field and charge carriers on an elastic wave-front (EWF) propagating in a piezoelectric semiconductor. The wave velocity of a FPCW is usually greater than the EWF as vibration frequency rises such that carrier behavior on and in front of the EWF will be disturbed in advance. This interaction between two waves can stimulate a few novel dynamic features which are of obvious significance for the research and development of innovative piezoelectric electronic devices. Hence, we firstly established a dynamic model on the propagation processes of elastic waves in piezoelectric semiconductors and developed an alternately iterative algorithm between piezoelectric and semiconducting properties in this paper. Then, the propagation behavior of an elastic wave in an n-type ZnO rod was taken as an example to elucidate the dispersion and dissipation arising from the coupling between electric field and charge carriers. It was found that the action of a FPCW on the EWF can stir up previously undiscovered bizarre features in the following two aspects. One is the energy transfer between different frequency wave components from low-order to high-order vibration modes implemented by the flow of charge carriers, where the transfer process bears a resemblance story to the ‘vacated room’ operation in Hilbert's paradox of the Grand Hotel. The other more intriguing one is that when a tensile/compressive deformation signal is input, an opposite phase signal will be induced at the leading edge of the EWF by the FPCW through the inverse piezoelectric effect, meaning the appearance of a compressive/tensile signal in front of the input tensile/compressive one. The reason to appear such a phenomenon is that the electric field phase of the FPCW is precisely opposite to the one on the corresponding EWF. Evidently, the present studies will advance the integration and development of elastic dynamics and semiconductor physics, thereby providing valuable guidance for the research and development of new electronic devices.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418653","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}

{"title":"Analytical solutions for thermoelastic stress-focusing in cylindrical and spherical solids","authors":"","doi":"10.1016/j.ijengsci.2024.104157","DOIUrl":"10.1016/j.ijengsci.2024.104157","url":null,"abstract":"<div><div>This work deals with finding the analytical displacements and stresses in thermoelasticity problems involving solid isotropic cylinders and spheres with an emphasis on stress-focusing phenomena relevant to the nuclear industry and high-temperature engineering. The study considers solid spheres and infinitely long solid cylinders with three different types of thermal loading: prescribed outer surface temperature, prescribed surface heat flux, and volumetric heat source. Both continuous and discontinuous thermal loading conditions are considered. It is shown that discontinuous loading, such as abrupt changes in prescribed surface temperature or heat flux prescriptions, results in unbounded stresses along the axis (in the case of an infinite cylinder) and the center (in the case of a solid sphere), while with continuous loading, we obtain finite stresses within the domains at all times.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418654","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}

{"title":"Mesoscale models for effective elastic properties of carbon-black/ultra-high-molecular-weight-polyethylene nanocomposites","authors":"","doi":"10.1016/j.ijengsci.2024.104159","DOIUrl":"10.1016/j.ijengsci.2024.104159","url":null,"abstract":"<div><div>In this paper, we apply mesoscale numerical modeling to predict the effective elastic properties of conductive carbon-black/ultra-high-molecular-weight-polyethylene nanocomposites. The models are based on X-ray microcomputed tomography images. The images show that for the considered range of carbon additive weight fractions, the conductive carbon black (CB) particles are distributed around the ultra-high-molecular-weight-polyethylene (UHMWPE) granules forming a carbon-containing layer of a thickness on the order of 1–2 <span><math><mrow><mi>μ</mi><mi>m</mi></mrow></math></span>.</div><div>Finite element models of representative volume elements (RVE), incorporating the CB-containing layer, are developed. The RVEs are generated based on the size and shape statistics extracted from processed microcomputed tomography images with further incorporation of the CB-containing layer by a custom image processing code. The layer is modeled analytically as a 2-phase composite consisting of spherical CB inclusions distributed in the UHMWPE matrix. Elastic moduli predicted in the models are compared to experimental data. Results show that the numerical simulations predict effective elastic moduli within the confidence intervals of the experimental measurements up to 7.5 wt % of CB inclusions.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418652","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}

{"title":"On the refined boundary condition at the edge of a thin elastic strip supported by a Winkler-type foundation under antiplane shear deformation","authors":"","doi":"10.1016/j.ijengsci.2024.104152","DOIUrl":"10.1016/j.ijengsci.2024.104152","url":null,"abstract":"<div><div>The derivation of the boundary conditions is the most challenging part of the asymptotic techniques underlying low-dimensional models for thin elastic structures. At the moment, these techniques do not take into consideration the effect of the environment, e.g., a Winkler foundation, when tackling boundary conditions, and have to be amended. In this paper as an example we consider an antiplane problem for a thin elastic strip contacting with a relatively compliant Winkler foundation. Refined boundary conditions at an edge loaded by prescribed stresses are established using a properly adjusted Saint-Venant’s principle. They appear to be useful for advanced structure modelling including analysis of the static equilibrium under self-equilibrated loading.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418648","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}