Pub Date : 2026-04-01Epub Date: 2026-01-08DOI: 10.1016/j.ijengsci.2025.104459
Enzo Brito , Claudio García-Herrera , Blanca González-Bermúdez , Gustavo R. Plaza , Diego Celentano , Bernardo J. Krause , Aldo Abarca-Ortega
In this study, an experimental and numerical characterization of the viscohyperelastic behavior of suspended epithelial ARPE-19 cells is carried out using the micropipette aspiration technique, with particular emphasis on the evaluation of two viscoelastic models with different mathematical formulations, which were implemented in an in-house finite element code. The tests, conducted under one and two-ramp aspiration protocols, revealed variations in the measured mechanical properties of the cells, which are first sensitive to the applied pressure levels; This dependency is attributed to the internal organization of subcellular components. Second, the aspiration tests show that the apparent elastic modulus is dependent to the applied pressure rate. Two visco-hyperelastic models were evaluated to replicate the experimentally observed behavior. Although both models successfully fit the results, the LM model proved to be more efficient, requiring fewer parameters and enabling a clearer physical interpretation of the viscoelastic properties. In the numerical calculations, a time- and geometry-dependent load function was implemented, which optimally replicated the experimental observations while maintaining low computational cost.
{"title":"Mechanical characterization and visco-hyperelastic modeling of epithelial cells: Pressure-rate dependency of the apparent elastic modulus","authors":"Enzo Brito , Claudio García-Herrera , Blanca González-Bermúdez , Gustavo R. Plaza , Diego Celentano , Bernardo J. Krause , Aldo Abarca-Ortega","doi":"10.1016/j.ijengsci.2025.104459","DOIUrl":"10.1016/j.ijengsci.2025.104459","url":null,"abstract":"<div><div>In this study, an experimental and numerical characterization of the viscohyperelastic behavior of suspended epithelial ARPE-19 cells is carried out using the micropipette aspiration technique, with particular emphasis on the evaluation of two viscoelastic models with different mathematical formulations, which were implemented in an in-house finite element code. The tests, conducted under one and two-ramp aspiration protocols, revealed variations in the measured mechanical properties of the cells, which are first sensitive to the applied pressure levels; This dependency is attributed to the internal organization of subcellular components. Second, the aspiration tests show that the apparent elastic modulus is dependent to the applied pressure rate. Two visco-hyperelastic models were evaluated to replicate the experimentally observed behavior. Although both models successfully fit the results, the LM model proved to be more efficient, requiring fewer parameters and enabling a clearer physical interpretation of the viscoelastic properties. In the numerical calculations, a time- and geometry-dependent load function was implemented, which optimally replicated the experimental observations while maintaining low computational cost.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"221 ","pages":"Article 104459"},"PeriodicalIF":5.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940292","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 : 2026-04-01Epub Date: 2026-01-21DOI: 10.1016/j.ijengsci.2026.104474
J. Kozlík , K. Tůma , O. Souček , J. Dobrzański , S. Stupkiewicz
In this paper, we revisit a classical multiwell phase-field model in the context of – phase transformations in titanium alloys. We propose a novel model by adjusting the algebraic part of the traditional interfacial free energy in a way that allows for a relaxation of the standard well-posedness constraints on surface tensions in the total-spreading case. The proposed adjustment effectively prevents the formation of a mixed – state in the resulting phase-field continuum model, aligning with the crystallographic impossibility of such a configuration in reality. We further introduce a chemical energy mixing function that preserves the local stability of purely two-phase – configurations, preventing the spontaneous appearance of additional phases. We illustrate the advantages of the novel model through numerical simulations in one, two and three spatial dimensions and outline a pathway toward a more realistic model of – transition model in titanium alloys.
{"title":"Multiwell phase-field model for arbitrarily strong total-spreading case","authors":"J. Kozlík , K. Tůma , O. Souček , J. Dobrzański , S. Stupkiewicz","doi":"10.1016/j.ijengsci.2026.104474","DOIUrl":"10.1016/j.ijengsci.2026.104474","url":null,"abstract":"<div><div>In this paper, we revisit a classical multiwell phase-field model in the context of <span><math><mi>β</mi></math></span>–<span><math><mi>ω</mi></math></span> phase transformations in titanium alloys. We propose a novel model by adjusting the algebraic part of the traditional interfacial free energy in a way that allows for a relaxation of the standard well-posedness constraints on surface tensions in the total-spreading case. The proposed adjustment effectively prevents the formation of a mixed <span><math><mi>ω</mi></math></span>–<span><math><mi>ω</mi></math></span> state in the resulting phase-field continuum model, aligning with the crystallographic impossibility of such a configuration in reality. We further introduce a chemical energy mixing function that preserves the local stability of purely two-phase <span><math><mi>β</mi></math></span>–<span><math><mi>ω</mi></math></span> configurations, preventing the spontaneous appearance of additional phases. We illustrate the advantages of the novel model through numerical simulations in one, two and three spatial dimensions and outline a pathway toward a more realistic model of <span><math><mi>β</mi></math></span>–<span><math><mi>ω</mi></math></span> transition model in titanium alloys.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"221 ","pages":"Article 104474"},"PeriodicalIF":5.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014989","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 : 2026-04-01Epub Date: 2026-01-10DOI: 10.1016/j.ijengsci.2025.104460
Alessandro Fortunati , Francesca Fantoni , Andrea Bacigalupo
This work presents a detailed and systematic analytical investigation of the transient elastic wave propagation in two-dimensional periodic heterogeneous composites. The study is conducted through two complementary methodologies: asymptotic homogenization and a recently proposed spectro-hierarchical approach, specifically designed to resolve higher-order microstructural effects. The asymptotic homogenization method derives effective macroscopic equations that accurately capture the averaged behavior of the periodic microstructure, providing a reduced-order but reliable representation of long-wave and low-frequency dynamics. In parallel, the spectro-hierarchical approach systematically reconstructs microstructural fluctuations using a combination of truncated Fourier expansions and a hierarchical sequence of differential problems, allowing the recovery of both first-order homogenized responses and higher-order corrections due to local heterogeneities. The analysis considers both zero and non-zero initial conditions, enabling the study of general transient excitations, including short-time dynamics and localized disturbances, rather than merely steady-state or frequency-limited responses.
{"title":"Multiscale modeling of transient problems in periodic Cauchy materials: Asymptotic and spectro-hierarchical homogenization","authors":"Alessandro Fortunati , Francesca Fantoni , Andrea Bacigalupo","doi":"10.1016/j.ijengsci.2025.104460","DOIUrl":"10.1016/j.ijengsci.2025.104460","url":null,"abstract":"<div><div>This work presents a detailed and systematic analytical investigation of the transient elastic wave propagation in two-dimensional periodic heterogeneous composites. The study is conducted through two complementary methodologies: asymptotic homogenization and a recently proposed spectro-hierarchical approach, specifically designed to resolve higher-order microstructural effects. The asymptotic homogenization method derives effective macroscopic equations that accurately capture the averaged behavior of the periodic microstructure, providing a reduced-order but reliable representation of long-wave and low-frequency dynamics. In parallel, the spectro-hierarchical approach systematically reconstructs microstructural fluctuations using a combination of truncated Fourier expansions and a hierarchical sequence of differential problems, allowing the recovery of both first-order homogenized responses and higher-order corrections due to local heterogeneities. The analysis considers both zero and non-zero initial conditions, enabling the study of general transient excitations, including short-time dynamics and localized disturbances, rather than merely steady-state or frequency-limited responses.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"221 ","pages":"Article 104460"},"PeriodicalIF":5.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940350","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 : 2026-04-01Epub Date: 2026-01-19DOI: 10.1016/j.ijengsci.2026.104473
Francesco Paolo Pinnola , Francesco Scudieri , Gioacchino Alotta , Francesco Marotti de Sciarra
The bending vibrations of nonlocal viscoelastic plates subjected to stochastic excitations are investigated within the framework of the axisymmetric Kirchhoff model. This study is particularly relevant to the design of mesoscale heterogeneous structures, biotissues, miniaturized two-dimensional structures and metamaterials, such as those employed in energy harvesters, sensors, actuators, wave energy converters, transistors, bioinspired devices, and microrobots, often fabricated from unconventional materials. For such systems, classical local continuum theories fail to accurately capture the underlying mechanics. To address this, the mechanical response is analyzed by accounting for two key features: viscoelasticity and nonlocality. The constitutive behavior is described through a stress-driven integral nonlocal model coupled with fractional-order viscoelastic stress–strain relation, allowing the formulation to incorporate both size-dependent and hereditary effects. Random excitation is introduced to account for the inherent variability of external dynamic environments, leading to a stochastic partial differential equation featuring fractional operators. Owing to the complexity of this equation, a semi-analytical solution procedure based on modal decomposition is developed in order to compute the time-dependent response and evaluate the power spectral densities. The results highlight the influence of nonlocal interactions and viscoelastic parameters on the dynamic response and natural frequencies of the system. These findings offer valuable insights for the design and optimization of advanced two-dimensional nano- and micro-scale devices and other devices where long-range interactions occur.
{"title":"On the stochastic dynamics of nonlocal viscoelastic plates","authors":"Francesco Paolo Pinnola , Francesco Scudieri , Gioacchino Alotta , Francesco Marotti de Sciarra","doi":"10.1016/j.ijengsci.2026.104473","DOIUrl":"10.1016/j.ijengsci.2026.104473","url":null,"abstract":"<div><div>The bending vibrations of nonlocal viscoelastic plates subjected to stochastic excitations are investigated within the framework of the axisymmetric Kirchhoff model. This study is particularly relevant to the design of mesoscale heterogeneous structures, biotissues, miniaturized two-dimensional structures and metamaterials, such as those employed in energy harvesters, sensors, actuators, wave energy converters, transistors, bioinspired devices, and microrobots, often fabricated from unconventional materials. For such systems, classical local continuum theories fail to accurately capture the underlying mechanics. To address this, the mechanical response is analyzed by accounting for two key features: viscoelasticity and nonlocality. The constitutive behavior is described through a stress-driven integral nonlocal model coupled with fractional-order viscoelastic stress–strain relation, allowing the formulation to incorporate both size-dependent and hereditary effects. Random excitation is introduced to account for the inherent variability of external dynamic environments, leading to a stochastic partial differential equation featuring fractional operators. Owing to the complexity of this equation, a semi-analytical solution procedure based on modal decomposition is developed in order to compute the time-dependent response and evaluate the power spectral densities. The results highlight the influence of nonlocal interactions and viscoelastic parameters on the dynamic response and natural frequencies of the system. These findings offer valuable insights for the design and optimization of advanced two-dimensional nano- and micro-scale devices and other devices where long-range interactions occur.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"221 ","pages":"Article 104473"},"PeriodicalIF":5.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146001123","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 : 2026-04-01Epub Date: 2026-01-08DOI: 10.1016/j.ijengsci.2025.104452
Adair R. Aguiar , Thomas J. Pence , Lucas A. Rocha
We investigate the local injectivity requirement , where is the deformation gradient, in the context of both the classical nonlinear elasticity theory and a constrained energy minimization theory with the explicit constraint , where . In the classical theory, the condition is guaranteed by Ball’s theorem provided that appropriate growth conditions are satisfied. For orthotropic hyperelastic solids, we consider equilibrated states of finite plane strain for which the principal axes of strain align with the axes of orthotropic symmetry. Two materials are considered: an orthotropic St. Venant–Kirchhoff material as considered in previous work, and an orthotropic compressible Mooney–Rivlin material. Basic issues are revealed by considering homogeneous plane strain deformation with applied in-plane uniaxial loading. In the absence of the condition , the St. Venant–Kirchhoff material permits complete volume loss, and hence material overlap, at zero applied load. The Mooney–Rivlin material has no such issue, although it exhibits stress–strain nonmonotonicity for certain parameter values. Material overlap for the St. Venant–Kirchhoff material is remedied by imposing the constraint and many features of the corresponding stress–strain behavior are then found to mirror that of the unconstrained Mooney–Rivlin material. The homogeneous deformation study serves as a prelude to the investigation of a nonhomogeneous deformation problem, that of a radially reinforced annular disk that is fixed on its inner radius and subjected to uniform pressure on its outer radius. The problem is solved both as a boundary value problem using a phase-plane technique and via direct minimization using nonlinear programming tools. For each material model, the two procedures give indistinguishable results. Sufficiently high applied pressures yield non-smooth deformations inside the disk. Solutions for the unconstrained Mooney–Rivlin material obtain close agreement with those for the constrained St. Venant material as tends to zero.
{"title":"On the classical and constrained theories for preventing self-intersection in orthotropic nonlinear elasticity","authors":"Adair R. Aguiar , Thomas J. Pence , Lucas A. Rocha","doi":"10.1016/j.ijengsci.2025.104452","DOIUrl":"10.1016/j.ijengsci.2025.104452","url":null,"abstract":"<div><div>We investigate the local injectivity requirement <span><math><mrow><mo>det</mo><mi>F</mi><mo>></mo><mn>0</mn></mrow></math></span>, where <span><math><mi>F</mi></math></span> is the deformation gradient, in the context of both the classical nonlinear elasticity theory and a constrained energy minimization theory with the explicit constraint <span><math><mrow><mo>det</mo><mi>F</mi><mo>≥</mo><mi>ɛ</mi></mrow></math></span>, where <span><math><mrow><mn>0</mn><mo><</mo><mi>ɛ</mi><mo><</mo><mn>1</mn></mrow></math></span>. In the classical theory, the condition <span><math><mrow><mo>det</mo><mi>F</mi><mo>></mo><mn>0</mn></mrow></math></span> is guaranteed by Ball’s theorem provided that appropriate growth conditions are satisfied. For orthotropic hyperelastic solids, we consider equilibrated states of finite plane strain for which the principal axes of strain align with the axes of orthotropic symmetry. Two materials are considered: an orthotropic St. Venant–Kirchhoff material as considered in previous work, and an orthotropic compressible Mooney–Rivlin material. Basic issues are revealed by considering homogeneous plane strain deformation with applied in-plane uniaxial loading. In the absence of the condition <span><math><mrow><mo>det</mo><mi>F</mi><mo>></mo><mn>0</mn></mrow></math></span>, the St. Venant–Kirchhoff material permits complete volume loss, and hence material overlap, at zero applied load. The Mooney–Rivlin material has no such issue, although it exhibits stress–strain nonmonotonicity for certain parameter values. Material overlap for the St. Venant–Kirchhoff material is remedied by imposing the constraint <span><math><mrow><mo>det</mo><mi>F</mi><mo>≥</mo><mi>ɛ</mi></mrow></math></span> and many features of the corresponding stress–strain behavior are then found to mirror that of the unconstrained Mooney–Rivlin material. The homogeneous deformation study serves as a prelude to the investigation of a nonhomogeneous deformation problem, that of a radially reinforced annular disk that is fixed on its inner radius and subjected to uniform pressure on its outer radius. The problem is solved both as a boundary value problem using a phase-plane technique and via direct minimization using nonlinear programming tools. For each material model, the two procedures give indistinguishable results. Sufficiently high applied pressures yield non-smooth deformations inside the disk. Solutions for the unconstrained Mooney–Rivlin material obtain close agreement with those for the constrained St. Venant material as <span><math><mi>ɛ</mi></math></span> tends to zero.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"221 ","pages":"Article 104452"},"PeriodicalIF":5.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940291","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 : 2026-04-01Epub Date: 2026-01-08DOI: 10.1016/j.ijengsci.2025.104458
Haining Liu , Ruifeng Zheng , Zichen Deng , Haimin Yao
This article investigates an inclined elliptic crack problem in one-dimensional (1D) hexagonal quasicrystals (QCs). The crack lies in a plane perpendicular to the transversely isotropic plane, and its orientation (the major axis of the ellipse) forms an arbitrary angle with the quasi-periodic axis of the QCs. A pair of uniform normal loading is applied symmetrically on the crack surfaces. Using the potential theory method, the governing equation is established and the phonon–phason field is obtained in terms of simple integrals. The fracture parameters including the crack opening displacement (COD) and the stress intensity factor (SIF) are derived. Numerical results validate the solutions and investigate the effects of the phason field, inclination angle and eccentricity on the fracture parameters. A simplified explicit expression for the SIF is developed via symbolic regression. This machine learning-based model offers an efficient and accurate computational alternative to complex theoretical solutions. As a model problem within the framework of QC elasticity theory, the present study offers insights into the fracture behavior of 1D hexagonal QCs and is expected to provide a theoretical reference for structural integrity evaluation and fracture-resistant design of QC materials.
{"title":"Inclined mode-I elliptic crack problem in one-dimensional hexagonal quasicrystals","authors":"Haining Liu , Ruifeng Zheng , Zichen Deng , Haimin Yao","doi":"10.1016/j.ijengsci.2025.104458","DOIUrl":"10.1016/j.ijengsci.2025.104458","url":null,"abstract":"<div><div>This article investigates an inclined elliptic crack problem in one-dimensional (1D) hexagonal quasicrystals (QCs). The crack lies in a plane perpendicular to the transversely isotropic plane, and its orientation (the major axis of the ellipse) forms an arbitrary angle with the quasi-periodic axis of the QCs. A pair of uniform normal loading is applied symmetrically on the crack surfaces. Using the potential theory method, the governing equation is established and the phonon–phason field is obtained in terms of simple integrals. The fracture parameters including the crack opening displacement (COD) and the stress intensity factor (SIF) are derived. Numerical results validate the solutions and investigate the effects of the phason field, inclination angle and eccentricity on the fracture parameters. A simplified explicit expression for the SIF is developed via symbolic regression. This machine learning-based model offers an efficient and accurate computational alternative to complex theoretical solutions. As a model problem within the framework of QC elasticity theory, the present study offers insights into the fracture behavior of 1D hexagonal QCs and is expected to provide a theoretical reference for structural integrity evaluation and fracture-resistant design of QC materials.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"221 ","pages":"Article 104458"},"PeriodicalIF":5.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940293","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 : 2026-04-01Epub Date: 2026-01-12DOI: 10.1016/j.ijengsci.2025.104453
A. Chauhan, C. Sasmal
This study presents extensive three-dimensional numerical simulations to investigate the hemodynamics within a stenosed artery under both steady and pulsatile inflow conditions. Two different blood rheology models are employed, namely, the conventional Newtonian model and the more physiologically accurate multimode simplified Phan–Thien–Tanner (sPTT) viscoelastic model. The parameters for the sPTT model are calibrated using experimental rheological data of real whole blood, obtained from standard viscometric flows such as steady simple shear and small-amplitude oscillatory shear (SAOS). This enables the model to capture both the shear-thinning and viscoelastic nature of blood, thus offering a more realistic representation of blood flow dynamics in a physiologically relevant arterial geometry. Under steady inflow conditions, a high-velocity jet is formed as blood flows through the stenosed region, which subsequently extends downstream into the post-stenotic area. This jet is found to be shorter in length but more turbulent and unsteady when simulated with the sPTT model compared to the Newtonian model. The sPTT model simulations reveal more concentrated small-scale vortical structures within and immediately downstream of the stenosis, indicating increased flow complexity due to viscoelastic and shear-thinning effects of blood. The same trend is also observed in the case of pulsatile flow conditions. Clinically significant hemodynamic parameters such as the pressure drop across the stenosis and wall shear stress (WSS) were also analyzed. The pressure drop is observed to decrease with increasing Reynolds number but increase with the degree of stenosis. WSS, a critical indicator in vascular health assessment, increases with stenosis severity and attains its maximum during the systolic (peak) phase of the pulsatile cycle, where blood velocity is at its highest. Throughout the simulations, the Newtonian model consistently overestimates both the pressure drop and WSS compared to the sPTT model. Therefore, reliance on Newtonian assumptions may lead to misinterpretation or overestimation of key hemodynamic metrics in both diagnostic and therapeutic contexts. Overall, this study provides in-depth insights into the complex flow behavior in stenosed arteries, with emphasis on the rheological fidelity of the blood model. The findings of this study have potential implications for improving clinical diagnosis, treatment planning, and the design of medical devices targeting vascular diseases in the context of atherosclerosis, a progressively prevalent cardiovascular condition.
{"title":"A comparative study of Newtonian and multi-mode viscoelastic models for blood flow in stenosed arteries at high physiologic Reynolds and Womersley numbers","authors":"A. Chauhan, C. Sasmal","doi":"10.1016/j.ijengsci.2025.104453","DOIUrl":"10.1016/j.ijengsci.2025.104453","url":null,"abstract":"<div><div>This study presents extensive three-dimensional numerical simulations to investigate the hemodynamics within a stenosed artery under both steady and pulsatile inflow conditions. Two different blood rheology models are employed, namely, the conventional Newtonian model and the more physiologically accurate multimode simplified Phan–Thien–Tanner (sPTT) viscoelastic model. The parameters for the sPTT model are calibrated using experimental rheological data of real whole blood, obtained from standard viscometric flows such as steady simple shear and small-amplitude oscillatory shear (SAOS). This enables the model to capture both the shear-thinning and viscoelastic nature of blood, thus offering a more realistic representation of blood flow dynamics in a physiologically relevant arterial geometry. Under steady inflow conditions, a high-velocity jet is formed as blood flows through the stenosed region, which subsequently extends downstream into the post-stenotic area. This jet is found to be shorter in length but more turbulent and unsteady when simulated with the sPTT model compared to the Newtonian model. The sPTT model simulations reveal more concentrated small-scale vortical structures within and immediately downstream of the stenosis, indicating increased flow complexity due to viscoelastic and shear-thinning effects of blood. The same trend is also observed in the case of pulsatile flow conditions. Clinically significant hemodynamic parameters such as the pressure drop across the stenosis and wall shear stress (WSS) were also analyzed. The pressure drop is observed to decrease with increasing Reynolds number but increase with the degree of stenosis. WSS, a critical indicator in vascular health assessment, increases with stenosis severity and attains its maximum during the systolic (peak) phase of the pulsatile cycle, where blood velocity is at its highest. Throughout the simulations, the Newtonian model consistently overestimates both the pressure drop and WSS compared to the sPTT model. Therefore, reliance on Newtonian assumptions may lead to misinterpretation or overestimation of key hemodynamic metrics in both diagnostic and therapeutic contexts. Overall, this study provides in-depth insights into the complex flow behavior in stenosed arteries, with emphasis on the rheological fidelity of the blood model. The findings of this study have potential implications for improving clinical diagnosis, treatment planning, and the design of medical devices targeting vascular diseases in the context of atherosclerosis, a progressively prevalent cardiovascular condition.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"221 ","pages":"Article 104453"},"PeriodicalIF":5.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956761","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 : 2026-04-01Epub Date: 2026-01-20DOI: 10.1016/j.ijengsci.2026.104476
Nithin Veerendranath Kammara, Anastasia Muliana
Many biological composites rely on interlocking arrangements of brittle (hard) and compliant (soft) constituents, which give rise to diverse load-transfer pathways and, in turn, exceptional resistance to mechanical loading, enhanced crack suppression, and effective energy dissipation under dynamic conditions. In this study, we develop a micromechanical model to explain how microstructural characteristics and mechanical properties of constituents govern the overall deformation of staggered composites. Our analysis examines how platelet (inclusion) geometry, arrangement, and packing density influence load transfer. We find that the size of staggered regions and packing density play more dominant roles than the platelet volume fraction in controlling the elastic moduli and nonlinear inelastic tensile response of the staggered composites. Furthermore, we identify design pathways for achieving high elastic stiffness in composites with low packing density and low platelet volume fraction by increasing the extent of staggered regions and forming connected platelet networks. A noteworthy and somewhat counterintuitive result is that platelet volume fraction has a minor effect on mechanical behavior in staggered architectures, in contrast to non-staggered microstructures, because staggered layouts activate multiple load-transfer mechanisms enabled by tailored platelet geometry and arrangement. We validate the prediction of our mechanical models against experimental data and other models.
{"title":"Microstructural characteristics and its role in load transfer within staggered architectures of brittle and compliant constituents","authors":"Nithin Veerendranath Kammara, Anastasia Muliana","doi":"10.1016/j.ijengsci.2026.104476","DOIUrl":"10.1016/j.ijengsci.2026.104476","url":null,"abstract":"<div><div>Many biological composites rely on interlocking arrangements of brittle (hard) and compliant (soft) constituents, which give rise to diverse load-transfer pathways and, in turn, exceptional resistance to mechanical loading, enhanced crack suppression, and effective energy dissipation under dynamic conditions. In this study, we develop a micromechanical model to explain how microstructural characteristics and mechanical properties of constituents govern the overall deformation of staggered composites. Our analysis examines how platelet (inclusion) geometry, arrangement, and packing density influence load transfer. We find that the size of staggered regions and packing density play more dominant roles than the platelet volume fraction in controlling the elastic moduli and nonlinear inelastic tensile response of the staggered composites. Furthermore, we identify design pathways for achieving high elastic stiffness in composites with low packing density and low platelet volume fraction by increasing the extent of staggered regions and forming connected platelet networks. A noteworthy and somewhat counterintuitive result is that platelet volume fraction has a minor effect on mechanical behavior in staggered architectures, in contrast to non-staggered microstructures, because staggered layouts activate multiple load-transfer mechanisms enabled by tailored platelet geometry and arrangement. We validate the prediction of our mechanical models against experimental data and other models.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"221 ","pages":"Article 104476"},"PeriodicalIF":5.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034943","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 : 2026-04-01Epub Date: 2026-01-08DOI: 10.1016/j.ijengsci.2025.104456
J. Kaplunov , L. Nazarenko , H. Altenbach
The basic concepts of gradient elasticity are interpreted by developing an asymptotic continualisation procedure for high-contrast lattices. As an example, a two-spring axial lattice supporting both direct and indirect interactions is considered, assuming the stiffness of the string related to the latter is much greater. In this case, the length scale of gradient phenomena considerably exceeds the distance between lattice nodes ensuring a continuous approximation. At leading order, it is given by a fourth-order singular perturbed equation degenerating to a second-order one, which is typical of the canonical asymptotic setup. It is shown that the gradient behaviour may also be incorporated by imposing effective boundary conditions for the mentioned second-order equation. The accuracy of the derived continuous framework is illustrated by comparison with the exact discrete solution.
{"title":"Asymptotic continualisation of high-contrast lattices and the interpretation of gradient elasticity","authors":"J. Kaplunov , L. Nazarenko , H. Altenbach","doi":"10.1016/j.ijengsci.2025.104456","DOIUrl":"10.1016/j.ijengsci.2025.104456","url":null,"abstract":"<div><div>The basic concepts of gradient elasticity are interpreted by developing an asymptotic continualisation procedure for high-contrast lattices. As an example, a two-spring axial lattice supporting both direct and indirect interactions is considered, assuming the stiffness of the string related to the latter is much greater. In this case, the length scale of gradient phenomena considerably exceeds the distance between lattice nodes ensuring a continuous approximation. At leading order, it is given by a fourth-order singular perturbed equation degenerating to a second-order one, which is typical of the canonical asymptotic setup. It is shown that the gradient behaviour may also be incorporated by imposing effective boundary conditions for the mentioned second-order equation. The accuracy of the derived continuous framework is illustrated by comparison with the exact discrete solution.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"221 ","pages":"Article 104456"},"PeriodicalIF":5.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940299","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}
This paper addresses a dynamic problem for a thin aerogel layer with one face fixed and a time-harmonic vertical displacement prescribed on the opposite face. The constitutive relations rely on Rajagopal’s nonlinear implicit model. To validate the material parameters, we conduct uniaxial compression experiments on organic–inorganic hybrid silica aerogels, confirming the predictive capability of the proposed model. A weakly nonlinear asymptotic analysis is conducted and the associated two-term approximate solution is obtained, for both the one-dimensional problem for transverse displacement and the plane-strain problem. Comparisons with numerical solutions are performed, highlighting the importance of the nonlinear corrector. The integrated approach involving asymptotic analysis, numerical investigations, and experimental characterization advances the understanding of the dynamic behaviour of aerogels and paves the way for the design of aerogel-based insulation applications.
{"title":"Weakly nonlinear dynamics of a thin aerogel coating governed by Rajagopal’s continuum model","authors":"Weibo Xiong , Danila Prikazchikov , Rasul Abdusalamov , Mikhail Itskov","doi":"10.1016/j.ijengsci.2025.104451","DOIUrl":"10.1016/j.ijengsci.2025.104451","url":null,"abstract":"<div><div>This paper addresses a dynamic problem for a thin aerogel layer with one face fixed and a time-harmonic vertical displacement prescribed on the opposite face. The constitutive relations rely on Rajagopal’s nonlinear implicit model. To validate the material parameters, we conduct uniaxial compression experiments on organic–inorganic hybrid silica aerogels, confirming the predictive capability of the proposed model. A weakly nonlinear asymptotic analysis is conducted and the associated two-term approximate solution is obtained, for both the one-dimensional problem for transverse displacement and the plane-strain problem. Comparisons with numerical solutions are performed, highlighting the importance of the nonlinear corrector. The integrated approach involving asymptotic analysis, numerical investigations, and experimental characterization advances the understanding of the dynamic behaviour of aerogels and paves the way for the design of aerogel-based insulation applications.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"221 ","pages":"Article 104451"},"PeriodicalIF":5.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940294","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}
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