International Journal of Engineering Science最新文献

{"title":"Multi-scale non-affine mechanics of electro-magneto-active elastomers: Taut domain exploitable convolution of polymer chain crosslinks, entanglements and finite extensibility","authors":"Aman Khurana ,&nbsp;Susmita Naskar ,&nbsp;M.M. Joglekar ,&nbsp;Tanmoy Mukhopadhyay","doi":"10.1016/j.ijengsci.2025.104378","DOIUrl":"10.1016/j.ijengsci.2025.104378","url":null,"abstract":"<div><div>Actuation devices fabricated using smart polymers often exhibit wrinkling and pull-in instability when they are subjected to external stimulation. These instabilities can disrupt the intended functionality of the actuation devices and hinder their reliability. The underlying reason for these instabilities is the complicated architecture of the polymer network, which results in a complex and chaotic arrangement of crosslinks and entanglements in smart elastomer membranes. This convoluted structure significantly influences the mechanical behavior of the polymers when external forces are applied. To better understand and characterize these instability phenomena, the present study develops a physics-based non-affine material model incorporating the effects of critical factors like polymer chain crosslinks, entanglements, and finite extensibility. By considering the intricate interplay among these factors, the model provides fundamental insights into the mechanisms behind the instability phenomena in smart polymers. Subsequently, the study explores the relationship between the applied electromagnetic field and the taut domains. The findings reveal that the size of the taut domains can be effectively altered by manipulating the levels of polymer chain crosslinks, entanglements, and finite extensibility. It is observed that, for a given level of applied electromagnetic field, increasing the entanglement and crosslink parameter leads to a larger taut domain. Conversely, an increase in the finite extensibility of the polymer chain diminishes the taut domain under the same level of electromagnetic loading. These understandings open up new avenues for optimizing actuation devices by adjusting the intricate properties of polymer chains to enhance stability and performance by unlocking the full multi-physical potential of smart elastomers.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104378"},"PeriodicalIF":5.7,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145095236","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":"Elastohydrodynamic instabilities in pressure-driven flow through a poroelastic channel","authors":"Ramkarn Patne","doi":"10.1016/j.ijengsci.2025.104379","DOIUrl":"10.1016/j.ijengsci.2025.104379","url":null,"abstract":"<div><div>The linear stability analysis of a pressure-driven flow through a saturated poroelastic channel sandwiched between two impermeable rigid walls is carried out in the present study. Mixture theory is employed to describe the dynamics of the interstitial fluid and elastic solid matrix. The resulting eigenvalue problem is solved using the pseudo-spectral method. Without the poroelastic solid matrix, the flow under consideration reduces to the classical plane Poiseuille flow for which the linear stability analysis predicts critical Reynolds number, <span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>=</mo><mn>5772</mn></mrow></math></span>. However, the present study, predicts that <span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow></math></span> could be as low as 5 for the flow under consideration owing to the deformability of the solid matrix. Further analysis reveals the existence of three new modes of instability. For low <span><math><mrow><mi>R</mi><mi>e</mi></mrow></math></span>, mode I dominates the instability, while at high <span><math><mrow><mi>R</mi><mi>e</mi></mrow></math></span>, mode III dominates the instability with characteristic scaling <span><math><mrow><msub><mrow><mi>Γ</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>∼</mo><mn>1</mn><mo>/</mo><mi>R</mi><mi>e</mi></mrow></math></span> where <span><math><msub><mrow><mi>Γ</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> is a measure of the deformability of the solid matrix. The driving mechanism of the predicted instability is found to be the coupling between the fluid and solid due to the pressure perturbation. The energy exchange between the base state velocity gradient and normal velocity perturbation via the convection term in the linearised Navier–Stokes equation plays a supporting role to the pressure perturbations in introducing unstable modes.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104379"},"PeriodicalIF":5.7,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145060540","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":"Lagrangian theory of extensible elastica with arbitrary undeformed shape","authors":"Alessandro Taloni ,&nbsp;Daniele Vilone ,&nbsp;Giuseppe Ruta","doi":"10.1016/j.ijengsci.2025.104383","DOIUrl":"10.1016/j.ijengsci.2025.104383","url":null,"abstract":"<div><div>This work presents a consistent formulation of the Lagrangian function for slender elastic bodies with arbitrary initial geometries, within a dynamic framework and under finite displacements. Building upon and extending previous research, we develop a rigorous expression for the kinetic energy, thereby completing the Lagrangian formulation. Our approach ensures consistency across geometric and dynamic nonlinearities. Furthermore, we derive pattern solutions for representative benchmark problems, illustrating the applicability and versatility of the proposed framework. These results open new avenues for the application of our formulation across various domains in applied science and engineering.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104383"},"PeriodicalIF":5.7,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145044522","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":"Effective field methods vs finite element models for microgeometries with ellipsoidal inclusions. Theory and application","authors":"E. Polyzos,&nbsp;L. Pyl","doi":"10.1016/j.ijengsci.2025.104373","DOIUrl":"10.1016/j.ijengsci.2025.104373","url":null,"abstract":"<div><div>This study compares the predictions of analytical and numerical models employing ellipsoidal inclusions to determine the effective properties of composite materials. Three groups of factors influencing homogenization accuracy are investigated: the type of homogenization problem (elasticity, expansion, and conductivity), the material phase characteristics (isotropy, inclusion orientation, and inclusion aspect ratio), and the modeling methodologies, where effective field methods (EFMs) – including the Non-Interaction, the Mori–Tanaka and Maxwell methods – are evaluated against the pseudo grain decomposition method (PGDM) and numerical finite element (FE) models in a parametric study. The study considers ellipsoidal inclusions with aspect ratios ranging from 0.2 to 5 and orientation scattering from completely random to fully aligned. The results indicate that the type of homogenization problem does not significantly affect the prediction accuracy of EFMs and that the Mori–Tanaka and Maxwell methods show excellent agreement with FE models for all properties. The PGDM is shown to yield reliable results only for certain elastic properties (e.g., <span><math><msub><mrow><mi>E</mi></mrow><mrow><mn>11</mn></mrow></msub></math></span>) for composites with inclusions of aspect ratios greater than 1. Therefore, it is concluded that the Mori–Tanaka and the Maxwell methods serve as the most suitable analytical alternatives to computationally intensive FE models.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104373"},"PeriodicalIF":5.7,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145044520","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":"A geometric one-fluid model of superfluid helium-4","authors":"Nadine Suzan Cetin ,&nbsp;Michal Pavelka ,&nbsp;Emil Varga","doi":"10.1016/j.ijengsci.2025.104377","DOIUrl":"10.1016/j.ijengsci.2025.104377","url":null,"abstract":"<div><div>A standard description of superfluid helium-4 is based on the concept of two components (superfluid and normal), which leads to the so called two-fluid models. However, as there are no two kinds of atoms in helium-4, the two components cannot be separated. Superfluid helium-4 is not a mixture of two components, being rather a single fluid with two motions. Here, we present a geometric one-fluid model of superfluid helium-4, which is based on the Hamiltonian formulation of fluid mechanics. The model is derived from the kinetic theory of excitations (treated as an ideal Bose gas under the temperature <span><math><mrow><mn>1</mn><mo>.</mo><mn>3</mn><mspace></mspace><mi>K</mi></mrow></math></span>) and average particle motions. It can be simplified to the Hall–Vinen–Bekharevich–Khalatnikov (HVBK) two-fluid model, where it removes one fitting parameter from the HVBK model, but it also gives extra terms beyond the HVBK model. Actually, we show that the two-fluid models are problematic in case of higher counter-flow velocities, where the usual splitting of total momentum to the superfluid and normal component becomes impossible. Finally, we show how vortex line density may be added to the state variables. The one-fluid model can be seen as a generalization of the two-fluid models that is geometrically consistent, fully compressible, with non-zero superfluid vorticity, and compatible with classical experiments.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104377"},"PeriodicalIF":5.7,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145044521","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":"Torsional vibration of a coupled cylinder","authors":"Igor Istenes ,&nbsp;Daniel Peck ,&nbsp;Yuriy Protserov ,&nbsp;Natalya Vaysfeld ,&nbsp;Zinaida Zhuravlova","doi":"10.1016/j.ijengsci.2025.104374","DOIUrl":"10.1016/j.ijengsci.2025.104374","url":null,"abstract":"<div><div>The torsion loading of a coupled cylinder, comprising distinct upper and lower cylindrical sections potentially made of different materials, is considered. The bottom of the cylinder is fixed in place, and induces the cylinder vibration. The torsion is applied via an arbitrary loading on the upper face. Three forms of coupling condition between the upper and lower cylinders are outlined: ideal, soft (weak), and rigid (hard/ stiff) contact. The resulting displacements and tangential stresses are obtained using the finite Hankel transform, and a Green’s function representation of the displacement. Numerical results are provided, and the impact of the differing coupling conditions investigated for a range of cylinder geometries, material properties and vibration rates. The resonance frequencies of the coupled cylinder are determined. A method for using the coupled cylinder model to approximate the displacement of a cylinder containing a damaged region via a weak interfacial layer is outlined. The properties of the weak interface layer needed for this approximation are determined, and the advantages of its use in non-destructive testing are discussed.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104374"},"PeriodicalIF":5.7,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145019237","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":"Effect of periodic lamellar inclusions on interface integrity","authors":"Chao Tang ,&nbsp;Fei Su ,&nbsp;Wen Zhao ,&nbsp;Jingyu Zhang ,&nbsp;Biao Wang ,&nbsp;Lifeng Ma","doi":"10.1016/j.ijengsci.2025.104380","DOIUrl":"10.1016/j.ijengsci.2025.104380","url":null,"abstract":"<div><div>The bond strength between dissimilar solids is highly sensitive to defects near or within the interface. Interfacial inclusions, which are ubiquitous in materials engineering, play a critical role in determining the local and global integrity of materials or structures. In this article, we propose a theoretical model for periodic rectangular lamellar inclusions at the interface of dissimilar solids. In view of the concept of line inclusion, the Kolosov–Muskhelishvili complex potentials for the homogeneous periodic inclusion problem are derived based on the Green’s function method within the framework of plane elasticity. The explicit analytical solution of the stress field of the inhomogeneous periodic rectangular lamellar inclusion problem with arbitrary eigenstrain distribution is derived with the aid of the equivalent eigenstrain principle. A new stress concentration factor (SCF) is consequently defined to assess the interface strength. The influence of the size and material of rectangular lamellar inclusions on the SCF is analyzed. The accuracy of the theoretical results is further verified by finite element simulations. The analytical formulae established in this study offer a straightforward yet effective approach for various inhomogeneous and homogeneous interfacial inclusion problems encountered in engineering practice.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104380"},"PeriodicalIF":5.7,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144996694","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":"Topology optimization of 2D chiral metamaterials with dilatation-shear and shear-shear coupling capabilities","authors":"Mohamed Shaat ,&nbsp;Xin-Lin Gao","doi":"10.1016/j.ijengsci.2025.104367","DOIUrl":"10.1016/j.ijengsci.2025.104367","url":null,"abstract":"<div><div>Metamaterials with chiral microstructures exhibit unique mechanical coupling among various deformation modes. Traditional approaches for designing such materials rely heavily on discrete models and unit cells with predefined architectures, and hence it has been challenging to develop methodologies that can explore a broad range of chiral configurations and optimize the mechanical coupling behavior without being constrained by specific unit cell geometries. In the current study, a new multi-objective topology optimization (TO) method is developed for designing 2D chiral metamaterials with prescribed mechanical coupling among dilatation and two distinct shear deformation modes. The new method incorporates material symmetry constraints (including the <span><math><msub><mi>C</mi><mn>2</mn></msub></math></span> and <span><math><msub><mi>C</mi><mn>4</mn></msub></math></span> symmetries) into the TO process. A strain energy-based homogenization approach is adopted to determine the effective elastic stiffness matrix for each periodic chiral metamaterial. The TO process begins with maximizing the trace of the stiffness matrix to avoid cases with vanishing bulk or shear moduli, which is followed by maximizing/minimizing a selected off-diagonal component to optimize the dilatation-shear or shear-shear coupling. The proposed method successfully identifies optimal topologies that exhibit chiral layouts consistent with the imposed material symmetry constraints, and it maximizes mechanical coupling among dilatation and shear deformation modes. This newly developed method enables the exploration of diverse chiral material configurations, achieving optimized mechanical coupling without relying on a specific unit cell architecture.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104367"},"PeriodicalIF":5.7,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144996695","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":"Micromechanism-based electrochemo-mechanical model for double polarization-actuation of PVC gel-based electronic electroactive polymer","authors":"Li Zhang ,&nbsp;Yiqi Mao ,&nbsp;Wenyang Liu ,&nbsp;Shujuan Hou","doi":"10.1016/j.ijengsci.2025.104375","DOIUrl":"10.1016/j.ijengsci.2025.104375","url":null,"abstract":"<div><div>The polyvinyl chloride gel (PVCG)-based electroactive polymer exhibits tunable stiffness and achieves large strains with rapid response at moderate drive voltages (200–3000 V), making it suitable for versatile engineering applications. The electric actuation response of PVCG involves a strong micromechanism-characterized coupling between the electrochemical mobility of the plasticizer and the electro-modulus of PVC chain. Specifically, plasticizer polarization-induced electromigration generates polarization stress and osmotic stress, which act as the active driving forces for high actuation strain in PVCG, while polymer skeleton polarization-induced conformational transformation influences the electro-modulus of PVCG, impeding the deformation process. This work formulates an electrochemo-mechanical model to unravel the double polarization-induced actuation mechanism of PVCG under a thermodynamically consistent large deformation frame. First, we solve the polarization and dynamic evolution of a single polymer chain under electric excitation, as well as a single plasticizer molecule. The total free energy function of PVCG is then integrated through statistical mechanics in line with the full-network model. Subsequently, micromechanism-based constitutive relations are simplified following the core principles of the eight-chain model, incorporating effective stretch and electric field through average directions analytically. The finite element implementation is realized and the model is calibrated through a series of tests. Double polarization-induced actuation properties and the memory effect of PVCG under cyclic activation are analyzed. Additionally, a telescopic driver and a self-sensing variable stiffness artificial muscle model are simulated to showcase the wider applicability of our numerical simulation capability. This work provides theoretical understanding and design guidelines for PVCG at macro/micro scales in the actuation field.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104375"},"PeriodicalIF":5.7,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144925071","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":"Creep fracture entropy: A thermomechanical damage-based failure index","authors":"Asghar Zajkani ,&nbsp;Michael Khonsari","doi":"10.1016/j.ijengsci.2025.104376","DOIUrl":"10.1016/j.ijengsci.2025.104376","url":null,"abstract":"<div><div>This paper presents an analytical framework for thermodynamical modeling of creep damage and fracture in materials through the lens of entropy production. Building on the second law of thermodynamics and principles of irreversible processes, the study establishes a unified coupling between a phenomenological damage law and continuum damage mechanics. The model links creep deformation to internal entropy generation and introduces a process-dependent damage exponent to ensure physically consistent and mathematically robust damage evolution. A key contribution is to introduce Creep Fracture Entropy (CFE)—a novel, material-specific thermodynamic index that serves as a reliable predictor of creep failure. By deriving time-dependent expressions for strain, strain rate, and entropy production, the model captures the full progression of creep behavior, without requiring empirical stage segmentation. The model is validated against a range of experimental data from various alloys, manifesting strong agreement with the observed strain and entropy trends. Notably, the calculated CFE values remain confined within a narrow range for each material, highlighting their intrinsic nature of constancy and reliability as fracture indicators. The thermodynamic formulation presented here enhances predictive accuracy for creep life assessment, emphasizing entropy as a pivotal damage variable in irreversible thermodynamics.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104376"},"PeriodicalIF":5.7,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144913286","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}