Mechanics Research Communications最新文献

{"title":"Bishop nanorods with stress-driven nonlocal elasticity and arbitrary boundary conditions","authors":"Francesco Paolo Pinnola ,&nbsp;Raimondo Luciano ,&nbsp;Francesco Marotti de Sciarra","doi":"10.1016/j.mechrescom.2025.104533","DOIUrl":"10.1016/j.mechrescom.2025.104533","url":null,"abstract":"<div><div>One-dimensional structural elements, such as thick rods, are essential in the development of nanoscale electromechanical systems. Their design and mechanical behavior at small scales can be effectively described using nonlocal continuum mechanics, which captures size-dependent effects and long-range interactions while reducing computational costs compared to atomistic methods. This study analyzes small-scale thick rods with realistic boundary conditions using Bishop’s model, incorporating a nonlocal integral constitutive relation. Usually, the nonlocal relation is derived from Eringen’s integral model, in which the nonlocal stress at a point depends on the entire strain field through a Fredholm-type convolution integral. However, this strain-driven formulation may lead to inconsistencies when applied to bounded domains. To address these issues, a stress-driven nonlocal integral formulation is adopted, providing a well-posed mechanical model that admits analytical solutions. A parametric study is conducted to evaluate the influence of nonlocal effects under various boundary conditions. Theoretical and numerical results contribute to a better understanding of the mechanical behavior of nanorods and offer valuable insights for the design of small-scale components.</div></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":"149 ","pages":"Article 104533"},"PeriodicalIF":2.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inclined flow of a second-gradient incompressible fluid with pressure-dependent viscosity","authors":"C. Balitactac,&nbsp;C. Rodriguez","doi":"10.1016/j.mechrescom.2025.104528","DOIUrl":"10.1016/j.mechrescom.2025.104528","url":null,"abstract":"<div><div>Many viscous liquids behave effectively as incompressible under high pressures but display a pronounced dependence of viscosity on pressure. The classical incompressible Navier–Stokes model cannot account for both features, and a simple pressure-dependent modification introduces questions about the well-posedness of the resulting equations. This paper presents the first study of a second-gradient extension of the incompressible Navier–Stokes model, recently introduced by the authors, which includes higher-order spatial derivatives, pressure-sensitive viscosities, and complementary boundary conditions. Focusing on steady flow down an inclined plane, we adopt Barus’ exponential law and impose weak adherence at the lower boundary and a prescribed ambient pressure at the free surface. Through numerical simulations, we examine how the flow profile varies with the angle of inclination, ambient pressure, viscosity sensitivity to pressure, and internal length scale.</div></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":"149 ","pages":"Article 104528"},"PeriodicalIF":2.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transient phenomena under the Crighton–Westervelt–Klein–Gordon equation: Controlling the onset of gradient catastrophe in bubbly liquids","authors":"N. Valdivia ,&nbsp;P.M. Jordan","doi":"10.1016/j.mechrescom.2025.104532","DOIUrl":"10.1016/j.mechrescom.2025.104532","url":null,"abstract":"<div><div>Employing a combination of analytical and numerical methodologies, we investigate the propagation and evolution of acoustic acceleration waves in lossless bubbly liquids under the (1D) finite-amplitude model termed the Crighton–Westervelt–Klein–Gordon (CWKG) equation. Exact acceleration wave results for the acoustic pressure field are derived and analyzed, and special/limiting cases are identified. It is shown that by varying the value of the parameter that represents the volume concentration of bubbles, one can control the instant at which “gradient catastrophe” (i.e., shock formation) occurs. Results obtained are also compared with those for both the bubble-free limiting case of the CWKG equation and the classic Klein–Gordon equation, which is the linearized version of the CWKG equation. Lastly, a link between the present model and an extension of the Fermi–Pasta–Ulam–Tsingou-<span><math><mi>α</mi></math></span> case is noted.</div></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":"149 ","pages":"Article 104532"},"PeriodicalIF":2.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fundamental frequency of an orthotropic rectangular plate with uniformly distributed point supports: Application to the design procedure","authors":"Alexander V. Lopatin ,&nbsp;Alexander V. Tololo ,&nbsp;Sergey A. Pikulin","doi":"10.1016/j.mechrescom.2025.104531","DOIUrl":"10.1016/j.mechrescom.2025.104531","url":null,"abstract":"<div><div>In the paper an analytical solution to the problem of determining the fundamental frequency of vibrations of a rectangular orthotropic plate with uniformly distributed point supports is obtained. The deflection and the two rotation angles of the tangents are equal to zero at each point of support of the plate. The edges of the plate are fully clamped. The solution to the required dynamic problem is reduced to the determination of the fundamental frequency of vibrations of a rectangular fragment of a plate supported at four corner points. At each of the edges of such a plate fragment, the angle of rotation of the tangent and the generalised shear force are both zero. The solution to the dynamic problem for the plate fragment was obtained by employing the Ritz method. An approximation of the deflection of a plate fragment supported at four corners was performed using a three-term combination of clamped–clamped beam functions. The implementation of the Ritz method enabled the derivation of a cubic equation, from which the desired frequency of vibration of the corned supported plate fragment was subsequently ascertained by the Cardano method. The analytical solution was utilised to calculate the fundamental frequency of vibrations of the orthotropic plate fragment with given sizes. The found frequency was then compared with the fundamental frequency of vibrations of whole plates with uniformly distributed point supports. The calculation of the latter was performed by means of the finite element method. The comparison demonstrated that the fundamental frequency of vibrations of whole plates slightly exceeds the frequency of vibrations of their fragments. It is evident that the discrepancy between these frequencies diminishes as the number of fragments along the edges of the plates increases. The paper demonstrates the use of the value of the fundamental frequency of fragment vibrations in the design of point-supported plates.</div></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":"149 ","pages":"Article 104531"},"PeriodicalIF":2.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FFT-based disclination mechanics for high angle grain boundaries and comparisons with atomistic simulations","authors":"Abdallah Wazne,&nbsp;Joé Petrazoller,&nbsp;Julien Guénolé,&nbsp;Thiebaud Richeton,&nbsp;Stéphane Berbenni","doi":"10.1016/j.mechrescom.2025.104529","DOIUrl":"10.1016/j.mechrescom.2025.104529","url":null,"abstract":"<div><div>The paper addresses the question of determining local stress fields using the numerically efficient Fast Fourier Transform (FFT) method as an application of the continuum defect theory in the presence of interfacial defects, and specifically High Angle Grain Boundaries (HAGBs). First, the Field Dislocation and Disclination Mechanics (FDDM) equations are reported highlighting the use of the Stokes-Helmholtz orthogonal decomposition for both elastic strain and curvature tensors which are involved for disclination-type defects. Then, following this decomposition, both incompatible and compatible fields can be solved. Second, the Green’s function method for heterogeneous media is used to derive the stress polarization field, which integrates both dislocation and disclination densities. The compatible elastic strain tensor is numerically solved with the spectral method using the FFT (fast Fourier transform) algorithm together with finite difference (FD) schemes for computing first- and second-order spatial derivatives (FDDM-FFT). As applications of the method, the stress fields of two specific HAGBs (symmetric tilt GBs with [001] tilt axis), precisely <span><math><mrow><mi>Σ</mi><mn>29</mn><mrow><mo>(</mo><mn>520</mn><mo>)</mo></mrow><mrow><mo>[</mo><mn>001</mn><mo>]</mo></mrow><mn>46</mn><mo>.</mo><mn>40</mn><mo>°</mo></mrow></math></span> and <span><math><mrow><mi>Σ</mi><mn>149</mn><mrow><mo>(</mo><mn>1070</mn><mo>)</mo></mrow><mrow><mo>[</mo><mn>001</mn><mo>]</mo></mrow><mn>20</mn><mo>.</mo><mn>02</mn><mo>°</mo></mrow></math></span> are obtained from the Disclination Structural Unit Model (DSUM). They are calculated assuming both isotropic and anisotropic elasticity with the present FDDM-FFT numerical method and assuming periodic disclination density tensors. Quantitative comparisons are first performed for both HAGBs with analytical solutions obtained from specific combinations of disclination dipole walls in linear isotropic elasticity. Then, the effect of anisotropic elasticity is analyzed for both HAGBS considering two different FCC metals, namely Al and Ag. Lastly, some comparisons between the FDDM-FFT-based results with molecular statics (MS) simulations, using the virial stress method and an interpolation method based on Gaussian kernel are reported for both HAGBs applied to Al and Ag. It is shown that, despite their relative simplicity in describing HAGB defect cores, the FDDM-FFT results reproduce the major trends of MS-based results for both hydrostatic and shear stress components.</div></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":"149 ","pages":"Article 104529"},"PeriodicalIF":2.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 shape and interpenetration of ellipsoidal pores on effective physical properties of closed-cell porous materials","authors":"Hiroyuki Ono ,&nbsp;Masaki Kobayashi ,&nbsp;Hirokazu Matsuura","doi":"10.1016/j.mechrescom.2025.104527","DOIUrl":"10.1016/j.mechrescom.2025.104527","url":null,"abstract":"<div><div>The purpose of this study is to clarify the effects of pore shape and interpenetration on the effective elastic modulus and thermal conductivity of closed-cell porous materials. For this purpose, the theoretical solutions for these effective physical properties of a model with ellipsoidal pores oriented randomly in the matrix are derived based on some homogenization methods such as the differential scheme (DS). The obtained solutions are expressed uniformly in terms of the geometrical factors given only by the aspect ratio of ellipsoidal pores. In addition, a model in which ellipsoidal pores are not only oriented randomly in the material but also interpenetrating is generated using <em>the regular polyhedron orientation method</em> associated with the golden ratio. Finite element method (FEM) analyses of this model are also performed. The effective physical properties of various closed-cell porous materials are calculated by the theoretical solutions and FEM. These results are compared with the experimental ones. When spherical pores do not interpenetrate, the DS results for effective physical properties show good agreement with the experimental and FEM results. However, when spherical pores interpenetrate, the DS results tend to be slightly higher than these results. This difference becomes negligible when the pore volume fraction is less than 0.5. Moreover, when the pore shape is non-spherical, such as elongated or flattened, the effect of interpenetration is reduced. As a result, the DS results show good quantitative agreement with the FEM results. These findings demonstrate that the DS can evaluate the effective physical properties of porous materials with a certain degree of accuracy, regardless of the shape and interpenetration of pores. The effective Young’s modulus and thermal conductivity tend to be highest when the pore shape is spherical and decrease as the pore shape becomes flatter. As an application of these findings, we present design guidelines for hybrid porous materials that improve insulation while maintaining stiffness.</div></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":"149 ","pages":"Article 104527"},"PeriodicalIF":2.3,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent developments in the modeling of thin-walled structures combining GBT and shell finite elements","authors":"Rodrigo Gonçalves ,&nbsp;Dinar Camotim ,&nbsp;David Manta","doi":"10.1016/j.mechrescom.2025.104525","DOIUrl":"10.1016/j.mechrescom.2025.104525","url":null,"abstract":"<div><div>This paper presents a state-of-the art report on recent developments concerning the modeling of thin-walled members and frames, by combining the advantages of Generalized Beam Theory (GBT) and conventional shell finite elements. Two approaches are reported. The first one combines, in the same model, GBT-based (beam) and shell finite elements, through appropriate constraint equations. The beam elements are employed only in the elastic and prismatic zones, since the remaining zones are handled more efficiently with shell elements. The second approach recovers the insightful GBT mode participations from shell finite element results, through post-processing operations. This approach is useful when GBT elements are not available, cannot be employed (e.g., in tapered members) or are not computationally advantageous, and has a significant potential of application in standard finite element programs, since its implementation is quite straightforward. Throughout the paper, several numerical examples are presented and discussed, to illustrate the application and show the capabilities of the two approaches.</div></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":"149 ","pages":"Article 104525"},"PeriodicalIF":2.3,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy harvesting from topological interface states in an elastic beam array system","authors":"Stepa Paunović ,&nbsp;Milan Cajić ,&nbsp;Danilo Karličić ,&nbsp;Mihailo Lazarević ,&nbsp;Sondipon Adhikari","doi":"10.1016/j.mechrescom.2025.104506","DOIUrl":"10.1016/j.mechrescom.2025.104506","url":null,"abstract":"<div><div>Recent discoveries of exotic topological phenomena in mechanical phononics and metamaterials have become a prominent focus in engineering research. These findings not only expanded the functionality and potential applications of such artificial materials and structures but also went well beyond the initial identification of effects such as band gaps. In this study, we propose energy harvesting from localized interface modes in a periodic beam array system. The system is composed of elastically connected parallel beams, with bimorph piezoelectric beams considered at the interface. We derive a system of governing equations, and respective eigenvalue problems for both the full finite lattice model and a reduced-order model based on Bloch mode synthesis are defined and solved. We analyze the topological properties, eigenspectrum, frequency–voltage relationships, and steady-state responses to explore localized interface modes and their energy harvesting capabilities. Additionally, we investigate the robustness of the frequency of topologically protected interface modes in the presence of a mass defect in the lattice, demonstrating the efficiency of the proposed energy harvesting system.</div></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":"149 ","pages":"Article 104506"},"PeriodicalIF":2.3,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Size effects in hexagonal and Re-entrant metamaterial beams under bending","authors":"Ahmad Baroutaji","doi":"10.1016/j.mechrescom.2025.104526","DOIUrl":"10.1016/j.mechrescom.2025.104526","url":null,"abstract":"<div><div>This paper investigates the effects of boundary conditions, cell topology, relative density, and functionally graded pattern on the size effects of metamaterial beams with a hexagonal unit cell subjected to concentrated transverse bending loads. Beams with clamped and simply supported end conditions were studied. Two hexagonal unit cell topologies (regular hexagonal and re-entrant geometries) and two functionally graded approaches (transversally functionally graded and axially functionally graded patterns) are adopted to create various metamaterial beams with different configurations. Numerical finite element analysis (FEA) simulations and the Euler-Bernoulli (EB) beam model were used to estimate the bending responses of the different metamaterial beams.</div><div>The results indicate that metamaterial beams with hexagonal unit cells exhibit stiffness-softening size effects under bending. This means that the smaller the difference between the unit cell size and the overall beam size, the larger the apparent deflection of the beam. This size-dependent behaviour of the hexagonal metamaterial beam is well captured by a nonlocal strain-gradient model. The cell topology and functionally graded patterns displayed limited impact on the size effects, while the relative density significantly influenced the size effects. Metamaterial beams with high relative density exhibit weaker size effects than their low relative density counterparts.</div></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":"149 ","pages":"Article 104526"},"PeriodicalIF":2.3,"publicationDate":"2025-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of two-dimensional airfoil ice fracture behavior and influencing factors under aerodynamic loading","authors":"Jiaqi Duan ,&nbsp;Xianlei Guan ,&nbsp;Xian Wang ,&nbsp;Xian Yi","doi":"10.1016/j.mechrescom.2025.104520","DOIUrl":"10.1016/j.mechrescom.2025.104520","url":null,"abstract":"<div><div>Aircraft frequently encounter icing and ice shedding during flight, which poses a serious threat to flight safety. To investigate the fracture and shedding mechanisms of ice accumulation on the wing surface under aerodynamic loads, a numerical model for the fracture and shedding of airfoil ice is established in this paper based on the bond-based peridynamics theory. The aerodynamic load distribution on the outer surface of the ice is obtained using the computational fluid dynamics method and applied as a boundary load to the outer particle layer of the peridynamics model to predict crack initiation and propagation behavior. The ice is formed by the icing of supercooled large water droplets, resulting in a ram’s horn shape. The effects of inflow velocity, angle of attack, ice elastic modulus, and ice critical bond stretch on the fracture behavior of airfoil ice are analyzed. The model effectively predicts the crack initiation time, location, propagation path, and propagation rate. Under low inflow velocity, no cracks were generated; however, as velocity exceeds a critical threshold and the angle of attack increases, cracks are more likely to develop in high-stress regions. Additionally, a lower elastic modulus and fracture toughness significantly accelerate crack formation and propagation. This study provides a theoretical foundation and technical reference for the design of aircraft ice protection systems.</div></div>","PeriodicalId":49846,"journal":{"name":"Mechanics Research Communications","volume":"149 ","pages":"Article 104520"},"PeriodicalIF":2.3,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}