Acta Mechanica最新文献

{"title":"Augmented simplified modelling of elastic pole shoe–rail frictional sliding contact in magnetic track brakes","authors":"Alois Steininger,&nbsp;Emin Kocbay,&nbsp;Eray Arslan,&nbsp;Johannes Edelmann","doi":"10.1007/s00707-026-04801-7","DOIUrl":"10.1007/s00707-026-04801-7","url":null,"abstract":"<div><p>The magnetic track brake, widely used as an emergency brake in railway vehicles, generates additional braking force through direct conformal contact with the rail. While finite element simulations can accurately reproduce this interaction, their computational cost is prohibitive for many applications. This work introduces an augmented contact model that extends a previously reported simplified elastic half-plane approach by additionally accounting for small overall elastic deformations while maintaining favourable computational efficiency. A two-step iterative scheme is employed, in which first contact resolution and then elastic deformations are handled in succession. The contact between a single pole shoe and the rail is simulated and compared with prior studies and reference results in the commercial finite element software <i>Abaqus</i>. The proposed model achieves good agreement with the reference solutions while preserving low computational cost. These findings establish the method as an efficient, reliable, and practical tool for pole shoe–rail contact analysis in both academic and engineering contexts.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"237 9","pages":"5625 - 5644"},"PeriodicalIF":4.0,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00707-026-04801-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149190028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An electromechanical coupling fractional-order constitutive model for dielectric elastomers with temperature and strain rate dependence","authors":"Jie Yang,&nbsp;Wei Cai,&nbsp;Zhengtong Han,&nbsp;Yanjie Wang","doi":"10.1007/s00707-026-04800-8","DOIUrl":"10.1007/s00707-026-04800-8","url":null,"abstract":"<div><p>Dielectric elastomers (DEs) exhibit significant electromechanical coupling deformation, which are simultaneously influenced by temperature and strain rate. This paper integrates an electrically equivalent Maxwell stress term into the fractional viscoelastic mechanical framework, thereby constructing a one-dimensional electromechanical coupling model that accounts for both temperature and strain rate dependence, and determining the quantitative relationship between material parameters and influencing factors. The Maxwell stress component has been modified to incorporate dynamic thickness variations in DEs during deformation. A unified framework spanning the characteristic temperature is developed, aiming to systematically characterize the complex mechanical responses across various temperature regimes. The model effectively predicts the softening behavior of DEs under increasing voltage, while confirming that the influence of low to moderate voltages on mechanical material parameters is negligible. In the absence of an applied electric field, the model can automatically degenerate into a purely mechanical model, ensuring physical consistency. With its simple structure and limited parameters, the proposed model has been comprehensively validated for uniaxial constant strain rate loading–unloading of DEs, showing high predictive accuracy.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"237 9","pages":"5601 - 5623"},"PeriodicalIF":4.0,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 welded stiffened microplate with surface elasticity containing a rigid line at the interface","authors":"F. Long,&nbsp;J. C. Wang,&nbsp;Z. L. Hu,&nbsp;X. Y. Zhang,&nbsp;X. F. Li","doi":"10.1007/s00707-026-04802-6","DOIUrl":"10.1007/s00707-026-04802-6","url":null,"abstract":"<div><p>In additive manufacturing, explosive welding, and related processes, rigid inclusions inevitably form at the interface of bimaterial plates. This article investigates the influence of interfacial rigid lines on the bending behavior of a welded microplate structure, with particular emphasis on the interfacial stress fields, through theoretical modeling and numerical analysis. The original problem is transformed into a mixed boundary value problem via the superposition principle. Then, it is reduced to a Cauchy singular integral equation of the first kind using the Fourier transform method. Explicit expressions for the whole fields of internal moments and stresses at any position of the welded microplate are derived analytically. The obtained numerical results reveal that, at the nanoscale, surface effects significantly affect the singularity coefficients at the tips of rigid lines. A singular interfacial shear stress is also induced along the rigid line. When the bi-plate system reduces to a homogeneous plate stiffened by a rigid line, the results agree with previously reported solutions, validating the effectiveness of the present model.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"237 9","pages":"5645 - 5664"},"PeriodicalIF":4.0,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on bandgap characteristics of nanoscale magneto-electro-elastic phononic crystal plates considering nonlocal effects","authors":"Guoqing Liu,&nbsp;Junchuan Niu","doi":"10.1007/s00707-026-04786-3","DOIUrl":"10.1007/s00707-026-04786-3","url":null,"abstract":"<div><p>With the rapid advancement of intelligent electromechanical systems and micro/nano engineering technologies, nanoscale magneto-electro-elastic phononic crystal (MEE-PC) plates have attracted significant attention in micro-/nano-acoustics and vibration control due to their superior elastic wave manipulation capability and flexible active tunability. Nevertheless, current research on bandgap characteristics of nanoscale MEE-PC plates still has limitations. The bandgap regulation mechanism involving nonlocal effects and multiphysical-field coupling remains unclear, and effective schemes for collaborative optimization of external field parameters are also lacking. To address these issues, the multiphysical-field-coupled wave governing equations are established based on Kirchhoff thin plate theory and Eringen’s nonlocal elasticity theory. The plane-wave expansion (PWE) method is subsequently employed to calculate the band structures of periodic MEE-PC plates. The effects of nonlocal parameters, prestress, magnetic potential, and applied voltage on the bandgap position and bandwidth are systematically investigated. Furthermore, a particle swarm optimization (PSO) algorithm is introduced to achieve coordinated optimization of multiple external physical-field parameters with the objective of maximizing the first bandgap width. The optimized parameter combination increases the first bandgap width from 17 to 81.2 GHz, representing an enhancement of approximately five times. Sensitivity analysis and repeated independent experiments further confirm the robustness and reliability of the proposed optimization strategy. The results reveal that nonlocal effects play a critical role in the evolution of high-frequency bandgaps, while external multiphysical fields provide an efficient and flexible approach for active bandgap manipulation. This study provides theoretical guidance for the design and optimization of intelligent vibration-control systems and micro-/nano-acoustic devices.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"237 9","pages":"5557 - 5576"},"PeriodicalIF":4.0,"publicationDate":"2026-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Higher-order dual phase-lag thermomechanical modeling of the human eye incorporating memory Kernels and Klein–Gordon nonlocal elasticity","authors":"Nitin Bhondge,&nbsp;Suryakant Charjan","doi":"10.1007/s00707-026-04794-3","DOIUrl":"10.1007/s00707-026-04794-3","url":null,"abstract":"<div><p>This study presents a comprehensive thermal–mechanical analysis within the framework of higher-order dual phase-lag (DPL) ocular thermomechanics, incorporating both memory-dependent kernels and Klein–Gordon-type nonlocal elasticity. The eye is idealized as six anatomically distinct zones—cornea, aqueous humor, lens, vitreous humor, retina, and sclera—with symmetry assumed along the pupillary axis to streamline geometric modeling and computational efficiency. Continuity conditions are enforced at interfacial boundaries to ensure smooth thermal transitions, while physiological and environmental heat exchange is represented through boundary conditions on the corneal and scleral surfaces. Realistic ocular exposure is simulated via an exponentially decaying external heat source, with traction-free and stress-free mechanical constraints imposed. The governing equations are solved analytically using Laplace transforms, followed by numerical inversion to obtain time-domain solutions. Temperature distributions, mechanical displacements, and thermal stresses are evaluated across ocular layers, with graphical results highlighting the pronounced sensitivity of these fields to variations in thermal relaxation times and kernel selection. The findings underscore the importance of non-Fourier effects in ocular bioheat transfer and provide valuable insights for biomedical applications, including precision laser therapies, noninvasive thermal diagnostics, and controlled drug delivery.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"237 9","pages":"5577 - 5600"},"PeriodicalIF":4.0,"publicationDate":"2026-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Static analysis of sandwich plates by using higher-order refined zigzag theory","authors":"Pei-Yu Wang,&nbsp;Chung-De Chen","doi":"10.1007/s00707-026-04740-3","DOIUrl":"10.1007/s00707-026-04740-3","url":null,"abstract":"<div><p>In this paper, the higher-order refined zigzag theory (HRZT) is utilized to investigate the static behavior of sandwich plates with soft middle layer. The HRZT is an extension of the refined zigzag theory (RZT) that cooperates with higher-order terms in kinematics assumption. Based on this theory, the free shear stress on top/bottom surfaces and shear stress continuity on interfaces are ensured. The equilibrium equations for HRZT plate are derived. Three types of HRZT plate element are developed to solve the static response of sandwich plates. The plates with various boundary conditions, CCCC, CFCF, SFSF and SSSS, are considered for numerical examinations. The results show that the deflections, inplane displacements, inplane stresses and transverse shear stresses calculated with HRZT agree well with those by three-dimensional model with ANSYS. The shear force resultants calculated by integrating the shear stress vanish on clamped edge due to higher-order shear deformation assumption, which violates the force equilibrium. By using the relationship among average shear strain, rotation due to bending and gradient of deflection, the HRZT plate elements simultaneously incorporate higher-order shear deformation, satisfy force equilibrium on the clamped edge, and yield a physically meaningful through-thickness shear stress distribution.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"237 9","pages":"5525 - 5555"},"PeriodicalIF":4.0,"publicationDate":"2026-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00707-026-04740-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation on thermoelastic vibration of FG multilayer hybrid nanocomposite microbeam reinforced by CNTs and GPLs under nonlocal strain gradient elasticity and three-phase-lag generalized thermoelastic theory","authors":"Xinfei Zhang,&nbsp;Tengjie Wang,&nbsp;Wei Peng,&nbsp;Tianhu He","doi":"10.1007/s00707-026-04792-5","DOIUrl":"10.1007/s00707-026-04792-5","url":null,"abstract":"<div><p>In recent years, extensive studies on carbon nanotubes-reinforced composites (CNTRC) and graphene platelets-reinforced composites (GPLRC) have been conducted primarily within the framework of the classical elasticity or thermoelasticity. With the development of micro/nano devices, the study of thermoelastic vibration and size-dependent effects in variable temperature environments is becoming more and more important. There is a notable absence of studies examining the thermoelastic behaviors of graphene platelets reinforced composite (GPLRC) or carbon nanotubes reinforced composite (CNTRC) structures within the framework of generalized thermoelasticity that considers non-Fourier heat conduction, particularly regarding the microstructures of CNTRC/GPLRC materials that require consideration of nonlocal effects. To address this gap, this study examines the thermoelastic vibration characteristics of a nanocomposite microbeam reinforced with both CNTs and GPLs within the framework of nonlocal strain gradient elasticity theory and the three-phase-lag (TPL) generalized thermoelastic theory for the first time. The Halpin–Tsai micromechanical model is employed to determine the effective elastic modulus of the composite microbeam. Subsequently, the problem is formulated using the Euler–Bernoulli beam model, and the resulting governing equations are solved using Navier’s method to derive the natural frequency. In calculation, besides unidirectional pattern for CNTs and GPLs, three different functionally graded (FG) distribution patterns, i.e., FG-A type, FG-X type, and FG-O type, are considered. Concurrently, the study evaluates the impacts of key factors including characteristic length parameters, surface effects, nonlocal parameters, volume fraction indices, and mass fractions of CNTs and GPLs on the natural frequencies. The results show that the dimensionless natural frequency of the FG-X type microbeam is approximately 26% higher than that of the UD type and 41% higher than that of the FG-A type. When the nonlocal parameter increases from 0 to 0.2, the natural frequency decreases by approximately 15–20%, while the strain gradient parameter increases it by 60–80%. Surface effects, mass fractions, and volume fraction index all positively correlate with the natural frequency.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"237 9","pages":"5499 - 5523"},"PeriodicalIF":4.0,"publicationDate":"2026-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exact analytical solution for static bending of bidirectionally functionally graded Timoshenko nanobeams based on nonlocal strain gradient theory","authors":"Minhaj Uddin Mahmood Siddique,&nbsp;I. M. Nazmul,&nbsp;Indronil Devnath","doi":"10.1007/s00707-026-04778-3","DOIUrl":"10.1007/s00707-026-04778-3","url":null,"abstract":"<div><p>An exact analytical solution is presented for the static bending response of bidirectionally functionally graded (BDFG) Timoshenko nanobeams within the framework of nonlocal strain gradient theory (NSGT). The material properties are assumed to vary simultaneously along the beam axis and through the thickness, described by an exponential law in the axial direction and a power-law distribution across the thickness. Based on Timoshenko beam kinematics, the coupled governing equations accounting for both nonlocal elasticity and strain-gradient effects are derived via Hamilton’s principle, together with consistent higher-order boundary conditions. To overcome the mathematical complexity associated with variable coefficients and higher-order operators, the Laplace transform method is employed, and closed-form expressions for transverse displacement and rotation are obtained through explicit inverse transformation in physical space. The proposed solution is validated through comparisons with available results for homogeneous and unidirectionally graded nanobeams, demonstrating excellent agreement and correct recovery of limiting cases. A detailed parametric study is conducted to examine the effects of axial and thickness-wise material gradation, nonlocal parameter, and strain-gradient length scale under various classical boundary conditions. The results reveal that axial gradation effectively tailors stiffness along the span, whereas increasing the thickness-wise gradation index leads to a more metal-dominated core and increased flexibility. A direct comparison between NSGT and classical nonlocal elasticity theory highlights the crucial role of strain-gradient hardening in mitigating nonlocal softening, resulting in more balanced and physically realistic predictions. The availability of exact closed-form solutions provides reliable benchmark results and offers new insight into the coupled influence of bidirectional material gradation and size-dependent effects in nanobeams, supporting future analytical, numerical, and multi-physics investigations.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"237 9","pages":"5471 - 5498"},"PeriodicalIF":4.0,"publicationDate":"2026-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 thermodynamic analysis of CFRP/Ti/CFRP sandwich cylindrical shells","authors":"Mohammad Rezaiee-Pajand,&nbsp;Mohammadreza Ramezani","doi":"10.1007/s00707-026-04649-x","DOIUrl":"10.1007/s00707-026-04649-x","url":null,"abstract":"<div><p>In this paper, nonlinear dynamic equations are established based on the enriched first-order shear deformation theory (FSDT). Moreover, the nonlinear driven and companion strain modes are taken into account. The nonlinear dynamic equations are transformed into the nonlinear differential equations in terms of time by employing the Galerkin method. Consequently, the nonlinear dynamic analysis of CFRP/Ti/CFRP sandwich cylindrical shells with carbon fiber reinforced polymer (CFRP) face sheets and honeycomb titanium (Ti) core containing fluid under mechanical and thermal loads is performed. Effects of geometric, material, temperature, and fluid parameters on the vibration and dynamic responses are investigated.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"237 9","pages":"5449 - 5470"},"PeriodicalIF":4.0,"publicationDate":"2026-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonlocal biaxial buckling analysis of nanoplates with multiple Gaussian defects using the finite difference method","authors":"Onur Kaya,&nbsp;Ahmet Sinan Oktem","doi":"10.1007/s00707-026-04785-4","DOIUrl":"10.1007/s00707-026-04785-4","url":null,"abstract":"<div><p>In this study, the biaxial buckling behavior of a nanoplate containing defects within the framework of nonlocal elasticity theory was investigated numerically by the finite difference method (FDM). The plate has a square geometry with four simply supported edges (SSSS), and the buckling differential equation was converted to a discrete form using the central difference method. Boundary conditions were imposed via ghost nodes, resulting in an eigenvalue problem. Gaussian-type defects were modeled with the parametric functions that attenuate the Young’s modulus. The effects of defect location, spread, and severity on buckling were thoroughly investigated. The validity of the model was confirmed by comparison with available molecular dynamics (MD) results in the literature. In addition, analyses performed for different nonlocal parameters and the defect scenarios demonstrated the decisive effects of defect location and spread on the buckling behavior. The findings highlighted the significance of defect modeling and the consideration of nonlocal effects in determining the mechanical stability of nanosystems. The proposed method offers a powerful tool for advanced nanoscale structural analysis with accuracy and flexibility.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"237 9","pages":"5425 - 5448"},"PeriodicalIF":4.0,"publicationDate":"2026-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00707-026-04785-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}