{"title":"Coupled bidirectional bending and torsional vibrations of axially loaded non-symmetrical thin-walled Timoshenko–Ehrenfest beams","authors":"Yunjie Yu, Dongfang Tian, Huanxia Wei, Lingli He, Baojing Zheng","doi":"10.1007/s00419-025-02952-y","DOIUrl":"10.1007/s00419-025-02952-y","url":null,"abstract":"<div><p>This paper introduces an analytical framework for examining the coupled bidirectional bending and torsional vibrations of non-symmetric, axially loaded thin-walled Timoshenko–Ehrenfest beams. By integrating axial loads, shear deformation, rotational inertia, and warping stiffness into the traditional Timoshenko–Ehrenfest beam theory, we enhance its ability to address complex bending-torsion interactions. Utilizing Hamilton’s principle, we derive five coupled differential equations and twelve boundary conditions to accurately describe the beam’s dynamic behavior. The normal mode method is used to derive closed-form expressions of frequency responses under arbitrary harmonic loads, and orthogonality conditions are established to obtain precise modal impulse and frequency response functions. Our framework provides accurate and computationally efficient solutions and examines the impact of axial loads on natural frequencies, offering practical guidance for engineering design. These findings contribute to the dynamic analysis of thin-walled Timoshenko–Ehrenfest beams, providing useful insights for engineers in designing and optimizing structures under complex loading conditions.</p></div>","PeriodicalId":477,"journal":{"name":"Archive of Applied Mechanics","volume":"95 11","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00419-025-02952-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145284386","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":"Closed-form analysis of the global–local buckling behavior of sandwich columns with additively manufactured lattice cores","authors":"Serhat Osmanoglu, Akshay Nair, C. Mittelstedt","doi":"10.1007/s00419-025-02950-0","DOIUrl":"10.1007/s00419-025-02950-0","url":null,"abstract":"<p>This study provides a comprehensive analysis of the global (in-plane and out-of-plane) and local (intracell and wrinkling) buckling behavior of sandwich columns with monolithically designed aluminum facesheets and face-centered body-centered cubic (FBCC) lattice cores. Approximate and numerical methods are employed to evaluate the influence of geometric parameters on buckling performance. A novel closed-form, higher-order approach is developed, incorporating core transverse compressibility and a refined displacement field. The finite element method (FEM) is employed to verify the approximate results for sandwich columns under various boundary conditions, using 3D solid elements for the facesheets and beam elements for the lattice core. The results demonstrate strong agreement with the closed-form approximate predictions, capturing both global and local buckling modes while revealing that the boundary conditions significantly affect global buckling but have a rather small influence on the local buckling behavior. The proposed approach offers enhanced accuracy and convergence with numerical methods, providing an efficient framework to analyze wrinkling failure modes in sandwich columns with lattice cores.</p>","PeriodicalId":477,"journal":{"name":"Archive of Applied Mechanics","volume":"95 10","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00419-025-02950-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256218","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":"Buckling analysis of nonlocal Timoshenko beams via an efficient semi-analytical approach","authors":"Ayşegül Tepe","doi":"10.1007/s00419-025-02956-8","DOIUrl":"10.1007/s00419-025-02956-8","url":null,"abstract":"<div><p>This study presents a semi-analytical method for analyzing the buckling behavior of nonlocal Timoshenko beams using Eringen’s nonlocal elasticity theory. The method combines the initial value method (IVM) with a segment-wise approximate transfer matrix (ATM) approach, enabling accurate and efficient computation of critical buckling loads under various boundary conditions. The IVM calculates displacements and stress resultants from initial conditions, while the ATM constructs the principal matrix required by the IVM through segment-wise integration, ensuring numerical stability. The IVM–ATM framework offers a practical alternative to traditional analytical and numerical methods, especially for size-dependent problems. The results show excellent agreement with existing solutions, validating the method’s accuracy. The method’s accuracy is further supported by detailed convergence analyses. Parametric studies highlight the effects of length-to-diameter ratio, nonlocal parameter, and boundary conditions on buckling behavior. The proposed method provides a reliable and efficient tool for nanoscale beam structures.</p></div>","PeriodicalId":477,"journal":{"name":"Archive of Applied Mechanics","volume":"95 10","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256213","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}
Abbas Shabudin, Nik Abdullah Nik Mohamed, Wahbi El-Bouri, Stephen Payne, Mohd Jamil Mohamed Mokhtarudin
{"title":"Multiscale modeling analysis of poroelastic properties of brain tissue with capillary networks","authors":"Abbas Shabudin, Nik Abdullah Nik Mohamed, Wahbi El-Bouri, Stephen Payne, Mohd Jamil Mohamed Mokhtarudin","doi":"10.1007/s00419-025-02954-w","DOIUrl":"10.1007/s00419-025-02954-w","url":null,"abstract":"<div><p>The cerebral microvasculature plays a key role in determining the blood perfusion and oxygen diffusion to surrounding tissue. Multiscale models have thus been developed to incorporate the effect of the microvasculature into overall brain function. Moreover, brain tissue poroelastic properties are also influenced by the microvasculature. This study aims to determine the pororelastic properties of brain tissue using multiscale modeling on microvasculature networks described by the following effective parametric tensors: blood flow permeability <span>({varvec{K}})</span>, interstitial fluid flow permeability <span>({varvec{G}})</span>, Biot’s coefficients for blood <span>({alpha }_{c})</span> and interstitial fluid <span>({alpha }_{t})</span>, Young’s modulus <span>(overline{E })</span>, and Poisson’s ratio <span>(overline{v })</span>. The microvasculature networks are built from a morphometric data of brain capillary distribution, which is represented using 1D lines. To allow for solving the microscale cell equations using finite element method, the microvasculature is modified into 3D shapes. The modifications resulted in 15% increment of the microvasculature volume. Validation is then performed by comparing the permeability tensor <span>({varvec{K}})</span> obtained using Poiseuille’s and Stokes’ equations, which resulted in the value of <span>({varvec{K}})</span> obtained through solving Stokes’ equation to be about 70% less than through solving Poiseuille’s equation. Based on these results, the other effective parameters have been estimated by considering the microvasculature volume increment due to the geometry modification. The volume increment significantly affects the parameter <span>({alpha }_{c})</span> but not the other parameters. The effective parameters are then used in a benchmark simulation, which further demonstrates the model value in describing the effects of brain capillary morphology in cerebrovascular diseases.</p></div>","PeriodicalId":477,"journal":{"name":"Archive of Applied Mechanics","volume":"95 10","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00419-025-02954-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256048","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}
Youssef Bassir, Mustapha Fouaidi, Achraf Wahid, Mohammad Jamal
{"title":"Nonlinear transient dynamics of polymer matrix nanocomposite straight beams strengthened with functionally graded graphene oxide powders","authors":"Youssef Bassir, Mustapha Fouaidi, Achraf Wahid, Mohammad Jamal","doi":"10.1007/s00419-025-02955-9","DOIUrl":"10.1007/s00419-025-02955-9","url":null,"abstract":"<div><p>This paper reports on a comprehensive nonlinear transient dynamic analysis of nanocomposite beams reinforced with graphene oxide powders (GOPs) dispersed in a functionally graded (FG) manner within the polymer matrix (PM). The Bernoulli–Euler beam structural model, incorporating von Kármán-type geometric nonlinearities, is adopted for modeling composite beams. The nanocomposite beams’ effective mechanical properties are determined using the modified Halpin–Tsai micromechanical model and the rule of mixture. The nonlinear governing equations of motion are derived using Hamilton’s principle and solved within a numerical framework that combines the finite element method for spatial discretization, the Newton–Raphson method for nonlinear resolution, and the Newmark time integration scheme for temporal discretization. After validating the results by ABAQUS software, parametric investigations are conducted to examine the influence of the GOPs diameter-to-thickness ratio, GOPs weight fraction, and various functionally graded distribution patterns on the nonlinear transient dynamic response of composite beams. The results reveal that an increase in the nanofillers’ geometric dimensions and content significantly enhances stiffness, leading to reduced deflection amplitudes and shorter oscillation periods of the beams. Additionally, among the distribution patterns, the FG-X configuration demonstrates the most favorable dynamic performance, followed by UD, FG-V, and FG-O. These findings offer valuable insights into the nonlinear dynamic characteristics of advanced nanocomposite beams and highlight the potential of FG-GOPs-reinforced PM nanocomposite structures for vibration-critical applications, such as aerospace and mechatronics. This work makes a substantial contribution to the ongoing development of smart materials and nonlinear structural dynamics in engineered systems.</p></div>","PeriodicalId":477,"journal":{"name":"Archive of Applied Mechanics","volume":"95 10","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256155","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":"Final solutions to benchmark engineering optimization problems by cylindrical algebraic decomposition","authors":"Aristotelis E. Charalampakis","doi":"10.1007/s00419-025-02953-x","DOIUrl":"10.1007/s00419-025-02953-x","url":null,"abstract":"<div><p>This study presents a method for determining globally optimal solutions to optimization problems in analytical form. The method is based on the Cylindrical Algebraic Decomposition (CAD) algorithm, in tandem with powerful symbolic computations. Exact solutions are derived for several widely used benchmark engineering optimization problems. These analytical solutions are final in the sense that they are feasible and cannot be improved. Building upon earlier work by Charalampakis and Chatzigiannelis on truss sizing optimization using CAD, the present study extends the methodology to a broader class of benchmark problems. To the best of our knowledge, no previous work has attempted such a general application of CAD-based symbolic optimization. Future advancements in CAD algorithm implementation and computing power may lead to the solution of even more complex problems.</p></div>","PeriodicalId":477,"journal":{"name":"Archive of Applied Mechanics","volume":"95 10","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145210596","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}
Leonardo Rogério da Silva Rodrigues, Dilberto da Silva Almeida Júnior, Isaac Elishakoff
{"title":"Optimal boundary control for the Timoshenko–Ehrenfest truncated model","authors":"Leonardo Rogério da Silva Rodrigues, Dilberto da Silva Almeida Júnior, Isaac Elishakoff","doi":"10.1007/s00419-025-02945-x","DOIUrl":"10.1007/s00419-025-02945-x","url":null,"abstract":"<div><p>In this work, we investigate the optimal control problem associated with a truncated version of the Timoshenko–Ehrenfest beam model, which captures essential features of transverse vibrations in elastic structures. We begin by establishing the well-posedness of the system through the Faedo–Galerkin approximation method, ensuring existence and uniqueness of solutions. The associated optimal control problem is then formulated, and the Pontryagin maximum principle is employed to characterize the optimality conditions. To obtain the analytical solution aiming numerical issues, we apply a Fourier series expansion, which allows for the explicit representation of both the state and the adjoint variables. Finally, we present numerical simulations that demonstrate the efficiency of the proposed control strategy in suppressing unwanted vibrations, confirming the theoretical results and highlighting the practical relevance of the method.</p></div>","PeriodicalId":477,"journal":{"name":"Archive of Applied Mechanics","volume":"95 10","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145210330","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}
Jihua Fan, Junjie Huang, Jie Yan, Haifeng Fang, Qunbiao Wu, Honglin Bai
{"title":"Research on the tension characteristics of a buoy-mooring line system with seabed contact","authors":"Jihua Fan, Junjie Huang, Jie Yan, Haifeng Fang, Qunbiao Wu, Honglin Bai","doi":"10.1007/s00419-025-02951-z","DOIUrl":"10.1007/s00419-025-02951-z","url":null,"abstract":"<div><p>Traditional modeling approaches for mooring lines exhibit limitations in capturing nonlinear behaviors under large displacement and deformation conditions. In this study, a buoy-enhanced mooring line model incorporating seabed contact is developed based on the Absolute Nodal Coordinate Formulation (ANCF). The influence of the buoy on tension characteristics is analyzed to provide insights for the optimization of mooring system design. First, the mass matrix, stiffness matrix, and generalized elastic force vector of the mooring line element are derived based on ANCF. The model incorporates external forces such as Morison’s hydrodynamic load, seabed contact forces, and the buoyancy provided by the added buoy. The dynamic equations of the mooring line are then formulated using the Lagrange multiplier method. Second, the accuracy and efficiency of the proposed model are validated through dynamic simulation case studies involving a flexible coiled beam model, an underwater buoy-mooring line model, a mooring system subjected to irregular wave excitation, and a system under harmonic motion excitation. Finally, the effects of buoy configuration and installation position on both static and dynamic tensions in the mooring line are analyzed. The influence of the buoy on the impact amplification factor and system stability under various harmonic excitations and ocean current conditions is also discussed. Results indicate that appropriate buoy configuration can significantly reduce the tension in the mooring line, mitigate the alternating slackening and tightening phenomena, and thereby enhance overall system stability.</p></div>","PeriodicalId":477,"journal":{"name":"Archive of Applied Mechanics","volume":"95 10","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00419-025-02951-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145210715","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":"Bending and vibration analysis of three-phase bi-directional functionally graded porous sandwich plates","authors":"Thanh-Huan Duong, Van-Long Nguyen, Huu-Quoc Tran, Van-Tham Vu, Minh-Tu Tran","doi":"10.1007/s00419-025-02947-9","DOIUrl":"10.1007/s00419-025-02947-9","url":null,"abstract":"<div><p>This study presents a semi-analytical approach for analyzing the bending and free vibration behavior of three-phase bi-directional functionally graded porous sandwich plates (2D-FGPSW). The sandwich plates considered feature face sheets with biaxial material gradation composed of three distinct constituents and a thickness-varying functionally graded porous core. Such structural configurations are relevant to advanced engineering applications requiring high strength-to-weight ratios and tailored mechanical performance. The analysis is based on Reddy’s third-order shear deformation theory and employs the pb2-Ritz method to obtain accurate solutions under various boundary conditions, with convergence checked through appropriate term selection. The model is validated through comparison with available benchmark solutions. A comprehensive parametric study is conducted to evaluate the effects of material gradation, geometric parameters, sandwich configurations, and boundary conditions on the structural response. The results contribute to a deeper understanding of the mechanical behavior of complex sandwich structures and support the design of efficient and lightweight composite systems.</p></div>","PeriodicalId":477,"journal":{"name":"Archive of Applied Mechanics","volume":"95 10","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145210741","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":"Propagation of unsteady waves in a layered cylinder","authors":"Safarov Ismoil, Teshaev Muhsin, Boltayev Zafar, Eliboyev Nurali","doi":"10.1007/s00419-025-02943-z","DOIUrl":"10.1007/s00419-025-02943-z","url":null,"abstract":"<div><p>The study of nonstationary vibrations and wave propagation in deformable waveguides is of considerable interest in many fields of science and engineering. This work addresses wave processes in extended multilayer cylindrical bodies. The aim of the study is to investigate the problems of wave propagation in an elastic hollow three-layered cylinder and to develop efficient analytical methods for solving the problem of nonstationary wave propagation in layered cylindrical structures. The problem is formulated and solved in a cylindrical coordinate system. Normal (radial) loads are applied at the free boundaries (either inner or outer) of the cylinder. The solution is constructed using the Laplace integral transform with respect to time, followed by its inversion. The solution in the original (time) domain is presented in a form that is convenient for numerical implementation. This formulation makes it possible to analyze wave propagation in a multilayer cylinder with an arbitrary number of coaxial layers. A spectral boundary value problem is derived for a system consisting of ordinary differential equations and partial differential equations, which is reduced to a system of ordinary differential equations with complex coefficients. The solution in the Laplace domain is expressed in terms of modified Bessel and Neumann functions of arbitrary order. The inverse transformation is carried out in a form free from contour integrals and is represented as a rapidly converging double series of cylindrical functions. It is established that, for large wave numbers, the limiting phase velocity of this mode coincides with the Rayleigh wave speed.</p></div>","PeriodicalId":477,"journal":{"name":"Archive of Applied Mechanics","volume":"95 10","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145145401","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}