European Journal of Mechanics A-Solids最新文献

{"title":"Thermal buckling of organic nanobeams resting on viscous elastic foundation","authors":"Pham Van Lieu","doi":"10.1016/j.euromechsol.2024.105455","DOIUrl":"10.1016/j.euromechsol.2024.105455","url":null,"abstract":"<div><div>This study presents an analytical solution for organic solar nanobeams by including the new high-order shear deformation theory and considering the impact of size effects using non-local elasticity theory. The beam is supported by a viscoelastic base and experiences thermal loads that are distributed in accordance with uniform and nonlinear principles. The calculation formulae are derived from the consideration of significant deformations in the beam, resulting in increased complexity of the calculations. The equilibrium equation is derived from the fundamental principle of maximum work potential. The explicit equation for the critical thermal load is derived, providing a convenient means for the calculation and analysis of the impacts of relevant factors. The critical thermal buckling load encompasses both real and imaginary components, with the real component corresponding to the thermal load responsible for inducing beam instability, and the imaginary component associated with the dissipation of this load. This consideration is particularly pertinent when accounting for the foundation resistance. This finding enhances the level of interest in the research outcomes. This study also examined the impact of certain characteristic factors of the foundation and organic beams on the thermal buckling behavior of the beam, establishing a scientific basis for practical design applications.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"109 ","pages":"Article 105455"},"PeriodicalIF":4.4,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0997753824002353/pdfft?md5=38ad219469c6500f614409623d2807d0&pid=1-s2.0-S0997753824002353-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142316273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Study on the energy absorption effect and impact resistance of a composite sandwich panel with carbon fiber reinforced re-entrant hexagonal honeycomb core with negative Poisson's ratio","authors":"Hao Liu ,&nbsp;Dong Li","doi":"10.1016/j.euromechsol.2024.105447","DOIUrl":"10.1016/j.euromechsol.2024.105447","url":null,"abstract":"<div><div>Negative Poisson's ratio (NPR) structures have excellent energy absorption and buffering properties, but they generally have disadvantage of low specific strength, which restricts their wide applications. Therefore, in this study, the carbon fiber reinforced Nylon material (Nylon 12CF) was prepared and used to construct re-entrant hexagonal honeycomb NPR structure. The reinforced (Nylon 12CF) and unreinforced (Nylon 12) specimens were fabricated by 3D printing technology and tested quasi-statically. Then, the quasi-static of the reinforced and unreinforced re-entrant NPR structure and the impact analysis of the composite sandwich panel (CSP) with re-entrant NPR carbon fiber reinforced core are carried out by finite element method. The results show that the NPR structure reinforced with carbon fiber has 112.5% higher failure stress and 113.9% higher energy absorption efficiency than the unreinforced structure. The finite element simulation results are in good agreement with the experimental results. Under the impact load of a 5 kg object with different initial velocities, the maximum of the displacement of the back face sheet's center point of the CSP with reinforced NPR core is smaller than that of CSP with unreinforced NPR core, especially when the impact velocity is 20 m/s. At different initial impact velocities, the CSP of the reinforced NPR structure core all showed high impact resistance, which was about 1.4 times that of the unreinforced NPR structure core. This research provides new ideas for designing more efficient energy-absorbing and impact-resistant structures.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"109 ","pages":"Article 105447"},"PeriodicalIF":4.4,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-helix buckling of a slender compression rod constrained by a cylinder","authors":"Qiang Zhang ,&nbsp;Dong Zhao ,&nbsp;Wei Li ,&nbsp;Yu Zhang ,&nbsp;Shuai Zhao","doi":"10.1016/j.euromechsol.2024.105456","DOIUrl":"10.1016/j.euromechsol.2024.105456","url":null,"abstract":"<div><div>As early as the mid-18th century, Euler proposed a critical load formula for compression rods with multiple half-sine wave modes. However, a critical load formula for compression rods constrained by cylinders with multi-helix buckling modes has not yet been proposed. In this paper, a mechanical model of multi-helix buckling of a slender compression constrained by a cylinder is established. Utilizing the dynamic relaxation method, a finite element solution strategy is presented. Its notable advantage lies in its capability to compute stable configurations of multiple helical buckling, effectively addressing challenges such as contact identification and convergence issues during computation. Furthermore, parameter analysis quantifies the influence of length, diameter, and annular gap on the critical load, while also analyzes the shear force, bending moment, and contact force after buckling. This paper presents formulas for the critical load of multi-helix buckling and the length of the multi-helix buckling modes, which is suitable for various length, diameter, and annular space gap conditions, and partially validates these results against finite element analysis.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"109 ","pages":"Article 105456"},"PeriodicalIF":4.4,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combined extension and torsion of hydrogels with chemo-mechanical coupling: Revealing positive poynting effect","authors":"Chengxiang Zheng ,&nbsp;Minghui Hu ,&nbsp;Wenyi Wang ,&nbsp;Qian Li ,&nbsp;Pasquale Ciarletta ,&nbsp;Tao Wu ,&nbsp;Zichen Deng","doi":"10.1016/j.euromechsol.2024.105453","DOIUrl":"10.1016/j.euromechsol.2024.105453","url":null,"abstract":"<div><div>In this paper, combined extension and torsion of hydrogel subject to a chemo-mechanical coupled loading is described in the framework of continuum mechanics, where the free energy density consists of the elastic, mixing and chemical contributions. A simplified, closed-form and exactly analytical solution to the mechanical response is obtained, which accounts for the coupling effect of external loading, chemical potential and microstructural parameters, such as crosslinking degree, Flory-Huggins parameter, etc. In particular, the effect of free swelling and microscopic diffusion on deformation of the hydrogel at equilibrium state is discussed, reaching some fundamental conclusions. Negative axial forces are captured, revealing the typical positive Poynting effect where the cylinder tends to elongate on twisting, and an inhomogeneous deformation, induced by torsion, along the radial direction is demonstrated. Furthermore, the dynamic competition between external loading and solvent environment is revealed and investigated, where the direct connection between internal micro-physical parameters and macroscopic deformation is demonstrated. The theoretical results presented in this paper may provide predictions and guidance for the mechanical analysis and design of hydrogel cylinder subject to extension and torsion in a solvent.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"109 ","pages":"Article 105453"},"PeriodicalIF":4.4,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid assessment of seismic performance of large monopile-supported offshore wind turbines under scour","authors":"Baran Bozyigit ,&nbsp;Irem Bozyigit ,&nbsp;Luke J. Prendergast","doi":"10.1016/j.euromechsol.2024.105451","DOIUrl":"10.1016/j.euromechsol.2024.105451","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This study focuses on investigating the seismic performance of a reference 15 MW offshore wind turbine (OWT) supported by a large-diameter monopile, under various scour conditions. Fully coupled nonlinear finite element models considering 3D soil continuum for seismic response analysis of monopile-supported OWTs are very complicated and computationally expensive. Therefore, it is important to have good insight on the dynamic behaviour of monopile-supported OWTs subjected to earthquake excitations before performing high-fidelity fully nonlinear 3D simulations, which will not generally be practical in cases considering various seismic loading and scouring scenarios. The purpose of this study is to provide a fast and efficient tool to understand the interaction between the seismic behaviour of emerging large-capacity OWTs when scour erosion affects the dynamic properties of the structure. The dynamic stiffness method (DSM) is applied for the free vibration analysis of the structure. Modal superposition is used to calculate the seismic responses of the OWT by using the exact mode shapes obtained from the dynamic stiffness formulations. The rotor-nacelle-assembly (RNA) is idealized as a lumped mass at the tower top. The tower and monopile are modelled as Timoshenko beam-columns under axial compressive loading. The soil-structure interaction (SSI) is modelled using the Winkler framework, whereby the soil contribution is assumed as elastic to take advantage of the modal superposition method. Two different approaches are considered for the soil stiffness; a constant profile, and a linearly-varying subgrade modulus along the embedded depth of the pile, and both are appraised in this paper. Firstly, natural frequencies obtained from dynamic stiffness formulations are validated using experimental data from literature for the case of controlled dynamic SSI experiments, and for operating OWTs. Additionally, the natural frequency provided by a technical document for the reference 15 MW OWT is compared to the result from the DSM, where a very good agreement is observed. The seismic response time-histories of the OWT model are obtained under different input earthquake conditions, and subsequently verified by comparison with the results of finite element simulations. The effects of different scour scenarios and foundation modelling approaches on the free vibration and seismic responses are subsequently investigated. A parametric analysis is also performed using different soil properties to observe the interaction between the soil stiffness, scour condition, and seismic response. Finally, the influence of the frequency content of seismic records on the dynamic response of the OWT, specifically the tower top acceleration, the mudline rotation, and the mudline stress, is investigated considering various scour scenarios. The specific numerical case study undertaken for a reference 15 MW OWT, which is supported by a large monopile in very dense sand, shows t","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"109 ","pages":"Article 105451"},"PeriodicalIF":4.4,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0997753824002316/pdfft?md5=c600ff7890f101e67bfe2e453e8cb998&pid=1-s2.0-S0997753824002316-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Localization of shear waves in cubic piezoelectric structure stratified with periodically arranged metallized interfaces","authors":"K. Ghazaryan ,&nbsp;D. Piliposyan ,&nbsp;S. Jilavyan ,&nbsp;G. Piliposian","doi":"10.1016/j.euromechsol.2024.105448","DOIUrl":"10.1016/j.euromechsol.2024.105448","url":null,"abstract":"<div><div>Electro-elastic guided waves in a supperlattice waveguide with a finite number of unit cells made of cubic piezoelectric material and subjected to coupled elastic anti-plane deformation and in-plane electric field are studied. Shear wave localization is discussed in a structure consisting of layers made of the same piezoelectric material of cubic symmetry, separated by periodically arranged metalized electrodes inserted parallel to the waveguide faces. It is shown that due to electrodes screening the quasistatic electric field shear elastic wave localization occurs if the electrodes are placed non-uniformly within the unit cell of the waveguide. In a finite thickness waveguide localization takes place only at some forbidden frequencies within an infinite waveguide band gaps. Localization of waves in semi-infinite waveguide is also considered. The results of the paper can be used in designing narrow band filters or multi-channel piezoelectric filters.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"109 ","pages":"Article 105448"},"PeriodicalIF":4.4,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0997753824002286/pdfft?md5=88e4facd298c67e3be20524197ae130a&pid=1-s2.0-S0997753824002286-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Methodology for the thermoelastic stress analysis of complex biomimetic structures: An alligator mandible case study","authors":"Joshua Rodrigues ,&nbsp;Raj Das ,&nbsp;Simon Barter ,&nbsp;Matthew Pelosi ,&nbsp;Wayne Foster","doi":"10.1016/j.euromechsol.2024.105450","DOIUrl":"10.1016/j.euromechsol.2024.105450","url":null,"abstract":"<div><div>Biomimetic designs that take inspiration from natural structures provide a unique approach to identifying innovative solutions to engineering problems. The experimental analysis of such structures, however, can be difficult due to complex, three-dimensional geometric features. This study presents a methodology for the analysis of complex biomimetic structures using thermoelastic stress analysis (TSA) illustrated through an alligator mandible case study. This structure has evolved to become optimal for its function and environment which has resulted in unique and intricate features. An additively manufactured alligator mandible structure was experimentally analysed using TSA under bending load conditions and compared to a finite element (FE) solution. TSA was found to be a suitable method for the qualitative and quantitative analysis of the complex biomimetic structure which correlated well with the FE model. This study demonstrates the accuracy of TSA for the assessment of biomimetic designs with unique, arbitrary geometric features that can be utilised for future nature-inspired engineering applications.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"109 ","pages":"Article 105450"},"PeriodicalIF":4.4,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0997753824002304/pdfft?md5=a61e7911471f01fdace5dbd4fa2e511e&pid=1-s2.0-S0997753824002304-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Multiphysics analysis of mechanical responses in micro-reactors under varied operating conditions","authors":"M. Anjum ,&nbsp;T. Gibson ,&nbsp;G.T. Craven ,&nbsp;S. Tretiak ,&nbsp;A. Abdelkefi","doi":"10.1016/j.euromechsol.2024.105452","DOIUrl":"10.1016/j.euromechsol.2024.105452","url":null,"abstract":"<div><div>Micro-reactors are a promising alternative for power production applications where traditional methods may not be feasible (e.g., space missions). Their design requires critical selection of materials, especially for moderator and fuel, to ensure long-term operation and optimal performance. This research focuses on developing computational analysis models for micro-reactors, aiming to explore their structural behavior under thermal and mechanical loadings. The micro-reactor model is based on the Zero Energy Breeder Reactor Assembly (Zebra) Kilowatt (kW) reactor design conceptualized at Los Alamos National Laboratory. This study investigates the thermal and mechanical responses of three distinct reactor models considering factors, such as boundary conditions, material properties, and thermal-mechanical loading. In this study, Beryllium Oxide (BeO), Beryllium (Be), Aluminum Oxide (Al₂O₃), and Magnesium Oxide (MgO) are chosen as materials for the reflector. Yttrium Hydride (YH) and Zirconium Hydride (ZH) are chosen as moderators. Uranium Nitride (UN) and Uranium Molybdenum (UMo) are chosen as reactor fuel materials. The thermal analysis predicts the deformation due to the thermal expansion within the reactor under steady operating conditions at 25 kW_th, mimicking the maximum rated power of the Zebra kW design. The mechanical study simulates the system's response to forced vibration loads applied along the cooling channels, matching the natural frequency of the system. The results from both analyses show that Beryllium Oxide, Yttrium Hydride, and Uranium Nitride demonstrate the most optimal stress distribution in the system compared to other configurations investigated here. The results of this study can be developed into datasets to facilitate future machine learning studies, enabling the prediction of mechanical and thermal responses for micro-reactors.</div></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"109 ","pages":"Article 105452"},"PeriodicalIF":4.4,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0997753824002328/pdfft?md5=308bcd232b80b9b0736bc967e5d905d9&pid=1-s2.0-S0997753824002328-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Dynamic response of novel sandwich structures with 3D sinusoid-parallel-hybrid honeycomb auxetic cores: The cores based on negative Poisson's ratio of elastic jump","authors":"Yang Yu,&nbsp;Tao Fu,&nbsp;Sen Wang,&nbsp;Chao Yang","doi":"10.1016/j.euromechsol.2024.105449","DOIUrl":"10.1016/j.euromechsol.2024.105449","url":null,"abstract":"<div><p>The design of three-dimensional (3D) honeycomb structure has been widely concerned in recent years. In this paper, the traditional hexagonal honeycomb structure and the concave circular-arc honeycomb structure were combined by the parallel method, and a 3D sinusoid-parallel-hybrid honeycomb (SPHH) structure based on the negative Poisson's ratio of elastic jump was designed. The mechanical analysis of the 3D honeycomb structure was conducted through the utilization of the finite element modeling (FEM) in conjunction with an experimental platform, and the study focused on analyzing the dynamic response of honeycomb sandwich panels subjected to low-speed impacts. The experimental results agreed well with the FEM results. By comparing the concave-parallel-hybrid honeycomb (CPHH) structure, the arc-parallel-hybrid honeycomb (APHH) structure, the SPHH structure has better mechanical properties, and the SPHH sandwich panel has better energy absorption and impact resistance characteristics. The energy absorption properties and shock resistance of the SPHH sandwich panels can be improved by adding the parameter <em>t</em>₃ and honeycomb cell filling, and the rigidity of the SPHH panel can be improved better. At a shock load of 10 J, the increase of arc radius <em>R</em> doesn't obviously influence for dynamic response of the SPHH panel structure, but at a shock load of 25 J, different arc radius significantly affects the energy absorption and shock resistance properties of the SPHH sandwich panels. It can improve the energy absorption characteristics and shock resistance by increasing the arc radius of the SPHH honeycomb cell.</p></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"109 ","pages":"Article 105449"},"PeriodicalIF":4.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0997753824002298/pdfft?md5=4a3a9b2f732a6cb7661fbef92d2554bb&pid=1-s2.0-S0997753824002298-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142240161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Semi-analytical layerwise solutions for FG MEE complex shell structures","authors":"J.C. Monge ,&nbsp;J.L. Mantari","doi":"10.1016/j.euromechsol.2024.105446","DOIUrl":"10.1016/j.euromechsol.2024.105446","url":null,"abstract":"<div><p>This paper presents a unique analytical layerwise solution for functionally graded magneto-electric-elastic shell with complex geometry. The middle surface of the shell is modeled by a parametric equation and the Lamé parameter and radii of curvature is modeled by Differential Geometry. The mechanical displacements, electrical and magnetic potentials are written in term of a simple cosine layerwise based on a unified formulation. The highly coupled differential equations are discretized by the Chebyshev-Gauss-Lobatto grid points and solved numerically via the Differential Quadrature Method (DQM). Lagrange interpolation polynomials are employed as the basis functions. The highly coupled differential equations are solved for shells subjected to different loads and boundary conditions. Since extremely few results on this topic is available in the literature, benchmarks complex shell problems and their solutions are introduced in this paper for the very first time.</p></div>","PeriodicalId":50483,"journal":{"name":"European Journal of Mechanics A-Solids","volume":"109 ","pages":"Article 105446"},"PeriodicalIF":4.4,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0997753824002262/pdfft?md5=d680ca8e8539b5eb3766518683e9b55c&pid=1-s2.0-S0997753824002262-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142240162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}