International Journal of Non-Linear Mechanics最新文献

{"title":"Hyperelasticity: Lennard-Jones potentials","authors":"S.V. Kuznetsov","doi":"10.1016/j.ijnonlinmec.2025.105014","DOIUrl":"10.1016/j.ijnonlinmec.2025.105014","url":null,"abstract":"<div><div>A set of the modified Lennard-Jones potentials used for modeling 1D hyperelasticity ensuring (i) positive definiteness of the tangent elastic modulus; (ii) a natural state at zero strain; and, (iii) negative stress at negative strain and vice versa. With these conditions the constructed set of the modified Lennard-Jones potentials allow modeling a broad range of elastic stress-strain states at both static and dynamic loadings. It has also been found that the considered potentials when applied to the problem of acoustic wave propagation, lead to the appearance of shock wave fronts, similar to those observed in bi-modular media with discontinuous elastic moduli.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"170 ","pages":"Article 105014"},"PeriodicalIF":2.8,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136482","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 shear creep test and nonlinear model of granite structural plane under coupled freeze-thaw cycle and chemical corrosion","authors":"Fengrui Zhang ,&nbsp;Wei Yin ,&nbsp;Kun Zhang ,&nbsp;Haopeng Jiang","doi":"10.1016/j.ijnonlinmec.2024.105012","DOIUrl":"10.1016/j.ijnonlinmec.2024.105012","url":null,"abstract":"&lt;div&gt;&lt;div&gt;To investigate the combined effect of freeze-thaw cycles and chemical corrosion on the shear creep characteristics of rock structural planes in cold regions, taking the granite structural planes of Huibai Tunnel in Jilin Province as the research object, microscopic structural observation and shear creep test were carried out on the structural surfaces treated by acidic, neutral and alkaline solution immersion and freeze-thaw cycles, analyzed the damage characteristics and creep mechanism of structural planes. The results show that: (1) With the increase of freeze-thaw and chemical corrosion, the structural plane of the mineral particles significantly reduced, the structural plane shows phenomena such as dissolution and hydrolysis, and the surface is gradually smoothed. (2) Compared with the natural condition, the instantaneous deformation of the samples under 20, 40, and 60 freeze-thaw cycles in H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; solution increased by 47.43%, 64.52%, and 128.57%, the creep deformation increased by 36.58%, 53.68%, and 107.31%, and the instantaneous shear modulus decreased by 25.34%, 40.31%, and 64.35%. The instantaneous deformation, creep deformation and creep rate of the structural plane gradually increase with the increase of freeze-thaw and chemical corrosion, while the instantaneous shear modulus and long-term shear strength show a decreasing trend. (3) Compared with the natural condition, the instantaneous deformation of the samples in H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;, NaOH and NaCl solutions increased by 128.57%, 68.29% and 85.36% respectively under 60 freeze-thaw cycles, the creep deformation increased by 107.31%, 62.52% and 76.88% respectively, and the instantaneous shear modulus decreased by 64.35%, 50.31% and 56.54% respectively. The acidic H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; solution has the greatest impact on the damage and creep parameters of the structural planes, followed by NaOH solution, with NaCl solution causing the least damage. Furthermore, in the damage process of structural planes, the freeze-thaw cycle and chemical corrosion promote each other mutually, since the combined influence of two-factor on damage and creep characteristics are greater than the influence of single factor. Based on the experimental results, considering the influence of freeze-thaw and chemical corrosion on model parameters, a nonlinear viscous element was introduced to describe the accelerated creep characteristics, the shear creep damage model of structural plane was established, and the reasonableness of the model was verified through test data. Finally, the three-dimensional roughness &lt;em&gt;JRC&lt;/em&gt;&lt;sup&gt;&lt;em&gt;3D&lt;/em&gt;&lt;/sup&gt; of the structural plane was selected as the evaluation index, and the influence of the three-dimensional roughness &lt;em&gt;JRC&lt;/em&gt;&lt;sup&gt;&lt;em&gt;3D&lt;/em&gt;&lt;/sup&gt; on the shear creep mechanical properties of the structural plane was discussed. The research results have guiding significance for the long-term stability evaluation of rock mass","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"170 ","pages":"Article 105012"},"PeriodicalIF":2.8,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137294","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":"Stability analysis of middle ear dynamic system after incudus joint repair under intense stimuli","authors":"Liang Wang ,&nbsp;Zhanli Liu ,&nbsp;Yongtao Sun ,&nbsp;Jie Wang ,&nbsp;Yueting Zhu ,&nbsp;Hongge Han ,&nbsp;Shuyi Xiang ,&nbsp;Qian Ding","doi":"10.1016/j.ijnonlinmec.2024.105011","DOIUrl":"10.1016/j.ijnonlinmec.2024.105011","url":null,"abstract":"<div><div>High intensity noise levels can lead to dislocation in the ossicular chain, particularly at the incus and the incudostapedial joint, significantly impacting hearing ability. However, the sensitivity of the middle ear system following ossicular chain restoration to intense external stimuli and the reconstructed material's nonlinear characteristics are still poorly understood. In order to investigate these aspects, a multi-degree-of-freedom mechanical model is developed on healthy and pathological ossicular chain reconstructions. Firstly, implant material parameters are determined by analyzing the natural frequencies of the system in an undamped condition. Secondly, the dynamic characteristics of the middle ear system are examined under various external excitations. Thirdly, utilizing a multi-time scale method, an approximate solution is derived for near-resonant frequency systems. Finally, the periodic solution stability is analyzed and assess how reconstructed middle ear parameters influence it. It is important to note that in healthy patients, post-ossicular chain reduction should be maintained in-ear sound pressure below 95 dB SPL, while for patients with pathology reconstruction, it should be kept below 65 dB SPL.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"171 ","pages":"Article 105011"},"PeriodicalIF":2.8,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172061","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":"Scattering of anti-plane surface wave due to irregularity in hyperelastic imperfectly bonded bi-material structure","authors":"Md Hasanuzzaman ,&nbsp;Santan Kumar ,&nbsp;Richa Kumari","doi":"10.1016/j.ijnonlinmec.2024.105004","DOIUrl":"10.1016/j.ijnonlinmec.2024.105004","url":null,"abstract":"<div><div>The crux of this work is to investigate the scattering phenomena of Love-type wave due to irregularity on the upper surface of a layered structure. This structure basically incorporates two unlike nearly incompressible elastic materials which are bonded to each other imperfectly at the common interface between layer and half-space. The imperfect interface is described by linear spring model. The analytical methods which are applied, in order to derive the solution of displacement components and obtain the dispersion relations of Love-type wave, include variable separable method and substitution method along with perturbation technique. The dispersion relations and the expressions of displacement components of Love-type wave are obtained for both the incident and the scattered wave fields. Further, the expressions of reflected displacement fields of Love-type wave for distinct cases of irregularity, viz., rectangular shaped, parabolic shaped and triangular shaped irregularities, at the free surface are also determined. The derived results of dispersion relations and reflected displacement fields of Love-type wave, as particular case, concur well with the results existing in the literature. By means of numerical simulation, the influences of irregularity shapes and involved parameters, viz., irregularity depth, irregularity width and imperfect bonding parameter, on reflected displacement field of Love-type wave are manifested graphically. The impacts of imperfect bonding parameter and wave number on phase velocity of Love-type wave are also depicted. The computational results signify the substantial effects of irregularity at the free surface and imperfectness at the interface on the characteristics of Love-type wave in the considered nearly incompressible elastic structure. The reported results of the study may play pivotal role in the realm of civil, mechanical and earthquake engineering for the purpose of vibration isolation, shock absorber, flex-joints, engine mounts, and so forth.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"170 ","pages":"Article 105004"},"PeriodicalIF":2.8,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136485","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 vibration analysis of a fluid-conveying pipe under harmonic excitation with elastic boundary constraints","authors":"Yuanfeng Wu ,&nbsp;Enwei Chen ,&nbsp;Zhiwei Ruan ,&nbsp;Panpan Zhang ,&nbsp;Pin Chen ,&nbsp;Yimin Lu","doi":"10.1016/j.ijnonlinmec.2024.104981","DOIUrl":"10.1016/j.ijnonlinmec.2024.104981","url":null,"abstract":"<div><div>Fluid-conveying pipes are extensively used in practical engineering in various industries and play an important role in industry and daily life. Under complicated working conditions, inevitable vibrations affect the stability and integrity of these pipes, drawing significant academic attention. Typically, the dynamic modeling of these pipes considers ideal rigid boundary conditions, including fixed support, simply support, and cantilever pipes, ignoring the effects of boundary elasticity. This paper investigates the effects of boundary elasticity on the harmonic excitation responses in sub-critical and super-critical regimes. The governing equations and boundary conditions are derived via the extended Hamilton's principle. Later, the non-trivial equilibrium configuration is analytically deduced, and the governing equations for fluid-conveying pipes with elastic supports are discretized into a set of nonlinear ordinary differential equations using the Galerkin method. The harmonic balance method (HBM) is employed to solve these differential equations, with its accuracy validated against the Runge-Kutta method. Finally, numerical examples are conducted in sub-critical and super-critical regimes to show the effects of boundary vertical stiffness, torsional stiffness, fluid velocity, and excitation on solution stability, natural frequencies, and amplitude of the steady-state response at the middle point. This paper provides important guidance for the design of boundary elasticity in sub-critical and sup-critical fluid-conveying pipes.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"170 ","pages":"Article 104981"},"PeriodicalIF":2.8,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136694","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":"Unveiling memory-driven dynamics: Fractional calculus and microswimmer trajectories in 1D shear flow","authors":"Elhoussine Azroul,&nbsp;Ghizlane Diki","doi":"10.1016/j.ijnonlinmec.2024.105005","DOIUrl":"10.1016/j.ijnonlinmec.2024.105005","url":null,"abstract":"<div><div>This study investigates the captivating dynamics of spherical microswimmers in a 1D shear flow, revealing the intricate interplay between memory effects and fluid mechanics through the lens of fractional calculus. By deriving exact solutions for the orientation and trajectory of these microswimmers, we uncover a rich tapestry of motion patterns that challenge traditional models. Our findings not only enhance the theoretical understanding of microswimmer behavior but also hold significant implications for practical applications in biophysics and targeted drug delivery. This research underscores the power of fractional calculus as a transformative tool in unraveling the complexities of biological systems, paving the way for innovative approaches in the study of fluid dynamics.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"170 ","pages":"Article 105005"},"PeriodicalIF":2.8,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136484","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":"Simulation of 3D turbulent flows using a discretized generative model physics-informed neural networks","authors":"Amirhossein Khademi ,&nbsp;Erfan Salari ,&nbsp;Steven Dufour","doi":"10.1016/j.ijnonlinmec.2024.104988","DOIUrl":"10.1016/j.ijnonlinmec.2024.104988","url":null,"abstract":"<div><div>Physics-informed neural networks (PINNs) demonstrated efficacy in approximating partial differential equations (PDEs). However, challenges arise when dealing with high-dimensional PDEs, particularly when characterized by nonlinear and chaotic behavior, such as turbulent fluid flows. We introduce a novel methodology that integrates domain discretization, a generative model in the Sobolev function space (<span><math><msup><mrow><mi>H</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span>), and a gating mechanism to effectively simulate high dimensional problems. The effectiveness of the method, Discretized Generative Model Physics-Informed Neural Networks (DG-PINN), is validated by its application to the simulation of a time-dependent 3D turbulent channel flow governed by the incompressible Navier–Stokes equations, a less explored problem in the existing literature. Domain discretization prevents error propagation by using different neural network models in different subdomains. The absence of initial conditions (IC) in subsequent time steps presents a challenge in identifying optimal network parameters. To address this, discretized generative models are used, improving the model’s overall performance. The global solutions’ regularity is enhanced compared to previous decomposition techniques by using the <span><math><msup><mrow><mi>H</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span> norm of error, rather than <span><math><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>. The effectiveness of the DG-PINN is validated through numerical test cases and compared against baseline PINNs and traditional domain decomposition PINNs. The DG-PINN demonstrates improvement in both approximation accuracy and computational efficiency, consistently maintaining accuracy even at later time instances. Moreover, the implementation of a distributed training strategy, facilitated by domain discretization, is discussed, resulting in improved convergence rates and more optimized memory usage.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"170 ","pages":"Article 104988"},"PeriodicalIF":2.8,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136698","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":"Data-driven structural identification of nonlinear assemblies: Uncertainty Quantification","authors":"Sina Safari ,&nbsp;Diogo Montalvão ,&nbsp;Julián M. Londoño Monsalve","doi":"10.1016/j.ijnonlinmec.2024.105002","DOIUrl":"10.1016/j.ijnonlinmec.2024.105002","url":null,"abstract":"<div><div>Nonlinear model identification from vibration data is challenging due to limited measured data collected during the testing campaign and since the identified model should be capable of accounting for the uncertainties arising from the reassembly of the structure, environmental effects, and slight changes in parameters as a result of wear during vibration testing. In this paper, a new technique based on ensembling is proposed for uncertainty quantification during the identification of nonlinear assemblies using multiple data sets. First, an ensemble of parsimonious models is identified using a physics-informed nonlinear model identification method from subsets of measured data. Aggregate model statistics are then employed to calculate inclusion probabilities for the candidate model, which enable uncertainty quantification and a probabilistic estimate of the dynamic response. This results in a robust nonlinear model identification with physical interoperability. An application on a single-degree-of-freedom system idealised for an experimental structure with geometric and friction nonlinearities is presented. The results obtained demonstrate the substantial performance of the proposed technique in selecting accurate nonlinear models that capture the response over a large range of variability and repeatability for real-world data sets.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"170 ","pages":"Article 105002"},"PeriodicalIF":2.8,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136481","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":"ML-based bevel gearbox fault diagnosis: An extensive time domain feature extraction approach with limited data","authors":"Sanjeev Kumar ,&nbsp;Om Prakash Singh ,&nbsp;Vikash Kumar ,&nbsp;Somnath Sarangi","doi":"10.1016/j.ijnonlinmec.2024.105003","DOIUrl":"10.1016/j.ijnonlinmec.2024.105003","url":null,"abstract":"<div><div>Data-driven based gear box fault diagnosis is one of the efficient approach as the gear drive train is highly nonlinear parametrically excited system. The data driven approach is solely dependent on the quality of the data acquired from the physical system. These data are direction-sensitive and carry different information depending on the state of the gearbox. In the literature, mostly one-directional data and their traditional time-domain feature matrix are utilized for gearbox fault diagnosis. The proposed work presents for the first time the effect of multi-directional data with a unique technique for data preparation based on various concatenation approaches. Along with this, the fifty extensive time domain features are extracted and fed to three different feature selection (FS) techniques and five popular machine learning (ML)-classifiers for fault diagnosis purposes. An experimental set-up with a bevel gearbox under different fault conditions was used to acquire the vibration signal data using a tri-axial accelerometer. The paper studies the three cases of data preparation: case 1: single-directional data at a time; case 2: horizontal concatenation of multi-directional data at a time; and case 3: vertical concatenation of multi-directional data at a time for gearbox fault diagnosis. Results show that overall, case 3 performed well and gave improved accuracy under different FS techniques and ML-classifiers as compared to cases 1 and 2.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"170 ","pages":"Article 105003"},"PeriodicalIF":2.8,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136480","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 general framework for symplectic geometric integration for stochastically excited Hamiltonian systems on manifolds","authors":"Satyam Panda ,&nbsp;Souvik Chakraborty ,&nbsp;Budhaditya Hazra","doi":"10.1016/j.ijnonlinmec.2024.105001","DOIUrl":"10.1016/j.ijnonlinmec.2024.105001","url":null,"abstract":"<div><div>This work introduces a new integration scheme in the field of Stochastic Geometric Integration on Manifolds, dedicated to precise modeling of real-world dynamic phenomena characterized by inherent randomness. Conventional numerical techniques often encounter difficulties when confronted with uncertainty and the preservation of manifold geometry, consequently leading to inaccuracies. In response to these challenges, the method proposed considers geometric precision, stochastic dynamics, and symplecticity all-together. Drawing inspiration from methods based on Lie groups, this work formulates a framework that can adapt to stochastic systems, aligning itself with the principles of geometric stochastic differential equations. By incorporating higher-order geometric integration schemes possessing inherent symplectic properties, the study achieves accurate solutions that simultaneously retain intricate system geometry, maintain symplecticity, and accommodate inherent randomness. The method maintains its general flavor by virtue of a completely intrinsic formulation which can be adopted to broad class of manifolds rather than a specific one. Through numerous representative benchmarks, the study substantiates the effectiveness of the proposed scheme. The results demonstrate a significant enhancement in the numerical scheme’s performance, owing to its utilization of the inherent symplectic nature.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"170 ","pages":"Article 105001"},"PeriodicalIF":2.8,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136479","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}