International Journal of Non-Linear Mechanics最新文献

{"title":"Dynamics of constrained mechanical systems around an equilibrium position","authors":"S. Natsiavas,&nbsp;C. Georgiadis,&nbsp;L. Papapostolou","doi":"10.1016/j.ijnonlinmec.2025.105088","DOIUrl":"10.1016/j.ijnonlinmec.2025.105088","url":null,"abstract":"<div><div>This study focuses on a special class of multibody dynamic systems, involving bilateral motion constraints. Specifically, both the equations of motion and the equations of the motion constraints appear in a linear equality form. First, following an appropriate Analytical Dynamics approach, the dominant dynamics of the systems examined is eventually represented by a coupled set of second order linear ordinary differential equations for both the system coordinates and the Lagrange multipliers corresponding to the motion constraints. This allows a thorough investigation of the dynamics, based on classical linear procedures. For this, the structure of the corresponding undamped eigenvalue problem is revealed first in a complete form. This opens the way to determine the response of the undamped system by applying an appropriate modal analysis technique. Next, damping terms leading to classical modes of vibration are also included in the governing equations and their effects are studied in detail. Finally, the analytical results are complemented and illustrated further by considering a typical set of mechanical examples. Besides predicting the dynamics of linear constrained systems, the new methodology provides a strong basis for investigating in depth several related theoretical and technical issues, like the stability properties of equilibrium solutions of mechanical systems or of numerical schemes applied to the solution of multibody systems with nonlinear characteristics.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"174 ","pages":"Article 105088"},"PeriodicalIF":2.8,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684758","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":"Hybrid piezoelectric-electromagnetic energy harvesting from limit cycle oscillation of the wing","authors":"Yun Cheng ,&nbsp;Daochun Li ,&nbsp;Tiejun Zhang","doi":"10.1016/j.ijnonlinmec.2025.105082","DOIUrl":"10.1016/j.ijnonlinmec.2025.105082","url":null,"abstract":"<div><div>As a nonlinear aeroelastic phenomenon, limit cycle oscillation (LCO) of the wing has the potential to supply continuous electrical power output through energy harvesting. In this paper, a basic wing-store structure with hybrid piezoelectric-electromagnetic energy harvesters is proposed to harvest the mechanical energy from bending-torsional coupling LCO response. The nonlinear structure model, the unsteady aerodynamic model and the hybrid energy harvesting model are built and form a piezoelectric-electromagnetic-aeroelastic state-space model. Results show that the extra store at the wingtip can alter the flutter speed and the frequency of the wing. It means that the wing store can lead to LCO response with a higher flutter frequency at lower wind speed. Changing the parameters of the structure and energy harvesting systems can change the intensities and the wind speed range that result in LCO response of the wing. The above features can impact the applicability and electrical power output of the energy harvesting systems. The additional electromagnetic energy harvester can further improve the overall energy conversion efficiency. The details of these effects are demonstrated and the methods for optimizing electric outputs are discussed.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"174 ","pages":"Article 105082"},"PeriodicalIF":2.8,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684756","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":"Responses of any arbitrary initially stressed reference and the stress-free reference","authors":"Soumya Mukherjee","doi":"10.1016/j.ijnonlinmec.2025.105070","DOIUrl":"10.1016/j.ijnonlinmec.2025.105070","url":null,"abstract":"<div><div>The constitutive relation for an initially stressed reference is often determined by using the response of a virtual stress-free reference. However, identifying the constitutive relation of the original stress-free body can be challenging without conducting destructive tests. This paper presents three approaches for determining the response of a stress-free reference—or any arbitrary initially stressed reference—when the response of a particular initially stressed reference is known. Unlike standard practice, these approaches of changing reference configurations do not begin with a known stress-free state. The first and third approaches directly derive the constitutive relations of one stressed reference from another. The first approach is applicable to a specific constitutive relation of the known initially stressed state, while the third approach extends the first and is applicable to any constitutive form. The second approach uses any general response of a given stressed reference to identify the stress-free material. The response of the stress-free material is further analyzed and processed to determine the response of any stressed reference. We observe that even when the known initially stressed state is Green elastic, the arbitrarily stressed or stress-free references may exhibit implicit elasticity. Several explicit constitutive relations are also exemplified. One of the examples utilizes the invariants of Seth’s generalized strain measures. For experimental validation of this model, we transform the Treloar data to various initially stressed references. Model parameters corresponding to a specific stressed state are optimized by corroborating the model against the Treloar data associated with that reference. These optimized parameters are then used to determine the constitutive relations for the stress-free and other stressed reference configurations. The resulting constitutive relations for various references show identical alignment with the corresponding Treloar data, thereby validating the present approaches for changing the reference configuration. It is demonstrated that the developed models satisfy all restrictions related to the change of references. Furthermore, we develop universal relations for stress-free isotropic implicit elastic materials.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"174 ","pages":"Article 105070"},"PeriodicalIF":2.8,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610573","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":"An improved constitutive model for the rate-dependent mechanical behaviour of rubbery materials","authors":"Bijuan Yan ,&nbsp;Guansen Qiao ,&nbsp;Yihang Geng ,&nbsp;Zhangda Zhao ,&nbsp;Tao Yang","doi":"10.1016/j.ijnonlinmec.2025.105077","DOIUrl":"10.1016/j.ijnonlinmec.2025.105077","url":null,"abstract":"<div><div>In order to accurately predict the mechanical behaviour of fluororubber and silicone rubber under different strain rates, an improved model based on the existing strain rate-dependent viscoelastic constitutive models is proposed in this article. Firstly, a strain rate-dependent variable-order fractional model is established. Then, the method of combining theory and experiment is adopted to explore the influence of the key parameters on prediction accuracy. Following this, the relaxation time is found to be the key factor affecting the accuracy of the predicted results of the mechanical properties through the analyses. Finally, the model is improved by replacing the relaxation time with the viscoelastic coefficient. The results show that the relative errors of the stress prediction results are within 3% for silicone rubber and reduced by 1.7%–4.5% for fluororubber. These findings can provide theoretical references and support for the analysis of the mechanical properties of the similar types of viscoelastic materials.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"174 ","pages":"Article 105077"},"PeriodicalIF":2.8,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619526","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":"Analytical study of the elastoplastic buckling of conical shells under external pressure","authors":"Gwladys Belone ,&nbsp;Van Dong Do ,&nbsp;Philippe Le Grognec ,&nbsp;Philippe Rohart ,&nbsp;Samir Assaf","doi":"10.1016/j.ijnonlinmec.2025.105069","DOIUrl":"10.1016/j.ijnonlinmec.2025.105069","url":null,"abstract":"<div><div>Pressure vessels are traditionally made up of cylindrical shells and hemispherical or ellipsoidal ends, but in some cases, conical sections are also present so as to ensure the transition between cylindrical sections of different radii. The buckling phenomenon is one of the main failure mode of such pressure equipments, due to the thinness of the components and the compressive stresses commonly undergone throughout standard loads like external pressure, and thus an essential dimensioning factor. If the buckling behavior of cylindrical and spherical shells has been widely investigated in the literature, the specific case of conical shells has received much less attention, all the more so in plasticity. Therefore, the present paper aims to address the problem of elastoplastic buckling of a conical shell under external pressure in an analytical way. This study is based on the plastic bifurcation theory and relies on the simplest possible hypotheses in terms of kinematics, constitutive law and boundary conditions. However, in absence of closed-form expressions, approximate solutions for the critical pressure are sought, based on the choice of appropriate shape functions in the framework of the Rayleigh–Ritz method. Unlike the case of cylindrical or spherical shells under external pressure which display uniform pre-critical stress states, the stress field appears to be heterogeneous in the length direction of a conical shell, so that three scenarios may occur. A conical shell may buckle elastically, entirely in the plastic range, or in an intermediate situation where the shell is partially elastic and plastic at the critical time. The present analytical solution is validated against reference numerical results obtained through finite element computations, considering a wide range of geometric and material parameters so as to cover all three scenarios.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"174 ","pages":"Article 105069"},"PeriodicalIF":2.8,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643558","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 the dynamics of particle-reinforced electro-magneto-active circular membrane","authors":"Ankush Agrawal,&nbsp;Aman Khurana","doi":"10.1016/j.ijnonlinmec.2025.105064","DOIUrl":"10.1016/j.ijnonlinmec.2025.105064","url":null,"abstract":"<div><div>Electro-magneto-active (EMA) membranes are materials that integrate electromagnetic and active properties to form flexible, responsive surfaces. These membranes typically consist of a soft, elastic matrix embedded with magnetic or electromagnetic particles, which can be manipulated by external magnetic fields or electrical currents. This paper investigates the nonlinear dynamics of an electro-magneto-active circular membrane, a sophisticated smart actuator. Specifically, a continuum physics-based model is implemented to predict the membrane’s dynamic response to applied electro-magneto-mechanical loads. The obtained results offer valuable preliminary insights into the influence of both DC and AC dynamic actuation modes on the membrane’s nonlinear behavior. Notably, we find that increased particle reinforcement, as indicated by the filler content, significantly enhances polymer strength and reduces deformation. Also, an increase in shear modulus ratio results in a reduction in oscillation intensity and an enhancement in excitation frequency. Additionally, time–history response, Poincaré maps, and phase diagrams are utilized to evaluate the membrane’s stability, periodicity, beating phenomena, and resonant behavior. These findings are pivotal for advancing the design and functionality of smart membranes in various biomedical applications.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"174 ","pages":"Article 105064"},"PeriodicalIF":2.8,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619565","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":"Numerical implementation for the cyclic elasto-plasticity model of Inconel 690 considering cyclic hardening followed by softening","authors":"Chengyue Liu ,&nbsp;Tao Hu ,&nbsp;Hai Xie ,&nbsp;Tengwu He ,&nbsp;Miaolin Feng","doi":"10.1016/j.ijnonlinmec.2025.105068","DOIUrl":"10.1016/j.ijnonlinmec.2025.105068","url":null,"abstract":"<div><div>This study investigates the cyclic elasto-plastic behavior of the nickel-based alloy 690 under fully reversed uniaxial strain load at room temperature. Through a series of experiments, it is found that the material undergoes initial cyclic hardening followed by prolonged softening. The strain range effect is also observed, as the rate of cyclic hardening/softening is influenced by strain amplitudes. To capture these behaviors, a nonlinear kinematic hardening rule combined with the strain memory surface is introduced, and the saturated value of backstress is considered as a function of both the accumulated plastic strain and the radius of the memory surface. Subsequently, the backward Euler method and the implicit integration algorithm are applied for numerical implementation. A user material subroutine UMAT is developed for the commercial software ABAQUS. Numerical simulations are conducted on the experiment specimens to validate the constitutive model. The results indicate that the model can describe the cyclic elasto-plastic behavior of the nickel-based alloy 690.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"174 ","pages":"Article 105068"},"PeriodicalIF":2.8,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552722","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":"Experimental and numerical analysis of nonlinear velocity response for a cantilever","authors":"Nasser Firouzi ,&nbsp;Fadi Dohnal ,&nbsp;Tobias Gorbach ,&nbsp;Tara Farizeh","doi":"10.1016/j.ijnonlinmec.2025.105067","DOIUrl":"10.1016/j.ijnonlinmec.2025.105067","url":null,"abstract":"<div><div>In this work, a comprehensive study on the large transient response of a clamped-free beam is done both experimentally and numerically. At the first stage, a custom setup is designed and the nonlinear velocity response of a cantilever is measured with high accuracy by a PSV QTec Scanning Vibrometer H Compact. In the next step, a nonlinear finite element analysis based on co-rotational formulation is derived by considering Euler-Bernoulli beam theory. Besides, to deal with time, the Newmark implicit method is utilized. The numerical evaluation of the derived formulation is validated with the experimental data. The results demonstrate that the obtained formulation can predict the nonlinear velocity response of the cantilever very well. The custom design and the numerical formulation in this work provide promising venue for design of advanced beam structures such as smart materials and adaptive systems.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"173 ","pages":"Article 105067"},"PeriodicalIF":2.8,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534136","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":"In-plane simultaneous resonance instability behaviors of a fixed arch under a two-frequency radial uniformly distributed excitation","authors":"Fulin Shen ,&nbsp;Zilin Zhong ,&nbsp;Xiaobin Xu ,&nbsp;Jianhua Li ,&nbsp;Qinxi Dong ,&nbsp;Jian Deng","doi":"10.1016/j.ijnonlinmec.2025.105056","DOIUrl":"10.1016/j.ijnonlinmec.2025.105056","url":null,"abstract":"<div><div>This paper delves into a theoretical and numerical exploration of the in-plane simultaneous resonance instability behaviors exhibited by a fixed arch subjected to a two-frequency radial uniformly distributed excitation. An intriguing and previously overlooked phenomenon of simultaneous resonance instability in fixed arches has been identified—specifically, the coexistence of superharmonic resonance and combination subharmonic resonance. The in-plane governing equation of motion was derived using Hamilton's principle and subsequently decoupled through the application of the Galerkin method. Employing the method of multiple scales, boundary excitation frequencies at varying amplitudes were determined, establishing dynamic instability zones and distinguishing between stable and unstable regions of the arch. These findings were further validated using both the finite element method and the fourth-order Runge-Kutta technique. The investigation brought to light a fascinating phenomenon wherein the concurrent manifestation of both 2-order superharmonic resonance and 1/2-order combination subharmonic resonance occurs when the sum of two excitation frequencies approaches twice the natural frequency of the arch, with one of them being approximately half of the natural frequency.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"174 ","pages":"Article 105056"},"PeriodicalIF":2.8,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552723","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":"Neural controller for targeting a desired stationary distribution in stochastic systems","authors":"Wantao Jia ,&nbsp;Zhe Jiao ,&nbsp;Zhengrong Jin","doi":"10.1016/j.ijnonlinmec.2025.105058","DOIUrl":"10.1016/j.ijnonlinmec.2025.105058","url":null,"abstract":"<div><div>One of the major missions in the field of stochastic control is to design efficient control policies that guarantee the stochastic systems stabilize within some specified stationary distribution. In this paper, we propose a neural controller based on the stochastic asymptotic stability theory and the condition of detailed balance. A novel physics-informed learning procedure is introduced to update the parameters in a multi-output neural network which is utilized to approximate the controller. We also prove rigorously that the proposed controller is unique if it exists, which is essential in applications. Furthermore, several representative stochastic systems are used to illustrate the usefulness of this neural controller for the stabilization of these dynamical systems in distribution.</div></div>","PeriodicalId":50303,"journal":{"name":"International Journal of Non-Linear Mechanics","volume":"174 ","pages":"Article 105058"},"PeriodicalIF":2.8,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521259","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}