Meccanica最新文献

{"title":"A systematic method for free and forced vibration analysis of axially loaded hybrid double-beam systems","authors":"Zhengquan Liu,&nbsp;Guoping Wang,&nbsp;Jianshu Zhang,&nbsp;Xiaoting Rui,&nbsp;Lilin Gu,&nbsp;Xizhe Zhang","doi":"10.1007/s11012-025-02026-x","DOIUrl":"10.1007/s11012-025-02026-x","url":null,"abstract":"<div><p>This paper introduces a systematic method for analyzing the free and forced vibrations of hybrid double-beam systems under axial force, utilizing the linear multibody system transfer matrix method. The hybrid double-beam system consists of two types of elements, the double-beam segments and the spring-supported rigid bodies. This configuration is commonly found in research and engineering applications. The frequency equation of the system can be directly obtained through successive multiplication of the element transfer matrices, accommodating arbitrary boundary conditions. The transfer equation for the axially loaded Timoshenko beam are derived analytically, thereby avoiding the accuracy loss due to spatial discretization. And there is no need to discuss the derivation for different cases. The orthogonality of the augmented eigenvectors of the hybrid double-beam system is mathematically proven. The forced vibration of the system is solved using the modal superposition method. Three numerical examples verify the systematicity, simplicity and high accuracy of the proposed method. Furthermore, the effects of axial force, spring support stiffness, and rigid body mass on the vibration characteristics of the hybrid double-beam system are analyzed, providing valuable insights for optimizing designs and avoiding undesirable vibrations.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 9","pages":"2731 - 2757"},"PeriodicalIF":2.1,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145248227","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":"Bifurcation analysis using modified stiffness method of group theoretic imperfections","authors":"Ichiro Ario,&nbsp;Ma Dong","doi":"10.1007/s11012-025-02001-6","DOIUrl":"10.1007/s11012-025-02001-6","url":null,"abstract":"<div><p>Multiple bifurcations due to symmetry often occur when analyzing nonlinear structural motifs with axial symmetry. The identification of multiple bifurcation points and the tracing of bifurcation paths become significant challenges in numerical analysis. In this paper, we address a numerical problem of nonlinear bifurcation in a symmetric structure exhibiting double bifurcation points. By focusing on the initial imperfection vector corresponding to the partial irreducible representation of its symmetry, we propose a modified stiffness method. This method utilizes the orthogonalization transformation differences to separate the multiple bifurcation points of the second-order irreducible representation of the stiffness matrix into a single bifurcation point. As a numerical example, bifurcation analysis of an axially symmetric fullerene truss structure is conducted to demonstrate the effectiveness of the proposed method. This study successfully addresses the issue of multiple bifurcations in axially symmetric structures by incorporating group-theoretic bifurcation theory and modifying the stiffness method, as validated by the numerical analysis of a fullerene truss structure.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 8","pages":"2131 - 2149"},"PeriodicalIF":2.1,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145230420","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":"Correction: Appraisal of the overburden mass and boundary conditions on the rocking behaviour of the vertical spanning strip wall","authors":"Georgios Vlachakis,&nbsp;Carla Colombo,&nbsp;Dario Vecchio,&nbsp;Anastasios I. Giouvanidis,&nbsp;Paulo B. Lourenço","doi":"10.1007/s11012-025-02014-1","DOIUrl":"10.1007/s11012-025-02014-1","url":null,"abstract":"","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 7","pages":"2125 - 2126"},"PeriodicalIF":2.1,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11012-025-02014-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888088","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":"Intelligent optimization based on the genetic algorithm for a customizable Stephenson III six-bar mechanical finger","authors":"Alejandro Rodríguez-Molina,&nbsp;José David Álvarez-Piedras,&nbsp;Miguel Gabriel Villarreal-Cervantes,&nbsp;Omar Serrano-Pérez,&nbsp;Geovanni Flores-Caballero","doi":"10.1007/s11012-025-02013-2","DOIUrl":"10.1007/s11012-025-02013-2","url":null,"abstract":"<div><p>The motion of the hand’s fingers allows humans to perform many activities. A mechanical model of these limbs can be used in industry and healthcare applications. Due to the sophisticated structure of such limbs, the generation of mechanisms to emulate them is complex but can be addressed with computational intelligence techniques such as metaheuristics. Current models consist of closed, open, or hybrid kinematic chains. Each alternative has advantages and disadvantages in terms of cost, energy, precision, variety of movements, and anthropometric and anthropomorphic characteristics. These mechanisms are derived from information obtained from hand biomechanical studies or clinical experience, so they are not considered customizable and are hardly anthropometric and anthropomorphic. This work presents an approach for the intelligent synthesis of customizable mechanical fingers with anthropomorphic and anthropometric features. This approach aims to exploit the relatively low cost, high precision, and complex trajectories that can develop the one-degree-of-freedom Stephenson III six-bar mechanism to perform cyclic flexion and extension movements as a human finger would. For this, the dimensional synthesis problem of the six-bar mechanism is proposed as an optimization one. So, anthropometric characteristics of the finger are accounted for by using a reference trajectory derived from precise measurements of the subject’s cyclic flexion and extension movements relative to the metacarpophalangeal joint. On the other hand, anthropomorphic features are incorporated by imposing constraints that induce dimensions of the mechanism that resemble the human finger, regulate the size of the links corresponding to hand bones, and place fixed points in locations that mirror the metacarpal structure. The characteristics obtained through this approach have not been found in any design similar to this one to date. With the proper synthesis of the mechanism, it is intended to track an anthropometric reference trajectory collected from the finger of a healthy individual through a commercial low-cost optical hand sensor and conditioned using the spectral clustering unsupervised learning technique. This approach successfully synthesized a customized mechanical finger for a test subject using a genetic algorithm. The design was implemented through low-cost additive manufacturing. After several analyses, the proposal proved to be accurate in tracking the finger movements of different individuals, flexible to anthropometric data, and possessing advantages over other alternative metaheuristics approaches.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 9","pages":"2689 - 2729"},"PeriodicalIF":2.1,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145248191","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 variational phase-field model for ductile fracture depending on hydrostatic stresses","authors":"Anne-Sophie Sur,&nbsp;Laura De Lorenzis,&nbsp;Corrado Maurini,&nbsp;Odd Sture Hopperstad","doi":"10.1007/s11012-025-01971-x","DOIUrl":"10.1007/s11012-025-01971-x","url":null,"abstract":"<div><p>We model ductile fracture for geometrically linear deformations by coupling plasticity and phase-field fracture models in a variationally consistent framework. The main aim of the proposed model is to account for the effect of stress triaxiality, in order to accurately reproduce ductile fracture, in particular, the instant and location of fracture initiation. For this purpose, we couple the modified Cam-Clay plasticity model with a phase-field fracture model. We study the behaviour of the model analytically in terms of homogeneous material responses, and numerically on plane-strain and axisymmetric specimens under tension with different notches.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 8","pages":"2151 - 2175"},"PeriodicalIF":2.1,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11012-025-01971-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145230541","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":"Inertio-elastic mode instabilities of viscoelastic flow in a periodic channel","authors":"Mohamed MADI,&nbsp;Khalid SOUHAR,&nbsp;Abdessamade RAFIKI,&nbsp;Hamid ZIDOUH","doi":"10.1007/s11012-025-02020-3","DOIUrl":"10.1007/s11012-025-02020-3","url":null,"abstract":"<div><p>In this paper, we analyze the local linear stability of plane Poiseuille flow of an upper convected Maxwell (UCM) fluid through a periodic channel under two flow regimes, i.e., inertial (<i>Re</i> <span>(ne)</span> 0) and purely elastic (<i>Re</i> <span>(equiv)</span> 0). The analysis is conducted with respect to the dimensionless control parameters: Reynolds number (<i>Re</i>), elasticity number (<i>E</i>), and Weissenberg number (<i>We</i>). We focus on the stability of two-dimensional perturbations, using spectral methods and Chebyshev collocation to discretize the dispersion equations. For creeping flow, we perform a numerical study to explore the combined effects of periodic modulation (<span>(epsilon)</span>), section (<i>x</i>), and control parameters (<i>E</i>, <i>We</i>) on the stability of UCM fluid flow, and to examine the elasto-inertial interplay in flow stability. Our results reveal two key findings: first, the existence of a critical position (<span>(x_{c})</span>=<span>(frac{pi }{2n})</span>) and (<span>(x_{c})</span>=<span>(frac{3pi }{2n})</span>) for small wavenumbers (<i>n</i>); and second, insights into the structure of the full elasto-inertial eigenspectrum, consisting of multiple discrete modes influenced by the section (<i>x</i>) and channel amplitude (<span>(epsilon)</span>). </p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 9","pages":"2671 - 2687"},"PeriodicalIF":2.1,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145248224","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 of the satellite droplet formation in piezoelectric jetting at short nozzle-to-substrate distances","authors":"Chongshuai Wang,&nbsp;Xuan Han,&nbsp;Di Zuo,&nbsp;Yadong Li,&nbsp;Yourui Tao,&nbsp;Ruifei Peng,&nbsp;Jia Wang","doi":"10.1007/s11012-025-02007-0","DOIUrl":"10.1007/s11012-025-02007-0","url":null,"abstract":"<div><p>Jet dispensing is a foundational technology in microelectronics packaging. Piezoelectric-driven jet dispensing involves short-distance jet processes, typically ranging between 0.7 and 1.2 mm. During this process, jet breakup occurs after the droplet contacts the substrate, leading to substrate contamination, irregular adhesive dot shapes, and various other challenges. The underlying mechanism of jet breakup is complex, and the formation mechanism for satellite droplets remains unclear. To address this issue, in this paper, a certain epoxy resin adhesive is investigated to analyze the mechanism of satellite droplet formation during short-distance jet dispensing through experiments, theoretical model, and numerical simulations. The results indicate that the second jet breakup above satellite droplets is most likely to form scattered spots, and the probability of satellite droplet generation is negatively correlated with jet breakup time. Reducing jet velocity, lowering jetting height, and adjusting nozzle temperature can effectively increase jet breakup time and reduce the generation of satellite droplets. Additionally, decreasing jet velocity by modifying parameters such as the length-to-diameter ratio of the micro-jet orifice and the nozzle cone angle can help suppress satellite droplet formation.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 5","pages":"1497 - 1512"},"PeriodicalIF":2.1,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145169509","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":"Gear tribological and contact fatigue prediction with rough topography and groove texture under elastohydrodynamic lubrication","authors":"Huifang Xiao,&nbsp;Fan Zhang,&nbsp;Zedong Li,&nbsp;Yihu Tang,&nbsp;Liting Li","doi":"10.1007/s11012-025-02019-w","DOIUrl":"10.1007/s11012-025-02019-w","url":null,"abstract":"<div><p>The introduction of micro-texture on gear tooth surface can potentially enhance the contact fatigue life and operational reliability of the gear pair, and is attracting increasing attention in an effort to provide improved tribological properties and contact performances. In this work, a new tribological model of micro-textured gear tooth in elastohydrodynamic lubrication (EHL) contact considering the coupled effect of rough surface topography is developed. The combined effect of micro-texture, surface roughness topography, elastic deformation of the tooth surface and lubrication on the contact characteristics of the meshing interface are included to obtain a revised oil film thickness equation. The rough surface contact of gear pair is characterized by the real rough morphology of gear tooth. The coefficient of friction at the transient meshing point of the micro-textured tooth surface is derived with the effect of flash temperature included. The sub-surface stress–strain distributions of the micro-textured gear are determined and the contact fatigue life is evaluated based on the Brown-Miller-Morrow multiaxial fatigue life criterion. Effects of surface roughness and micro-texture parameters on the lubrication behavior, friction coefficient and fatigue life are investigated and discussed. Experimental validation is performed and good agreement is observed between the model predictions and experimental results.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 9","pages":"2641 - 2669"},"PeriodicalIF":2.1,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145248261","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 investigation of contact behavior for elastoplastic hemisphere considering yield plateau and strain hardening under cyclic tangential loading","authors":"Juncheng Luo,&nbsp;Fuli Zhang,&nbsp;Jianhua Liu,&nbsp;Huanxiong Xia,&nbsp;Xuerui Zhang","doi":"10.1007/s11012-025-02017-y","DOIUrl":"10.1007/s11012-025-02017-y","url":null,"abstract":"<div><p>Spherical contact under combined normal and cyclic tangential loading is a simple but representative issue in contact mechanics. This work developed a generalized three-phase constitutive model considering elastic, yield plateau, and strain hardening characteristics and contributed an energy conservation model of quasi-static contact under various sliding conditions. The von Mises stress, equivalent plastic strain, contact behaviors, and energy components were examined under different material parameters and loading conditions. The results indicate that the stress concentration zone appears in the heading area of the sliding direction and vanishes in the trailing area; junction growth derives from a new increased zone and an accumulated plastic deformation inside the original contact zone; large normal force decrement, substantial junction growth, and considerable energy dissipation occur in the material more prone to higher plastic deformations; there are more complex responses related to single frictional dissipation and plastic dissipation.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 5","pages":"1477 - 1496"},"PeriodicalIF":2.1,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145168817","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":"Buckling and post-buckling analysis of masonry walls using Virtual Elements and cohesive interfaces","authors":"Marco Nale,&nbsp;Cristina Gatta,&nbsp;Daniela Addessi,&nbsp;Elena Benvenuti,&nbsp;Elio Sacco","doi":"10.1007/s11012-025-02016-z","DOIUrl":"10.1007/s11012-025-02016-z","url":null,"abstract":"<div><p>This paper focuses on a novel and computationally efficient large-displacement methodology utilizing a corotational approach for the stability analysis of masonry structural elements. By virtue of the flexibility offered by the Virtual Element Method, each brick is modeled using a single Virtual Element. In contrast, the mortar layer is modeled through multiple cohesive damage-frictional elements. Furthermore, the adopted Virtual Element formulation does not require stabilization. The advantages of the proposed approach are showcased through several examples demonstrating the striking accuracy of the obtained results compared to analytical solutions. The proposed approach is used to assess the sensitivity of the load-bearing capacity and ductility of masonry walls under vertical loading to mortar tensile strength, boundary conditions, load eccentricity, and block irregularity.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 7","pages":"1917 - 1937"},"PeriodicalIF":2.1,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888083","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}