Meccanica最新文献_第10页

Combining machine learning with computational fluid dynamics using OpenFOAM and SmartSim 利用 OpenFOAM 和 SmartSim 将机器学习与计算流体动力学相结合

IF 2.7 3区工程技术

Meccanica Pub Date : 2024-04-20 DOI: 10.1007/s11012-024-01797-z

Tomislav Maric, Mohammed Elwardi Fadeli, Alessandro Rigazzi, Andrew Shao, Andre Weiner

引用次数: 0

Energy of acceleration of a perfect unbounded fluid surrounding an arbitrary moving rigid body 围绕任意运动刚体的完美无界流体的加速度能量

IF 1.9 3区工程技术

Meccanica Pub Date : 2024-04-20 DOI: 10.1007/s11012-024-01794-2

Thiago S. Hallak, Serge Sutulo, C. Guedes Soares

{"title":"Energy of acceleration of a perfect unbounded fluid surrounding an arbitrary moving rigid body","authors":"Thiago S. Hallak, Serge Sutulo, C. Guedes Soares","doi":"10.1007/s11012-024-01794-2","DOIUrl":"10.1007/s11012-024-01794-2","url":null,"abstract":"<div><p>This paper introduces the Gibbs–Appell formalism into fluids. It devises the energy of acceleration of a perfect fluid surrounding a moving impermeable rigid body and the hydrodynamic forces acting on the body. The fluid is considered infinite, and the rigid body may have any closed tridimensional form. Therefore, the velocity field is non-divergent and irrotational; the density field is homogeneous in space and non-dependent on time, and all viscous effects are neglected. Under these assumptions, an explicit formulation for the hydrodynamic forces acting on the body is known as a-priori, and it is recovered in this text following an approach based on generalized quasi-velocities and the Gibss–Appell formalism, that may handle a vaster class of mechanical problems in comparison to Newtonian mechanics, especially non-holonomic constrained systems. The devised formulation is applied to the two-dimensional case study of a disc in unsteady rectilinear motion: the analytical form for the generalized hydrodynamic forces acting on the disc is evaluated, as well as the explicit formulae for the hydrodynamic coefficients of the body and the total energy of acceleration of the surrounding fluid.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140625309","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}

引用次数: 0

Linear variations in conductivity and viscosity as particles’ basic profile for convective instability in nanofluids under various boundary conditions 在各种边界条件下，纳米流体对流不稳定性中作为颗粒基本轮廓的电导率和粘度的线性变化

IF 1.9 3区工程技术

Meccanica Pub Date : 2024-04-18 DOI: 10.1007/s11012-024-01784-4

Jyoti Sharma

引用次数: 0

Acceleration waves in thermoelastic complex media with temperature-dependent phase fields 热弹性复合介质中的加速波与温度相关相场

IF 2.7 3区工程技术

Meccanica Pub Date : 2024-04-15 DOI: 10.1007/s11012-024-01792-4

Pasquale Giovine, Paolo Maria Mariano, Federica Mugnaioni

引用次数: 0

Correlation and modal analysis techniques for the study of the VIV response of a twin-box deck based on 3D LES simulations 基于三维 LES 模拟研究双箱甲板 VIV 响应的相关性和模态分析技术

IF 2.7 3区工程技术

Meccanica Pub Date : 2024-04-13 DOI: 10.1007/s11012-024-01774-6

Antonio J. Álvarez, Félix Nieto

{"title":"Correlation and modal analysis techniques for the study of the VIV response of a twin-box deck based on 3D LES simulations","authors":"Antonio J. Álvarez, Félix Nieto","doi":"10.1007/s11012-024-01774-6","DOIUrl":"https://doi.org/10.1007/s11012-024-01774-6","url":null,"abstract":"<p>Twin-box decks are prone to vortex-induced vibration (VIV) at moderate wind speeds, and previous studies have shown a complex interplay between the flow and the two parallel box girders. OpenFOAM is used to model the aerodynamic and aeroelastic responses of the twin-box deck of the Stonecutters Bridge by means of 3D LES simulations. Two cases are thoroughly analysed under smooth incoming flow: (i) static deck and ii) heave peak amplitude response at VIV excitation. The computational data provided by the CFD simulations have been exploited aiming at better understanding the complex aerodynamic and aeroelastic phenomena taking place. First, spanwise correlation analyses are applied to understand the level of organisation of the forcing flow actions, and identify the regions of the deck affected by different flow structures. Second, three different mode decomposition techniques (POD, SPOD and DMD) are applied to the time-dependent pressure distributions, revealing the pivotal role played by the leeward box in the twin-box deck response under wind action. The modal analyses are of utmost interest in the development of Reduced Order Models (ROM) for the VIV response of twin-box long-span bridges.</p>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140575675","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}

引用次数: 0

Limit analysis of masonry arches and domes with finite strength: funicular analysis versus stability area method 具有有限强度的砌体拱和穹顶的极限分析：漏斗分析法与稳定面积法的比较

IF 2.7 3区工程技术

Meccanica Pub Date : 2024-04-07 DOI: 10.1007/s11012-024-01781-7

Danila Aita, Matteo Bruggi, Alberto Taliercio

{"title":"Limit analysis of masonry arches and domes with finite strength: funicular analysis versus stability area method","authors":"Danila Aita, Matteo Bruggi, Alberto Taliercio","doi":"10.1007/s11012-024-01781-7","DOIUrl":"https://doi.org/10.1007/s11012-024-01781-7","url":null,"abstract":"<p>This study, framed within the context of the lower bound theorem of limit analysis, aims to assess the anti-funicular equilibrium of masonry arches and domes using a computational approach based on the constrained force density method. In contrast to the commonly adopted classical Heyman’s assumptions, the approach proposed here considers the effects of finite compressive strength in the material. Assuming a fixed plan projection for a network with independent sets of branches, a suitable set of local constraints is enforced at each joint to account for the limit bending moment resulting from the material’s assumptions, including limited compressive strength and zero tensile strength. Additionally, the stereotomy of the voussoirs is considered by assigning a geometric law to the joint inclination. The collapse load is determined by formulating a multi-constrained maximization problem. The method is validated using a modern version of the semi-analytical Durand-Claye’s method. For benchmark case studies, such as symmetric masonry arches and domes with specific stereotomies subjected to axi-symmetrical load conditions, the set of statically admissible solutions compatible with equilibrium and strength requirements is graphically determined in terms of the horizontal thrust and its eccentricity at the crown, examining the shape of the stability area. Assuming an infinite value for the friction coefficient, the collapse condition is reached when the stability area shrinks to a single point. The results obtained from both of these methods are in excellent agreement. The influence of compressive strength on the bearing capacity of the structures is also discussed.</p>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140602693","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}

引用次数: 0

XFEM analysis of cracked media under thermal shock considering Chandrasekharaiah–Tzou theory 考虑 Chandrasekharaiah-Tzou 理论的热冲击下裂纹介质 XFEM 分析

IF 1.9 3区工程技术

Meccanica Pub Date : 2024-04-07 DOI: 10.1007/s11012-024-01787-1

Vahid Jafari, Mohammad Bagher Nazari, Masoud Mahdizadeh Rokhi

{"title":"XFEM analysis of cracked media under thermal shock considering Chandrasekharaiah–Tzou theory","authors":"Vahid Jafari, Mohammad Bagher Nazari, Masoud Mahdizadeh Rokhi","doi":"10.1007/s11012-024-01787-1","DOIUrl":"10.1007/s11012-024-01787-1","url":null,"abstract":"<div><p>In this paper, an isotropic environment with a static crack under thermal shock is studied using generalized thermoelasticity equations of Chandrasekharaiah–Tzou. The discretization of the governing equations in dimensionless space is done using the extended finite element method and the matrix form of the equations is extracted. Newmark’s method is used to solve the resulting system of nonlinear equations in the time domain. Some examples are solved using the numerical method and the temperature, displacements and stress fields along the length of the homogeneous layer are obtained. Also, the stress intensity factors under thermal shock are calculated using the interaction integral method and compared with the values obtained from the classical thermoelasticity theory. The results show that the speed of temperature, displacement and stress waves in the Chandrasekharaiah–Tzou theory are limited, unlike the classical thermoelasticity theory. Also, the maximum values of displacement and stress according to the theory of Chandrasekharaiah–Tzou occur at a smaller distance from the edge to which the thermal shock is applied.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140575226","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}

引用次数: 0

Breaking the left-right symmetry in fluttering artificial cilia that perform nonreciprocal oscillations 打破进行非互惠振荡的人工纤毛的左右对称性

IF 1.9 3区工程技术

Meccanica Pub Date : 2024-04-06 DOI: 10.1007/s11012-024-01765-7

Ariel Surya Boiardi, Roberto Marchello

{"title":"Breaking the left-right symmetry in fluttering artificial cilia that perform nonreciprocal oscillations","authors":"Ariel Surya Boiardi, Roberto Marchello","doi":"10.1007/s11012-024-01765-7","DOIUrl":"10.1007/s11012-024-01765-7","url":null,"abstract":"<div><p>Recent investigations on active materials have introduced a new paradigm for soft robotics by showing that a complex response can be obtained from simple stimuli by harnessing dynamic instabilities. In particular, polyelectrolyte hydrogel filaments actuated by a constant electric field have been shown to exhibit self-sustained oscillations as a consequence of flutter instability. Owing to the nonreciprocal nature of the emerging oscillations, these <i>artificial cilia</i> are able to generate flows along the stimulus. Building upon these findings, in this paper we propose a design strategy to break the left-right symmetry in the generated flows, by endowing the filament with a natural curvature at the fabrication stage. We develop a mathematical model based on morphoelastic rod theory to characterize the stability of the equilibrium configurations of the filament, proving the persistence of flutter instability. We show that the emerging oscillations are nonreciprocal and generate thrust at an angle with the stimulus. The results we find at the level of the single cilium open new perspectives on the possible applications of artificial ciliary arrays in soft robotics and microfluidics.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11012-024-01765-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140575311","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}

引用次数: 0

Well-posedness and exponential stability in nonlocal theory of nonsimple porous thermoelasticity 非简单多孔热弹性非局域理论中的好拟性和指数稳定性

IF 2.7 3区工程技术

Meccanica Pub Date : 2024-04-05 DOI: 10.1007/s11012-024-01768-4

Moncef Aouadi, Michele Ciarletta, Vincenzo Tibullo

{"title":"Well-posedness and exponential stability in nonlocal theory of nonsimple porous thermoelasticity","authors":"Moncef Aouadi, Michele Ciarletta, Vincenzo Tibullo","doi":"10.1007/s11012-024-01768-4","DOIUrl":"https://doi.org/10.1007/s11012-024-01768-4","url":null,"abstract":"<p>In this paper, a nonlocal model for porous thermoelasticity is derived in the framework of the Mindlin’s strain gradient theory where the thermal behavior is based on the entropy balance postulated by Green–Naghdi models of type II or III. In this context, we add the second gradient of volume fraction field and the second gradient of deformation to the set of independent constituent variables. The elastic nonlocal parameter <span>(varpi)</span> and the strain gradient length scale parameter <i>l</i> are also considered in the derived model. New mathematical difficulties then appeared due to the higher gradient terms in the resulting system which is a coupling of three second order equations in time. By using the theories of monotone operators and the nonlinear semigroups, we prove the well-posedness of the derived model in the one dimensional setting. The exponential stability of the corresponding semigroup to type II and type III models is proved. The proof is essentially based on a characterization stated in the book of Liu and Zheng. This result of exponential stability of the type II model confirms the results of the classic theory for which the exponential decay cannot hold (for type II) without adding a dissipative mechanism.</p>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140575668","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}

引用次数: 0

Correction to: Optimized Gauss–Legendre–Hermite 2-point (O-GLH-2P) method for nonlinear time-history analysis of structures 更正：用于结构非线性时程分析的优化高斯-列根德-赫米特 2 点 (O-GLH-2P) 方法

IF 1.9 3区工程技术

Meccanica Pub Date : 2024-04-03 DOI: 10.1007/s11012-024-01783-5

Mehdi Babaei

引用次数: 0