Acta Mechanica最新文献_第8页

Equivalence between micromorphic, nonlocal gradient, and two-phase nonlocal beam theories

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-12-17 DOI: 10.1007/s00707-024-04180-x

Noël Challamel, C. M. Wang, J. N. Reddy, S. A. Faghidian

{"title":"Equivalence between micromorphic, nonlocal gradient, and two-phase nonlocal beam theories","authors":"Noël Challamel, C. M. Wang, J. N. Reddy, S. A. Faghidian","doi":"10.1007/s00707-024-04180-x","DOIUrl":"10.1007/s00707-024-04180-x","url":null,"abstract":"<div><p>This paper explores the potential to unify gradient and nonlocal elastic beam theories using strain- or stress-driven nonlocal frameworks, focusing on nonlocal Euler–Bernoulli beam kinematics. It presents a two-length-scale gradient/nonlocal beam model that connects bending moments to curvature through a two-scale differential law, derivable via strain- or stress-based variational principles. The strain-driven micromorphic, two-phase strain-driven nonlocal, and nonlocal strain gradient beam theories share identical governing equations and higher-order boundary conditions for normalized nonlocal kernels on finite beams. However, the positive nonlocal potential energy constrains each theory’s validity, depending on the length-scale ratio. The nonlocal strain gradient theory can encompass the others to ensure positive potential energy across varying length scales. Differences between the finite-beam exponential kernel model and the infinite-beam model are clarified; though governed by the same differential equation but each has unique higher-order boundary conditions. The interest of the theory based on a normalized kernel along the finite beam is highlighted on a pure bending test which preserves the uniform curvature field. Additionally, the stress-driven micromorphic, two-phase stress-driven nonlocal, and nonlocal stress gradient theories share the same governing equations and boundary conditions for finite-beam kernels. The study concludes that these theories—micromorphic, nonlocal gradient, and two-phase nonlocal—can be unified within strain- and stress-driven frameworks for specific nonlocal kernels.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"236 2","pages":"871 - 902"},"PeriodicalIF":2.3,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513422","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

SH surface waves in piezoelectric semiconductors loaded with a finite viscous liquid layer

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-12-17 DOI: 10.1007/s00707-024-04181-w

Lele Zhang, Haocheng Guo, Jinxi Liu, Yuantai Hu

引用次数: 0

Correction: Surface waves propagating in an elastic half-space considering both the effects of strain gradient and surface elasticity

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-12-16 DOI: 10.1007/s00707-024-04188-3

Jianmin Long, Bowen Zhao

引用次数: 0

Brinkman-medium resistance hampers periodic motions of sedimenting particles

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-12-16 DOI: 10.1007/s00707-024-04146-z

Marta Gruca, Marek Bukowicki, Maria L. Ekiel-Jeżewska

引用次数: 0

Dynamics of a nanotube supported on the lateral and rotational restrained using doublet mechanics theory

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-12-15 DOI: 10.1007/s00707-024-04173-w

Murat Akpınar, Büşra Uzun, Mustafa Özgür Yaylı

引用次数: 0

Mathematical aspect of normal moving load on an irregular micropolar layer imperfectly bonded to an orthotropic half-space under initial stress

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-12-14 DOI: 10.1007/s00707-024-04182-9

Pooja Singh, Brijendra Paswan, Sonali Mondal

{"title":"Mathematical aspect of normal moving load on an irregular micropolar layer imperfectly bonded to an orthotropic half-space under initial stress","authors":"Pooja Singh, Brijendra Paswan, Sonali Mondal","doi":"10.1007/s00707-024-04182-9","DOIUrl":"10.1007/s00707-024-04182-9","url":null,"abstract":"<div><p>In this paper, we have investigated the stress distribution induced by a normal load moving across an irregular micropolar layer imperfectly bonded to an orthotropic half-space under initial stress. The analysis considers a parabolic surface irregularity on the layer and an imperfect interface between the layer and half-space. Using appropriate boundary conditions and a perturbation technique closed-form mathematical expressions are derived for normal, tangential, and couple stresses. Numerical computations and graphical analyses have been conducted to illustrate the significant effects of dimensionless parameters such as frictional coefficient, irregularity depth, irregularity factor, coupling factor, bonding parameters, and initial stresses on the normal, tangential, and couple stresses. The results reveal that these characteristics significantly influence the stress distribution within both the irregular upper layer and the underlying half-space. These findings have practical implications across various fields, including highway and airport runway construction, heavy haulage, civil engineering, and earthquake engineering, where accurate stress modeling is essential for infrastructure stability and safety.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"236 2","pages":"789 - 807"},"PeriodicalIF":2.3,"publicationDate":"2024-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513299","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

Impact of fibers on pumping flow: an analysis by CFD-DEM simulations and experiments

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-12-14 DOI: 10.1007/s00707-024-04176-7

Qihua Zhang, Chengcheng Zhong, Zhou Fang, Zhiang Xie, Shun Kang

{"title":"Impact of fibers on pumping flow: an analysis by CFD-DEM simulations and experiments","authors":"Qihua Zhang, Chengcheng Zhong, Zhou Fang, Zhiang Xie, Shun Kang","doi":"10.1007/s00707-024-04176-7","DOIUrl":"10.1007/s00707-024-04176-7","url":null,"abstract":"<div><p>The quantitative studies on pumping flow of fiber particles are very rare. In this research, CFD-DEM simulations, as well as experiments, were conducted to investigate the flow field and fiber behaviors. The mass concentration of the fiber suspension was increased, starting gradually from 0.5 to 1.0% and ultimately reaching 1.5%. The velocity profiles at varying radius positions were obtained by PIV. The CFD-DEM reveals that fiber particles exert an inhibitory effect on swirling flows. Furthermore, the PIV data reveal that the velocity from suction to pressure surface of the blade decreases in a linear manner. The trend of variation in fiber suspension is similar to that observed in clean water. The external characteristic data reveal an improvement in efficiency as concentration increases, aligning with the flow profile variation. As the concentration grows from 1.0 to 1.5%, the peak efficiency turns down by a noticeable trend. To investigate this turning, high-speed photography was employed to capture the fiber behaviors. It was observed that the fibers cluster near the pressure surface of the blade. Then, the fiber clusters undergo deformation and ultimately disperse as they leave the channel. Therefore, the fiber aggregation exerts a destabilizing influence on the flow field, leading to a reduction in the pumping capacity.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"236 2","pages":"767 - 787"},"PeriodicalIF":2.3,"publicationDate":"2024-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513298","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: The meshless local Petrov–Galerkin cumulant lattice Boltzmann method: strengths and weaknesses in aeroacoustic analysis

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-12-14 DOI: 10.1007/s00707-024-04175-8

Mohsen Gorakifard, Clara Salueña, Ildefonso Cuesta, Ehsan Kian Far

引用次数: 0

Analysis of bulk wave propagation of fluid-conveying FG biocomposite tubes

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-12-12 DOI: 10.1007/s00707-024-04169-6

Zhiwei Liu, Tiancheng Ji, Yunzhu An, Tao Huang, Shijun Huang, Wei Liu, Xintong Mao, Meng Cheng

{"title":"Analysis of bulk wave propagation of fluid-conveying FG biocomposite tubes","authors":"Zhiwei Liu, Tiancheng Ji, Yunzhu An, Tao Huang, Shijun Huang, Wei Liu, Xintong Mao, Meng Cheng","doi":"10.1007/s00707-024-04169-6","DOIUrl":"10.1007/s00707-024-04169-6","url":null,"abstract":"<div><p>Novel biomaterials like functionally graded (FG) bio-composite materials for use as constituent materials of artificial biodevices e.g., dental implants have lately attracted much attention because of their great potential and benefits in assuring biocompatibility and mechanical properties at the same time. In this research, the dispersion of elastic waves in FG bio-composite tube resting on Winkler-Pasternak substrate with consideration of the fluid flow effect is evaluated for the first time. Three common materials i.e., Gold alloy, Titanium, and Hydroxyapatite used in prosthetic implants are considered constituent materials of the studied structure. The modified Wakashima–Tsukamoto micromechanical model is implemented to determine the effective properties of FG bio-composite material. The tube structure is modeled based on first-order shear deformation theory and for examining the effect of fluid flow which is assumed to be fully developed, Newtonian and laminar, the Navier–Stokes equation is employed. At last, the obtained equations are analytically solved through a harmonic function and the effects of significant parameters including wave number, fluid flow velocity, inhomogeneity index, radius and length to thickness ratios, and Winkler and Pasternak parameters on wave dispersion behavior of FG bio-composite tube are assessed and discussed. The novelty of this work lies in the first-time evaluation of elastic wave dispersion in an FG bio-composite tube, considering fluid flow effects and resting on a Winkler-Pasternak substrate. The combination of advanced materials (Gold alloy, Titanium, Hydroxyapatite) with a modified micromechanical model and comprehensive analysis of wave behavior under various critical parameters brings a new dimension to the design of medical devices, particularly in improving the performance of prosthetic implants.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"236 3","pages":"1469 - 1486"},"PeriodicalIF":2.3,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638132","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

Large eddy simulation of flow separation-induced disturbance evolution inside a sudden contracting nozzle

IF 2.3 3区工程技术

Acta Mechanica Pub Date : 2024-12-12 DOI: 10.1007/s00707-024-04157-w

Jagannath Mahato, Toshan Lal Sahu, Ujjwal Chetan, Prabir Kumar Kar, Dhananjay Kumar Srivastava, Rajaram Lakkaraju

{"title":"Large eddy simulation of flow separation-induced disturbance evolution inside a sudden contracting nozzle","authors":"Jagannath Mahato, Toshan Lal Sahu, Ujjwal Chetan, Prabir Kumar Kar, Dhananjay Kumar Srivastava, Rajaram Lakkaraju","doi":"10.1007/s00707-024-04157-w","DOIUrl":"10.1007/s00707-024-04157-w","url":null,"abstract":"<div><p>The contracting section of a nozzle defines outcomes like downstream velocity and its fluctuations. We studied the flow dynamics inside a three-dimensional sudden contracting nozzle using large eddy simulation. Flow obstruction by the nozzle contracting step induces flow detachment from the walls, creating separation bubbles and vortex shedding. The span-wise movement of fluid particles upstream of the nozzle step, along with the vortex shedding phenomena and unstable flow separation layer, develops a three-dimensional flow motion inside the nozzle throat. Turbulent kinetic energy inside the nozzle throat propagates in a definite pattern. A two-dimensional disturbance first develops on the flow separation layer, followed by a three-dimensional nature at the separation bubble reattachment zone near the step-wise walls, which then move toward the span-wise walls. Finally, flow motions from all the walls disturb the nozzle centerline region. We studied velocity fluctuations through different cross-sectional locations like the centerline and areas near the step and span-wise walls. Flow disturbance through the nozzle throat is categorized as two-dimensional, near-wall three-dimensional, bulk three-dimensional transition, and fully randomized zones based on the velocity fluctuations. Finally, we studied the cross-sectional stream-wise velocity distribution. After passing through the nozzle step section, the flow does not form a conventional channel velocity profile (maximum at the centerline). Instead, the peak average stream-wise velocity offsets symmetrically about the centerline.</p></div>","PeriodicalId":456,"journal":{"name":"Acta Mechanica","volume":"236 2","pages":"745 - 765"},"PeriodicalIF":2.3,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513256","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