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Elastoplastic homogenization of particulate composites complying with the Mohr–Coulomb criterion and undergoing isotropic loading

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Acta Mechanica Sinica 2015年第3期31卷 392-405页

作者： D.Yang Q.C.He School of Mechanical Engineering Southwest Jiaotong University Université Paris-Est Laboratoire Modélisation et Simulation Multi Echelle UMR 8208 CNRS

This work aims at determining the overall response of a two-phase elastoplastic composite to isotropic loading. The composite under investigation consists of elastic particles embedded in an elastic perfectly plastic matrix governed by the Mohr-Coulomb yield criterion and a non-associated plastic flow rule. The composite sphere assemblage model is adopted, and closed-form estimates are derived for the effective elastoplastic properties of the composite either under tensile or compressive isotropic loading. In the case when elastic particles reduce to voids, the composite in question degenerates into a porous elastoplastic material. The results obtained in the present work are of interest, in particular, for soil mechanics.

关键词： Composite Porous medium. Elastoplasticity Mohr-Coulomb yield criterion Non-associated flow rule Homogenization

Stochastic framework for modeling the linear apparent behavior of complex materials:Application to random porous materials with interphases

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Acta Mechanica Sinica 2013年第6期29卷 773-782页

作者： J.Guilleminot T.T.Le C.Soize Universit Paris-Est Laboratoire Modlisation et Simulation Multi EchelleMSME UMR8208 CNRS5 Bd Descartes77454 Marne la ValleFrance

This paper is concerned with the modeling of randomness in multiscale analysis of heterogeneous materials. More specifically, a framework dedicated to the stochastic modeling of random properties is first introduced. A probabilistic model for matrix-valued second-order random fields with symmetry propertries, recently proposed in the literature, is further reviewed. Algorithms adapted to the Monte Carlo simulation of the proposed representation are also provided. The derivations and calibration procedure are finally exemplified through the modeling of the apparent properties associated with an elastic porous microstructure containing stochastic interphases.

关键词： Apparent properties MaxEnt Probabilistic model

Mathematical modeling and numerical computation of the effective interfacial conditions for Stokes flow on an arbitrarily rough solid surface

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Applied Mathematics and Mechanics(English Edition) 2021年第5期42卷 721-746页

作者： A.T.TRAN H.LE QUANG Q.C.HE D.H.NGUYEN Research and Application Center for Technology in Civil Engineering University of Transport and CommunicationsHanoi 10000Vietnam laboratoire modelisation et simulation multi-echelle Unite Mixte de Recherche 8208Centre National de la Recherche ScientifiqueUniversite Gustave EiffelMarne-la-Vallee F-77454France School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China

The present work is concerned with a two-dimensional(2D)Stokes flow through a channel bounded by two parallel solid *** distance between the walls may be arbitrary,and the surface of one of the walls can be arbitrarily *** main objective of this work consists in homogenizing the heterogeneous interface between the rough wall and fluid so as to obtain an equivalent smooth slippery fluid/solid interface characterized by an effective slip *** solve the corresponding problem,two efficient numerical approaches are elaborated on the basis of the method of fundamental solution(MFS)and the boundary element methods(BEMs).They are applied to different cases where the fluid/solid interface is periodically or randomly *** results obtained by the proposed two methods are compared with those given by the finite element method and some relevant ones reported in the *** comparison shows that the two proposed methods are particularly efficient and accurate.

关键词： effective slip length method of fundamental solution(MFS) boundary element method(BEM) Stokeslet micro-channel fluid/solid interface

High-Order Two-Scale Asymptotic Paradigm for the Elastodynamic Homogenization of Periodic Composites

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Acta Mechanica Solida Sinica 2024年第1期37卷 124-138页

作者： Wei-Zhi Luo Mu He Liang Xia Qi-Chang He State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China laboratoire Modélisation et simulation multi-echelle MSME UMR 8208 CNRSUniversite Gustave Eiffel77454 Marne-la-ValléeFrance

The classical two-scale asymptotic paradigm provides macroscopic and microscopic analyses for the elastodynamic homogenization of periodic composites based on the spatial or/and temporal variable,which offers an approximate framework for the asymptotic homogenization analysis of the motion ***,in this framework,the growing complexity of the homogenization formulation gradually becomes an obstacle as the asymptotic order *** such a context,a compact,fast,and accurate asymptotic paradigm is *** work reviews the high-order spatial two-scale asymptotic paradigm with the effective displacement field representation and optimizes the implementation by symmetrizing the tensor to be ***,the modified implementation gets rid of the excessive memory consumption required for computing the high-order tensor,which is demonstrated by representative one-and two-dimensional *** numerical results show that(1)the contrast of the material parameters between media in composites directly affects the convergence rate of the asymptotic results for the homogenization of periodic composites,(2)the convergence error of the asymptotic results mainly comes from the truncation error of the modified asymptotic homogenized motion equation,and(3)the excessive norm of the normalized wavenumber vector in the two-dimensional inclusion case may lead to a non-convergence of the asymptotic results.

关键词： Composites Homogenization Asymptotic analysis Dynamics Dispersion

A general solution for Stokes flow and its application to the problem of a rigid plate translating in a fluid

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Acta Mechanica Sinica 2015年第1期31卷 32-44页

作者： Xiang-Yu Li Si-Cong Ren Qi-Chang He School of Mechanics and Engineering Southwest Jiaotong University School of Mechanical Engineering Southwest Jiaotong University Universit'e Paris-Est Laboratoire Mod'elisation et Simulation Multi Echelle UMR 8208 CNRS 5 Boulevard Descartes77454 Marne-la-Vall'ee France

A general solution for 3D Stokes flow is given which is different from, and more compact than the exist ing ones and more compact than them in that it involves only two scalar harmonic functions. The general solution deduced is combined with the potential theory method to study the Stokes flow induced by a rigid plate of arbitrary shape trans lating along the direction normal to it in an unbounded fluid. The boundary integral equation governing this problem is derived. When the plate is elliptic, exact analytical results are obtained not only for the drag force but also for the ve locity distributions. These results include and complete the ones available for a circular plate. Numerical examples are provided to illustrate the main results for circular and ellip tic plates. In particular, the elliptic eccentricity of a plate is shown to exhibit significant influences.

关键词： Stokes flow 3D general solutions Potentialtheory method Circular plate Elliptic plate

Modeling of a Parabolic Cylindrical Solar Concentrator

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Open Journal of Applied Sciences 2025年第1期15卷 53-69页

作者： Bati Ernest Boya Bi Kpeusseu Angeline Kouambla Epse Yeo Ekoun Paul Magloire Koffi Prosper Gbaha laboratoire de Mcanique et Sciences des Matriaux Groupe Energies Renouvelables Institut National Polytechnique Houphout Boigny Yamoussoukro Cte dIvoire

This work aims at the mathematical modeling of a parabolic trough concentrator, the numerical resolution of the resulting equation, as well as the simulation of the heat transfer fluid heating process. To do this, a thermal balance was established for the heat transfer fluid, the absorber and the glass. This allowed us to establish an equation system whose resolution was done by the finite difference method. Then, a computer program was developed to simulate the temperatures of the heat transfer fluid, the absorber tube and the glass as a function of time and space. The numerical resolution made it possible to obtain the temperatures of the heat transfer fluid, the absorber and the glass. The simulation of the fluid heating process was done in one-hour time steps, from six in the morning to six in the afternoon. The results obtained show that the temperature difference between the inlet and the outlet of the sensor is very significant. These results obtained, regarding the variation of the temperatures of the heat transfer fluid, the absorber and the glass, as well as the powers and efficiency of the parabolic trough concentrator and various factors, allow for the improvement of the performances of our prototype.

关键词： Modeling simulation Parabolic Trough Concentrator Heat Transfer Fluid Temperature

Mechanical Properties of Soil-Rock Mixture Filling in Fault Zone Based on Mesostructure

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Computer Modeling in Engineering & Sciences 2022年第8期132卷 681-705页

作者： Mei Tao Qingwen Ren Hanbing Bian Maosen Cao Yun Jia Department of Engineering Mechanics Hohai UniversityNanjing210098China laboratoire de Genie Civil et g´eo-Environnement Universite de LilleLille59000France laboratoire de Mecanique MultiphysiqueMulti-´echelleUniversite de LilleLille59000France

Soil-rock mixture(SRM)filling in fault zone is an inhomogeneous geomaterial,which is composed of soil and rock *** controls the deformation and stability of the abutment and dam foundation,and threatens the long-term safety of high arch *** study the macroscopic and mesoscopic mechanical properties of SRM,the development of a viable mesoscopic numerical simulation method with a mesoscopic model generation technology,and a reasonable parametric model is crucially desired to overcome the limitations of experimental conditions,specimen dimensions,and experiment *** this end,this study presents a mesoscopic numerical method for simulating the mechanical behavior of SRM by proposing mesoscopic model generation technology based on its mesostructure features,and a rock parameter model considering size *** validity and rationality of the presented mesoscopic numerical method is experimentally verified by the triaxial compression tests with different rock block contents(RBC).The results indicate that the rock block can increase the strength of SRM,and it is proved that the random generation technique and the rock parameter model considering size effect are ***,there are multiple failure surfaces for inhomogeneous geomaterial of SRM,and the angle of the failure zone is no longer 45◦.The yielding zones of the specimen are more likely to occur in thin sections of soil matrix isolated by blocks with the failure path avoiding the rock *** proposed numerical method is effective to investigate the meso-damage mechanism of SRM.

关键词： Soil-rock mixture(SRM) triaxial compression tests random generation technique mesostructure rock parameter model size effect finite element method

A weak formulation of heterogenous viscoacoustic wave propagation in infinite domain

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Earthquake Engineering and Engineering Vibration 2025年第1期24卷 31-51页

作者： Xie Zhinan Zheng Yonglu Paul Cristini Alexis Bottero Shan Zhendong Lu Jianqi Zhang Xubin Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationKey Laboratory of Earthquake Disaster MitigationMinistry of Emergency ManagementHarbin 150080China laboratoire de Mecanique et d’Acoustique du CNRS Aix Marseille Univ.CNRSMarseille F-13353France Marine Physical Laboratory Scripps Institution of OceanographyUniversity of CaliforniaSan Diego 92093USA

The accurate simulation of wave propagation in real media requires properly taking the attenuation into account,which leads to wave dissipation together with its causal companion,wave *** this study,to obtain a weak formulation of heterogenous viscoacoustic wave propagation in an infinite domain,the viscoacoustic medium is first characterized by its frequency-dependent complex bulk compliance instead of the classically used complex bulk ***,a mechanical model using serially connected standard linear solids(SSLS)is built to obtain the rational approximation of the complex bulk compliance whose parameters are calculated via an adapted nonlinear optimization *** the obtained bulk compliance-based constitutive relation,a novel second-order viscoacoustic wave equation in the frequency domain is derived,of which the weak formulation can be physically explained as the virtual work equation and can thus be discretized using a continuous spectral element method in ***,a new method is introduced to address the convolution terms involved in the inverse Fourier transform,whose accurate time integration can then be achieved using an explicit time scheme,which avoids the transient growth that exists in the classical *** resulting full time-space decoupling scheme can handle wave propagation in arbitrary heterogeneous ***,to treat the wave propagation in an infinite domain,a perfectly matched layer in weak formulation is derived for the truncation of the infinite domain via complex coordinate stretching of the virtual work *** only minor modification,the resulting perfectly matched layer can be implemented using the same time scheme as for the wave equation inside the truncated *** accuracy,numerical stability,and versatility of the new proposed scheme are demonstrated with numerical examples.

关键词： viscoacoustic wave standard linear solid complex bulk compliance heterogenous media perfectly matched layer Legendre spectral element method

Reliability Analysis of a 2D Model of a Solar Still Developed Using Comsol® multiphysics

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Open Journal of Modelling and simulation 2025年第1期13卷 20-50页

作者： Manampy Randrianantenaina Tsiry Angelos Andriamanampisoa Mino Patricia Randrianarison Karl Zimmermann Harry Chaplin Edouard Andrianarison cole Suprieure Polytechnique dAntananarivo University of Antananarivo Antananarivo Madagascar laboratoire de Recherche en Matriaux Procds et Gnie Civil Antananarivo Madagascar Tatirano Social Enterprise Fort-Dauphin Madagascar

Solar stills represent a promising solution for desalinating saline waters, providing a sustainable alternative in regions with limited access to drinking water. This study evaluates the reliability of a two-dimensional (2D) numerical model of a solar still, developed using COMSOL® multiphysics software, focusing on a passive cascading device called “Pano Rano.” Two physical prototypes were constructed: one with a standard concrete basin and the other with acrylic plastic. The simulations revealed significant differences in theoretical yield based on the material used. With a radiation of 1200 W/m2, the acrylic prototype displayed an evaporation of 4455.53 mL/m2 and a production of 2925.98 mL/m2 of distilled water, while the concrete model showed an evaporation of 2109.95 mL/m2 and produced 1383.93 mL/m2 of distilled water. The results indicate that evaporation significantly exceeds condensation, highlighting an underutilized evaporation potential. The evaluation of the numerical model’s performance against experimental results was conducted using the mean squared error (MSE) and the coefficient of determination (R2). The best performance was observed in summer (MSE of 16.24;R2 of 0.95), while winter results were less convincing (MSE of 204.77;R2 of −2.78). This variability underscores the model’s limitations and the need for future research. The study also demonstrates that the choice of basin material significantly influences productivity, with acrylic plastic outperforming concrete in terms of thermal efficiency.

关键词： Solar Desalination Passive Cascade Solar Still Distilled Water Production Pano Rano