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The analysis of composite laminated beams using a 2D interpolating meshless technique

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Acta mechanica Sinica 2018年第1期34卷 99-116页

作者： S.H.m.Sadek j.Belinha m.P.L.Parente R.m.Natal jorge j.m.A.César de Sá A.j.m.Ferreira Department of mechanical Engineering Faculty of EngineeringUniversity of Porto Institute of mechanical Engineering and Industrial management University of Porto

Laminated composite materials are widely implemented in several engineering constructions. For its relative light weight, these materials are suitable for aerospace, military, marine, and automotive structural applications. To obtain safe and economical structures, the modelling analysis accuracy is highly relevant. Since meshless methods in the recent years achieved a remarkable progress in computational mechanics, the present work uses one of the most flexible and stable interpolation meshless technique available in the literature—the Radial Point Interpolation method(RPIm).Here, a 2 D approach is considered to numerically analyse composite laminated beams. Both the meshless formulation and the equilibrium equations ruling the studied physical phenomenon are presented with detail. Several benchmark beam examples are studied and the results are compared with exact solutions available in the literature and the results obtained from a commercial finite element software. The results show the efficiency and accuracy of the proposed numeric technique.

关键词： Radial point interpolators RPIm Laminated beam meshless method

Spin-correlation function of the fully frustrated Ising model and ±j Ising spin glass on a square lattice

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Chinese Physics B 2013年第6期22卷 549-552页

作者： m Y Ali j Poulter Department of mathematics Faculty of ScienceMahidol University

In this work we study the correlation function of the ground state of a two-dimensional fully frustrated Ising model as well as spin glass. The Pfaffian method is used to calculate free energy and entropy as well as the correlation function. We estimate the exponent of spin correlation function for the fully frustrated model and spin glass. In this paper an overview of the latest results on the spin correlation function is presented.

关键词： spin glass correlation function exponent square lattice

3D printing of patient-specific 316L–stainless–steel medical implants using fused filament fabrication technology: two veterinary case studies

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Bio-Design and manufacturing 2022年第4期5卷 808-815页

作者： j.m.Chacón P.j.Núñez m.A.Caminero E.García-Plaza j.Vallejo m.Blanco Escuela Técnica Superior de Ingeniería Industrial Universidad de Castilla-La ManchaAvdaCamilo JoséCela213071 Ciudad RealSpain Protresde Ingeniería y Soluciones C/Solana 60nave 313005 Ciudad RealSpain

Biomedical fracture fixation implants have complex sculptured geometries to adapt perfectly to fractured bones,making them difficult and expensive to manufacture with conventional machining methods. Fused filament fabrication(FFF) is a very popular Additive manufacturing technology that simplifies the manufacture of parts with complex geometries, making it ideal for the manufacture of customized medical implants.

关键词： steel fracture fused

magnetic, Dielectric and Complex Impedance Properties of xBa_(0.95)Sr_(0.05)TiO_3–(1-x)BiFe_(0.9)Gd_(0.1)O_3multiferroic Ceramics

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Acta metallurgica Sinica(English Letters) 2016年第6期29卷 505-517页

作者： m.j.miah A.K.m.Akther Hossain Department of Physics Bangladesh University of Engineering and Technology Department of Physics Comilla University

xBa_（0.95）Sr_（0.05）TiO_3–（1-x）BiFe_（0.9）Gd_（0.1）O_3[x BST–（1-x）BFGO]（x = 0.00, 0.10, 0.20 and 0.25） multiferroic ceramics were prepared by the standard solid-state reaction technique. Structural characterization was performed by X-ray diffraction. All the samples showed rhombohedral distorted perovskite structure. Surface morphology of the ceramics was studied by the field emission scanning electron microscope（FESEm）. From the FESEm observation, the grain size was observed to be decreased with increasing BST content. Enhanced magnetic properties were observed in BFGO with the increase in BST content because of large lattice distortion. The complex initial permeability increased with the increasing of BST content. The study of dielectric properties showed that the dielectric constant increased, whereas dielectric loss decreased with increasing of BST content due to the reduction of oxygen vacancies. An analysis of the electric impedance and modulus with frequency was performed at different temperatures. Non-Debye-type relaxation processes occur in the compound which was confirmed from the nature of the Cole–Cole plot. The DC conductivity was found to increase with the rise in temperature which indicates the semiconducting behavior of the compound with characteristics of the negative temperature coefficient of resistance. The activation energy, responsible for the relaxation determined from the modulus spectra（0.246 eV）, was found to be almost same as the value obtained from the impedance study（0.240 eV）, indicating that charge carriers overcome the same energy barrier during relaxation. The frequency response of imaginary parts of electric impedance and modulus suggested that the relaxation in xB ST–（1-x）BFGO ceramics follows the same mechanism at various temperatures.

关键词： magnetic properties Dielectric properties Impedance spectroscopy Activation energy

REITERATED HOmOGENIZATION OF DEGENERATE NONLINEAR ELLIPTIC EQUATIONS

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Chinese Annals of mathematics,Series B 2002年第3期23卷 325-334页

作者： j.BYSTRm j.ENGSTRm P.WALL Dedicated to the memory of jacques-Louis Lions Dedicated to the memory of Jacques-Louis LionsDedicated to the memory of Jacques-Louis Lions

The authors study homogenization of some nonlinear partial differential equations of the form -div (?(hx, h2x,Duh)) =f, where a is periodic in the first two arguments and monotone in the third. In particular the case where a satisfies degenerated structure conditions is studied. It is proved that uh converges weakly in W01,1 (?) to the unique solution of a limit problem as h ? '. moreover, explicit expressions for the limit problem are obtained.

关键词： Homogenization Reiterated monotone Degenerated

Algebraic and group treatments to nonlinear displaced number states and their nonclassicality features:A new approach

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Chinese Physics B 2015年第6期24卷 334-340页

作者： N Asili Firouzabadi m K Tavassoly m j Faghihi Atomic and molecular Group Faculty of PhysicsYazd University The Laboratory of Quantum Information Processing Yazd University Physics and Photonics Department Graduate University of Advanced Technology

Recently, nonlinear displaced number states （NDNSs） have been manually introduced, in which the deformation function f（n） has been artificially added to the previously well-known displaced number states （DNSs）. Indeed, just a simple comparison has been performed between the standard coherent state and nonlinear coherent state for the formation of NDNSs. In the present paper, after expressing enough physical motivation of our procedure, four distinct classes of NDNSs are presented by applying algebraic and group treatments. To achieve this purpose, by considering the DNSs and recalling the nonlinear coherent states formalism, the NDNSs are logically defined through an algebraic consideration. In addition, by using a particular class of Gilmore-Perelomov-type of SU（1,1） and a class of SU（2） coherent states, the NDNSs are introduced via group-theoretical approach. Then, in order to examine the nonclassical behavior of these states, sub-Poissonian statistics by evaluating mandel parameter and Wigner quasi-probability distribution function associated with the obtained NDNSs are discussed, in detail.

关键词： displaced number state nonlinear coherent state Wigner function nonclassical state

Two-fluid modeling of Geldart A particles in gas-fluidized beds

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Particuology 2008年第6期6卷 540-548页

作者： m.A. van der Hoef j.A.m. Kuipers Faculty of Science & Technology University of Twente

We have investigated the effect of cohesion and drag models on the bed hydrodynamics of Geldart A particles based on the two-fluid （TF） model. For a high gas velocity U0 = 0.03 m/s, we found a transition from the homogeneous fluidization to bubbling fluidization with an increase of the coefficient C1, which is used to account for the contribution of cohesion to the excess compressibility. Thus cohesion can play a role in the bed expansion of Geldart A particles. Apart from cohesion, we have also investigated the influence of the drag models. When using the Wen and Yu drag correlation with an exponent n = 4.65, we find an under-prediction of the bed expansion at low gas velocities （U0 = 0.009 m/s）. When using a larger exponent （n = 9.6）, as reported in experimental studies of gas-fluidization, a much better agreement with the experimental bed expansion is obtained. These findings suggest that at low gas velocity, a scale-down of the commonly used drag model is required. On the other hand, a scale-up of the commonly used drag model is necessary at high gas velocity （U0 = 0.2 and 0.06 m/s）. We therefore conclude that scaling the drag force represent only an ad hoc way of repairing the deficiencies of the TF model, and that a far more detailed study is required into the origin of the failure of the TF model for simulating fluidized beds of fine powders.

关键词： Gas-fluidized bed Geldart A particles Two-fluid model Cohesive force Drag correlation

Two-fluid modelling for cylindrical fluidized beds using kinetic theory for rough spheres

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Particuology 2020年第3期18卷 25-34页

作者： Lei Yang j.T.Padding j.A.m.Kuipers Helmholtz Institute Erlangen-Nürnberg for Renewable Energy(IEK-11) Fürther Straβe 24890429 NurnbergGermany Department of Process and Energy Delft University of Technology2628CB DelftThe Netherlands Department of Chemical Engineering and Chemistry Eindhoven University of Technology5600MB EindhovenThe Netherlands

Recently,we have extended the kinetic theory of granular flow (KTGF) to include friction between the spherical particles and tested it in rectangular *** this study,the extended KTGF implemented in cylindrical coordinates is used to model the more-commonly employed cylindrical bubbling fluidized *** attention is paid to the anti-symmetric part of the velocity gradient in the solids stress *** verification of the implementation,a comparison of the present model in the limit of zero friction with the original (frictionless) KTGF model was ***,simulations of bubbling fluidized beds of inelastic particles were performed using our extended KTGF and an effective KTGF model for inelastic particles of jenkins and *** simulation results show good agreement for the time-averaged solids volume fraction distribution and solids circulation ***,our model is validated by predicting the individual bubble behavior in dense bubbling fluidized beds containing different granular materials in a comparison with experimental data from Verma et al.(2014).The extended KTGF leads to an improved agreement with experimental bubble *** to previous work (Yang et al.,2016b,2017c),and by introducing cylindrical coordinates,the current work demonstrates that the extended KTGF improves predictions for the temporal bubble behavior of cylindrical fluidized beds.

关键词： Fluidization Frictional collision Rough particles Cylindrical bed hydrodynamics Two-fluid model

Composition and evolution of the continental crust:Retrospect and prospect

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Geoscience Frontiers 2022年第5期13卷 1-15页

作者： j.L.R.Touret m.Santosh j.m.Huizenga Institut de minéralogie Physique des MatériauxCosmochimieSorbonne Universités4 Place JussieuF-75005 ParisFrance 121 Rue de la Réunion 75020 ParisFrance School of Earth Sciences and Resources China University of GeosciencesBeijing 100083China Department of Earth Science University of AdelaideAdelaideSA 5005Australia Faculty of Environmental Sciences and Natural Resource management Norwegian University of Life SciencesP.O.Box 5003NO-1432ÅsNorway EGRU(Economic Geology Research Centre) James Cook UniversityTownsvilleQueensland 4811Australia Department of Geology University of JohannesburgPO Box 524Auckland Park 2006South Africa

Until the middle of the 20th century,the continental crust was considered to be dominantly *** hypothesis was revised after the Second World War when several new studies led to the realization that the continental crust is dominantly made of metamorphic *** rocks were emplaced at peak metamorphic conditions in domains,which can be defined by geophysical *** to medium-grade metamorphic rocks constitute the upper crust,granitic migmatites and intrusive granites occur in the middle crust,and the lower crust,situated between the Conrad and moho discontinuities,comprises charnockites and *** continental crust acquired its final structure during metamorphic episodes associated with mantle upwelling,which mostly occurred in supercontinents prior to their disruption,during which the base of the crust experienced ultrahigh temperatures(>1000℃,ultrahigh temperature granulite-facies metamorphism).Heat is provided by underplating of mantle-derived mafic magmas,as well as by a massive influx of low H_(2)O activity mantle fluids,***-density CO_(2) and highsalinity *** fluids are initially stored in ultrahigh temperature domains,and subsequently infiltrate the lower crust,where they generate anhydrous granulite mineral *** brines can reach upper crustal levels,possibly even the surface,along major shear zones,where granitoids are generated through brine streaming in addition to those formed by dehydration melting in upper crustal levels.

关键词： Brines CO_(2) Continental crust Granulite Lower crust