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International Journal of Smart and Nano materials 2010年第3期1卷 224-235页

作者： Pelin Berik Ayech Benjeddou institute of Technical mechanics Johannes Kepler University of LinzLinzAustria institut supérieur de mécanique de paris(supméca) ParisFrance

An experimental benchmark is proposed for piezoelectric,direct-torsion actuation using mono-morph piezoceramic d_(15)shear *** is reached by designing and assembling an adaptive plate having two identical composite faces sandwiching a core made of connected six oppositely polarized(OP)piezoceramic d15 shear patches along the *** electronic speckle pattern interferometry system was used to measure the static tip deflection of the adaptive sandwich composite plate that was mounted in a cantilever configuration and actuated in torsion by progressively applied voltages on the piezoceramic shear core electroded major ***,the effective rate of twist was post-processed and proposed as an evaluation criterion for smart composites under piezoelectric torsion *** verification of the experimental results,the proposed experimental benchmark was simulated using three-dimensional piezoelectric finite elements(FE)within ABAQUS®commercial *** comparison of the obtained experimental and simulation results showed reasonable agreement,but the slight nonlinear experimental response was not confirmed by the linear FE *** experimentally proved torsion actuation mechanism,produced by OP piezoceramic d15 shear patches,can be applied actively to prevent torsion in many applications,such as in wind turbines,helicopter blades,robot arms,flexible space structures,etc.

关键词： torsion actuation shear-mode piezoceramic benchmark experiment simulation

Static experimentations of the piezoceramic d_(15)-shear actuation mechanism for sandwich structures with opposite or same poled patches-assembled core and composite faces

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International Journal of Smart and Nano materials 2011年第4期2卷 230-244页

作者： Pelin Berik Ayech Benjeddou institute of Technical mechanics Johannes Kepler University of LinzLinzAustria institut supérieur de mécanique de paris(supméca) ParisFrance

Static d_(15)-shear actuated smart composites consisting of glass fiber/epoxy layers sandwiching piezoceramic shear patches-assembled cores were investigated experimentally and *** piezoceramic cores were formed by connecting two or three patches with the same or opposite polarization *** each cantilevered benchmark the shear-induced transverse tip deflection,under increasing actuation voltage,ranging from 61.5 V to 198 V,was measured by an electronic speckle pattern interferometer *** performance of the shear actuated smart composites was characterized by their shear-induced transverse deflection per length per *** was found that this performance is much better at high voltages for which the response becomes *** verification of the experimental results the proposed benchmarks were simulated within ABAQUS®commercial code using three-dimensional piezoelectric finite *** comparison of the obtained experimental and simulation results show a nonlinear dependence of the transverse deflection for voltages higher than around 92 V.

关键词： piezoceramic d_(15)-shear static actuation smart composite

macroscale fluorescence imaging against autofluorescence under ambient light

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Light(Science & Applications) 2018年第1期7卷 151-162页

作者： Ruikang Zhang Raja Chouket marie-Aude Plamont Zsolt Kelemen Agathe Espagne Alison G.Tebo Arnaud Gautier Lionel Gissot Jean-denis Faure Ludovic Jullien Vincent Croquette Thomas Le Saux PASTEUR Département de ChimieÉcole Normale SupérieurePSL UniversitySorbonne UniversitéCNRS75005 ParisFrance institut Jean-Pierre Bourgin INRAAgroParisTechCNRSSaclay Plant Science(SPS)UniversitéParis-SaclayVersaillesFrance Laboratoire de Physique Statistique École Normale SupérieurePSL Research UniversityUniversitéParis Diderot Sorbonne Paris-CitéSorbonne UniversitéCNRS75005 ParisFrance institut de biologie de l’École normale supérieure(IBENS) École Normale SupérieureCNRSINSERMPSL Research University75005 ParisFrance

macroscale fluorescence imaging is increasingly used to observe biological ***,it may suffer from spectral interferences that originate from ambient light or autofluorescence of the sample or its *** this manuscript,we built a simple and inexpensive fluorescence macroscope,which has been used to evaluate the performance of Speed OPIOm(Out of Phase Imaging after Optical modulation),which is a reference-free dynamic contrast protocol,to selectively image reversibly photoswitchable fluorophores as labels against detrimental autofluorescence and ambient *** tuning the intensity and radial frequency of the modulated illumination to the Speed OPIOm resonance and adopting a phase-sensitive detection scheme that ensures noise rejection,we enhanced the sensitivity and the signal-to-noise ratio for fluorescence detection in blot assays by factors of 50 and 10,respectively,over direct fluorescence observation under constant ***,we overcame the strong autofluorescence of growth media that are currently used in microbiology and realized multiplexed fluorescence observation of colonies of spectrally similar fluorescent bacteria with a unique configuration of excitation and emission ***,we easily discriminated fluorescent labels from the autofluorescent and reflective background in labeled leaves,even under the interference of incident light at intensities that are comparable to *** proposed approach is expected to find multiple applications,from biological assays to outdoor observations,in fluorescence macroimaging.

关键词： ambient illumination light

Field-dependent nonlinear piezoelectricity:a focused review

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International Journal of Smart and Nano materials 2018年第1期9卷 68-84,I0004页

作者： Ayech Benjeddou ROBERVAL UmR 7337 UTC/CNRS Universitéde Technologie de Compiègne(UTC)CompiègneFranceInstitut Supérieur de Mécanique de Paris(SUPMECA)Saint OuenFrance

This contribution presents a multidisciplinary review of the so-called field-dependent nonlinear *** starts with an introduction that poses the literature analysis framework,through defining this operational(that is oftenmet in practice)piezoelectric field-dependent ***,the latter is a less known phenomenon although it is inherent to stress-free actuation responses of corresponding smart materials,actuators and ***,related experimental observations from piezoelectric materials,actuator devices and smart structures tests are multidisciplinary surveyed for understanding the underlying mechanisms of the encountered field-dependent ***,empirical material and numerical structural modelling and simulation approaches are critically reviewed from,respectively,the constitutive and finite element analysis points of *** conclusions and few future directions for research are finally provided as a *** is worth mentioning that,although it is concise(retains only experiments and experimentally-correlated models and simulations),this critical review covers the last three decades period which is almost the whole age of the piezoelectric materials,actuators and smart structures research field.

关键词： Stress-free actuation field-dependent nonlinearity piezoelectric materials actuators smart structures experiments,modelling and simulation

Serrated Flow model for metallic Glasses under Compressive Loading

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Acta metallurgica Sinica(English Letters) 2013年第5期26卷 503-508页

作者： m.A.Yousfi K.Hajlaoui Z.Tourki A.R.Yavari Laboratoire de mcanique de Sousse LMS ENISo Universit de Sousse SImaP-LTPCm Institut National Polytechnique de Grenoble

A rheological model is proposed that incorporates the serrated flow nature of metallic glasses. It involves the process of the nucleation, propagation and the arrest of a shear bands in the samples subjected to compressive deformation at room temperature. Numerical resolution of the constitutive equations resulting from the model is compared with the stress-strain curve obtained from in-situ nano-compression test in SEm of Zrbased metallic glass. Parametric identification method was applied and enabled us to release the physical parameters of the model. The obtained results showed that the model is adequately valid to describe the experimental data and the almost adjustable model parameters are physically meaningful and comparable to literature.

关键词： metallic glasses Shear bands Serrated flow Rheological modelling Nanocrystallization

Numerical study of the performance of multistage Scaba 6SRGT impellers for the agitation of yield stress fluids in cylindrical tanks

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Journal of Hydrodynamics 2015年第3期27卷 436-442页

作者： AmEUR Houari BOUZIT mohamed GHENAIm Abdellah Laboratoire de mécanique Appliquée Faculté de Génie MécaniqueUSTO-MB institut de Technologie Université Ibn Khaldoun INSA de Strasbourg-24 Bd de la Victoire-67084 Strasbourg-France

The 3-D flow fields and power consumption in a vessel stirred by multistage Scaba 6SRGT impeller have been investiga- ted. The Xanthan gum solutions in water were used, which have a shear thinning behavior with yield stress. This study was carried out with the help of a CFD package （CFX 13.0, Ansys Inc.） which is based on the finite volume method to solve the momentum equations. The effects of stirring rate, fluid rheology, impeller number, impeller location and vessel size on the performance of such stirred system are presented. To validate the CFD model, our predicted results have been compared with other literature data and a satisfactory agreement has been found.

关键词： Scaba 6SRGT impeller multistage agitator yield stress fluid stirred tank power consumption

Thermal Convection in a Spherical Shell with melting/Freezing at either or both of Its Boundaries

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Journal of Earth Science 2013年第5期24卷 669-682页

作者： Renaud deguen institut de mécanique des Fluides de Toulouse Université de Toulouse (INPT UPS) and CNRS

In a number of geophysical or planetological settings, including Earth＇s inner core, a sili- cate mantle crystallizing from a magma ocean, or an ice shell surrounding a deep water ocean--a situa- tion possibly encountered in a number of Jupiter and Saturn＇s icy satellites--a convecting crystalline layer is in contact with a layer of its melt. Allowing for melting/freezing at one or both of the boundaries of the solid layer is likely to affect the pattern of convection in the layer. We study here the onset of thermal convection in a viscous spherical shell with dynamically induced melting/freezing at either or both of its boundaries. It is shown that the behavior of each interface---permeable or impermeable-- depends on the value of a dimensionless number P （one for each boundary）, which is the ratio of a melting/freezing timescale over a viscous relaxation timescale. A small value of P corresponds to perme- able boundary conditions, while a large value of P corresponds to impermeable boundary conditions. Linear stability analysis predicts a significant effect of semi-permeable boundaries when the number P characterizing either of the boundary is small enough： allowing for melting/freezing at either of the boundary allows the emergence of larger scale convective modes. The effect is particularly drastic when the outer boundary is permeable, since the degree 1 mode remains the most unstable even in the case of thin spherical shells. In the case of a spherical shell with permeable inner and outer boundaries, the most unstable mode consists in a global translation of the solid shell, with no deformation. In the limit of a full sphere with permeable outer boundary, this corresponds to the ＂convective translation＂ mode recently proposed for Earth＇s inner core. As another example of possible application, we discuss the case of thermal convection in Enceladus＇ ice shell assuming the presence of a global subsurface ocean, and found that melting/freezing could have an importa

关键词： planetary mantle thermal convection phase change linear stability analysis.

Smart structures,materials and nano technology in engineering

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International Journal of Smart and Nano materials 2018年第2期9卷 85-87,I0001页

作者： Ayech Benjeddou ROBERVAL Universitéde Technologie de Compiègne(UTC)–Centre National de la Recherche Scientifique(CNRS)CompiègneFrance institut supérieur de mécanique de paris(supmECA) Saint OuenFrance

Smart materials are active materials that are nowadays commonly used for sensing,actuation,and transduction for structural noise(acoustic),shape(morphing)and vibration control and health monitoring of(in historical order)offshore petroleum,aerospace,aeronautic,mechanical,civil(including infra-structures and wind turbines)and biomedical *** recently,they were also used for energy harvesting from environment for autonomously and wirelessly powering of various temperature or pressure monitoring sensors and some medical(fluidic)implants and(surgery)devices.

关键词： Smart structures harvesting

Numerical Analysis of the Behavior of A New Aeronautical Alloy (Ti555-03) Under the Effect of A High-Speed Water Jet

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China Ocean Engineering 2019年第1期33卷 114-126页

作者： I.Ben Belgacem L.Cheikh E.m.Barhoumi W.Khan W.Ben Salem Laboratoire de Génie mécanique Ecole Nationale d’Ingénieurs de MonastirUniversité de Monastir institut Préparatoire aux Etudes d’Ingénieur de monastir Université de Monastir department of Electrical and Computer Engineering College of EngineeringDhofar University University of Waterloo institut supérieur des Arts et métiers de mahdia Université de Monastir

In this paper, we present a numerical simulation of a water jet impacting a new aeronautical material Ti555-03 *** Computational Fluid Dynamics(CFD) behavior of the jet is investigated using a FV(Finite Volume) *** Fluid–Structure Interaction(FSI) is studied using a coupled SPH(Smoothed Particle Hydrodynamics)-FE(Finite Element) method. The jets hit the metal sheet with an initial velocity 500 m/s. Two configurations which differ from each other by the position(angle of inclination) of the plate relatively to the axis of revolution of the jet inlet are investigated in this study. The objective of this study is to predict the impact of the fluid produced at high pressure and high speed especially at the first moment of impact. Numerical simulations are carried out under ABAQUS. We have shown in this study that the inclination of the titanium alloy plate by 45° stimulates the phenomenon of recirculation of water. This affects the velocity profile, turbulence and boundary layers in the impact zone. The stagnation zone and the phenomenon of water recirculation are strongly influenced by the slope of the plate which gives a pressure gradient and displacement very important between the two configurations. Fluctuations of physical variables(displacement and pressure) prove the need for a noise and vibratory study. These predictions will subsequently be used for the modeling of the problem of an orthogonal cut in a high-speed machining process assisted by high-pressure water jet.

关键词： Titanium alloy(Ti555-03) CFD turbulence ABAQUS Smoothed Particle Hydrodynamics(SPH) Fluid Structure Interaction(FSI)

Fuzz-TImE: an intelligent system for managing fuzzy temporal information

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International Journal of Intelligent Computing and Cybernetics 2017年第2期10卷 200-222页

作者： Aymen Gammoudi Allel Hadjali Boutheina Ben Yaghlane institut superieur de Gestion de Tunis LARODECTunisTunisia Laboratoire d’Informatique et d’Automatique pour les Systèmes École nationale supérieure de mécanique et d’aérotechniqueChasseneuil-du-PoitouFrance IHECT University of CarthageTunisTunisia

Purpose-Time modeling is a crucial feature in many application ***,temporal information often is not crisp,but is subjective and *** purpose of this paper is to address the issue related to the modeling and handling of imperfection inherent to both temporal relations and ***/methodology/approach-On the one hand,fuzzy extensions of Allen temporal relations are investigated and,on the other hand,extended temporal relations to define the positions of two fuzzy time intervals are ***,a database system,called Fuzzy Temporal Information management and Exploitation(Fuzz-TImE),is developed for the purpose of processing fuzzy temporal ***-To evaluate the proposal,the authors have implemented a Fuzz-TImE system and created a fuzzy historical database for the querying *** demonstrative scenarios from history domain are proposed and *** limitations/implications-The authors have conducted some experiments on archaeological data to show the effectiveness of the Fuzz-TImE ***,thorough experiments on large-scale databases are highly desirable to show the behavior of the tool with respect to the performance and time execution *** implications-The tool developed(Fuzz-TImE)can have many practical applications where time information has to be dealt *** particular,in several real-world applications like history,medicine,criminal and financial domains,where time is often perceived or expressed in an imprecise/fuzzy *** implications-The social implications of this work can be expected,more particularly,in two domains:in the museum to manage,exploit and analysis the piece of information related to archives and historic data;and in the hospitals/medical organizations to deal with time information inherent to data about patients and ***/value-This paper presents the design and characterization of a novel and intelligent database system to process and manage

关键词： Information retrieval Fuzzy set theory Fuzzy temporal relations Fuzzy time intervals Temporal databases