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Vibrational frequency analysis of finite elastic tube filled with compressible viscous fluid

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Acta mechanica Solida Sinica 2017年第4期30卷 435-444页

作者： Ilyess mnassri Adil El Baroudi arts et métiers paristech

The vibrational frequency analysis of finite elastic tube filled with compressible viscous fluid has received plenty of attention in recent years. To apply frequency analysis to defect detection for example, it is necessary to investigate the vibrational behavior under appropriate boundary conditions. In this paper, we present a detailed theoretical study of the three dimensional modal analysis of compressible fluid within an elastic cylinder. The dispersion equations of flexura], torsional and longitudinal modes are derived by elastodynamic theory and the unsteady Stokes equation. The symbolic software mathematica is used in order to find the coupled vibration frequencies. The dispersion equation is deduced and analytically solved. The finite element results are compared with the present method for validation and an acceptable match between them are obtained.

关键词： Frequency analysis Compressible Stokes flow Coupled vibration Elastodynamic

Lateral ring compression test applied to a small caliber steel jacket:Identification of a constitutive model

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Defence Technology（防务技术） 2024年第6期36卷 133-148页

作者： Yann Coget Yael Demarty Christophe Czarnota Anthony Bracq Jean-Sebastien Brest Alexis Rusinek French-German Research Institute of Saint-Louis 5 Rue Du General Cassagnou68300 Saint-LouisFrance Laboratoire d'etude des microstructures et de mecanique des materiaux(LEm3) CNRSUniversite de LorraineArts&Metiers ParisTechF-57000 MetzFrance

The evolution of threats and scenarios requires continuous performance improvements of ballistic protections for armed *** a modeling point of view,it is necessary to use sufficiently precise material behavior models to accurately describe the phenomena observed during the impact of a projectile on a protective *** this context,the goal of this paper is to characterize the behavior of a small caliber steel jacket by combining experimental and numerical *** experimental method is based on the lateral compression of ring specimens directly machined from the thin and small *** speeds and temperatures are considered in a quasi-static regime in order to reveal the strain rate and temperature dependencies of the tested *** Finite Element Updating method(FEmU)is *** results are coupled with an inverse optimization method and a finite element numerical model in order to determine the parameters of a constitutive model representative of the jacket *** of the present model are verified against experimental results and a parametric study as well as a discussion on the identified material parameters are *** results indicate that the strain hardening parameter can be neglected and the behavior of the thin steel jacket can be described by a modeling without strain hardening sensitivity.

关键词： Full metal jacket ammunition Lateral ring compression Inverse identification Numerical simulation

modelling the viscoplastic behaviour of Callovo-Oxfordian claystone with consideration of damage effect

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Journal of Rock mechanics and Geotechnical Engineering 2024年第1期16卷 303-316页

作者： Hao Wang Yu-Jun Cui minh Ngoc Vu Jean Talandier Ecole des Ponts paristech Laboratoire Navier/CERMES6 et 8 avenue Blaise PascalMarne La Vallée cedex 277455France Andra R&D DepartmentChâtenay-Malabry92290France

In order to evaluate the performance of deep geological disposal of radioactive waste,an underground research laboratory(URL)was constructed by Andra in the Callovo-Oxfordian(COx)claystone formation at the meuse/Haute-marne(mHm).The construction of URL induced the excavation damage of host formations,and the ventilation in the galleries desaturated the host formation close to the gallery ***,it is expected that the mechanical behaviour of COx claystone is *** study presents a constitutive model developed to describe the viscoplastic behaviour of unsaturated and damaged COx *** this model,the unsaturation effect is considered by adopting the Bishop effective stress and the van Genuchten(VG)water retention *** terms of the viscoplastic behaviour,the nonstationary flow surface(NSFS)theory for unsaturated soils is used with consideration of the coupled effects of strain rate and suction on the yield stress.A progressive hardening law is ***,a non-associated flow rule is used,which is similar to that in Barcelona basic model(BBm).In addition,to describe the damage effect induced by suction change and viscoplastic loading,a damage function is defined based on the crack volume *** damage function contains two variables:unsaturated effective stress and viscoplastic volumetric strain,with the related parameters determined based on the mercury intrusion porosimetry(mIP)*** the model validation,different tests on COx claystone under different loading paths are *** between experimental and simulated results indicated that the present model is able to well describe the viscoplastic behaviour of damaged COx claystone,including swelling/shrinkage,triaxial extension and compression,and triaxial creep.

关键词： Callovo-Oxfordian(COx)claystone Excavation damage Time-dependent behaviour Suction Viscoplastic model

Analysis of semi-solid response under rapid compression tests using multi-scale modelling and experiments

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Transactions of Nonferrous metals Society of China 2010年第9期20卷 1691-1695页

作者： V.FAVIER H.ATKINSON arts et métiers paristech CNRS PIMM151 Boulevard de l'Hpital Department of Engineering University of Leic esterUniversity Road

Simulating semi-solid metal forming requires modelling semi-solid ***, such modelling is difficult because semi-solid behavior is thixotropic and depends on the liquid-solid spatial distribution within the *** order to better understand and model relationships between microstructure and behavior, a model based on micromechanical approaches and homogenisation techniques is *** model is an extension of a previous model established in a pure viscoplastic framework to account for ***, experimental load-displacement signals reveal the presence of an elastic-type response in the earlier stages of deformation when semi-solids are loaded under rapid *** elastic feature of the behaviour is attributed to the response of the porous solid skeleton saturated by incompressible liquid.A good quantitative agreement is found between the elastic-viscoplastic predicted response and the experimental *** precisely, the strong initial rising part of the load-displacement curve, the peak load and the subsequent fall in load are well *** effect of solid fraction on mechanical response is in qualitative agreement with experiments.

关键词： semi-solid metal aluminium solid fraction elastic-viscoplasticity homogenization

Rotating instability in the vaneless diffuser of a radial flow pump

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Journal of Thermal Science 2008年第4期17卷 368-374页

作者： A.Dazin O.Coutier-Delgosha P.Dupont S.Coudert G.Caignaert G.Bois Laboratoire de mécanique de Lille(UmR CNRS 8107) Arts et Métiers ParisTech Laboratoire de mécanique de Lille Ecole Centrale de Lille Laboratoire de mécanique de Lille CNRS

The paper refers to the behavior of a vaneless diffuser of a radial flow pump in partial flow operating conditions. Some experimental data have been obtained using 2D/2C PIV and unsteady pressure measurements within the diffuser, in various operating conditions. The experimental results at the lower flow rate are compared with two-dimensional numerical calculations.

关键词： Vaneless diffuser Radial flow pump Instability Particle Image Velocimetry Pressure measurements 2D calculations.

Influence of random uncertainties of anisotropic fibrous model parameters on arterial pressure estimation

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Applied mathematics and mechanics(English Edition) 2013年第5期34卷 529-540页

作者： A.EDDHAHAK-OUNI I.mASSON F.mOHAND-KACI m.ZIDI arts et mtiers paristech(ENSAm-ESTP/IRC) Institut de Recherche en ConstructibilitUniversit Paris-Est Crteil Centre de Recherches Chirurgicales Facult de MdecineUniversit Paris-Est Crteil

This paper deals with a stochastic approach based on the principle of the maximum entropy to investigate the effect of the parameter random uncertainties on the arterial pressure. motivated by a hyperelastic, anisotropic, and incompressible constitutive law with fiber families, the uncertain parameters describing the mechanical behavior are considered. Based on the available information, the probability density functions are attributed to every random variable to describe the dispersion of the model parameters. Numerous realizations are carried out, and the corresponding arterial pressure results are compared with the human non-invasive clinical data recorded over a mean cardiac cycle. Furthermore, the monte Carlo simulations are performed, the convergence of the probabilistic model is proven. The different realizations are useful to define a reliable confidence region, in which the probability to have a realization is equm to 95%. It is shown through the obtained results that the error in the estimation of the arterial pressure can reach 35% when the estimation of the model parameters is subjected to an uncertainty ratio of 5%. Finally, a sensitivity analysis is performed to identify the constitutive law relevant parameters for better understanding and characterization of the arterial wall mechanical behaviors.

关键词： arterial pressure non-invasive clinical data hyperelasticity anisotropy random confidence region

Blockage and distortion effects on a vane-island type diffuser performance of centrifugal pumps for various flow rates

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排灌机械工程学报 2016年第12期34卷 1013-1021页

作者： SI Qiaorui DAZIN Antoine DUPONT Patrick ROUSSetTE Olivier BOIS Gérard National Research Center of Pumps Jiangsu University Laboratoire de mécanique de Lille (UmR CNRS 8107) Arts et Métiers ParisTech Laboratoire de mécanique de Lille(UmR CNRS 8107) Ecole Centrale de Lille

Experimental investigation of mean flow velocity and pressure inside the vane-island type diffuser passage of a test centrifugal pump model is presented.A directional three-hole probe was used to investigate hub-to-shroud flow properties at diffuser leading and trailing edge *** addition,the mid-section between suction and pressure sides along the diffuser passage was also *** these measurements were performed at five different flow *** flow structures at the inlet section of the diffuser and along with the passage were analyzed in detail,with a focus on the flow distribution and the pressure recovery evolution of different diffuser *** and distortion effects were analyzed by using existing published particle image velocimetry(PIV)measurements in the outer part of the impeller and around the diffuser throat in order to get a better understanding of the overall performances and local flow structures of such a diffuser *** results show that back flows occur on the shroud region from impeller exit plane up to the semi-vaneless part of the diffuser at low flow *** blockage effects combining with blade thickness geometrical blockage tend to diminish the effects of theoretical high positive *** high flow rates,negative incidence effects induce high local velocity on the pressure side of the diffuser just after the *** aerodynamic blockage associated with low flow distortions are found to have a beneficial effect on pressure recovery for low flow *** the contrary,high flow distortions are found for increased flow rates,resulting in a low pressure recovery inside the semi-vane less part of the diffuser and after the throat.

关键词： vane island diffuser flow structure pressure recovery three-hole probe particle image velocimetry

On the origin of the high tensile strength and ductility of additively manufactured 316L stainless steel: multiscale investigation

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Journal of materials Science & Technology 2020年第6期41卷 209-218页

作者： Bassem Barkia Pascal Aubry Paul Haghi-Ashtiani Thierry Auger Lionel Gosmain Frédéric Schuster Hicham maskrot DEN-Service d’etudes Analytiques et de Réactivitédes Surfaces CEAUniversitéParis-Saclay91191France Laboratoire de mécanique des Sols Structures et MatériauxCentralesupélecUMR CNRS 8579UniversitéParis-Saclay92295France arts et métiers paristech PIMMUMR CNRS 800675013 ParisFrance CEA Cross-Cutting Program on materials and Processes Skills 91191Gif-sur-YvetteFrance

We report that 316L austenitic stainless steel fabricated by direct laser deposition(DLD),an additive manufacturing(Am)process,have a higher yield strength than that of conventional 316L while keeping high *** interestingly,no clear anisotropy in tensile properties was observed between the building and the scanning direction of the 3D printed *** examination of the as-built parts shows a heterogeneous solidification cellular *** electron microscopy observations coupled with Energy Dispersive X-ray Spectrometry(EDS)reveal the presence of chemical micro-segregation correlated with high dislocation density at cell boundaries as well as the in-situ formation of well-dispersed oxides and transition-metal-rich *** hierarchical heterogeneous microstructure in the Am parts induces excellent strength of the 316L stainless steel while the low staking fault energy of the as-built 316L promotes the occurrence of abundant deformation twinning,in the origin of the high ductility of the Am *** additional post-process treatments,the Am 316L proves that it can be used as a structural material or component for repair in mechanical construction.

关键词： Additive manufacturing Austenitic stainless steel Dislocation structure Twinning mechanical behavior Anisotropy

multi-dimensional morphology of hydride diffusion layer and associated sequential twinning in commercial pure titanium

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Journal of materials Science & Technology 2022年第8期103卷 105-112页

作者： Qian Wang Shun Xu Yajun Zhao Jean-Sébastien Lecomte Christophe Schuman Laboratoire d’etude des microstructures et de mécanique des matériaux(LEm3) Universitéde Lorraine CNRSArts et Métiers ParisTechMetz57073France Laboratory of Excellence on Design of Alloy metals for low-mAss Structures(DAmAS) University of Lorraine57073France School of Iron and Steel Soochow UniversitySuzhou 215021China School of materials Science and Engineering Dalian Jiaotong UniversityDalian 116021China

The dominant hydride precipitates have been well demonstrated to follow two types of orientation relationships(ORs)with Ti matrix:OR1 with{0001}//{001},//and OR2 with{0001}//{111},//.Within the grains with special orientations,the complicated interactions of different hydride variants inside Ti-hydride diffusion layer are characterized in this *** OR1 hydride layer,the orientations of{1010}plane parallel to the sample surface and a-axis parallel to the normal direction prefer multiple OR1 *** orientations favorable for OR2 hydride layer are:{1013}plane parallel to sample surface corresponding to the layer with one OR2 variant dominated and c-axis parallel to the surface normal with multiple OR2 variant layer ***,{1012}extension twins and{1122}contraction twins are activated to accommodate the OR2 hydride-induced surface expansion and local misfit *** stimulation of these two twins is also orientation-dependent:{1012}and{1122}twins are observed in the grains with c-axis parallel to and deviated from the surface normal,*** further variant selection for each twin mode is performed through shear accommodation of hydride-twin pairs.

关键词： Titanium Hydride Cross section Twin Variant selection