Documents disponibles écrits par cet auteur

Buckling analysis of nonuniform and axially graded columns with varying flexural rigidity / Y. Huang in Journal of engineering mechanics, Vol. 137 N° 1 (Janvier 2011) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 137 N° 1 (Janvier 2011) . - pp.73-81 Titre : Buckling analysis of nonuniform and axially graded columns with varying flexural rigidity Type de document : texte imprimé Auteurs : Y. Huang, Auteur ; X.-F. Li, Auteur Année de publication : 2011 Article en page(s) : pp.73-81 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Buckling  Critical  loads  Bending  Stiffness  Columns. Résumé : In this paper, we present a novel analytic approach to solve the buckling instability of Euler-Bernoulli columns with arbitrarily axial nonhomogeneity and/or varying cross section. For various columns including pinned-pinned columns, clamped columns, and cantilevered columns, the governing differential equation for buckling of columns with varying flexural rigidity is reduced to a Fredholm integral equation. Critical buckling load can be exactly determined by requiring that the resulting integral equation has a nontrivial solution. The effectiveness of the method is confirmed by comparing our results with existing closed-form solutions and numerical results. Flexural rigidity may take a majority of functions including polynomials, trigonometric and exponential functions, etc. Examples are given to illustrate the enhancement of the load-carrying capacity of tapered columns for admissible shape profiles with constant volume or weight, and the proposed method is of benefit to optimum design of columns against buckling in engineering applications. This method can be further extended to treat free vibration of nonuniform beams with axially variable material properties. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i1/p73_s1?isAuthorized=no [article] Buckling analysis of nonuniform and axially graded columns with varying flexural rigidity [texte imprimé] / Y. Huang, Auteur ; X.-F. Li, Auteur . - 2011 . - pp.73-81. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 137 N° 1 (Janvier 2011) . - pp.73-81 Mots-clés : Buckling  Critical  loads  Bending  Stiffness  Columns. Résumé : In this paper, we present a novel analytic approach to solve the buckling instability of Euler-Bernoulli columns with arbitrarily axial nonhomogeneity and/or varying cross section. For various columns including pinned-pinned columns, clamped columns, and cantilevered columns, the governing differential equation for buckling of columns with varying flexural rigidity is reduced to a Fredholm integral equation. Critical buckling load can be exactly determined by requiring that the resulting integral equation has a nontrivial solution. The effectiveness of the method is confirmed by comparing our results with existing closed-form solutions and numerical results. Flexural rigidity may take a majority of functions including polynomials, trigonometric and exponential functions, etc. Examples are given to illustrate the enhancement of the load-carrying capacity of tapered columns for admissible shape profiles with constant volume or weight, and the proposed method is of benefit to optimum design of columns against buckling in engineering applications. This method can be further extended to treat free vibration of nonuniform beams with axially variable material properties. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i1/p73_s1?isAuthorized=no

Concerning the use of constant phase elements (CPEs) in the analysis of impedance data / Y. Huang in Materials and corrosion, Vol. 61 N° 4 (Avril 2010) 

Public ISBD [article]  in Materials and corrosion > Vol. 61 N° 4 (Avril 2010) . - pp. 302–305 Titre : Concerning the use of constant phase elements (CPEs) in the analysis of impedance data Type de document : texte imprimé Auteurs : Y. Huang, Auteur ; H. Shih, Auteur ; F. Mansfeld, Auteur Année de publication : 2010 Article en page(s) : pp. 302–305 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Constant  phase  element;  equivalent  circuit;  oxide  coatings Résumé : Impedance spectra obtained for Al6061 samples that had been anodized and sealed in two different processes and subjected to thermal cycling at three different temperatures have been analyzed using the Equivcrt software using a three-time constant model with four constant phase elements (CPEs). Excellent agreement has been observed between the experimental and the fit data. The high-frequency data have also been analyzed using the ANODAL software. Excellent agreement between the experimental data and the fit data was found in both cases; however, the fit parameters were quite different. The relationship between the CPEs and the surface properties of the anodized samples has been discussed. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905385/abstract [article] Concerning the use of constant phase elements (CPEs) in the analysis of impedance data [texte imprimé] / Y. Huang, Auteur ; H. Shih, Auteur ; F. Mansfeld, Auteur . - 2010 . - pp. 302–305. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 61 N° 4 (Avril 2010) . - pp. 302–305 Mots-clés : Constant  phase  element;  equivalent  circuit;  oxide  coatings Résumé : Impedance spectra obtained for Al6061 samples that had been anodized and sealed in two different processes and subjected to thermal cycling at three different temperatures have been analyzed using the Equivcrt software using a three-time constant model with four constant phase elements (CPEs). Excellent agreement has been observed between the experimental and the fit data. The high-frequency data have also been analyzed using the ANODAL software. Excellent agreement between the experimental data and the fit data was found in both cases; however, the fit parameters were quite different. The relationship between the CPEs and the surface properties of the anodized samples has been discussed. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905385/abstract

Dynamic overbooking scheduling system to improve patient access / Y. Huang in Journal of the operational research society (JORS), Vol. 63 N° 6 (Juin 2012) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 63 N° 6 (Juin 2012) . - pp. 810–820 Titre : Dynamic overbooking scheduling system to improve patient access Type de document : texte imprimé Auteurs : Y. Huang, Auteur ; P. Zuniga, Auteur Année de publication : 2012 Article en page(s) : pp. 810–820 Note générale : Operationa research 810–820 Langues : Anglais (eng) Mots-clés : Health  services  Overbooking  No-shows  Outpatient  scheduling Index. décimale : 001.424 Résumé : Patient no-show has long been a recognized problem in modern outpatient health-care delivery systems. The common impacts are reduced clinic efficiency and provider productivity, wasted medical resources, increased health-care cost and limited patient access to care. The main goal of this research is to develop an effective dynamic overbooking policy into any scheduling system that accounts for the predictive probability of no-shows for any given patient. This policy increases the quality of patient care in terms of wait time and access to care while minimizing the clinic's costs. This proposed model is also illustrated to be more cost-effective than overbooking patients evenly throughout a clinic session. This paper also suggests that overbooking should be performed at better patient flow and higher no-show rate so that the costs are minimized. Consequently, this research improves the outpatient experience for both patients and medical providers. DEWEY : 001.424 ISSN : 0160-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v63/n6/abs/jors201183a.html [article] Dynamic overbooking scheduling system to improve patient access [texte imprimé] / Y. Huang, Auteur ; P. Zuniga, Auteur . - 2012 . - pp. 810–820. Operationa research 810–820 Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 63 N° 6 (Juin 2012) . - pp. 810–820 Mots-clés : Health  services  Overbooking  No-shows  Outpatient  scheduling Index. décimale : 001.424 Résumé : Patient no-show has long been a recognized problem in modern outpatient health-care delivery systems. The common impacts are reduced clinic efficiency and provider productivity, wasted medical resources, increased health-care cost and limited patient access to care. The main goal of this research is to develop an effective dynamic overbooking policy into any scheduling system that accounts for the predictive probability of no-shows for any given patient. This policy increases the quality of patient care in terms of wait time and access to care while minimizing the clinic's costs. This proposed model is also illustrated to be more cost-effective than overbooking patients evenly throughout a clinic session. This paper also suggests that overbooking should be performed at better patient flow and higher no-show rate so that the costs are minimized. Consequently, this research improves the outpatient experience for both patients and medical providers. DEWEY : 001.424 ISSN : 0160-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v63/n6/abs/jors201183a.html

Study of plastic shear localization via the flow theory of mechanism-based strain gradient plasticity / Z. Shi in Journal of engineering mechanics, Vol. 135 N°3 (Mars 2009) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 135 N°3 (Mars 2009) . - pp. 132-138 Titre : Study of plastic shear localization via the flow theory of mechanism-based strain gradient plasticity Type de document : texte imprimé Auteurs : Z. Shi, Auteur ; Y. Huang, Auteur ; J. Song, Auteur Article en page(s) : pp. 132-138 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Shear  flow  Plasticity  Material  properties. Résumé : The plastic shear localization is studied via the flow theory of mechanism-based strain gradient plasticity. The shear strain rate displays a rather sharp decrease from the center to the boundary of shear band, and gradually approaches the uniform remote shear strain rate outside the shear band. The shear band thickness obtained analytically is linearly proportional to the (length of) Burgers vector, and also depends on the softening modulus and mesoscale cell size. The maximum shear strain rate in the shear band, however, is sensitive to other material properties such as the ultimate tensile strength and intrinsic material length in strain gradient plasticity. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...] [article] Study of plastic shear localization via the flow theory of mechanism-based strain gradient plasticity [texte imprimé] / Z. Shi, Auteur ; Y. Huang, Auteur ; J. Song, Auteur . - pp. 132-138. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 135 N°3 (Mars 2009) . - pp. 132-138 Mots-clés : Shear  flow  Plasticity  Material  properties. Résumé : The plastic shear localization is studied via the flow theory of mechanism-based strain gradient plasticity. The shear strain rate displays a rather sharp decrease from the center to the boundary of shear band, and gradually approaches the uniform remote shear strain rate outside the shear band. The shear band thickness obtained analytically is linearly proportional to the (length of) Burgers vector, and also depends on the softening modulus and mesoscale cell size. The maximum shear strain rate in the shear band, however, is sensitive to other material properties such as the ultimate tensile strength and intrinsic material length in strain gradient plasticity. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...]

The formation of nanograin structures and accelerated room-temperature theta precipitation in a severely deformed Al–4 wt.% Cu alloy / Y. Huang in Acta materialia, Vol. 58 N° 5 (Mars 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 5 (Mars 2010) . - pp. 1643–1657 Titre : The formation of nanograin structures and accelerated room-temperature theta precipitation in a severely deformed Al–4 wt.% Cu alloy Type de document : texte imprimé Auteurs : Y. Huang, Auteur ; J.D. Robson, Auteur ; P.B. Prangnell, Auteur Année de publication : 2011 Article en page(s) : pp. 1643–1657 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Severe  plastic  deformation  (SPD)  Nanocrystalline  Accelerated  ageing  Theta  phase  Nucleation Résumé : The grain size achievable and long-term stability of a severely deformed aluminium copper alloy have been investigated when copper is used in solution to inhibit recovery. It is shown that copper is more effective than magnesium in inhibiting dynamic recovery. A grain width of only ∼70 nm was obtained in an Al–4 wt.% Cu alloy, after processing by equal-channel angular extrusion to a strain of εeff = 10, resulting in a lamellar nanograin structure. However, post-processing, the severely deformed solid solution was found to be unstable at room temperature and copious precipitation of θ occurred at grain boundaries within the deformed state, leading to recovery of the deformation structure and a loss of strength. The solute level fell to equilibrium within ∼9 months. The precipitation kinetics were shown to occur at many orders of magnitude higher than can be predicted by classical nucleation and growth theory. The reasons for this discrepancy are discussed. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645409007836 [article] The formation of nanograin structures and accelerated room-temperature theta precipitation in a severely deformed Al–4 wt.% Cu alloy [texte imprimé] / Y. Huang, Auteur ; J.D. Robson, Auteur ; P.B. Prangnell, Auteur . - 2011 . - pp. 1643–1657. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 5 (Mars 2010) . - pp. 1643–1657 Mots-clés : Severe  plastic  deformation  (SPD)  Nanocrystalline  Accelerated  ageing  Theta  phase  Nucleation Résumé : The grain size achievable and long-term stability of a severely deformed aluminium copper alloy have been investigated when copper is used in solution to inhibit recovery. It is shown that copper is more effective than magnesium in inhibiting dynamic recovery. A grain width of only ∼70 nm was obtained in an Al–4 wt.% Cu alloy, after processing by equal-channel angular extrusion to a strain of εeff = 10, resulting in a lamellar nanograin structure. However, post-processing, the severely deformed solid solution was found to be unstable at room temperature and copious precipitation of θ occurred at grain boundaries within the deformed state, leading to recovery of the deformation structure and a loss of strength. The solute level fell to equilibrium within ∼9 months. The precipitation kinetics were shown to occur at many orders of magnitude higher than can be predicted by classical nucleation and growth theory. The reasons for this discrepancy are discussed. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645409007836