Papers by Moez Ben Jaber
This dataset contains a user subroutine "UMAT" of the 3D strain-based constitutive mode... more This dataset contains a user subroutine "UMAT" of the 3D strain-based constitutive model for shape memory alloys proposed by Ben Jaber et al. [1,2]. This subroutine allows you to implement this model to the software "Abaqus" and hence to simulate SMA parts behavior.
L'amortisseur dynamique est un système utilisé pour contrôler l'amplitude de vibrations d... more L'amortisseur dynamique est un système utilisé pour contrôler l'amplitude de vibrations de la structure sur laquelle il sera ajouté. Il s'agit d'un système oscillant à un seul degré de liberté (dit système auxiliaire) qu'on vient ajouter à la structure vibrante (dite système principal). On étudie ici un système auxiliaire à plusieurs degrés de liberté (d.d.l.), son optimisation et son influence sur le comportement vibratoire de la structure vibrante. Pour ce faire on compare ses performances à celles d'un système auxiliaire à un seul degré de liberté.
In this work, a novel artificial circular muscle based on shape memory alloy (S.M.A.) is propose... more In this work, a novel artificial circular muscle based on shape memory alloy (S.M.A.) is proposed. The design is inspired from the natural circular muscles found in certain organs of the human body such as the small intestine. The heating of the prestrained SMA artificial muscle will induce its contraction. In order to measure the mechanical work provided in this case, the muscle will be mounted on a silicone rubber cylindrical tube prior to heating. After cooling, the reaction of the rubber tube will involve the return of the muscle to its prestrained state. A finite element model of the new SMA artificial muscle was built using the software "ABAQUS". The SMA thermomechanical behavior law was implemented using the user subroutine "UMAT".The numerical results of the finite element analysis of the SMA muscle are presented to shown that the proposed design is able to mimic the behavior of a natural circular muscle.
In this paper, a new 1D constitutive model for shape memory alloy using strain and temperature as... more In this paper, a new 1D constitutive model for shape memory alloy using strain and temperature as control variables is presented. The new formulation is restricted to the 1D stress case and takes into account the martensite reorientation and the asymmetry of the SMA behavior in tension and compression. Numerical implementation of the new model in a finite element code was conducted. The numerical results for superelastic behavior in tension and compression tests are presented and were compared to experimental data taken from the literature. Other numerical tests are presented, showing the model's ability to reproduce the main aspects of SMA behavior such as the shape memory effect and the martensite reorientation under cyclic loading. Finally, to demonstrate the utility of the new constitutive model, a dynamic test of a bi-clamped SMA bending beam under forced oscillation is described.
The drilling operation is considered by manufacturers as complex and difficult process (rapid wea... more The drilling operation is considered by manufacturers as complex and difficult process (rapid wear of the cutting edge as well as problems of chip evacuation). Faced with these failures, manufacturers have shifted in recent years towards the drilling process assisted by forced vibrations. This method consist to add an axial oscillation with a low frequency to the classical feed movement of the drill so as to ensure good fragmentation and better chip evacuation.
This paper presents a model for prediction of cutting forces during a drilling operation assisted by forced low-frequency vibration. The model allows understanding the interaction between the tool and the workpiece and identifying numerically the three-dimensional evolution of the cutting force components generated by the vibratory drilling operation. The effects of cutting parameters, tool parameters and those of forced vibrations on the cutting forces distributions will be discussed.
The potential use of Cu-based shape memory alloys (SMA) in retrofitting historical monuments is i... more The potential use of Cu-based shape memory alloys (SMA) in retrofitting historical monuments is investigated in this paper. This study is part of the ongoing work conducted in Tunisia within the framework of the FP6 European Union project (WIND-CHIME) on the use of appropriate modern seismic protective systems in the conservation of Mediterranean historical buildings in earthquake-prone areas. The present investigation consists of a finite element simulation, as a preliminary to an experimental study where a cantilever masonry wall, representing a part of a historical monument, is subjected to monotonic and quasi-static cyclic loadings around a horizontal axis at the base level. The wall was retrofitted with an array of copper SMA wires with different cross-sectional areas. A new model is proposed for heat-treated copper SMAs and is validated based on published experimental results. A series of nonlinear finite element analyses are then performed on the wall for the purpose of assessing the SMA device retrofitting capabilities. Simulation results show an improvement of the wall response for the case of monotonic and quasi-static cyclic loadings.
In the present work a modified phenomenological model of the shape memory alloy (SMA) constituti... more In the present work a modified phenomenological model of the shape memory alloy (SMA) constitutive law is proposed that is capable of reproducing some aspects of SMA thermomechanical behavior like superelasticity and the one-way shape memory effect. The modified law uses strain and temperature as control variables, which eliminates the need for transformation correctors in finite element analysis. It is implemented in a structural model developed to analyze three-dimensional (3D) structures made out of thick beam elements with features such as taper and curvature, given that SMA products typically fall in this category of shapes. Moreover, a finite strain and large displacement description is adopted to account for the large deformations exhibited during phase transformation. Results, produced by the proposed model, of simulated tensile, three-point and four-point bending tests are presented and compared with experimental data taken from the literature.
L'amortisseur dynamique est un système utilisé pour contrôler l'amplitude de vibrations de la str... more L'amortisseur dynamique est un système utilisé pour contrôler l'amplitude de vibrations de la structure sur laquelle il sera ajouté. Il s'agit d'un système oscillant à un seul degré de liberté (dit système auxiliaire) qu'on vient ajouter à la structure vibrante (dite système principal). On étudie ici un système auxiliaire à plusieurs degrés de liberté (d.d.l.), son optimisation et son influence sur le comportement vibratoire de la structure vibrante. Pour ce faire on compare ses performances à celles d'un système auxiliaire à un seul degré de liberté.
Conference Presentations by Moez Ben Jaber
Récemment, plusieurs travaux étudiant le comportement dynamique des alliages à mémoire de forme (... more Récemment, plusieurs travaux étudiant le comportement dynamique des alliages à mémoire de forme (AMF) ont été envi-sagés. Dans ce cas et plus précisément dans le cas d’une sollicita-tion 1D l’AMF subit un chargement cyclique de traction-compression. A basse température ceci induit à l’échelle de la mi-crostructure une combinaison de deux types de transformation de phase solide-solide: une transformation de l’austénite en marten-site et une autre due à la réorientation cyclique des variantes de martensite suite au changement du sens des contraintes. Dans le présent travail une modification de la loi proposée par Ben Jaber et al. [1]a été introduite. La nouvelle formulation est restreinte au cas de sollicitation 1D et prend en considération la réorientation de la martensite. Une implémentation numérique à un code de calcul par éléments finis est établit. Les résultats des simulations numériques ont montré la capacité du modèle à reproduire les principaux aspects du comportement des AMF comme la super-élasticité, l’effet mémoire de forme,… Des essais numériques ont été étudiés et présentés dans ce travail montrent la réussite du modèle à reproduire le comportement de l’AMF sous un charge-ment cyclique. Enfin, une application du modèle à l’étude du com-portement vibratoire d’une poutre bi-encastrée en flexion est présentée.
The dynamic vibration absorber is used to control the vibration amplitude of structure and machin... more The dynamic vibration absorber is used to control the vibration amplitude of structure and machine on which it
will be mounted. It is composed of single or multiple degrees of freedom (d.o.f.) auxiliary systems attached
to vibrating system (called primary system) . The usage of a multi-degree of freedom auxiliary system at the end
of the crankshaft, will make us able to confirm its practice interest in torsional vibration control of reciprocating
engine. Therefore, we should show its performances and compare them to those of a single degree of freedom
auxiliary system.
A pre-stretched shape memory alloy bone staple, when heated to body temperature, develops an impo... more A pre-stretched shape memory alloy bone staple, when heated to body temperature, develops an important
compressive force that stabilizes the bone and accelerates consolidation. In spite of the great success of SMA
staples for bone fracture treatment, design of these devices has been difficult because of the lack of appropriate
analysis tools for SMA structures. Existing numerical models generally use 3D solid finite elements which result
in computationally costly analysis and design procedures. In this paper, an efficient analysis tool for SMA bone
staples is proposed using a 3D SMA beam finite element model based on a finite strain description and a new
phenomenological SMA constitutive law. Numerical examples are presented and compared with experimental data
taken from the literature.
L'objet de ce travail est de développer un
muscle circulaire artificiel à base d'alliage à mémoir... more L'objet de ce travail est de développer un
muscle circulaire artificiel à base d'alliage à mémoire de forme
(A.M.F.). L'idée consiste à imiter le mode d'action des muscles
circulaires naturels retrouvés dans certains organes du corps humain
comme ceux de l'intestin grêle. Plusieurs conceptions ont été
proposées et une étude comparative entre elles a conduit à en
choisir la meilleure. Pour analyser le comportement du nouveau
muscle un modèle numérique sous le logiciel commercial
"ABAQUS" a été construit. Ceci est réalisé par l'implémentation à
ce logiciel d’une loi de comportement des A.M.F en utilisant la
procédure Fortran "UMAT". Les résultats des simulations numériques du modèle éléments finis du muscle ont montré la réussite de la conception proposée à produire un effort et un déplacement de contraction radiale acceptable.
Dans le présent article, nous intéresserons à l’étude du
comportement dynamique de l’outil en cou... more Dans le présent article, nous intéresserons à l’étude du
comportement dynamique de l’outil en cours d’une opération de perçage vibratoire forcé. Cette étude nous permettra en particulier de discuter l’influence du comportement vibratoire de l’outil sur le processus d’usinage (efforts de coupe et déplacements relatifs outil pièce).
In this work, the effect of a number of design parameters on the performances of a Darrieus type ... more In this work, the effect of a number of design parameters on the performances of a Darrieus type vertical axis wind turbine (VAWT) is studied. A CFD model of the turbine is built using the commercial software "Ansys-Fluent". The geometry of the VAWT and the imposed boundary conditions are introduced in a completely parameterized way. The air flow around the turbine is considered viscous, unsteady, turbulent and incompressible. The k- turbulence model is adopted for the resolution of the Reynolds Averaged Navier-Stokes equations. The comparison of simulation results with experimental data taken from the literature shows a good agreement between them.
Courses by Moez Ben Jaber
Cours de mécanique des solides pour les classes préparatoires aux études d'ingénieurs
Sujets de mini-projets d'optimisation des structures pour les classes terminales MEST de l'école ... more Sujets de mini-projets d'optimisation des structures pour les classes terminales MEST de l'école polytechnique de Tunisie
Cours de technologie de conception mécanique pour les classes préparatoires aux études d'ingénieu... more Cours de technologie de conception mécanique pour les classes préparatoires aux études d'ingénieurs niveau 2éme année préparation technologique
Drafts by Moez Ben Jaber
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Papers by Moez Ben Jaber
This paper presents a model for prediction of cutting forces during a drilling operation assisted by forced low-frequency vibration. The model allows understanding the interaction between the tool and the workpiece and identifying numerically the three-dimensional evolution of the cutting force components generated by the vibratory drilling operation. The effects of cutting parameters, tool parameters and those of forced vibrations on the cutting forces distributions will be discussed.
Conference Presentations by Moez Ben Jaber
will be mounted. It is composed of single or multiple degrees of freedom (d.o.f.) auxiliary systems attached
to vibrating system (called primary system) . The usage of a multi-degree of freedom auxiliary system at the end
of the crankshaft, will make us able to confirm its practice interest in torsional vibration control of reciprocating
engine. Therefore, we should show its performances and compare them to those of a single degree of freedom
auxiliary system.
compressive force that stabilizes the bone and accelerates consolidation. In spite of the great success of SMA
staples for bone fracture treatment, design of these devices has been difficult because of the lack of appropriate
analysis tools for SMA structures. Existing numerical models generally use 3D solid finite elements which result
in computationally costly analysis and design procedures. In this paper, an efficient analysis tool for SMA bone
staples is proposed using a 3D SMA beam finite element model based on a finite strain description and a new
phenomenological SMA constitutive law. Numerical examples are presented and compared with experimental data
taken from the literature.
muscle circulaire artificiel à base d'alliage à mémoire de forme
(A.M.F.). L'idée consiste à imiter le mode d'action des muscles
circulaires naturels retrouvés dans certains organes du corps humain
comme ceux de l'intestin grêle. Plusieurs conceptions ont été
proposées et une étude comparative entre elles a conduit à en
choisir la meilleure. Pour analyser le comportement du nouveau
muscle un modèle numérique sous le logiciel commercial
"ABAQUS" a été construit. Ceci est réalisé par l'implémentation à
ce logiciel d’une loi de comportement des A.M.F en utilisant la
procédure Fortran "UMAT". Les résultats des simulations numériques du modèle éléments finis du muscle ont montré la réussite de la conception proposée à produire un effort et un déplacement de contraction radiale acceptable.
comportement dynamique de l’outil en cours d’une opération de perçage vibratoire forcé. Cette étude nous permettra en particulier de discuter l’influence du comportement vibratoire de l’outil sur le processus d’usinage (efforts de coupe et déplacements relatifs outil pièce).
Courses by Moez Ben Jaber
Drafts by Moez Ben Jaber
This paper presents a model for prediction of cutting forces during a drilling operation assisted by forced low-frequency vibration. The model allows understanding the interaction between the tool and the workpiece and identifying numerically the three-dimensional evolution of the cutting force components generated by the vibratory drilling operation. The effects of cutting parameters, tool parameters and those of forced vibrations on the cutting forces distributions will be discussed.
will be mounted. It is composed of single or multiple degrees of freedom (d.o.f.) auxiliary systems attached
to vibrating system (called primary system) . The usage of a multi-degree of freedom auxiliary system at the end
of the crankshaft, will make us able to confirm its practice interest in torsional vibration control of reciprocating
engine. Therefore, we should show its performances and compare them to those of a single degree of freedom
auxiliary system.
compressive force that stabilizes the bone and accelerates consolidation. In spite of the great success of SMA
staples for bone fracture treatment, design of these devices has been difficult because of the lack of appropriate
analysis tools for SMA structures. Existing numerical models generally use 3D solid finite elements which result
in computationally costly analysis and design procedures. In this paper, an efficient analysis tool for SMA bone
staples is proposed using a 3D SMA beam finite element model based on a finite strain description and a new
phenomenological SMA constitutive law. Numerical examples are presented and compared with experimental data
taken from the literature.
muscle circulaire artificiel à base d'alliage à mémoire de forme
(A.M.F.). L'idée consiste à imiter le mode d'action des muscles
circulaires naturels retrouvés dans certains organes du corps humain
comme ceux de l'intestin grêle. Plusieurs conceptions ont été
proposées et une étude comparative entre elles a conduit à en
choisir la meilleure. Pour analyser le comportement du nouveau
muscle un modèle numérique sous le logiciel commercial
"ABAQUS" a été construit. Ceci est réalisé par l'implémentation à
ce logiciel d’une loi de comportement des A.M.F en utilisant la
procédure Fortran "UMAT". Les résultats des simulations numériques du modèle éléments finis du muscle ont montré la réussite de la conception proposée à produire un effort et un déplacement de contraction radiale acceptable.
comportement dynamique de l’outil en cours d’une opération de perçage vibratoire forcé. Cette étude nous permettra en particulier de discuter l’influence du comportement vibratoire de l’outil sur le processus d’usinage (efforts de coupe et déplacements relatifs outil pièce).