Abdelghani Saouab - Academia.edu (original) (raw)

Papers by Abdelghani Saouab

Research paper thumbnail of Complementarity and coordination of conflict resolution efforts in the conflicts over Abkhazia, South Ossetia, and Transdniestria

Research paper thumbnail of Analytical Modeling of Composite Molding by Resin Infusion with Flexible Tooling: VARI and RFI processes

Journal of Composite Materials, Jul 9, 2009

We present analytical modeling and closed form solutions for composite resin infusion processes s... more We present analytical modeling and closed form solutions for composite resin infusion processes such as the vacuum assisted resin infusion (VARI) process and the resin film infusion (RFI) process. As a flexible bag is placed on the top of fabric stack, while a rigid tooling is still used on the other side, a fabric deformation takes place as the resin pressure changes during the resin infiltration process. Subsequently, it is important to take into account the reinforcement compaction as well as the resin flow in the analysis of resin infusion processes. We present a fully analytical modeling of resin pressure distribution, resin flow front position, fiber volume fraction distribution, and part height change during the resin infusion process. Parametric studies are provided to investigate the influences of process parameters on the process feasibility. The evaluation of bulk permeability in the RFI process implies that the fabric compaction should be taken into account to exactly characterize the through-thickness permeability of fibrous reinforcement.

Research paper thumbnail of Génération de maillages adaptatifs par une méthode variationnelle

Ce memoire est compose de deux volets et concerne l'etude de l'adaptation geometrique et ... more Ce memoire est compose de deux volets et concerne l'etude de l'adaptation geometrique et physique des maillages structures. Dans le premier volet, on s'interesse a la generation des maillages alignes avec les frontieres. Une revue des techniques existantes avec comparaisons et exemples d'application est presentee. Le second volet constitue le coeur de cette these. Nous y presentons la methode variationnelle etudiee et developpee pour l'optimisation et l'adaptation de maillages, ainsi que la procedure de minimisation du type gradient conjugue adoptee. La methode introduite par Dulikravitch, Kennon et Carcaillet, et simplement validee sur des cas tests classiques est utilisee. Differentes ameliorations de cette methode sont introduites, telles que: 1) procede pour eviter le chevauchement des lignes du maillage; 2) technique d'interpolation de la fonction poids, tres peu couteuse en temps C. P. U. Les differents cas tests etudies nous permettent de confirmer la robustesse et l'efficacite de cette methode. De plus, des resultats tres interessants sont obtenus par son application dans divers calculs d'ecoulements. On observe une nette amelioration dans la resolution numerique et particulierement dans la capture d'eventuelles singularites

Research paper thumbnail of Modeling of air bubble dynamics during resin transfer molding by pore doublet model

The International Journal of Advanced Manufacturing Technology, Oct 29, 2019

Research paper thumbnail of Comparison of the properties of flax shives based particleboards prepared using binders of bio-based lignin and partially bio-based epoxy resin

International Journal of Adhesion and Adhesives, Sep 1, 2021

Abstract EIn order to reduce formaldehyde emissions, an experimental investigation of lightweight... more Abstract EIn order to reduce formaldehyde emissions, an experimental investigation of lightweight flax shives based particleboards, prepared using two different binders: bio-based lignin (lignosulfonate) and partially bio-based epoxy resin (greenpoxy 56), was undertaken. The flax based particleboards (with a target density of 500 kg/m³), were elaborated by a thermo-compression process using 20 wt% of binder content. The flax shives were directly valorised as they had no pre-treatment, in order to qualify their potential as a raw material. Bending, compression and fire resistance tests showed that the mechanical and flame performances of lignosulfonate-based particleboards were high compared to those of greenpoxy56 based panels. Nevertheless, the latter were found to have an interesting dimensional stability after water immersion and good insulating properties. Moreover, both lignosulfonate and greenpoxy 56 based particleboards met the minimum EN 15197 requirements for non-load bearing flaxboards for use in dry conditions (Type FB2). Such results illustrated the competitiveness of the studied particleboards, as bio-sourced structures, compared to urea-formaldehyde based panels.

Research paper thumbnail of Influence of silica fillers on failure modes of glass/vinyl ester composites under different mechanical loadings

Engineering Fracture Mechanics, Sep 1, 2019

Research paper thumbnail of Process Induced Residual Stresses

Springer eBooks, Dec 12, 2022

Research paper thumbnail of Application of a variational method in compressible flow computations

A variational method for grid optimization with application to complex flow calculations is repor... more A variational method for grid optimization with application to complex flow calculations is reported. Good results using it are obtained in several 2D cases. The method can be naturally extended to 3D flows without special difficulty.

Research paper thumbnail of Towards a numerical modeling of the coupling between RTM process and induced mechanical properties for rigid particle-filled composites

The International Journal of Advanced Manufacturing Technology, Jan 6, 2023

Research paper thumbnail of Numerical simulation of liquid composite molding processes

Revue européenne des éléments finis, 2005

This work proposes to perform an analysis about the numerical simulation of LCM processes. After ... more This work proposes to perform an analysis about the numerical simulation of LCM processes. After a description of the modelling context of these processes, our first part will describe the formulation of the laws, and a second step the application with the Thermo- Hydro-Mechanical coupling. We present a finite element procedure to simulate mold filling in the three dimensional case.

Research paper thumbnail of Analytical Modeling of CRTM and RTM Processes. Part II: Applications to the Analysis of the Process

International journal of forming processes, Sep 30, 2006

International audienc

Research paper thumbnail of Effect of matrix and hybrid reinforcement on fibre metal laminates under low–velocity impact loading

Composite Structures, May 1, 2022

Research paper thumbnail of Modeling and simulation of voids and saturation in liquid composite molding processes

Composites Part A-applied Science and Manufacturing, Jun 1, 2011

Research paper thumbnail of Modelling the effect of temperature on unsaturated soil behaviour

Comptes Rendus Geoscience, Dec 1, 2010

Research paper thumbnail of Effect of silica particle loading on shape distortion in glass/vinyl ester-laminated composite plates

Journal of The Textile Institute, Aug 7, 2017

Abstract Fibre-reinforced composites loaded with micro/nano particles are being employed in indus... more Abstract Fibre-reinforced composites loaded with micro/nano particles are being employed in industry for their functional properties. However, behaviour of such composites is different while fabrication is due to the presence of particles. One major parameter needs to be investigated is process-induced residual stress which cause shape distortion in the part. These stresses are generated due to the mismatch of thermal expansion behaviour between the plies, resulting in shape distortion of the composite part. The current study focuses to determine the effect of silica fillers on shape distortion of glass/vinyl ester-laminated composite plates. The resin samples reinforced with 0, 2, 4, 5 and 6% (vol%) of silica particles were prepared and their thermal expansion coefficients (CTE) were determined using Dilatometer. The fillers tend to decrease the CTE of reinforced resin and increase its modulus, as determined using UTM. Composite plates with UD glass were prepared with and without fillers to investigate the distortion behaviour. The experimental results showed that the curvature reduced from 4.3243 to 2.0973 mm by addition of 5% silica particles. The curvature in plates was also simulated in COMSOL Multiphysics, and results are correlated with the experimental values.

Research paper thumbnail of Injection simulations of thick composite parts manufactured by the RTM process

Composites Science and Technology, Feb 1, 2001

In order to simulate the resin flow occurring in a reinforcement during manufacture of composite ... more In order to simulate the resin flow occurring in a reinforcement during manufacture of composite materials by resin transfer moulding (RTM); the numerical codes need data such as the permeability, K, of the reinforcement. In the case of thick parts (e.g. a few centimetres thick), the spatial components of the permeability can be deduced from experimental kinetics if we are able to visualise the resin path in the reinforcement opaque bulk. Here we describe the original technique we used to achieve this aim and we demonstrate the results of X-ray spectrography for the determination of the kinetics of spatial flows through a porous medium. We then propose a mathematical approach in order to treat our experimental results and calculate the values of K. Finally, examples of simulations are compared to the corresponding experimental observations. These simulations are obtained from two numerical codes based on the finite-differences technique with curvilinear meshes and finite elements with control volumes, respectively.

Research paper thumbnail of Effect of annealing temperature on electrochemical characteristics of ruthenium oxide/multi-walled carbon nanotube composites

Materials Science And Engineering: B, Feb 1, 2010

The preparation and characterization of high-surface-area ruthenium oxide (RuO2)/multi-walled car... more The preparation and characterization of high-surface-area ruthenium oxide (RuO2)/multi-walled carbon nanotubes (MWCNTs) composite electrodes for use in supercapacitors is reported in this work. The RuO2/MWCNTs composites were prepared by the polyol process of RuO2 into MWCNTs and by Ru annealing in air before mixed with MWCNTs. The chemically oxidized and annealed Ru nanoparticles contribute a pseudocapacitance to the electrodes and

Research paper thumbnail of Numerical simulation of void formation in LCM

Composites Part A-applied Science and Manufacturing, Jun 1, 2003

Research paper thumbnail of Interaction of a flame front with its self-generated flow in an enclosure: The “tulip flame” phenomenon

Combustion and Flame, Feb 1, 1992

... FLAME FRONT/FLOWFIELD INTERACTION IN A CLOSED VESSEL 217 unburned medium, it is found that th... more ... FLAME FRONT/FLOWFIELD INTERACTION IN A CLOSED VESSEL 217 unburned medium, it is found that the velocity of the burned gases is directed toward the left end wall while the fresh gases flow alternately against the flame and toward the back end of the tube. ...

Research paper thumbnail of Analytical Modeling of CRTM and RTM Processes. Part I: General Mathematical Development

International journal of forming processes, Sep 30, 2006

International audienc

Research paper thumbnail of Complementarity and coordination of conflict resolution efforts in the conflicts over Abkhazia, South Ossetia, and Transdniestria

Research paper thumbnail of Analytical Modeling of Composite Molding by Resin Infusion with Flexible Tooling: VARI and RFI processes

Journal of Composite Materials, Jul 9, 2009

We present analytical modeling and closed form solutions for composite resin infusion processes s... more We present analytical modeling and closed form solutions for composite resin infusion processes such as the vacuum assisted resin infusion (VARI) process and the resin film infusion (RFI) process. As a flexible bag is placed on the top of fabric stack, while a rigid tooling is still used on the other side, a fabric deformation takes place as the resin pressure changes during the resin infiltration process. Subsequently, it is important to take into account the reinforcement compaction as well as the resin flow in the analysis of resin infusion processes. We present a fully analytical modeling of resin pressure distribution, resin flow front position, fiber volume fraction distribution, and part height change during the resin infusion process. Parametric studies are provided to investigate the influences of process parameters on the process feasibility. The evaluation of bulk permeability in the RFI process implies that the fabric compaction should be taken into account to exactly characterize the through-thickness permeability of fibrous reinforcement.

Research paper thumbnail of Génération de maillages adaptatifs par une méthode variationnelle

Ce memoire est compose de deux volets et concerne l'etude de l'adaptation geometrique et ... more Ce memoire est compose de deux volets et concerne l'etude de l'adaptation geometrique et physique des maillages structures. Dans le premier volet, on s'interesse a la generation des maillages alignes avec les frontieres. Une revue des techniques existantes avec comparaisons et exemples d'application est presentee. Le second volet constitue le coeur de cette these. Nous y presentons la methode variationnelle etudiee et developpee pour l'optimisation et l'adaptation de maillages, ainsi que la procedure de minimisation du type gradient conjugue adoptee. La methode introduite par Dulikravitch, Kennon et Carcaillet, et simplement validee sur des cas tests classiques est utilisee. Differentes ameliorations de cette methode sont introduites, telles que: 1) procede pour eviter le chevauchement des lignes du maillage; 2) technique d'interpolation de la fonction poids, tres peu couteuse en temps C. P. U. Les differents cas tests etudies nous permettent de confirmer la robustesse et l'efficacite de cette methode. De plus, des resultats tres interessants sont obtenus par son application dans divers calculs d'ecoulements. On observe une nette amelioration dans la resolution numerique et particulierement dans la capture d'eventuelles singularites

Research paper thumbnail of Modeling of air bubble dynamics during resin transfer molding by pore doublet model

The International Journal of Advanced Manufacturing Technology, Oct 29, 2019

Research paper thumbnail of Comparison of the properties of flax shives based particleboards prepared using binders of bio-based lignin and partially bio-based epoxy resin

International Journal of Adhesion and Adhesives, Sep 1, 2021

Abstract EIn order to reduce formaldehyde emissions, an experimental investigation of lightweight... more Abstract EIn order to reduce formaldehyde emissions, an experimental investigation of lightweight flax shives based particleboards, prepared using two different binders: bio-based lignin (lignosulfonate) and partially bio-based epoxy resin (greenpoxy 56), was undertaken. The flax based particleboards (with a target density of 500 kg/m³), were elaborated by a thermo-compression process using 20 wt% of binder content. The flax shives were directly valorised as they had no pre-treatment, in order to qualify their potential as a raw material. Bending, compression and fire resistance tests showed that the mechanical and flame performances of lignosulfonate-based particleboards were high compared to those of greenpoxy56 based panels. Nevertheless, the latter were found to have an interesting dimensional stability after water immersion and good insulating properties. Moreover, both lignosulfonate and greenpoxy 56 based particleboards met the minimum EN 15197 requirements for non-load bearing flaxboards for use in dry conditions (Type FB2). Such results illustrated the competitiveness of the studied particleboards, as bio-sourced structures, compared to urea-formaldehyde based panels.

Research paper thumbnail of Influence of silica fillers on failure modes of glass/vinyl ester composites under different mechanical loadings

Engineering Fracture Mechanics, Sep 1, 2019

Research paper thumbnail of Process Induced Residual Stresses

Springer eBooks, Dec 12, 2022

Research paper thumbnail of Application of a variational method in compressible flow computations

A variational method for grid optimization with application to complex flow calculations is repor... more A variational method for grid optimization with application to complex flow calculations is reported. Good results using it are obtained in several 2D cases. The method can be naturally extended to 3D flows without special difficulty.

Research paper thumbnail of Towards a numerical modeling of the coupling between RTM process and induced mechanical properties for rigid particle-filled composites

The International Journal of Advanced Manufacturing Technology, Jan 6, 2023

Research paper thumbnail of Numerical simulation of liquid composite molding processes

Revue européenne des éléments finis, 2005

This work proposes to perform an analysis about the numerical simulation of LCM processes. After ... more This work proposes to perform an analysis about the numerical simulation of LCM processes. After a description of the modelling context of these processes, our first part will describe the formulation of the laws, and a second step the application with the Thermo- Hydro-Mechanical coupling. We present a finite element procedure to simulate mold filling in the three dimensional case.

Research paper thumbnail of Analytical Modeling of CRTM and RTM Processes. Part II: Applications to the Analysis of the Process

International journal of forming processes, Sep 30, 2006

International audienc

Research paper thumbnail of Effect of matrix and hybrid reinforcement on fibre metal laminates under low–velocity impact loading

Composite Structures, May 1, 2022

Research paper thumbnail of Modeling and simulation of voids and saturation in liquid composite molding processes

Composites Part A-applied Science and Manufacturing, Jun 1, 2011

Research paper thumbnail of Modelling the effect of temperature on unsaturated soil behaviour

Comptes Rendus Geoscience, Dec 1, 2010

Research paper thumbnail of Effect of silica particle loading on shape distortion in glass/vinyl ester-laminated composite plates

Journal of The Textile Institute, Aug 7, 2017

Abstract Fibre-reinforced composites loaded with micro/nano particles are being employed in indus... more Abstract Fibre-reinforced composites loaded with micro/nano particles are being employed in industry for their functional properties. However, behaviour of such composites is different while fabrication is due to the presence of particles. One major parameter needs to be investigated is process-induced residual stress which cause shape distortion in the part. These stresses are generated due to the mismatch of thermal expansion behaviour between the plies, resulting in shape distortion of the composite part. The current study focuses to determine the effect of silica fillers on shape distortion of glass/vinyl ester-laminated composite plates. The resin samples reinforced with 0, 2, 4, 5 and 6% (vol%) of silica particles were prepared and their thermal expansion coefficients (CTE) were determined using Dilatometer. The fillers tend to decrease the CTE of reinforced resin and increase its modulus, as determined using UTM. Composite plates with UD glass were prepared with and without fillers to investigate the distortion behaviour. The experimental results showed that the curvature reduced from 4.3243 to 2.0973 mm by addition of 5% silica particles. The curvature in plates was also simulated in COMSOL Multiphysics, and results are correlated with the experimental values.

Research paper thumbnail of Injection simulations of thick composite parts manufactured by the RTM process

Composites Science and Technology, Feb 1, 2001

In order to simulate the resin flow occurring in a reinforcement during manufacture of composite ... more In order to simulate the resin flow occurring in a reinforcement during manufacture of composite materials by resin transfer moulding (RTM); the numerical codes need data such as the permeability, K, of the reinforcement. In the case of thick parts (e.g. a few centimetres thick), the spatial components of the permeability can be deduced from experimental kinetics if we are able to visualise the resin path in the reinforcement opaque bulk. Here we describe the original technique we used to achieve this aim and we demonstrate the results of X-ray spectrography for the determination of the kinetics of spatial flows through a porous medium. We then propose a mathematical approach in order to treat our experimental results and calculate the values of K. Finally, examples of simulations are compared to the corresponding experimental observations. These simulations are obtained from two numerical codes based on the finite-differences technique with curvilinear meshes and finite elements with control volumes, respectively.

Research paper thumbnail of Effect of annealing temperature on electrochemical characteristics of ruthenium oxide/multi-walled carbon nanotube composites

Materials Science And Engineering: B, Feb 1, 2010

The preparation and characterization of high-surface-area ruthenium oxide (RuO2)/multi-walled car... more The preparation and characterization of high-surface-area ruthenium oxide (RuO2)/multi-walled carbon nanotubes (MWCNTs) composite electrodes for use in supercapacitors is reported in this work. The RuO2/MWCNTs composites were prepared by the polyol process of RuO2 into MWCNTs and by Ru annealing in air before mixed with MWCNTs. The chemically oxidized and annealed Ru nanoparticles contribute a pseudocapacitance to the electrodes and

Research paper thumbnail of Numerical simulation of void formation in LCM

Composites Part A-applied Science and Manufacturing, Jun 1, 2003

Research paper thumbnail of Interaction of a flame front with its self-generated flow in an enclosure: The “tulip flame” phenomenon

Combustion and Flame, Feb 1, 1992

... FLAME FRONT/FLOWFIELD INTERACTION IN A CLOSED VESSEL 217 unburned medium, it is found that th... more ... FLAME FRONT/FLOWFIELD INTERACTION IN A CLOSED VESSEL 217 unburned medium, it is found that the velocity of the burned gases is directed toward the left end wall while the fresh gases flow alternately against the flame and toward the back end of the tube. ...

Research paper thumbnail of Analytical Modeling of CRTM and RTM Processes. Part I: General Mathematical Development

International journal of forming processes, Sep 30, 2006

International audienc