Papers by Mohamed Guenfoud
Mechanics based design of structures and machines, Jun 30, 2024
Mechanics based design of structures and machines, Jun 30, 2024
Revue Nature et Technologie, Jun 30, 2011
Advances in Mechanical Engineering, Nov 1, 2020
The present paper describes the formulation of a new moderately thick plate bending triangular fi... more The present paper describes the formulation of a new moderately thick plate bending triangular finite element based on Mindlin-Reissner plate theory. It is called a Great Triangular Moderately Thick Plate Finite Element, or GTMTPFE. The formulation is based on the strain approach, on solution of Airy's function and on the analytical integration in the construction of the stiffness matrix. The strengths associated with this approach consist of: automatic verification of equilibrium conditions and kinematic compatibility conditions, the enrichment of the degrees of the interpolation polynomials of displacements, strains and constraints (refinement p), the consideration distortions sections related to Poisson effects, the treatment of blocking phenomena related to transverse shear. In general, this approach results in a competitive, robust and efficient new moderately thick plate finite element. This is visible, on the one hand, through its stability against patch tests (constant twists, state of constants moments, transverse shear locking phenomenon, isotropy test). This is visible, through its good response to the patch tests to which it is subjected (constant torsions, state of constant moments, phenomenon of blocking in transverse shears, isotropy test). As has excellent convergence to the reference solution. Thus, it exhibits better performance behavior than other existing plate elements in the literature, particularly for moderately thick plates and for thin plates (L/h ratio greater than 4).
Periodica Polytechnica Civil Engineering
Functionally Graded Material (FGM) is a new generation of composite materials, it can be used for... more Functionally Graded Material (FGM) is a new generation of composite materials, it can be used for different engineering fields according to the loading environment, but the study of its mechanical behavior requires sophisticated numerical and analytical models. Several investigations in these models are available in the literature, however, most of those investigations are based on simplifying assumptions. In this paper, we present a three-dimensional finite element modeling of functionally graded material (FGM) beams subjected to static loading. Material properties are assumed to vary continuously along the beam thickness according to the power-law distribution with linear elastic behavior. The FGM beams are discretized by hexahedral finite elements type C3D20R (continuum stress/displacement, three-dimensional 20-node, reduced integration). We studied several numerical examples of FGM beams and compare the obtained numerical results with those of analytical models in the literature.
Advances in Civil and Architectural Engineering
This paper presents a simple incremental approach of analysing the static behaviour of functional... more This paper presents a simple incremental approach of analysing the static behaviour of functionally graded tapered beams. This approach involves dividing the non-uniform beam into segments with uniform cross-sections, and using two separate finite element models to analyse the structural behavior of slender beams (Euler-Bernoulli model) and deep beams (Timoshenko beam theory). The material properties of the beam vary according to a power law distribution through the thickness, resulting in smooth variations in the mechanical properties. The finite element system of equations is obtained using the principle of virtual work. Detailed information on the shape functions and stiffness matrix of the beam is provided, and the numerical results are evaluated and validated using data from the literature. The comparison demonstrates that the response of the functionally graded tapered beams is accurately assessed by the proposed approach. Additionally, the effects of material distribution, bo...
Periodica Polytechnica Civil Engineering
The static bending-torsion problem of functionally graded cantilever beams is studied using a ref... more The static bending-torsion problem of functionally graded cantilever beams is studied using a refined 1D/3D beam theory (Refined beam theory RBT and Refined beam theory with distortion modes RBT*) built on the 3D Saint-Venant (SV) solution. In these theories, the displacement models include Poisson's effects, out-of-plane deformations and distortions. For a given section, the sectional displacement modes are derived from the computation of the particular 3D Saint-Venant’s solution. These modes, which reflect the mechanical behavior of the cross-section, lead to a beam theory that actually corresponds to the cross-section type in terms of shape and material. In addition, the models take into account edge effects to predict a 3D solution in a larger internal region to better describe the overall behavior of FGM beams. The models examined are implemented on the CSB (Cross-Section and Beam Analysis) tool. It is based on the RBT/SV (Refined Beam Theory based on the 3D SV’s solution) ...
Geomechanics and Engineering, 2018
This paper focuses on the development of a new non-linear macro-element for the modelling of soil... more This paper focuses on the development of a new non-linear macro-element for the modelling of soil-foundation interaction. Material and geometrical nonlinearities (soil yielding and foundation uplift respectively) are taken into account in the present macro-element to examine the response of shallow foundations under monotonic and cyclic loads. Several applications of soil-foundation systems are studied. The results obtained from these applications are in very favourable agreement with those obtained through other numerical models in the literature.
Dans la présente communication, nous présentons la formulation d'un élément fini mixte basé s... more Dans la présente communication, nous présentons la formulation d'un élément fini mixte basé sur le principe de variation de Reissner dont le but de son utilisation pour modéliser les interfaces fissurées entre deux matériaux différents. Cet élément d'interface est développé sur la base de la méthode d'extension de fissure virtuelle pour évaluer le taux d'énergie libre. Les résultats obtenus à partir du présent élément fini mixte d'interface se sont révélés être en bon accord avec les solutions analytiques pour les biomatériaux isotropes. Le comportement à la rupture des fissures d'interface entre matériaux dissemblables est un problème très important des matériaux composites. Williams en 1959 a effectué une analyse asymptotique du champ élastique à la pointe de fissure ouverte et il a découvert que le champ de contraintes possède un caractère oscillatoire. Il a d'abord étudié le problème d'une fissure inter faciale entre deux matériaux isotropes disse...
Dans cette communication, nous avons présenté une modélisation tridimensionnelle du comportement ... more Dans cette communication, nous avons présenté une modélisation tridimensionnelle du comportement mécanique d'une poutre sandwich sollicitée à la flexion simple, en utilisant la théorie des poutres de Saint-Venant (3D) dans laquelle la section est libre de se déformer dans son plan (effets de Poisson) et hors plan (gauchissement). Cette poutre est composée par une couche d'âme isotrope intercalée entre deux peaux isotropes. Les résultats numériques obtenus sont très satisfaisants et prouvent la performance de la modélisation tridimensionnelle.
Au cours de son histoire, l'Algérie a subi plusieurs séismes destructeurs. Selon les constati... more Au cours de son histoire, l'Algérie a subi plusieurs séismes destructeurs. Selon les constations faites durant ces tremblements de terre, la règlementation parasismique algérienne : RPA 82, RPA 83 et RPA 99révisé en 2003, parait insuffisante et les constructions ont subi des dommages considérables. Ce qui explique la présence de défaillances et insuffisances dans le code parasismique algérien. Pour résoudre ce problème, plusieurs chercheurs ont préconisé l'introduction des voiles de contreventement pour améliorer le comportement des structures vis-à-vis du séisme. Dans le règlement parasismique algérien, aucun article n'est relatif à ce paramètre. L'objectif recherché dans cette étude est d'étudier l'influence de la position des voiles de contreventements sur le comportement des structures à travers: la demande en ductilité μD, le déplacement inter-étage Dp et la raideur Kp au point de performance, la raideur élastique Ke et l'indicateur de dégradation gl...
Une Modélisation bidimensionnelle par éléments finis multicouches du comportement non-linéaire de... more Une Modélisation bidimensionnelle par éléments finis multicouches du comportement non-linéaire des structures en béton armé sous charge monotone et cyclique est présentée. La non linéarité matérielle est caractérisée par plusieurs phénomène tels que : la non-linéarité physique des matériaux béton et acier, le comportement du béton fissuré, l'effet d'interaction entre les matériaux représentée par le domaine post-fissuration. Ces paramètres sont pris en considération dans cet article pour examiner la réponse des structures en béton armé à comportement non linéaire. Quatre exemples d'applications sont présentés. Les résultats numériques obtenus, sont en concordance très favorable avec ceux obtenus par l'expérience et d'autres modèles numériques de la littérature.
In the present paper, we offer a higher-order shear deformation theory for bending of functionall... more In the present paper, we offer a higher-order shear deformation theory for bending of functionally graded beam. A new polynomial shear function is used which satisfies the stress-free boundary conditions (exact boundary conditions on the stress) at both, top and bottom surfaces of the beam. Hence, the shear correction factor is not necessary. Additionally, the present theory has strong similarities with Timoshenko beam theory in some concepts such as equations of movement, boundary conditions and stress resultant expressions. The governing equations and boundary conditions are derived from the principle of minimum potential energy. Functionally graded material FGM beams have a smooth variation of material properties due to continuous (unbroken) change in micro structural details. The variation of material properties is along the beam thickness and assumed to follow a power-law of the volume fraction of the constituents. Finite element numerical solutions obtained with the new polyno...
International Journal of Engineering, 2013
This paper presents the results of theoretical study of the behaviour of anchors in a homogeneous... more This paper presents the results of theoretical study of the behaviour of anchors in a homogeneous soil (pulverulent medium).The originality of the theoretical study is in the determination of model based on the kinematics approach of the theory of the limit analysis; in the case of the criteria of Mohr Coulomb. The type of failure of the ground around the anchor, obtained by this approach, is close to the reality
Cet article presente l’analyse d’une classe de structures en cas dynamique par la methode des ban... more Cet article presente l’analyse d’une classe de structures en cas dynamique par la methode des bandes finies. Cette methode consiste a subdiviser la structure en des elements appeles bandes finies. Ces bandes se caracterisent par deux directions, l’une transversale discretisee par element finis et l’autre, privilegiee, longitudinale discretisee par series de Fourier. Le but de ce travail est de formuler et implanter les matrices de rigidite [K0 ]et de masse [M] pour les elements des bandes finies a deux, trois et quatre noeuds; pour le calcul en vibration propre des structures formees de plaques ou de coques d’epaisseur mince ou epaisse. Les resultats obtenus sur de nombreux exemples sont compares avec d’autres resultats numeriques (STAAD III et \ SAP2000), ces derniers revelent certaines realites indeniables qui prouvent la fiabilite et l’efficacite des elements developpes.
International Journal of Applied Mechanics and Engineering, 2007
An accurate procedure to determine the free vibrations of beams and plates is presented. The dyna... more An accurate procedure to determine the free vibrations of beams and plates is presented. The dynamic behavior of the structures under consideration is analyzed by using the theory of the orthotropic plate simply supported on two sides and free on the two others. The plate can be excited by a convoy of moving loads. The determination of the dynamic response requires the knowledge of the natural frequencies and the shape modes of vibrations. The boundary conditions of the differential equations of vibrations lead to a homogeneous system. The determination of the noncommonplace solutions led to a nonlinear problem in Eigen frequencies. Thus, we have developed a computer code for the determination of the eigenvalues. It is based on a method of bisection with interpolation, with the accuracy up to 12 10 . Moreover, to determine the corresponding modes, the calculation algorithm developed uses the Gauss method with a partial optimization of the “pivots” combined with an inverse power pro...
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Papers by Mohamed Guenfoud