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Meftah Sid Ahmed,Abdelouahed Tounsi,Pham Van Vinh 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.4
In this paper, the nonlinear buckling analysis of rectangular hollow sections (RHS) beams considering distortional and the shear fl exibility deformation eff ects is investigated. The kinematic model is based on the incorporation of non-classical terms, related to shear fl exibility, according to Timoshenko model and distortion and warping. This analysis is carried out by proposing a new 3D fi nite element, formulated in the context of large torsion, incorporating fl exural torsion, and distortion coupling eff ects. A 3D RHS beam element with two nodes and eleven degrees of freedom per node is proposed to perform the nonlinear buckling analysis. For this aim, the arc-length method is employed as a solution strategy to solve the nonlinear equilibrium equations, established as a function of the trigonometric functions of the twist angle. Many examples are proposed to check the validity of the proposed 3D fi nite element and the numerical procedure, either in pre-and postbuckling states. The present numerical results are compared to those of the commercial software ABAQUS using the brick fi nite elements. The incidences of the compressive load and the incorporated lateral stiff eners in the RHS beams in pre- and post-buckling behaviour are studied.
Investigation of the Instability of FGM box beams
Noureddine Ziane,Sid Ahmed Meftah,Giuseppe Ruta,Abdelouahed Tounsi,El Abbas Adda Bedia 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.3
A general geometrically non-linear model for lateral-torsional buckling of thick and thin-walled FGM box beams is presented. In this model primary and secondary torsional warping and shear effects are taken into account. The coupled equilibrium equations obtained from Galerkin's method are derived and the corresponding tangent matrix is used to compute the critical moments. General expression is derived for the lateral-torsional buckling load of unshearable FGM beams. The results are validated by comparison with a 3D finite element simulation using the code ABAQUS. The influences of the geometrical characteristics and the shear effects on the buckling loads are demonstrated through several case studies.
Investigation of the Instability of FGM box beams
Ziane, Noureddine,Meftah, Sid Ahmed,Ruta, Giuseppe,Tounsi, Abdelouahed,Adda Bedia, El Abbas Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.3
A general geometrically non-linear model for lateral-torsional buckling of thick and thin-walled FGM box beams is presented. In this model primary and secondary torsional warping and shear effects are taken into account. The coupled equilibrium equations obtained from Galerkin's method are derived and the corresponding tangent matrix is used to compute the critical moments. General expression is derived for the lateral-torsional buckling load of unshearable FGM beams. The results are validated by comparison with a 3D finite element simulation using the code ABAQUS. The influences of the geometrical characteristics and the shear effects on the buckling loads are demonstrated through several case studies.
Abdelkader Saoula,Sid Ahmed Meftah 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.4
This paper treats the distortional and shear deformation eff ects on the elastic lateral torsional buckling of thin-walled box beam elements, under combined bending and axial forces. For the purpose, a nonlinear kinematic model based on higher order theory is used applicable to both short and long thin-walled box beams. Because in the kinematic model of the higher order theory integrates additional fl exibility terms related to shear, distortion and warping eff ects, it accurately predicts the lateral torsional buckling of the straight box beams. Ritz’s method is adopted as solution strategy in order to obtain the nonlinear governing equilibrium equations, then the buckling loads are computed by solving the eigenvalue problem basing on the singularity of the tangential stiff ness matrix. Owing to fl exural–torsional and distortional couplings, new matrices are obtained in both geometric and initial stress parts of the tangent stiff ness matrix. The proposed method with the new stiff ness terms, is effi cient and accurate in lateral torsional buckling predictions, when compared with the commercial FEM code ABAQUS results. Based on the existing European guidelines EC3, an extensive numerical investigation is performed to demonstrate the eff ects of both shear and distortional deformations on the moment carrying capacity. The convenience of the model is outlined and the limit of models developed without shear and distortion deformation eff ects on lateral buckling loads evaluation is discussed.
Hadj Youzera,Abbache Ali,Sid Ahmed Meftah,Abdelouahed Tounsi,Muzamal Hussain 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.44 No.1
The purpose of the present work is to study the parametric nonlinear vibration behavior of three layered symmetric laminated plate. In the analytical formulation; both normal and shear deformations are considered in the core layer by means of the refined higher-order zig-zag theory. Harmonic balance method in conjunction with Galerkin procedure is adopted for simply supported laminate plate, to obtain its natural and damping properties. For these aims, a set of complex amplitude equations governed by complex parameters are written accounting for the geometric nonlinearity and viscoelastic damping factor. The frequency response curves are presented and discussed by varying the material and geometric properties of the core layer.
Distortional effect on global buckling and post-buckling behaviour of steel box beams
Noureddine Benmohammed,Noureddine Ziane,Sid Ahmed Meftah,Giuseppe Ruta 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.35 No.6
The homotopy perturbation method (HPM) to predict the pre- and post-buckling behaviour of simply supported steel beams with rectangular hollow section (RHS) is presented in this paper. The non-linear differential equations solved by HPM derive from a kinematics where large twist and cross-sections distortions are considered. The results (linear and non-linear paths) given by the present HPM are compared to those provided by the Newton–Raphson algorithm with arc length and by the commercial FEM code Abaqus. To investigate the effect of cross-sectional distortion of beams, some numerical examples are presented.
Abbache Ali,Hadj Youzera,Moussa Abualnour,Mohammed Sid Ahmed Houari,Sid Ahmed Meftah,Abdelouahed Tounsi 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.80 No.2
This paper deals with the secondary vibration problem in the superharmonic case near the harmonic excitation of 1/3ωl, arising from the vibration nonlinearity that characterizes the slender and less damping laminated beam with composite material core. For this aim the multiple scale method in conjunction with the higher order zigzag theories are used to obtain the resonance responses. In the present work the nonlinear forced vibration problem of sandwich beams under harmonic excitation is solved by the multiples scales method, based by the introduction of an artificial parameter with higher order expansions, to control the nonlinear analytical solutions. The application of this method demonstrates the sensitivity of the sandwich beams with viscoelastic composite layer to the secondary superharmonic vibrations. Following, parametric study is conducted to demonstrate the vulnerability of the laminated structures to the superharmonic vibrations and to reduce as far as possible the amplitude vibrations achieved by more appropriated structural design. The results reveal the effect of the slenderness of the sandwich beams on the hardening changes. In the other hand the results demonstrate the importance of fibre orientation angle to reduce as far as possible the amplitude responses of the sandwich structures in superharmonic vibration case.
Abdelhak Benaoum,Hadj Youzera,Moussa Abualnour,Mohammed Sid Ahmed Houari,Sid Ahmed Meftah,Abdelouahed Tounsi 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.80 No.6
In this work, mathematical modeling of the passive vibration controls of a three-layered sandwich beam under hard excitation is developed. Kelvin-Voigt Viscoelastic model is considered in the core. The formulation is based on the higher-order zig-zag theories where the normal and shear deformations are taken into account only in the viscoelastic core. The dynamic behaviour of the beam is represented by a complex highly nonlinear ordinary differential equation. The method of multiple scales is adopted to solve the analytical frequency-amplitude relationships in the super-harmonic resonance case. Parametric studies are carried out by using HSDT and first-order deformation theory by considering different geometric and material parameters.
Redha Yeghnem,Hicham Zakaria Guerroudj,Lemya Hanifi Hachemi Amar,Sid Ahmed Meftah,Samir Benyoucef,Abdelouahed Tounsi,El Abbas Adda Bedia 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.19 No.5
Creep and shrinkage are the main types of volume change with time in concrete. These changes cause deflection, cracking and stresses that affect durability, serviceability, long-term reliability and structural integrity of civil engineering infrastructure. Although laboratory test may be undertaken to determine the deformation properties of concrete, these are time-consuming, often expensive and generally not a practical option. Therefore, relatively simple empirically design code models are relied to predict the creep strain. This paper reviews the accuracy of creep and shrinkage predictions of reinforced concrete (RC) shear walls structures strengthened with carbon fibre reinforced polymer (CFRP) plates, which is characterized by a widthwise varying fibre volume fraction. This review is yielded by three commonly used international “code type” models. The assessed are the: CEB-FIP MC 90 model, ACI 209 model and Bazant & Baweja (B3) model. The time-dependent behavior was investigated to analyze their seismic behavior. In the numerical formulation, the adherents and the adhesives are all modelled as shear wall elements, using the mixed finite element method. Several tests were used to dem¬onstrate the accuracy and effectiveness of the proposed method. Numerical results from the present analysis are presented to illustrate the significance of the time-dependency of the lateral displacements and eigenfrequencies modes.
Ali Meksi,Hadj Youzera,Mohamed Sadoune,Ali Abbache,Sid Ahmed Meftah,Abdelouahed Tounsi,Muzamal Hussain 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.44 No.1
The purposes of the present work it to study the effect of shear deformation on the static post-buckling response of simply supported functionally graded (FGM) axisymmetric beams based on classical, first-order, and higher-order shear deformation theories. The behavior of postbuckling is introduced based on geometric nonlinearity. The material properties of functionally graded materials (FGM) are assumed to be graded in the thickness direction according to a simple power law distribution in terms of the volume fractions of the constituents. The equations of motion and the boundary conditions derived using Hamilton’s principle. This article compares and addresses the efficiency, the applicability, and the limits of classical models, higher order models (CLT, FSDT, and HSDT) for the static post-buckling response of an asymmetrically simply supported FGM beam. The amplitude of the static post-buckling obtained a solving the nonlinear governing equations. The results showing the variation of the maximum post-buckling amplitude with the applied axial load presented, for different theory and different parameters of material and geometry. In conclusion: The shear effect found to have a significant contribution to the post-buckling behaviors of axisymmetric beams. As well as the classical beam theory CBT, underestimate the shear effect compared to higher order shear deformation theories HSDT.