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Aicha, Kablia,Rabia, Benferhat,Daouadji, Tahar Hassaine,Bouzidene, Ahmed Techno-Press 2020 Coupled systems mechanics Vol.9 No.6
Equilibrium equations of a porous FG plate resting on Winkler-Pasternak foundations with various boundary conditions are derived using a new refined shear deformation theory. Different types of porosity distribution rate are considered. Governing equations are obtained including the plate-foundation interaction. This new model meets the nullity of the transverse shear stress at the upper and lower surfaces of the plate. The novel rule of mixture is proposed to describe and approximate material properties of the FG plates with different distribution case of porosity. The validity of this theory is studied by comparing some of the present results with other higher-order theories reported in the literature. Effects of variation of porosity distribution rate, boundary conditions, foundation parameter, power law index, plate aspect ratio, side-to-thickness ratio on the deflections and stresses are all discussed.
Chemical Composition and Antioxidant Activity of Algerian Juniperus Phoenicea Essential Oil
Aicha Harhour,Moussa Brada,Marie-Laure Fauconnier,Georges Lognay 한국생약학회 2018 Natural Product Sciences Vol.24 No.2
Berries and branches essential oil of Juniperus phoenicea were obtained by electromagnetic induction heating assisted extraction and by hydrodistillation with a yield varied from (1.2 ? 0.3 to 2.4 ? 0.7%) and from (0.6 ? 0.1% to 1.1 ? 0.1%), respectively. forty eight compounds were identified representing (97.2 - 99.7%) of the oil. a-Pinene (40.3 - 67.8%) and d-3-carene (13.5 - 26.8%) were the main compounds in berries and branches essential oils. Antioxidant activity was evaluated by three means: inhibition of 2, 2-diphenyl-1-picryl hydrazyl (DPPH) free radical, reducing power and b-Carotene/linoleic acid bleaching. The antioxidant activity of essential oils showed IC50 ranging from 67.6 ? 1.02 mg/mL to 131.5 ? 0.8 mg/mL for berries and from 98 ? 1.25 mg/mL to 166.8 ? 0.29 mg/mL for the branches. Berries oil show more potent antioxidant activity compared to branches. This result is supported by the three methods investigated in this work.
Nonlocal strain gradient theory for bending analysis of 2D functionally graded nanobeams
Aicha Bessaim,Mohammed Sid Ahmed Houari,Smain Bezzina,Ali Merdji,Ahmed Amine Daikh,Mohamed-Ouejdi Belarbi,Abdelouahed Tounsi 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.86 No.6
This article presents an analytical approach to explore the bending behaviour of of two-dimensional (2D) functionally graded (FG) nanobeams based on a two-variable higher-order shear deformation theory and nonlocal strain gradient theory. The kinematic relations are proposed according to novel trigonometric functions. The material gradation and material properties are varied along the longitudinal and the transversal directions. The equilibrium equations are obtained by using the virtual work principle and solved by applying Navier’s technique. A comparative evaluation of results against predictions from literature demonstrates the accuracy of the proposed analytical model. Moreover, a detailed parametric analysis checks for the sensitivity of the bending and stresses response of (2D) FG nanobeams to nonlocal length scale, strain gradient microstructure scale, material distribution and geometry.
Free vibration of various types of FGP sandwich plates with variation in porosity distribution
Aicha Kablia,Rabia Benferhat,Tahar Hassaine Daouadji,Rabahi Abderezak 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.85 No.1
The use of functionally graded materials in applications involving severe thermal gradients is quickly gaining acceptance in the composite mechanics community, the aerospace and aircraft industry. In the present study, a refined sandwich plate model is applied to study the free vibration analysis of porous functionally graded material (FGM) sandwich plates with various distribution rate of porosity. Two types of common FG sandwich plates are considered. The first sandwich plate is composed of two FG material (FGM) face sheets and a homogeneous ceramic or metal core. The second one consists of two homogeneous fully metal and ceramic face sheets at the top and bottom, respectively, and a FGM core. The displacement field of the present theory is chosen based on nonlinear variations in the in-plane displacements through the thickness of the sandwich plate. The number of unknowns and equations of motion of the present theory is reduced and hence makes them simple to use. In the analysis, the equation of motion for simply supported sandwich plates is obtained using Hamilton’s principle. In order to present the effect of the variation of the porosity distribution on the dynamic behavior of the FGM sandwich plates, new mixtures are proposed which take into account different rate of porosity distribution between the ceramic and the metal. The present method is applicable to study the dynamic behavior of FGM plates and sandwich plates. The frequencies of two kinds of FGM sandwich structures are analyzed and discussed. Several numerical results have been compared with the ones available in the literature.
Aicha Benchiha,Kouider Madani 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.5
In this study, the finite element method was used to analyze the distribution of the adhesive shear stresses in the single-lap bonded joint of two plates 2024-T3 aluminum with and without defects. The effects of the adhesive properties (shear modulus, the thickness and the length of the adhesive were highlighted. The results prove that the shear stresses are located on the free edges of the adhesively bonding region, and reach maximum values near the defect, because the concentration of high stress occurs near this area.
A nonlocal quasi-3D trigonometric plate model for free vibration behaviour of micro/nanoscale plates
Aicha Bessaim,Mohammed Sid Ahmed Houan,Fabrice Bernard,Abdelouahed Tounsi 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.56 No.2
In this work, a nonlocal quasi-3D trigonometric plate theory for micro/nanoscale plates is proposed. In order to introduce the size influences, the Eringen’s nonlocal elasticity theory is utilized. In addition, the theory considers both shear deformation and thickness stretching effects by a trigonometric variation of all displacements within the thickness, and respects the stress-free boundary conditions on the top and bottom surfaces of the plate without considering the shear correction factor. The advantage of this theory is that, in addition to considering the small scale and thickness stretching effects (εz≠0), the displacement field is modelled with only 5 unknowns as the first order shear deformation theory (FSDT). Analytical solutions for vibration of simply supported micro/nanoscale plates are illustrated, and the computed results are compared with the available solutions in the literature and finite element model using ABAQUS software package. The influences of the nonlocal parameter, shear deformation and thickness stretching on the vibration behaviors of the micro/nanoscale plates are examined.
Aicha Benchiha,Kouider Madani,Sebastien Touzain,Xavier Feaugas,Mohan Ratwani 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.20 No.4
The determination of the stress intensity factor at the crack tip is one of the most widely used methods to predict the fatigue life of aircraft structures. This prediction is more complicated for repaired cracks with bonded composite patch. This study is used to compute the stress intensity factor (SIF) and crack opening displacement (COD) for cracks repaired with single and double-sided composite patches. The effect of the presence of disbond region in adhesive at the crack was taken into consideration. The results show that there is a considerable reduction in the asymptotic value of the stress-intensity factors and the crack opening displacement at the crack tip. The use of a double-sided patch suppresses the bending effect due to the eccentricity of the patch on one side only.
Aicha Boussaha,Halim Zeghdoudi,Raman Vinoth 한국전산응용수학회 2024 Journal of applied mathematics & informatics Vol.42 No.2
This article explains how solitons propagate when there is a detuning factor involved. The explanation is based on the nonlinear complex Ginzburg-Landau equation, and we first consider this equation before systematically deriving its solutions using Jacobian elliptic functions. We illustrate that one specific ellipticity modulus is on the verge of occurring. The findings from this study can contribute to the understanding of previous research on the Ginzburg-Landau equation. Additionally, we utilize Jacobi's elliptic functions to define specific solutions, especially when the ellipticity modulus approaches either unity or zero. These solutions correspond to particular periodic wave solitons, which have been previously discussed in the literature.
A simple HSDT for bending, buckling and dynamic behavior of laminated composite plates
Aicha Remil,Kouider Halim Benrahou,Kada Draiche,Abdelmoumen Anis Bousahla,Abdelouahed Tounsi 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.70 No.3
In the present article, cross ply laminated composite plates are considered and a simple sinusoidal shear deformation model is tested for analyzing their flexural, stability and dynamic behaviors. The model contains only four unknown variables that are five in the first order shear deformation theory (FSDT) or other higher order models. The in-plane kinematic utilizes undetermined integral terms to quantitatively express the shear deformation influence. In the proposed theory, the conditions of zero shear stress are respected at bottom and top faces of plates without considering the shear correction coefficient. Equations of motion according to the proposed formulation are deduced by employing the virtual work principle in its dynamic version. The analytical solution is determined via double trigonometric series proposed by Navier. The stresses, displacements, natural frequencies and critical buckling forces computed using present method are compared with other published data where a good agreement between results is demonstrated.
Benchiha, Aicha,Madani, Kouider Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.5
In this study, the finite element method was used to analyze the distribution of the adhesive shear stresses in the single-lap bonded joint of two plates 2024-T3 aluminum with and without defects. The effects of the adhesive properties (shear modulus, the thickness and the length of the adhesive were highlighted. The results prove that the shear stresses are located on the free edges of the adhesively bonding region, and reach maximum values near the defect, because the concentration of high stress occurs near this area.