A novel first-order shear deformation theory for laminated composite plates

Mohamed Sadoune,Abdelouahed Tounsi,Mohammed Sid Ahmed Houari,El Abbes Adda Bedia 국제구조공학회 2014 Steel and Composite Structures, An International J Vol.17 No.3

In the present study, a new simple first-order shear deformation theory is presented for laminated composite plates. Moreover, the number of unknowns of this theory is the least one comparing with the traditional first-order and the other higher-order shear deformation theories. Equations of motion and boundary conditions are derived from Hamilton's principle. Analytical solutions of simply supported antisymmetric cross-ply and angle-ply laminates are obtained and the results are compared with the exact three-dimensional (3D) solutions and those predicted by existing theories. It can be concluded that the proposed theory is accurate and simple in solving the static bending and free vibration behaviors of laminated composite plates.

Vibration analysis of thick orthotropic plates using quasi 3D sinusoidal shear deformation theory

Sadoun, Mohamed,Houari, Mohammed Sid Ahmed,Bakora, Ahmed,Tounsi, Abdelouahed,Mahmoud, S.R.,Alwabli, Afaf S. Techno-Press 2018 Geomechanics & engineering Vol.16 No.2

In this current work a quasi 3D "trigonometric shear deformation theory" is proposed and discussed for the dynamic of thick orthotropic plates. Contrary to the classical "higher order shear deformation theories" (HSDT) and the "first shear deformation theory" (FSDT), the constructed theory utilizes a new displacement field which includes "undetermined integral terms" and presents only three "variables". In this model the axial displacement utilizes sinusoidal mathematical function in terms of z coordinate to introduce the shear strain impact. The cosine mathematical function in terms of z coordinate is employed in vertical displacement to introduce the impact of transverse "normal deformation". The motion equations of the model are found via the concept of virtual work. Numerical results found for frequency of "flexural mode", mode of shear and mode of thickness stretch impact of dynamic of simply supported "orthotropic" structures are compared and verified with those of other HSDTs and method of elasticity wherever considered.

Effect of visco-Pasternak foundation on thermo-mechanical bending response of anisotropic thick laminated composite plates

Fatima Bounouara,Mohamed Sadoune,Mahmoud Mohamed Selim Saleh,Abdelbaki Chikh,Abdelmoumen Anis Bousahla,Abdelhakim Kaci,Fouad Bourada,Abdeldjebbar Tounsi,Abdelouahed Tounsi 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.47 No.6

This article investigates the static thermo-mechanical response of anisotropic thick laminated composite plates on Visco-¬Pasternak foundations under various thermal load conditions (linear, non-linear, and uniform) along the transverse direction (thickness) of the plate, while keeping the mechanical load constant. The governing equations, which represent the thermo-mechanical behavior of the composite plate, are derived from the principle of virtual displacements. Using Navier's type solution, these equations are solved for the composite plate with simply supported condition. The Visco-¬Pasternak foundation type is included by considering the impact of the damping on the classical foundation model, which is modeled by Winkler’s linear modulus and Pasternak’s shear modulus. The excellent accuracy of the present solution is confirmed by comparing the results with those available in the literature. The study investigates the impact of geometric ratios, thermal expansion coefficient ratio, damping coefficient and foundation parameters on the thermo-mechanical flexural response of the composite plate. Overall, this article provides insights into the behavior of composite plates on visco-Pasternak foundations and may be useful for designing and analyzing composite structures in practical applications.

The effect of transverse shear deformation on the post-buckling behavior of functionally graded beams

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.

On the effect of porosity on the shear correction factors of functionally graded porous beams

Ben Abdallah Medjdoubi,Mohammed Sid Ahmed Houari,Mohamed Sadoun,Aicha Bessaim,Ahmed Amine Daikh,Mohamed-Ouejdi Belarbi,Abdelhak Khechai,Aman Garg,Mofareh Hassan Ghazwani Techno-Press 2023 Coupled systems mechanics Vol.12 No.3

This article presents a new analytical model to study the effect of porosity on the shear correction factors (SCFs) of functionally graded porous beams (FGPB). For this analysis, uneven and logarithmic-uneven porosity functions are adopted to be distributed through the thickness of the FGP beams. Critical to the application of this theory is a determination of the correction factor, which appears as a coefficient in the expression for the transverse shear stress resultant; to compensate for the assumption that the shear strain is uniform through the depth of the cross-section. Using the energy equivalence principle, a general expression is derived from the static SCFs in FGPB. The resulting expression is consistent with the variationally derived results of Reissner's analysis when the latter are reduced from the two-dimensional case (plate) to the one-dimensional one (beam). A convenient algebraic form of the solution is presented and new study cases are given to illustrate the applicability of the present formulation. Numerical results are presented to illustrate the effect of the porosity distribution on the (SCFs) for various FGPBs. Further, the law of changing the mechanical properties of FG beams without porosity and the SCFare numerically validated by comparison with some available results.

Effects of porosity models on static behavior of size dependent functionally graded beam

Mostafa A. Hamed,Ayman M. Sadoun,Mohamed A. Eltaher 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.71 No.1

In this study, the mechanical bending behaviors of functionally graded porous nanobeams are investigated. Four types of porosity which are, the classical power porosity function, the symmetric with mid-plane cosine function, bottom surface distribution and top surface distribution are proposed in analysis of nanobeam for the first time. A comparison between four types of porosity are illustrated. The effect of nano-scale is described by the differential nonlocal continuum theory of Eringen by adding the length scale into the constitutive equations as a material parameter comprising information about nanoscopic forces and its interactions. The graded material is designated by a power function through the thickness of nanobeam. The beam is simply-supported and is assumed to be thin, and hence, the kinematic assumptions of Euler-Bernoulli beam theory are held. The mathematical model is solved numerically using the finite element method. Numerical results show effects of porosity type, material graduation, and nanoscale parameters on the static deflection of nanobeam.