A. Frikha

Non-linear Dynamics Analysis of Multilayer Composite Shells with Enhanced Solid-Shell Elements

This paper presents the non linear dynamic response of multilayer composites with an enhanced solid-shell element. The transverse shear and transverse normal locking are treated using the Assumed Natural Strain formulation (ANS) . For the enhanced part, one, three and five parameters are examined. Comparisons of numerical results with those extracted from literature show the good performance of the developed formulation in the isotropic case. The three enhancement choices give the same results in the multilayer composite case.

A Four-Node Shell Element for Geometrically Nonlinear Analysis of Thin FGM Plates and Shells

This chapter presents a static behavior of geometrically nonlinear of Functionally Graded Material (FGM) thin shell structures. The proposed model, based on Kirchhoff shell element, consists in annulling the transverse shear deformation. The developed model is generalized to plates and shells such as cylindrical, conical, spherical, and hyperboloid shells. Material properties are assumed to be graded through the thickness by varying the volume fraction of the ceramic and the metallic constituents using power-law distribution. Numerical results are presented for pinched hemisphere. The load parameter is plotted versus the deflection in the two loading point A and B. Numerical results are compared with previous works. A good agreement between the present results and the literature confirms the high accuracy of the current nonlinear model for an isotropic material. The load parameter of FGM pinched hemisphere is plotted versus the deflection at the loading points by varying the power index from metal to ceramic. The deflection gap between the loading points A and B increases with the power index.

Post-buckling of FSDT of Functionally Graded Material Shell Structures

Based on the First-order Shear Deformation Theory (FSDT), this paper performs the geometric nonlinear analysis of Functionally Graded Material (FGM) shell structures. In this theory, a constant transverse shear deformation is considered and a shear correction factor is required. In order to avoid transverse shear locking, the assumed natural strain method (ANS) is incorporated in the finite element formulation. In addition, the variational principle is used to obtain the governing equation and the Newton–Raphson iterative method is adopted to solve the nonlinear equations. The constituent of FG shells consists of ceramic and metal. These constituents are graded through the thickness by varying the volume fraction using a power-law distribution. The post-buckling responses of simply supported cylindrical panel are examined. The effects of volume fraction are also investigated. Numerical results are compared with previous works. A good agreement among the present results and the literature confirms the high accuracy of the current nonlinear model.