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Showing papers by "J. N. Reddy published in 1985"


Journal ArticleDOI
J. N. Reddy1, C.F. Liu1
TL;DR: In this article, a higher-order shear deformation theory for elastic shells was developed for shells laminated of orthotropic layers, which is a modification of the Sanders' theory and accounts for parabolic distribution of the transverse shear strains through thickness of the shell and tangential stress-free boundary conditions on the boundary surfaces.

1,009 citations


Journal ArticleDOI
J. N. Reddy1, N.D. Phan1
TL;DR: In this article, a higher-order shear deformation theory is used to demonstrate the natural frequencies and buckling loads of elastic plates, which accounts for parabolic distribution of the transverse shear strains through the thickness of the plate and rotary inertia.

629 citations


Journal ArticleDOI
N. D. Phan1, J. N. Reddy1
TL;DR: In this paper, a higher-order deformation theory is used to analyse laminated anisotropic composite plates for deflections, stresses, natural frequencies and buckling loads, and applications of the element to bending, vibration and stability of laminated plates are discussed.
Abstract: A higher-order deformation theory is used to analyse laminated anisotropic composite plates for deflections, stresses, natural frequencies and buckling loads. The theory accounts for parabolic distribution of the transverse shear stresses, and requires no shear correction coefficients. A displacement finite element model of the theory is developed, and applications of the element to bending, vibration and stability of laminated plates are discussed. The present solutions are compared with those obtained using the classical plate theory and the three-dimensional elasticity theory.

364 citations


Journal ArticleDOI
TL;DR: In this article, a dynamic, shear deformation theory of a doubly curved shell is used to develop a finite element for geometrically nonlinear (in the von Karman sense) transient analysis of laminated composite shells.
Abstract: A dynamic, shear deformation theory of a doubly curved shell is used to develop a finite element for geometrically non-linear (in the von Karman sense) transient analysis of laminated composite shells. The element is employed to determine the transient response of spherical and cylindrical shells with various boundary conditions and loading. The effect of shear deformation and geometric non-linearity on the transient response is investigated. The numerical results presented here for transient analysis of laminated composite shells should serve as references for future investigations.

119 citations



Journal ArticleDOI
TL;DR: In this paper, a doubly curved, shear deformable shell element is presented for geometrically nonlinear analysis of laminated composite shells, based on an extension of Sanders' shell theory and accounts for the von Karman and transverse shear strains.
Abstract: Numerical results obtained using a doubly curved, shear deformable shell element are presented for geometrically nonlinear analysis of laminated composite shells. The element is based on an extension of Sanders' shell theory and accounts for the von Karman strains and transverse shear strains. The sample numerical results presented here for the geometrically nonlinear analysis of laminated composite shells should serve as references for future investigations.

70 citations


Journal ArticleDOI
TL;DR: In this article, a quasi-three dimensional formulation and associated finite element model for the stress analysis of a symmetric composite laminate with free-edge reinforcement is described. And the effect of a reinforcing cap on the stress distribution is determined.
Abstract: : The paper describes a quasi-three dimensional formulation and associated finite element model for the stress analysis of a symmetric laminate with free-edge reinforcement. Numerical results are presented to show the effect of the reinforcement on the reduction of free-edge stresses. It is observed that the interlaminar normal stresses are reduced considerably more than the interlaminar shear stresses due to the free-edge reinforcement. A proposed method of reducing the intensity of these large stresses is to reinforce the stiffness at the free edge by wrapping a lamina or collection of laminae around the free edge, forming a cap. The cap is intended to reduce the large displacement gradients near the free edge, thereby decreasing the interlaminar stresses and reducing the probability of delamination. Experimental studies indicate that a reinforcing cap is a viable method of maintaining laminate strength 15. The purpose of this study is to determine the effect of a reinforcing cap on the stress distribution in a symmetric composite laminate under uniform axial extension. Parametric studies are performed by varying the thickness, length, and lamination scheme of the cap. Numerical results are presented for several representative test cases.

20 citations


Book ChapterDOI
01 Jan 1985
TL;DR: In this article, the unilateral contact of plates on elastic foundation is considered and both vanishing and finite tensile contact strength between the plate and the foundation are considered, and the relationship with the brittle fracture mechanics approach is also discussed.
Abstract: The unilateral contact of plates on elastic foundation is considered. Both vanishing and finite tensile contact (or adhesion) strength between the plate and the foundation are considered. The approach is used to study delamination due totransverse loads in two layer plates. The relationship with the brittle fracture mechanics approach is also discussed. Numerical results are presented to validate the present approach.

13 citations