The Experts below are selected from a list of 1863 Experts worldwide ranked by ideXlab platform
S G Hong - One of the best experts on this subject based on the ideXlab platform.
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pseudo Membrane Shell Theory of hybrid anisotropic materials
Composite Structures, 2017Co-Authors: Samuel W Chung, S G HongAbstract:Abstract The behavior and characteristics of classical Membrane Theory of isotropic materials are different from that of anisotropic materials, care must be taken to prevent secondary bending moments due to the unbalanced arrangement of laminates of anisotropic materials. At times, bending Theory may have to be adopted and the current design codes, such as ASME, API and ACI must be reviewed for the case of anisotropic materials. The stresses and strains can be significantly different between the pure Membrane and bending theories. This paper derives a Membrane type Shell Theory of hybrid anisotropic materials, governing differential equations together with the procedures to locate the mechanical neutral axis. The Theory is derived by first considering generalized stress strain relationship of a three dimensional anisotropic body which is subjected to 21 compliance matrix and then non-dimensionalizing each variable with asymptotic expansion. After applying to the equilibrium and stress-displacement equations, we are allowed to proceed asymptotic integration to reach the first approximation Theory. Also possible secondary moments due to the unbalanced built up of lamination are quantifiably expressed. The Theory is different from the so called pure Membrane or the semi-Membrane analysis.
Samuel W Chung - One of the best experts on this subject based on the ideXlab platform.
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details of semi Membrane Shell Theory of hybrid anisotropic materials
International Journal of Composite Materials, 2018Co-Authors: Samuel W ChungAbstract:A new version of partial differential equations and prescribed boundary conditions of already formulated semi-Membrane Shell Theory of anisotropic materials is presented. It is based on the theories been developed by authors previously. The isotropic versions of the Theory has been known to be developed nearly a century ago by Vlasov and it has been efficiently utilized for design and analysis. The aerospace vehicle structures and outer space rocket fuel storage tanks designed efficiently however not much for composite materials, while most of recent structural materials are of the combination of anisotropic materials. The semi-Membrane cylindrical Shell theories are classified as that of very long effective length scale and we adopted here the longest possible longitudinal and short circumferential length scales, respectively, for the formulation. The edge effects due to the prescribed boundary condition penetrate differently depending on material orientation of each layer but all within the limit of length scale (ah)1/2 where Donnell-Vlasov bending Theory is valid. Demonstrated that beyond the limit of edge effective zone, Membrane or pseudo-Membrane state dominates, it is traditionally named semi-Membrane state. New simplified governing equations of semi-Membrane Theory of cylindrical Shell are formulated and the physical interpretation of the Theory is described.
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pseudo Membrane Shell Theory of hybrid anisotropic materials
Composite Structures, 2017Co-Authors: Samuel W Chung, S G HongAbstract:Abstract The behavior and characteristics of classical Membrane Theory of isotropic materials are different from that of anisotropic materials, care must be taken to prevent secondary bending moments due to the unbalanced arrangement of laminates of anisotropic materials. At times, bending Theory may have to be adopted and the current design codes, such as ASME, API and ACI must be reviewed for the case of anisotropic materials. The stresses and strains can be significantly different between the pure Membrane and bending theories. This paper derives a Membrane type Shell Theory of hybrid anisotropic materials, governing differential equations together with the procedures to locate the mechanical neutral axis. The Theory is derived by first considering generalized stress strain relationship of a three dimensional anisotropic body which is subjected to 21 compliance matrix and then non-dimensionalizing each variable with asymptotic expansion. After applying to the equilibrium and stress-displacement equations, we are allowed to proceed asymptotic integration to reach the first approximation Theory. Also possible secondary moments due to the unbalanced built up of lamination are quantifiably expressed. The Theory is different from the so called pure Membrane or the semi-Membrane analysis.
Friedrich Gruttmann - One of the best experts on this subject based on the ideXlab platform.
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a consistent finite element formulation of nonlinear Membrane Shell Theory with particular reference to elastic rubberlike material
Finite Elements in Analysis and Design, 1993Co-Authors: Adnan Ibrahimbegovic, Friedrich GruttmannAbstract:Abstract In this paper we present a nonlinear Membrane Theory for rubberlike Shells accounting for large elastic strains. We discuss the material model given as a general coaxial form of stress and strain measures. It includes, as a special case, the hypereleastic model in terms of principal stretches which is often used to characterize rubberlike materials. The displacement-based finite elements are used. Cartesian coordinate systems are constructed locally at each numerical integration point in order to simplify computations. Numerical examples demonstrate a very satisfying performance of the proposed formulation.
Adnan Ibrahimbegovic - One of the best experts on this subject based on the ideXlab platform.
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a consistent finite element formulation of nonlinear Membrane Shell Theory with particular reference to elastic rubberlike material
Finite Elements in Analysis and Design, 1993Co-Authors: Adnan Ibrahimbegovic, Friedrich GruttmannAbstract:Abstract In this paper we present a nonlinear Membrane Theory for rubberlike Shells accounting for large elastic strains. We discuss the material model given as a general coaxial form of stress and strain measures. It includes, as a special case, the hypereleastic model in terms of principal stretches which is often used to characterize rubberlike materials. The displacement-based finite elements are used. Cartesian coordinate systems are constructed locally at each numerical integration point in order to simplify computations. Numerical examples demonstrate a very satisfying performance of the proposed formulation.
Alain Cimetière - One of the best experts on this subject based on the ideXlab platform.
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An Eulerian approach of non-linear Membrane Shell Theory
International Journal of Non-Linear Mechanics, 2003Co-Authors: Olivier Millet, Aziz Hamdouni, Alain CimetièreAbstract:The purpose of this article is to develop an asymptotic Eulerian approach in plate and Shell Theory valid for large displacements. With this Eulerian approach, the dead load assumption generally used with Lagrangian approaches can be dropped. We also obtain a Membrane model which takes into account following forces, whose direction can vary during large displacements.