Exact Analysis of a Thick Sandwich Conical Shell by Forward Integration

1972 ◽  
Vol 39 (2) ◽  
pp. 495-500 ◽  
Author(s):  
D. H. Seitz
Keyword(s):  
Numerical Method ◽  
Shell Theory ◽  
Elasticity Analysis ◽  
The Core ◽  
Transverse Normal Stress ◽  
Arbitrary Thickness ◽  
Sandwich Plates And Shells ◽  
Classical Shell Theory ◽  
Plates And Shells ◽  
Forward Integration

A numerical method for stress analysis of three-layered, honeycomb-type sandwich plates and shells of arbitrary thickness is illustrated by application to a thick conical frustum. Results are demonstrated in a numerical example. The method features an exact elasticity analysis of the core including transverse shear and transverse normal stress. The facings are treated by classical shell theory. The numerical method used is forward integration.

scholarly journals Free Vibration of Sandwich Plates and Shells by Using Zig-Zag Function

2009 ◽  
Vol 16 (5) ◽  
pp. 495-503 ◽  
Author(s):  
S. Brischetto ◽  
E. Carrera ◽  
L. Demasi
Keyword(s):  
Free Vibration ◽  
Free Vibration Analysis ◽  
Sandwich Plates ◽  
Vibration Modes ◽  
Fundamental Vibration ◽  
First Derivative ◽  
The Core ◽  
Sandwich Plates And Shells ◽  
Plates And Shells ◽  
Free Vibration Response

This paper analyses the free vibration response of sandwich curved and flat panels by introducing the zig-zag function (—1)kζk(ZZF) in the displacement models of classical and higher order two-dimensional shell theories. The main advantage of ZZF is the introduction of a discontinuity in the first derivative, zig-zag effect, of the displacements distribution with correspondence to the core/faces interfaces. Results including and discarding ZZF are compared. Several values of face-to-core stiffness ratio (FCSR) and geometrical plate/shell parameters have been analyzed. Both fundamental vibration modes and those corresponding to high wave numbers are considered in the analysis. It is concluded that: (1) ZZF is highly recommended in the free vibration analysis of sandwich plates and shells; (2) the use of ZZF makes the error almost independent by FCSR parameter; (3) ZZF is easy to implement and its use should be preferred with respect to other `more cumbersome' refined theories.

Bending Due to Ring Loading of a Cylindrical Shell With an Elastic Core

1965 ◽  
Vol 32 (1) ◽  
pp. 99-103 ◽  
Author(s):  
John C. Yao
Keyword(s):  
Cylindrical Shell ◽  
Stress Function ◽  
Shell Theory ◽  
Soft Core ◽  
Thin Cylindrical Shell ◽  
Displacement Fields ◽  
Material Constants ◽  
The Core ◽  
Stress And Displacement Fields ◽  
Classical Shell Theory

The problem of a long, thin cylindrical shell with a soft core and subjected to a radial ring load is solved with the use of the Boussinesq-Neuber stress function for the core in conjunction with classical shell theory. Numerical results for stress and displacement fields are given for various values of the cylinder geometry parameters and material constants.

scholarly journals Alternative derivation of the higher-order constitutive model for six-parameter elastic shells

2021 ◽  
Vol 72 (2) ◽  
Author(s):  
Mircea Bîrsan
Keyword(s):  
Energy Density ◽  
Constitutive Model ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Shell Theory ◽  
Constitutive Relations ◽  
Three Dimensional ◽  
Classical Shell Theory ◽  
Three Dimensional Elasticity ◽  
General Method

AbstractIn this paper, we present a general method to derive the explicit constitutive relations for isotropic elastic 6-parameter shells made from a Cosserat material. The dimensional reduction procedure extends the methods of the classical shell theory to the case of Cosserat shells. Starting from the three-dimensional Cosserat parent model, we perform the integration over the thickness and obtain a consistent shell model of order $$ O(h^5) $$ O ( h 5 ) with respect to the shell thickness h. We derive the explicit form of the strain energy density for 6-parameter (Cosserat) shells, in which the constitutive coefficients are expressed in terms of the three-dimensional elasticity constants and depend on the initial curvature of the shell. The obtained form of the shell strain energy density is compared with other previous variants from the literature, and the advantages of our constitutive model are discussed.

On buckling and free vibration studies of sandwich plates and cylindrical shells: A review

2018 ◽  
Vol 33 (5) ◽  
pp. 673-724 ◽  
Author(s):  
Pavan Kumar ◽  
CV Srinivasa
Keyword(s):  
Free Vibration ◽  
Laminated Composite ◽  
Free Vibration Analysis ◽  
Functionally Graded ◽  
Future Research ◽  
Sandwich Plates ◽  
Composite Sandwich ◽  
Sandwich Plates And Shells ◽  
Graded Material ◽  
Plates And Shells

Many review articles were published on free vibration and buckling of laminated composites, sandwich plates, and shells. The present article reviews the literature on the buckling and free vibration analysis of shear deformable isotropic and laminated composite sandwich plates and shells using various methods available for plates in the past few decades. Various theories, finite element modeling, and experimentations have been reported for the analysis of sandwich plates and shells. Few papers on functionally graded material plates, plates with smart skin (electrorheological, magnetorheological, and piezoelectric), and also viscoelastic materials were also reviewed. The scope for future research on sandwich plates and shells was also accessed.

scholarly journals Size Effect in Fracture of Sandwich Structure Components: Foam and Laminate

2001 ◽  
Author(s):  
Zdeněk P. Bažant ◽  
Yong Zhou ◽  
Drahomír Novák ◽  
Isaac M. Daniel
Keyword(s):  
Size Effect ◽  
Size Effects ◽  
Sandwich Structure ◽  
Maximum Load ◽  
Material Strength ◽  
Large Structures ◽  
Nominal Strength ◽  
Sandwich Plates And Shells ◽  
Extensive Test ◽  
Plates And Shells

Abstract In the design of sandwich plates and shells for very large structures, such as ships in the range of 100 m length, it is very important to take the size effect on the nominal strength into account, and do so in a realistic, physically justified, manner. Before the size effect is addressed for a sandwich structure, it must be understood for its components — the foam core and the laminate skins. In the current practice, the size effects are automatically attributed to the randomness of material strength, as described by the Weibull theory. The purpose of this paper is to show that in both the foam and the laminate there are deterministic size effects, which are generally more pronounced. They are caused by stress redistribution and energy release due to the growth of large fractures or large cracking zones prior to attaining the maximum load. This deterministic size effect is verified and calibrated by new tests of notched specimens of rigid close-cell vinyl foam. A combined deterministic-probabilistic theory of size effect of the laminates is proposed and verified by extensive test data.

Effect of Accuracy Loss in Classical Shell Theory

1992 ◽  
Vol 59 (2S) ◽  
pp. S217-S223 ◽  
Author(s):  
V. Berdichevsky ◽  
V. Misyura
Keyword(s):  
Shell Theory ◽  
Underlying Causes ◽  
Classical Shell Theory

It is shown that classical shell theory does not yield correct values of displacements in some shell problems. Underlying causes of this effect are discussed.

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