scholarly journals FREE OSCILLATIONS OF PIPELINES LIKE THIN CYLINDRICAL SHELLS WITH REGARDS TO INTERNAL PRESSURE

2019 ◽  
Vol 3 (1) ◽  
pp. 46-52
Author(s):  
Nuriddin Kurbonovich Esanov ◽  
Keyword(s):  
Cylindrical Shell ◽  
Internal Pressure ◽  
Cross Section ◽  
Modulus Of Elasticity ◽  
Poisson’S Ratio ◽  
Cylindrical Shells ◽  
Poisson's Ratio ◽  
Free Oscillations ◽  
Closed Cylindrical Shell ◽  
The Cross

The paper deals with the free oscillations of pipelines as thin cylindrical shells with regard to internal pressure. The pipeline is presented in the form of a closed cylindrical shell with a radius of the midline of the cross section. The material is considered isotropic with density, modulus of elasticity, and Poisson’s ratio

Structural bionic design for thin-walled cylindrical shell against buckling under axial compression

2011 ◽  
Vol 225 (11) ◽  
pp. 2619-2627 ◽  
Author(s):  
D Xing ◽  
W Chen ◽  
J Ma ◽  
L Zhao
Keyword(s):  
Cylindrical Shell ◽  
Axial Compression ◽  
Cross Section ◽  
Cylindrical Shells ◽  
High Load ◽  
Vascular Bundles ◽  
Bionic Design ◽  
Load Bearing ◽  
Thin Walled ◽  
The Cross

In nature, bamboo develops an excellent structure to bear nature forces, and it is very helpful for designing thin-walled cylindrical shells with high load-bearing efficiency. In this article, the cross-section of bamboo is investigated, and the feature of the gradual distribution of vascular bundles in bamboo cross-section is outlined. Based on that, a structural bionic design for thin-walled cylindrical shells is presented, of which the manufacturability is also taken into consideration. The comparison between the bionic thin-walled cylindrical shell and a simple hollow one with the same weight showed that the load-bearing efficiency was improved by 44.7 per cent.

Vibrations of Functionally Graded Shells

2007 ◽  
Author(s):  
Serge Abrate
Keyword(s):  
Composite Material ◽  
Modulus Of Elasticity ◽  
Poisson’S Ratio ◽  
Functionally Graded ◽  
New Method ◽  
Poisson's Ratio ◽  
Tabular Form ◽  
Graded Structures ◽  
Functionally Graded Structures

The behavior of functionally graded structures has received a great deal of attention in recent years. Usually, these structures are made out of a composite material with a modulus of elasticity, a Poisson’s ratio, and a density that vary through the thickness. The non-uniformity through the thickness introduces coupling between the transverse deformations and the deformations of the mid-surface. Previous publications have shown how to account for these added complexities and have presented extensive results in tabular form. In this article, available results are used to show that the behavior of functionally graded shells is similar to that of homogeneous isotropic shells. It is well known that for isotropic shells, results can be presented in non-dimensional form so that, once results are obtained for one material, they can be simply scaled to obtain the corresponding results for shells made out of another material. The same can then be done for functionally graded shells. In addition, if functionally graded shells behave like homogeneous shells, no new method of analysis is required. The second part of the paper examines why this is true.

Tables for Frequencies and Modes of Free Vibration of Infinitely Long Thin Cylindrical Shells

1954 ◽  
Vol 21 (2) ◽  
pp. 178-184
Author(s):  
M. L. Baron ◽  
H. H. Bleich
Keyword(s):  
Free Vibration ◽  
Poisson’S Ratio ◽  
Cylindrical Shells ◽  
Bending Stiffness ◽  
Poisson's Ratio ◽  
Underlying Theory ◽  
Half Wave ◽  
Quick Determination ◽  
Circumferential Waves

Abstract Tables are presented for the quick determination of the frequencies and shapes of modes of infinitely long thin cylindrical shells. To make the problem tractable, the shells are first treated as membranes without bending stiffness, and the bending effects are introduced subsequently as corrections. The underlying theory is based on the energy expressions for cylindrical shells. The tables cover the following range: lengths of longitudinal half wave L from 1 to 10 radii a; number n of circumferential waves from 0 to 6. The results apply for Poisson’s ratio ν = 0.30.

Nonlinear Effects on the Discontinuity Stresses in a Cylindrical Shell With a Flat Head Closure

1974 ◽  
Vol 96 (1) ◽  
pp. 44-46
Author(s):  
C. K. McDonald ◽  
R. E. McDonald
Keyword(s):  
Cylindrical Shell ◽  
Modulus Of Elasticity ◽  
Nonlinear Effect ◽  
Cylindrical Shells ◽  
Nonlinear Effects ◽  
Thin Shells ◽  
Large Displacements ◽  
Low Modulus

The effect of large displacements on the flexural edge stresses in thin cylindrical shells with flat head closures subjected to axisymmetric loads is considered. Results are presented which show that neglecting this nonlinear effect leads to nonconservative results. However, it is shown that these effects can usually be safely neglected except for very thin shells or for shells with a low modulus of elasticity. Curves are given which illustrate this effect for selected shell parameters.

Free Vibration and Elastic Critical Load of Functionally Graded Material Thin Cylindrical Shells Under Internal Pressure

2018 ◽  
Vol 18 (11) ◽  
pp. 1850138 ◽  
Author(s):  
Yueyang Han ◽  
Xiang Zhu ◽  
Tianyun Li ◽  
Yunyan Yu ◽  
Xiaofang Hu
Keyword(s):  
Cylindrical Shell ◽  
Free Vibration ◽  
Internal Pressure ◽  
Critical Load ◽  
Natural Frequency ◽  
Functionally Graded Material ◽  
Present Method ◽  
Cylindrical Shells ◽  
Functionally Graded ◽  
Graded Material

An analytical approach for predicting the free vibration and elastic critical load of functionally graded material (FGM) thin cylindrical shells filled with internal pressured fluid is presented in this study. The vibration of the FGM cylindrical shell is described by the Flügge shell theory, where the internal static pressure is considered as the prestress term in the shell equations. The motion of the internal fluid is described by the acoustic wave equation. The natural frequencies of the FGM cylindrical shell under different internal pressures are obtained with the wave propagation method. The relationship between the internal pressure and the natural frequency of the cylindrical shell is analyzed. Then the linear extrapolation method is employed to obtain the elastic critical load of the FGM cylindrical shell from the condition that the increasing pressure has resulted in zero natural frequency. The accuracy of the present method is verified by comparison with the published results. The effects of gradient index, boundary conditions and structural parameters on the elastic critical load of the FGM cylindrical shell are discussed. Compared with the experimental and numerical analyses based on the external pressure, the present method is simple and easy to carry out.

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