Buckling Loads of Small Cylindrical Shells under Axial Compressive Loads

2009 ◽  
Author(s):  
J. de Vries
Keyword(s):  
Cylindrical Shells ◽  
Buckling Loads ◽  
Compressive Loads

Buckling Design of Axially Compressed Cylindrical Shells Based on Energy Barrier Approach

2021 ◽  
pp. 2150165
Author(s):  
Haigui Fan ◽  
Wenguang Gu ◽  
Longhua Li ◽  
Peiqi Liu ◽  
Dapeng Hu
Keyword(s):  
Experimental Data ◽  
Energy Barrier ◽  
Thin Shell ◽  
Design Method ◽  
Lightweight Design ◽  
Cylindrical Shells ◽  
Design Criterion ◽  
The Other ◽  
Shell Structures ◽  
Buckling Loads

Buckling design of axially compressed cylindrical shells is still a challenging subject considering the high imperfection-sensitive characteristic in this kind of structure. With the development of various design methods, the energy barrier concept dealing with buckling of imperfection-sensitive cylindrical shells exhibits a promising prospect in recent years. In this study, buckling design of imperfection-sensitive cylindrical shells under axial compression based on the energy barrier approach is systematically investigated. The methodology about buckling design based on the energy barrier approach is described in detail first taking advantage of the cylindrical shells whose buckling loads have been extensively tested. Then, validation and discussion about this buckling design method have been carried out by the numerical and experimental analyses on the cylindrical shells with different geometrical and boundary imperfections. Results in this study together with the available experimental data have verified the reliability and advantage of the buckling design method based on energy barrier approach. A design criterion based on the energy barrier approach is therefore established and compared with the other criteria. Results indicate that buckling design based on energy barrier approach can be used as an efficient way in the lightweight design of thin-shell structures.

Buckling of Stiffened Curved Panels and Cylindrical Shells: A Study of Comparison Among Various Theories

2012 ◽  
Author(s):  
S. Harutyunyan ◽  
D. J. Hasanyan ◽  
R. B. Davis
Keyword(s):  
Cylindrical Shell ◽  
Circular Cylindrical Shell ◽  
Cylindrical Shells ◽  
Laminated Composite ◽  
Physical Parameters ◽  
Buckling Loads ◽  
Isotropic Cylindrical Shell ◽  
Analytical Formulas ◽  
Laminated Composite Shells ◽  
Curved Panels

Formulation is derived for buckling of the circular cylindrical shell with multiple orthotropic layers and eccentric stiffeners acting under axial compression, lateral pressure, and/or combinations thereof, based on Sanders-Koiter theory. Buckling loads of circular cylindrical laminated composite shells are obtained using Sanders-Koiter, Love, and Donnell shell theories. These theories are compared for the variations in the stiffened cylindrical shells. To further demonstrate the shell theories for buckling load, the following particular case has been discussed: Cross-Ply with N odd (symmetric) laminated orthotropic layers. For certain cases the analytical buckling loads formula is derived for the stiffened isotropic cylindrical shell, when the ratio of the principal lamina stiffness is F = E2/E1 = 1. Due to the variations in geometrical and physical parameters in theory, meaningful general results are complicated to present. Accordingly, specific numerical examples are given to illustrate application of the proposed theory and derived analytical formulas for the buckling loads. The results derived herein are then compared to similar published work.

An Experiential Optimization Design Method for Orthogonal Rib-Stiffened Thin Walled Cylindrical Shells under Axial Loading

2011 ◽  
Vol 110-116 ◽  
pp. 1773-1783
Author(s):  
Jia Mao ◽  
Yu Feng Chen ◽  
Wei Hua Zhang
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Mass Parameter ◽  
Cylindrical Shells ◽  
Reference Value ◽  
Buckling Load ◽  
Element Analysis ◽  
Buckling Loads ◽  
Load Optimization ◽  
Thin Walled

Parametric structural FEA (Finite Element Analysis) models of the orthogonal rib-stiffened thin walled cylindrical shells are established using APDL (ANSYS Parametric Design Language). An experiential optimization design method is then developed based on conclusions of series numerical analysis investigating the effects of parameters’ modification upon buckling loads and modes of the structure. The effects of single design parameter modification under both variational and fixed volume (mass) constraints upon the buckling loads and modes indicate that, only one design scheme is able to obtain maximum buckling load when deployment of the strengthening ribs and volume (mass) parameter were settled previously, and minimum mass would be obtained while this maximum buckling load equals to the required design load. Optimization calculations for aluminum alloy material and layered C/E (Carbon/Epoxy) composite material shells with three layering styles are implemented and discussed, and some useful conclusions are obtained. Method and approach developed in this paper provide certain reference value for the optimal design of such structures.

Mechanical buckling of cylindrical shells with varying material properties

2010 ◽  
Vol 224 (8) ◽  
pp. 1551-1557 ◽  
Author(s):  
P Khazaeinejad ◽  
M M Najafizadeh
Keyword(s):  
Exponential Function ◽  
Power Law ◽  
Material Properties ◽  
Volume Fraction ◽  
Cylindrical Shells ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Buckling Loads ◽  
Young’S Moduli ◽  
Wave Numbers

The analytical solutions of the first-order shear deformation theory are developed to study the buckling behaviour of functionally graded (FG) cylindrical shells under three types of mechanical loads. The Poisson's ratios of the FG cylindrical shells are assumed to be constant, while the Young's moduli vary continuously throughout the thickness direction according to the volume fraction of constituents given by power-law or exponential function. The stability equations are employed to obtain the closed-form solutions for critical buckling loads of each loading case. The dependence of the critical buckling loads on the variations of the material properties with a power-law or exponential function is studied. It is observed that these effects change appreciably the critical buckling loads. Results for critical loads are tabulated for thin and moderately thick shells. Although the critical buckling load of FG cylindrical shells decreases as the circumferential wave numbers increase, it rises for axially compressed long shells as the longitudinal wave numbers increase.

Buckling Analysis of Advanced Grid Stiffened Composite Cylinders

2014 ◽  
Vol 875-877 ◽  
pp. 755-762 ◽  
Author(s):  
Kang Hee Lim ◽  
He Wei ◽  
Zhi Dong Guan
Keyword(s):  
Cylindrical Shells ◽  
Computational Cost ◽  
Structure Design ◽  
Grid Structure ◽  
Constant Weight ◽  
Buckling Loads ◽  
Design Variables ◽  
Weight Design ◽  
Composite Cylinders ◽  
Composite Cylindrical Shells

Advanced Grid Stiffened(AGS) composite cylindrical shells are widely used in aerospace industry. This study analyzes the buckling loads for various types of grid structures of AGS composite cylindrical shells. The grid structures are classified as Angle-grid, Iso-grid, Kagome-grid, Ortho-grid, Orthotropic-grid and the characteristics had been analyzed for each grid type. In this study, the various types of grid structure were designed that weight of the whole structure keeps a constant. Under the condition of constant-weight, design variables such as grid angle, number of the grid, h/t ratio of the grid were controlled, and buckling loads of the grid structures were analyzed. The results were analyzed for each type of grid and each design variable of the structures. This study was performed through finite element method and the accuracy of the analysis was verified by previous studies. Finally, buckling modes were analyzed with the thickness of the skin. The selection for the most appropriate design variables had been verified for each grid type and the result can be applied to the optimization of grid structure design, and is also very helpful for reducing the computational cost and obtaining optimization values more accurately.

Analytical Study on Dynamic Buckling of Cylindrical Shells with General Thickness Variations Subjected to Exponentially Increasing External Pressure

2020 ◽  
Vol 20 (12) ◽  
pp. 2050133
Author(s):  
Licai Yang ◽  
Ying Luo ◽  
Tian Qiu ◽  
Hao Zheng ◽  
Yang Qiu
Keyword(s):  
Cylindrical Shells ◽  
Analytical Investigation ◽  
External Pressure ◽  
Variable Coefficients ◽  
Dynamic Buckling ◽  
Thickness Variation ◽  
Power Exponent ◽  
Buckling Loads ◽  
Critical Dynamic ◽  
Thickness Variations

This paper presents an analytical investigation on dynamic buckling of cylindrical shells with general thickness variations under exponentially increasing external pressure over the time. Different from the previous studies in literatures, the shell thickness varies arbitrarily and is common in actual engineering, which leads to failure of the existing methods. A new analytical method is first developed to solve the fourth-order governing partial differential equations with variable coefficients for the shell subjected to varying external pressure. Then the asymptotic formulae for dynamic buckling loads considering general thickness variations are derived and expressed by geometry sizes of the shell and thickness variation functions. To validate the presented results, two specific non-axisymmetric thickness cases are discussed in detail. The critical dynamic buckling loads show a great agreement with the previous ones by other researchers for simple and axial thickness variation situation. Finally, example calculations and parametric discussion are performed, and influences of thickness variation types, speed of external pressure and the power exponent of time on the critical dynamic buckling loads are discussed.

Buckling of Cracked Cylindrical Shells With Internal Pressure Subjected to an Axial Load

2002 ◽  
Author(s):  
A. Vaziri ◽  
H. E. Estekanchi ◽  
H. Nayeb-Hashemi
Keyword(s):  
Internal Pressure ◽  
Crack Length ◽  
Cylindrical Shells ◽  
High Stress ◽  
Pressure Vessels ◽  
Buckling Load ◽  
Critical Crack Length ◽  
Buckling Loads ◽  
Buckling Behavior ◽  
Crack Angle

Cylindrical shells constitute the main structural component in pressure vessels and pipelines. Buckling is one of the main failure considerations when designing these cylindrical shells. Defects such as cracks may develop during manufacturing or service life of these structures. These defects can severely affect their buckling behavior due to high stress field generated around these defects. Finite Element Analyses are performed to study the buckling behavior of cylindrical shells with and without a crack, under various internal pressures. Effects of crack length and its orientation on the buckling loads of cylindrical shells having a through or a thumbnail crack are studied. The results show that the buckling loads are not significantly affected for cylindrical shells with a crack less than a critical length. However, longer cracks cause local buckling of the cracked shells and can severely affect their buckling loads. This critical crack length depends on the crack orientation and the shell internal pressure. The results indicate that the buckling loads of cracked shells with internal pressure are quite sensitive to the crack angle. For cylindrical shells with an axial crack, the first buckling load drastically reduces with increasing the shell internal pressure. In contrast, the buckling load increases with the shell internal pressure for circumferentially cracked shells. The buckling loads of cracked shells with internal pressure are quite sensitive to crack angle. However, the bucking loads are little dependent to the crack angle for shells with no internal pressure.

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