Nonlinear Postbuckling of Auxetic-Core Sandwich Toroidal Shell Segments with CNT-Reinforced Face Sheets Under External Pressure

2021 ◽  
Author(s):  
Nguyen Van Tien ◽  
Vu Minh Duc ◽  
Vu Hoai Nam ◽  
Nguyen Thi Phuong ◽  
Lanh Si Ho ◽  
...  
Keyword(s):  
Core Layer ◽  
Elastic Interaction ◽  
Radial Pressure ◽  
Equation System ◽  
External Pressure ◽  
Toroidal Shell ◽  
Postbuckling Behavior ◽  
Nonlinear Buckling ◽  
Foundation Model ◽  
Nonlinear Buckling Analysis

Nonlinear buckling analysis for honeycomb auxetic-core sandwich toroidal shell segments with CNT-reinforced face sheets surrounded by elastic foundations under the radial pressure is presented in this study. The basic equation system of shells is established based on the von Kármán–Donnell nonlinear shell theory, combined with Stein and McElman approximation. Meanwhile, the foundation-shell elastic interaction is simulated by the foundation model based on the Pasternak assumption. The Galerkin procedure is utilized to achieve the pre-buckling and post-buckling responses for the shell, from which the radially critical buckling load is determined. Numerical analysis shows the various influences of auxetic-core layer, CNT-reinforced face sheets, and elastic foundation on the pre-buckling and postbuckling behavior of sandwich shells with CNT reinforced face sheets.

Stability of Elastic Orthotropic Circular Cylindrical Vessels

2010 ◽  
Author(s):  
Krzysztof Magnucki ◽  
Leszek Wittenbeck
Keyword(s):  
Numerical Analysis ◽  
Critical Pressure ◽  
Linear Analysis ◽  
External Pressure ◽  
Second Step ◽  
Nonlinear Buckling ◽  
Post Buckling ◽  
Analytical Formulas ◽  
Linear And Nonlinear ◽  
Nonlinear Buckling Analysis

This paper is devoted to stability investigation of orthotropic circular cylindrical vessels subjected to external pressure. An untypical orthotropic structure that consist of two layers: smooth-external and corrugated-internal is proposed. The investigation is divided into two steps. In first one analytical formulas describing buckling behaviour are derived. In second step numerical analysis is performed by using FEM to obtain the correlation between analytical and numerical results. Authors also considered linear and nonlinear buckling analysis. During the linear analysis the influence of vessel geometry on critical pressure is determined. Nonlinear analysis is carried out to create equilibrium paths which show the behaviour of vessels in post-buckling state. The results of the analysis are presented in figures.

NONLINEAR BUCKLING OF MARINE ELASTICA PIPES TRANSPORTING FLUID

2001 ◽  
Vol 01 (03) ◽  
pp. 333-365 ◽  
Author(s):  
S. CHUCHEEPSAKUL ◽  
T. MONPRAPUSSORN
Keyword(s):  
Large Strain ◽  
Slenderness Ratio ◽  
Internal Flow ◽  
Pipe Material ◽  
Postbuckling Behavior ◽  
Limit States ◽  
Nonlinear Buckling ◽  
Critical Weight ◽  
Strain Formulation ◽  
Nonlinear Buckling Analysis

This paper addresses the nonlinear buckling and post-buckling behavior of an extensible marine elastica pipe conveying fluid. The mathematical model employed in the nonlinear buckling analysis is developed based on the extensible elastica theory and the large strain formulation, so that the high extensibility of the pipe due to large axial strains is tackled thoroughly. The boundary value problem of the model is solved by the shooting method, and the numerical elastica solutions are obtained. For stability examination, the method of adjacent nonlinear equilibrium is exploited. It is revealed that the fundamental mode of nonlinear buckling of the pipe is reached when the pipe experiences either the critical top tension or the critical weight. Postbuckling behavior of the pipe is recognized to be unstable. The investigation is extended to studying various parameters that impinge on the limit states of the pipe. These parameters are the dimensionless quantities that relate to density of pipe material, densities of external and internal fluids, applied top tension, Poisson's ratio, slenderness ratio, vessel offset, seawater depth, current-drag coefficients, current velocity, and internal flow velocity.

Case Study of Nonlinear Buckling With Shape Distortion due to Thermal Load

2018 ◽  
Author(s):  
Jun Shen ◽  
Yanfang Tang ◽  
Heng Peng ◽  
Hui Peng ◽  
Yinghua Liu
Keyword(s):  
Thermal Stress ◽  
Thermal Load ◽  
Small Deformation ◽  
External Pressure ◽  
Pressure Vessels ◽  
Engineering Practice ◽  
Shape Distortion ◽  
Nonlinear Buckling ◽  
Typical Structure ◽  
Nonlinear Buckling Analysis

Thermal load is one of the most important design conditions that should be considered carefully in engineering practice. Most inner-pressure vessels suffer thermo-mechanical ratcheting or unacceptable plastic deformation under cyclic thermal stress produced by inside heat source and pressure-induced primary stress. However, thermal load is also a crucial factor for external-pressure vessels where the failure model of buckling should not be ignored. The effect of thermal load on buckling is not only thermal stress itself but also shape distortion due to thermal load. In some cases, the latter is more important. In this paper, an external-pressure thin-walled ellipsoidal head with heating jackets has been studied. The temperature of this structure is uniformly distributed along the thickness direction but changes alternately between hot and cold along the meridional direction, which will have a significant effect on buckling behavior of this typical structure. Buckling load is sensitive to initial defect and small deformation. Several comparative calculations based on nonlinear buckling analysis have been conducted and some laws are established. Finally, some useful conclusions and suggestions are proposed for engineering design.

Stability Analysis of a Processor Unit Served in Deep-Sea

2011 ◽  
Vol 697-698 ◽  
pp. 769-773
Author(s):  
D.D. Bian ◽  
H.W. Zhang ◽  
Y.H. Liu ◽  
H.Z. Liu
Keyword(s):  
Critical Pressure ◽  
Autonomous Underwater Vehicle ◽  
External Pressure ◽  
Pressure Vessels ◽  
Wave Number ◽  
Nonlinear Buckling ◽  
Processor Unit ◽  
The Stability ◽  
Nonlinear Buckling Analysis ◽  
Good Agreement

Stability is the key of designing thin-walled external-pressure Vessels. Nonlinear buckling analysis using finite element method has been carried out on a processor unit of an autonomous underwater vehicle to study the stability of the processor unit considering the screw tightening. Effects of the cylinder thickness on the critical pressure are discussed. Results show that the buckling wave number is 4 in the circumferential direction, and the critical pressure decreases with decreasing the cylinder thickness exponentially, which is in good agreement with the theoretical calculation.

scholarly journals Nonlinear Buckling Behavior of Spiral Corrugated Sandwich FGM Cylindrical Shells Surrounded by an Elastic Medium

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1984
Author(s):  
Vu Tho Hung ◽  
Dang Thuy Dong ◽  
Nguyen Thi Phuong ◽  
Le Ngoc Ly ◽  
Tran Quang Minh ◽  
...  
Keyword(s):  
Cylindrical Shells ◽  
Geometrical Nonlinearity ◽  
Equation System ◽  
External Pressure ◽  
Functionally Graded ◽  
Homogenization Theory ◽  
Nonlinear Buckling ◽  
Solution Form ◽  
Buckling Behavior ◽  
The Galerkin Method

This paper presents a semi-analytical approach for investigating the nonlinear buckling and postbuckling of spiral corrugated sandwich functionally graded (FGM) cylindrical shells under external pressure and surrounded by a two-parameter elastic foundation based on Donnell shell theory. The improved homogenization theory for the spiral corrugated FGM structure is applied and the geometrical nonlinearity in a von Karman sense is taken into account. The nonlinear equilibrium equation system can be solved by using the Galerkin method with the three-term solution form of deflection. An explicit solution form for the nonlinear buckling behavior of shells is obtained. The critical buckling pressure and the postbuckling strength of shells are numerically investigated. Additionally, the effects of spiral corrugation in enhancing the nonlinear buckling behavior of spiral corrugated sandwich FGM cylindrical shells are validated and discussed.

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