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.

Nonlinear Buckling Analysis of Cylindrical Shell With Normal Nozzle Subjected to Axial Loads

2017 ◽  
Author(s):  
Qianyu Shi ◽  
Zhijian Wang ◽  
Hui Tang
Keyword(s):  
Cylindrical Shell ◽  
Industrial Development ◽  
Large Scale ◽  
Pressure Vessels ◽  
Buckling Analysis ◽  
Fe Model ◽  
Axial Loads ◽  
Nonlinear Buckling ◽  
Buckling Failure ◽  
Nonlinear Buckling Analysis

Design of Large-scale and light-weight pressure vessels is an inexorable trend of industrial development. These large thin-walled vessels are prone to buckling failure when subjected to compression loads and other destabilizing loads. Thus, buckling analysis is a primary and even the most important part of design for these pressure vessels. Local buckling failure will probably occur when cylindrical shells with nozzle subjected to axial loads. In this paper, a FE model of cylindrical shell with a normal nozzle is established in ANSYS Workbench. The bifurcation buckling analysis is performed by using an elastic-plastic stress analysis with the effect of nonlinear geometry, and a collapse analysis is performed with an initial imperfection. The axial buckling loads are obtained by these two types of method. Some issues about nonlinear buckling analysis are discussed through this study case.

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 Behavior of Cylindrical Shells of Uniform Thickness under Wind Load

2012 ◽  
Vol 594-597 ◽  
pp. 2753-2756
Author(s):  
Lei Chen ◽  
Yi Liang Peng ◽  
Li Wan ◽  
Hong Bo Li
Keyword(s):  
Cylindrical Shells ◽  
External Pressure ◽  
Pressure Vessels ◽  
Wind Pressure ◽  
Uniform Thickness ◽  
Nonlinear Buckling ◽  
Buckling Modes ◽  
Uniform External Pressure ◽  
Aspect Ratios ◽  
Buckling Behavior

Abstract: Cylindrical shells are widely used in civil engineering. Examples include cooling towers, nuclear containment vessels, metal silos and tanks for storage of bulk solids and liquids, and pressure vessels. Cylindrical shells subjected to non-uniform wind pressure display different buckling behaviours from those of cylinders under uniform external pressure. At different aspect ratios, quite complex buckling modes occur. The geometric nonlinearity may have a significant effect on the buckling behavior. This paper presents a widely study of the nonlinear buckling behavior of cylindrical shells of uniform thickness under wind loading. The finite element analyses indicate that for stocky cylinders, the nonlinear buckling modes are the circumferential compression buckling mode, which is similar to cylinders under uniform external pressure, while for cylinders in mediate length, pre-buckling ovalization of the cross-section has an important influence on the buckling strength.

Nonlinear Buckling Analysis of Pipelines Subjected to Creep of Supporting Soil

1989 ◽  
Vol 111 (2) ◽  
pp. 191-196 ◽  
Author(s):  
A. M. Vinogradov
Keyword(s):  
Structural Model ◽  
Small Deformation ◽  
Buckling Analysis ◽  
Frozen Soil ◽  
Soil Pressure ◽  
Nonlinear Buckling ◽  
Soil System ◽  
Overburden Soil ◽  
Supporting Soil ◽  
Nonlinear Buckling Analysis

The paper deals with the nonlinear buckling analysis of pipelines supported by frozen soil and subjected to differential soil movements. The adopted structural model affords a parametric examination of various loading factors generated by the overburden soil pressure, restrained thermal expansion of heated pipelines and possible load imperfections. The influence of time and temperature effects induced by the mechanical properties of supporting soil is examined. Based on the obtained analytical solution, the critical condition for the pipelines is formulated, and the post-buckling response of the pipeline-soil system is examined in detail. The results of the nonlinear analysis are compared with those derived from the linear approach yielding an assessment of the small deformation theory.

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.

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