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.

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.

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.

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 Analysis of the Radiant Cable Suspendome

2012 ◽  
Vol 226-228 ◽  
pp. 1185-1189
Author(s):  
Jian Kang ◽  
Xiang Yu Liu
Keyword(s):  
Stability Analysis ◽  
Single Layer ◽  
Hybrid Structure ◽  
Buckling Analysis ◽  
Nonlinear Buckling ◽  
Geometrical Imperfection ◽  
String Structure ◽  
The Stability ◽  
Nonlinear Buckling Analysis ◽  
Lattice Shell

Radiant cable suspendome based on single-layer lattice shell is proposed in this paper whose cable-strut system is like that of Radiant Beam String Structure, the purpose of this paper is to do stability analysis of the structure.The linear buckling analysis of the hybrid structure and the single-layer lattice shell who has the same geometry parameters is carried out, we can preliminarily understand the stability of the hybrid structure. At the same time, nonlinear buckling analysis is carried out to study the stability of the hybrid structure under different rise-span ratios, different prestress level and half-span load. The results show that the introduction of prestressed cables greatly improve the structure's stability and reduce the structure sensitivity to original geometrical imperfection.

Progressive Failure Analysis of Pipeline Repaired by Composite Wrapping

2016 ◽  
Vol 853 ◽  
pp. 483-487
Author(s):  
Yan Yv Wang ◽  
Zhi Qiang Cheng ◽  
Bao Sheng Liu
Keyword(s):  
Failure Analysis ◽  
Critical Pressure ◽  
Progressive Failure ◽  
Failure Criteria ◽  
Pressure Vessels ◽  
Progressive Failure Analysis ◽  
Failure Propagation ◽  
Hashin Failure Criteria ◽  
Two Stages ◽  
Good Agreement

Composite overwrap systems have been widely used to repair damaged pipelines. Its effectiveness has been proven by many researches and engineering applications. However, the research on progressive failure mode of the repaired structure has not been reported. In the present paper, finite element method with Hashin failure criteria is developed to realize the progressive failure analysis. The predicted burst pressure is in good agreement with the burst experiment. Different from widely-reported failure progress in Composite Overwrapped Pressure Vessels (COPV), the progressive failure analysis for the defected pipeline overwrapped by composite reveals very different failure stages: stable failure propagation and rapid failure propagation. The identification of critical pressure between these two stages is valuable in composite reparation design for the defected pipeline.

Nonlinear Buckling Analysis of Long-Span Suspended Latticed Intersected Cylindrical Shell

2014 ◽  
Vol 919-921 ◽  
pp. 169-176 ◽  
Author(s):  
Ming Liang Zhu ◽  
Yan Sun
Keyword(s):  
Cylindrical Shell ◽  
Bearing Capacity ◽  
Single Layer ◽  
Ultimate Bearing Capacity ◽  
Buckling Analysis ◽  
Nonlinear Buckling ◽  
Long Span ◽  
The Stability ◽  
Nonlinear Buckling Analysis ◽  
Material Nonlinear

The Suspended Latticed Intersected Cylindrical Shell (SLICS) is a new structural system, composed by the single layer Latticed Intersected Cylindrical Shell (LICS) and the prestressed cable-strut system. Mechanical properties of this structure were investigated through nonlinear buckling analysis by the consistent imperfect buckling analysis method, compared with the single layer LICS. Structure parameters including prestress level, member section, length of bar, rise-span ratio, obliquity were analyzed. And the effect of material nonlinearity on the stability was studied. Results show that the ultimate bearing capacity of the SLICS is improved as the introduction of prestress. However the prestress level has a limited impact on the ultimate bearing capacity. And the material nonlinear is very important to the stability of the SLICS.

A Temporary Local Rigid Clamping Structure to Improve Antibuckling Ability of the Thin-Walled Cylinder Under External Pressure

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
BingJun Gao ◽  
Zongxun Yin ◽  
Fuhai Zhao ◽  
Chengwen Shang
Keyword(s):  
Critical Pressure ◽  
Leak Detection ◽  
External Pressure ◽  
Cryogenic Liquid ◽  
The Finite Element Method ◽  
Rigid Ring ◽  
Inner Pressure ◽  
Thin Walled ◽  
The Stability ◽  
Walled Cylinder

Although the inner container of the cryogenic liquid semitrailer works under inner pressure, it needs to be vacuumed during the helium leak detection. Furthermore, the inner container usually cannot meet the stability requirements during the evacuation, though equipped with stiffening structures such as supporting rings for baffles inside the container. Therefore, a kind of temporary local rigid clamping structure was proposed to improve the antibuckling ability of the inner container during the helium leak detection. “Lulu” can was taken as the thin-walled cylindrical shell specimen under external pressure and was clamped with the temporary local rigid ring on the outside surface. The critical pressures were experimentally and numerically studied for the specimen with local clamping rings of different sizes, in which eigenvalue buckling analysis and nonlinear analysis were employed with the aid of ANSYS. It indicates that the critical pressure of the specimen with the local clamping ring is higher than that without the clamping ring. Finally, the optimal clamping scheme including size and location of clamping rings for the inner container of DC18 type cryogenic liquid semitrailer was studied with the finite element method, which aimed to improve the antibuckling capacity of the inner container during the helium leak detection.

Parameter Influence Analysis of Stability for Suspendome Structure

2013 ◽  
Vol 351-352 ◽  
pp. 309-314
Author(s):  
Kai Rong Shi ◽  
Zheng Rong Jiang ◽  
Zhi Jian Ruan
Keyword(s):  
Shape Factor ◽  
Hybrid Structure ◽  
Nonlinear Buckling ◽  
Stability Performance ◽  
New Type ◽  
Plane Shape ◽  
Analysis Of Stability ◽  
The Stability ◽  
Nonlinear Buckling Analysis ◽  
Parameter Influence

Taking the new type hybrid structure of suspendome as the analytical object, its stability performance is studied in detail. Through the method of nonlinear buckling analysis, the influences of different parameters on the stability are systematically analyzed i.e. rise-span ratio, plane shape factor, prestress and length of strut. The results show that rise-span ratio, plane shape factor and length of strut have great effects on the structural stability while prestress has small effect.

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.

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