Pressure Vessels under External Pressure

2009 ◽  
pp. 357-386 ◽  
Author(s):  
C.T.F. Ross
Keyword(s):  
External Pressure ◽  
Pressure Vessels

Analysis of Half-Pipe Heating Channels on Pressure Vessel Shells

1986 ◽  
Vol 108 (4) ◽  
pp. 526-529
Author(s):  
A. E. Blach
Keyword(s):  
Pressure Vessel ◽  
Analytical Method ◽  
External Pressure ◽  
Pressure Vessels ◽  
Numerical Examples ◽  
Asme Code

Half-pipe heating channels are used on the outside of pressure vessels such as agitators, mixers, reactors, etc., to avoid the high external pressure associated with heating jackets. No applicable method of analysis is contained in the ASME Code and proof tests are normally required for registration with governing authorities. An analytical method is presented which permits the evaluation of stresses in shell and half pipe; numerical examples are included.

Remaining Life Assessment of an External Pressure Vessel in Creep Range and Inspection Findings

2017 ◽  
Author(s):  
Yoichi Ishizaki ◽  
Futoshi Yonekawa ◽  
Takeaki Yumoto ◽  
Teppei Suzuki ◽  
Shuji Hijikawa
Keyword(s):  
Pressure Vessel ◽  
Creep Damage ◽  
External Pressure ◽  
Pressure Vessels ◽  
Life Assessment ◽  
Remaining Life ◽  
Assessment Technique ◽  
Creep Cavity ◽  
Creep Analysis ◽  
Remaining Life Assessment

As widely recognized in the industry, it is important to evaluate the creep damage of an elevated temperature vessel so that the mechanical integrity of the vessel can be achieved through the adequate repair and replacement planning. This is quite straight forward procedure for internal pressure vessels. For an external pressure vessel, it is not easy to assess the creep damage due to the complexity of the creep buckling analysis. Eventually, creep cavity evaluation technique without identifying the correct stress distribution has been used so often. However, due to the uncertainty of the technique itself plus conservative mindset of the inspectors, it tends to leads to an excessive maintenance most of the cases. In order to conduct a reasonable remaining life assessment, it is desirable to use the creep cavity inspection in conjunction with another assessment technique such as FEM creep analysis as stated in API 579-1/ASME FFS-1 10.5.7. In this paper, comprehensive approach with FEM and field inspection such as creep cavity evaluation to reinforce the uncertainty of each method will be demonstrated.

Buckling of Externally Pressurized Prolate Ellipsoidal Domes

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
P. Smith ◽  
J. Błachut
Keyword(s):  
New York ◽  
Test Procedure ◽  
External Pressure ◽  
Pressure Vessels ◽  
European Convention ◽  
Numerical Predictions ◽  
Current Design ◽  
Base Radius ◽  
Division 2 ◽  
Prolate Ellipsoidal

Details are given of a numerical and experimental study into buckling of steel ellipsoidal domes loaded by static external pressure. A range of geometries and thicknesses of domes is examined, as is the influence of different boundary conditions. Shells are examined on the basis of having the same mass. The main focus of the study is on prolate domes, i.e., those taller than a hemisphere of the same base radius. Numerical predictions are confirmed by pressurizing six laboratory scale prolate domes to destruction. Details are given of the manufacture and test procedure for the domes. The adverse effects of variations in shape and wall thickness are discussed, and finite element predictions are made for geometrically imperfect domes. Correlation between the two sets of results is good. Numerically and experimentally obtained results are related to the current design codes: ASME Boiler and Pressure Vessel Code, Sec. 8, Division 2 (described hereon as ASME VIII), PD5500, and ECCS recommendations (ASME B&PV Code, 2004 ed., Sec. 8, Division 2, New York, NY; BSI 2003 “Published Document PD5500: Specification for Unfired Pressure Vessels,” BSI London; European Convention for Constructional Steelwork Recommendations, 1988 “Buckling of Stell Shells-European Recommendations,” ECCS-TWG 8.4, 4th ed., Brussels), which at present make no provision for prolate domes. Suggestions are made for the possible inclusion of such domes into the standards.

scholarly journals Buckling analysis of thin-walled metal liner of cylindrical composite overwrapped pressure vessels with depressions after autofrettage processing

2021 ◽  
Vol 28 (1) ◽  
pp. 540-554
Author(s):  
Guo Zhang ◽  
Haiyang Zhu ◽  
Qi Wang ◽  
Xiaowen Zhang ◽  
Mingfa Ren ◽  
...  
Keyword(s):  
Pressure Vessel ◽  
Local Buckling ◽  
Bending Moment ◽  
High Strength ◽  
External Pressure ◽  
Pressure Vessels ◽  
Buckling Analysis ◽  
Straight Section ◽  
Metal Liner ◽  
Autofrettage Pressure

Abstract The cylindrical filament wound composite overwrapped pressure vessels (COPV) with metal liner has been widely used in spaceflight due to their high strength and low weight. After the autofrettage process, the plastic deformation of the metal liner is constrained by composite winding layers, which introduce depressions to the metal liner that causes local buckling. To predict the local buckling of the inner liner with depressions of the pressure vessel after the autofrettage process, a local buckling analysis method for the metal liner of COPV was developed in this article. The finite element method is used to calculate the overall stress distribution in the pressure vessel before and after the autofrettage process, and the influence of local depressions on the buckling is evaluated. The axial buckling of the pressure vessel under external pressure is analyzed. The control equation of the metal liner with depressions is developed, considering the changes in the pressure and the bending moment of the liner depressions and its vicinity during the loading and unloading process. Taking the cylindrical COPV (38 L) with aluminum alloy liner as an example, the effects of liner thickness, liner radius, the thickness-to-diameter ratio, autofrettage pressure, and the length of straight section on the autofrettage process are discussed. The results show that the thickness of the inner liner has the most significant influence on the buckling of the liner, followed by the length of the straight section and the radius of the inner liner, while the autofrettage pressure has the least influence.

Collapse Strength of Complex Metal Shell Intersections by the Effective Area Method

1998 ◽  
Vol 120 (3) ◽  
pp. 217-222 ◽  
Author(s):  
J. G. Teng
Keyword(s):  
Effective Area ◽  
External Pressure ◽  
Pressure Vessels ◽  
Metal Shell ◽  
Local Pressure ◽  
Area Method ◽  
Different Types ◽  
Bending Stresses ◽  
Slope Discontinuity ◽  
Shell Intersections

Cone-cone intersections and cone-cylinder intersections with or without ring stiffeners are common features in silos, tanks, pressure vessels, piping components, and other industrial shell structures. Under internal or external pressure, these intersections are subject to high circumferential membrane stresses as well as high bending stresses due to the presence of a slope discontinuity. As a result, they are susceptible to local plastic collapse. This paper first provides a summary of the effective area method initially proposed by Rotter for the plastic limit loads of cone-cylinder intersections in silos. The method is then generalized for complex intersections of cones and cylinders under uniform pressure and improved by including the local pressure effect. Results from the effective area method are compared with rigorous finite element results for a number of cases to demonstrate its accuracy. It is shown that the method is not only elegant and accurate, but also leads to a single simple formula for different types of intersections which is particularly suitable for codification purposes.

Experimental Perspective on the Buckling of Pressure Vessel Components

2013 ◽  
Vol 66 (1) ◽  
Author(s):  
J. Błachut
Keyword(s):  
New York ◽  
Wall Thickness ◽  
Glass Fibers ◽  
Static Stability ◽  
External Pressure ◽  
Pressure Vessels ◽  
Conical Shells ◽  
Thin Walled Structures ◽  
External Pressures ◽  
Spherical Caps

This review aims to complement a milestone monograph by Singer et al. (2002, Buckling Experiments—Experimental Methods in Buckling of Thin-Walled Structures, Wiley, New York). Practical aspects of load bearing capacity are discussed under the general umbrella of “buckling.” Plastic loads and burst pressures are included in addition to bifurcation and snap-through/collapse. The review concentrates on single and combined static stability of conical shells, cylinders, and their bowed out counterpart (axial compression and/or external pressure). Closed toroidal shells and domed ends onto pressure vessels subjected to internal and/or external pressures are also discussed. Domed ends include: torispheres, toricones, spherical caps, hemispheres, and ellipsoids. Most experiments have been carried in metals (mild steel, stainless steel, aluminum); however, details about hybrids (copper-steel-copper) and shells manufactured from carbon/glass fibers are included in the review. The existing concerns about geometric imperfections, uneven wall thickness, and influence of boundary conditions feature in reviewed research. They are supplemented by topics like imperfections in axial length of cylinders, imperfect load application, or erosion of the wall thickness. The latter topic tends to be more and more relevant due to ageing of vessels. While most experimentation has taken place on laboratory models, a small number of tests on full-scale models are also referenced.

Theory and Application of a Bi-Metal Ring-Stiffened Cylinder Under External Pressure

1989 ◽  
Vol 33 (04) ◽  
pp. 291-297
Author(s):  
A. Moshaiov ◽  
E. R. Joelson
Keyword(s):  
Metal Structure ◽  
Failure Criteria ◽  
External Pressure ◽  
Pressure Vessels ◽  
Metal Ring ◽  
Principal Stresses ◽  
Collapse Pressure ◽  
Metal Structures ◽  
Young’S Moduli ◽  
Metal Case

Ring-stiffened pressure vessels have historically been constructed of one material only (for example, steel); this is especially true in naval submarines. Existing codes for the design of pressure vessels subjected to external pressure such as ASME and the British Standard BS5500 refer explicitly to unimetal designs only where the stiffening rings and the shell are made of one material only. Bi-metal structures are not accommodated in the design codes. A bi-metal structure would have one type of metal for the shell plating and another type for the ring stiffeners, possibly differing both in Young's modulus and material yield stress. An analytical study of the axisymmetric elastic deformations and stresses in a bi-metal ring-stiffened cylindrical shell under external hydrostatic pressure is given. A closedform solution to the governing differential equation for the bi-metal case is obtained and compared with the uni-metal case. A parametric study is conducted by varying the Young's moduli ratio for the shell and stiffeners of a typical design. Trends in the vessel's critical collapse pressure, shell deflection, and principal stresses are analyzed and the significance of different failure criteria is examined. An approach for modifying current uni-metal design methodologies to accommodate bi-metal structures is suggested. Preliminary comparisons of resulting bi-metal designs with "equivalent" uni-metal designs indicate that a bi-metal pressure hull can have significant advantages. Finally, recommendations for further research studies are made.

Bauschinger Effect Design Procedures for Compound Tubes Containing an Autofrettaged Layer

2000 ◽  
Vol 123 (2) ◽  
pp. 203-206 ◽  
Author(s):  
Anthony P. Parker
Keyword(s):  
Bauschinger Effect ◽  
Design Procedure ◽  
External Pressure ◽  
Pressure Vessels ◽  
Design Procedures ◽  
Shrink Fitting ◽  
Stress Profiles ◽  
Hoop Stresses ◽  
Shrink Fit ◽  
Outside Diameter

Autofrettage is used to introduce advantageous residual stresses into pressure vessels. The Bauschinger effect can produce less compressive residual hoop stresses near the bore than are predicted by “ideal” autofrettage solutions. A design procedure was recently proposed which models material removal from the bore or outside diameter of a single, plain autofrettaged tube in the presence of Bauschinger effect. This paper extends the procedure to model the addition of pressure or of material (via shrink-fit) to the tube, providing associated residual stress profiles following various amounts of further yielding due to a net external pressure. Simple criteria are developed for determining, and avoiding, further yielding in the autofrettaged tube when it is used as part of a compound assembly involving shrink-fitting; these criteria are based upon net pressure differential between the bore and outside diameter of the autofrettaged tube. An alternative criterion, based upon bore hoop stress, is shown to be erroneous.

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