Design of Cylindrical Steel Storage Tanks: A Linear Elastic Analysis Approach

2016 ◽  
Author(s):  
Eyas Azzuni ◽  
Sukru Guzey
Keyword(s):  
Hydrostatic Pressure ◽  
Circumferential Stress ◽  
Liquid Product ◽  
Analysis Approach ◽  
Storage Tanks ◽  
Bottom Edge ◽  
Linear Elastic ◽  
Cylindrical Steel ◽  
The One ◽  
Thin Shell Theory

A cylindrical steel storage tank is a cylindrical shell subjected to internal hydrostatic pressure due to the stored liquid product. The hydrostatic pressure causes the shell to experience circumferential stress. This circumferential stress can lead to the yielding of the shell if its thickness is not designed properly. The design of step-walled steel storage tanks requires the calculation of the required thickness of each shell course. A conservative way of calculating each course’s thickness is using the one-foot method (1FM). This method calculates the required thickness to withstand the hydrostatic pressure one foot above the bottom edge of the shell course under consideration. Another method, which is more refined than the 1FM, is the variable-design-point method (VDM), which finds the point in the course where the maximum circumferential stress is. VDM calculates the required shell thickness to withstand that maximum circumferential stress. However, VDM does not capture the circumferential stress resulting from the bottom edge yielding moment accurately for some thank geometries. A new linear analysis approach using thin-shell theory is presented in this paper. The approach captures the plastic yielding moment of the bottom edge accurately, and may produce more economical and safe designs than 1FM and VDM.

A Review of the Shell Buckling and Stiffener Ring Design for Cylindrical Steel Storage Tanks

2016 ◽  
Author(s):  
Eyas Azzuni ◽  
Sukru Guzey
Keyword(s):  
Circumferential Stress ◽  
Local Buckling ◽  
Design Procedure ◽  
Wind Load ◽  
External Pressure ◽  
Storage Tanks ◽  
Design Standards ◽  
Buckling Mode ◽  
Load Pressure ◽  
Cylindrical Steel

Cylindrical steel storage tanks are shells designed to store different types of products such as liquids or grain. The thickness of the shell is calculated to withstand the circumferential stress resulting from the hydrostatic pressure due to the stored product. A unique situation when there is no stored product leads to the vulnerability of the shell to buckle when there is wind load due to external pressure. There are two major types of buckling modes: local and general. The local buckling mode is studied analytically in various studies and is easy to mitigate. The general buckling mode can be more damaging to the tank and more costly to mitigate. The prevention of general buckling due to wind load pressure is achieved through the addition of stiffener rings. However, the stiffener rings design procedure used by various design standards has little known background. This paper reviews the current design approach’s origin and explains a semi-analytical justification for it. The unfolding of the design expressions can lead to more freedom in design variables selection leading to more economical designs.

Sloshing Characteristics of Single Deck Floating Roofs in Aboveground Storage Tanks: Natural Periods and Vibration Modes

2009 ◽  
Author(s):  
Shoichi Yoshida ◽  
Kazuyoshi Sekine ◽  
Katsuki Iwata
Keyword(s):  
Structural Integrity ◽  
Oil Refining ◽  
Vibration Modes ◽  
Storage Tanks ◽  
Severe Damage ◽  
Element Analysis ◽  
Linear Elastic ◽  
Oil Storage ◽  
Hydrodynamic Coupling ◽  
Roof Design

The floating roofs are widely used to prevent evaporation of content in large oil storage tanks. The 2003 Tokachi-Oki earthquake caused severe damage to the floating roofs due to liquid sloshing. The structural integrity of the floating roofs for the sloshing is urgent issue to establish in the petrochemical and oil refining industries. This paper presents the sloshing characteristics of the single deck floating roofs in cylindrical storage tanks. The hydrodynamic coupling of fluid and floating roof is taken into consideration in the axisymmetric finite element analysis. It is assumed that the fluid is incompressible and inviscid, and the floating roof is linear elastic while the sidewall and the bottom are rigid. The basic vibration characteristics, natural periods and vibration modes, of the floating roof due to the sloshing are investigated. These will give engineers important information on the floating roof design.

scholarly journals PLASTIC DEFORMATION OF THICK-WALLED SNOW-ICE CYLINDERS UNDER HYDROSTATIC PRESSURE

1962 ◽  
Vol 40 (10) ◽  
pp. 1310-1318 ◽  
Author(s):  
H. H. G. Jellinek
Keyword(s):  
Activation Energy ◽  
Plastic Deformation ◽  
Hydrostatic Pressure ◽  
Strain Rate ◽  
Plastic Flow ◽  
Constant Pressure ◽  
Circumferential Stress ◽  
Sine Function ◽  
Kcal Mole ◽  
Flow Process

The results of experiments on the plastic deformation of hollow snow-ice cylinders, closed at one end, as a function of circumferential stress and temperature are discussed. Data are graphed on deformation as a function of time for a snow-ice cylinder under 7.03 and 14.06 kg/cm2 hydrostatic pressure at −4.5 °C, deformation as a function of hydrostatic pressure from 2.11 to 7.03 kg/cm2, and deformation as a function of temperature at a constant pressure of 10.55 kg/cm2. The natural strain rate of closure at constant circumferential stress and temperature was a constant, which varied with circumferential stress as a sine function and was "exponentially dependent on temperature, with an activation energy of 14.1 kcal/mole at an average circumferential stress of 3.1 kg/cm2. The experiments agree well with an earlier interpretation of the plastic flow process representing flow between grain boundaries.

THE EFFECT OF HYDROSTATIC PRESSURE ON METAL–INSULATOR TRANSITION IN QUANTUM WELL SEMICONDUCTOR SYSTEMS II

2005 ◽  
Vol 04 (01) ◽  
pp. 45-53 ◽  
Author(s):  
A. JOHN PETER
Keyword(s):  
Hydrostatic Pressure ◽  
Quantum Well ◽  
Ionization Energy ◽  
Critical Concentration ◽  
Shallow Donor ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Mass Approximation ◽  
The One

Using a variational procedure within the effective mass approximation, the ionization energies of a shallow donor in a quantum well (QW) of GaAs/Ga 1-x Al x As superlattice system under the influence of pressure with the exact dielectric function are obtained. The vanishing of ionization energy initiating Mott transition is observed within the one-electron approximation. The effects of Anderson localization using a simple model, and exchange and correlation in the Hubbard model are included in this model. It is found that the ionization energy (i) increases when well width increases for a given pressure, (ii) decreases and reaches a bulk value for a larger well width, (iii) increases with increasing external hydrostatic pressure for a given QW thickness, and (iv) the critical concentration at which the metal–insulator transition (MIT) occurs is increased when pressure is applied. It also is demonstrated that MIT is not possible in a hydrostatic pressure in a quantum well supporting scaling theory of localization. All the calculations have been carried out with finite and infinite barriers and the results are compared with available data in the literature.

A corpus-based study of metaphors used to describe Syrian refugees in Jordanian politico-economic discourse

2020 ◽  
Vol 11 (4) ◽  
pp. 640-663
Author(s):  
Aseel Zibin
Keyword(s):  
Data Analysis ◽  
The Other ◽  
Analysis Approach ◽  
Syrian Refugees ◽  
Metaphor Analysis ◽  
Economic Discourse ◽  
Critical Metaphor Analysis ◽  
Internal Struggle ◽  
The One

Abstract This study aims to examine the metaphors used to describe Syrian refugees in Jordanian politico-economic discourse, adopting a Critical Metaphor Analysis Approach for data analysis. I compiled a specialised corpus containing political and economic articles from two daily Jordanian newspapers. The data was analysed using WordSmith Tools (Scott 2012), which is compatible with Arabic data. The data analysis reveals that several metaphors are used to describe Syrian refugees in Jordanian politico-economic discourse. The majority of metaphors employed have negative connotations in the contexts in which they are used, especially in the years 2015 and 2016 compared with 2012. The metaphors used reflect the internal struggle of Jordanians in relation to whether Syrian refugees should stay or leave. The struggle stems from deeply-entrenched Arab traditions, which make receiving guests perceived as a duty on the one hand, and the economic struggle of Jordanians living in a fragile economy, on the other.

The Effect of Hydrostatic Pressure and Thermal Load on Buckling Analysis of Large Scale Tank Roof

2020 ◽  
Author(s):  
Qianyu Shi ◽  
Zhijian Wang ◽  
Hui Tang ◽  
Qi Li
Keyword(s):  
High Temperature ◽  
Hydrostatic Pressure ◽  
Power Systems ◽  
Molten Salt ◽  
Large Scale ◽  
Thermal Power ◽  
Buckling Analysis ◽  
Storage Tanks ◽  
Nonlinear Buckling ◽  
Nonlinear Buckling Analysis

Abstract Large scale molten salt storage tanks are widely used in the solar thermal power systems. For these tanks, buckling is a primary failure mode because of its features such as large scale, thinned wall and high temperature. Suffering high temperature condition is a major distinction between molten salt storage tanks and other water or oil tanks. High temperature can cause large thermal deformation for large scale structures which may have an effect on the safety assessment, especially on buckling assessment. Meanwhile, the hydrostatic pressure of molten salt can also cause the change of tank’s configuration. In this paper, a typical large molten salt storage tank has been studied. The critical buckling loads of the tank roof are obtained using nonlinear buckling analysis considering thermal loads and hydrostatic pressure. The results are discussed and some conclusions are proposed for engineering design.

scholarly journals Approximation of Linear Elastic Shells by Curved Triangular Finite Elements Based on Elastic Thick Shells Theory

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Joseph Nkongho Anyi ◽  
Robert Nzengwa ◽  
Jean Chills Amba ◽  
Claude Valery Abbe Ngayihi
Keyword(s):  
Thin Shell ◽  
Thick Shell ◽  
Absolute Value ◽  
Linear Elastic ◽  
Limit Value ◽  
Shell Equations ◽  
Third Fundamental Form ◽  
Nodal Displacements ◽  
Thick Shells ◽  
Thin Shell Theory

We have developed a curved finite element for a cylindrical thick shell based on the thick shell equations established in 1999 by Nzengwa and Tagne (N-T). The displacement field of the shell is interpolated from nodal displacements only and strains assumption. Numerical results on a cylindrical thin shell are compared with those of other well-known benchmarks with satisfaction. Convergence is rapidly obtained with very few elements. A scaling was processed on the cylindrical thin shell by increasing the ratioχ=h/2R(half the thickness over the smallest radius in absolute value) and comparing results with those obtained with the classical Kirchhoff-Love thin shell theory; it appears that results diverge at2χ=1/10=0.316because of the significant energy contribution of the change of the third fundamental form found in N-T model. This limit value of the thickness ratio which characterizes the limit between thin and thick cylindrical shells differs from the ratio 0.4 proposed by Leissa and 0.5 proposed by Narita and Leissa.

The tapered beam model for bottom plate uplift analysis of unanchored cylindrical steel storage tanks

2009 ◽  
Vol 31 (3) ◽  
pp. 623-632 ◽  
Author(s):  
Masoud Nourali Ahari ◽  
Sassan Eshghi ◽  
Mohsen Ghafory Ashtiany
Keyword(s):  
Bottom Plate ◽  
Beam Model ◽  
Storage Tanks ◽  
Tapered Beam ◽  
Cylindrical Steel

Buckling Characteristics of Floating Roof Pontoons in Aboveground Storage Tanks Subjected to Bending Load in Two Directions

2008 ◽  
Author(s):  
Shoichi Yoshida ◽  
Kazuhiro Kitamura
Keyword(s):  
Large Diameter ◽  
Bending Moment ◽  
Bottom Plate ◽  
Storage Tanks ◽  
Buckling Strength ◽  
Linear Elastic ◽  
Structural Problems ◽  
Oil Storage ◽  
Bending Load ◽  
Shell Finite Element

The 2003 Tokachi-Oki earthquake caused severe damage to aboveground oil storage tanks due to liquid sloshing. Seven single-deck floating roofs had experienced structural problems as evidenced by sinking failure in large diameter tanks at the refinery in Tomakomai, Japan. The pontoons of the floating roofs might be buckled due to circumferential bending moment during the sloshing. The content in the tank was spilled on the floating roof from small failures which were caused at the welding joints of pontoon bottom plate by the buckling. Then the floating roof began to lose buoyancy and submerged into the content slowly. The authors had reported the buckling strength of the pontoons with and without ring stiffeners subjected to circumferential bending load in the previous papers. This paper presents the buckling strength of the pontoons subjected to both circumferential and radial bending load. The axisymmetric shell finite element method is used in the analysis. Linear elastic bifurcation buckling analysis is carried out and the buckling characteristics of the pontoon with and without ring stiffeners are investigated.

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