Behavior of Localized Bottom Bulge in Aboveground Oil Storage Tanks Under Liquid Pressure

2001 ◽  
Vol 124 (1) ◽  
pp. 59-65
Author(s):  
Shoichi Yoshida
Keyword(s):  
Plastic Strain ◽  
Plate Thickness ◽  
Deformation Analysis ◽  
Bottom Plate ◽  
Storage Tanks ◽  
Liquid Pressure ◽  
Element Analysis ◽  
Oil Storage ◽  
Relationship Of ◽  
The Relationship

The bottom plate of aboveground oil storage tanks can bulge, separating from the foundation due to welding deformation. When such a bulge is subjected to liquid pressure, it deforms continuously to make contact with the foundation from the edge, and the remaining area of the bulge decreases with increasing liquid pressure. As a result, the deformation is extremely localized and plastic strain occurs at the bulge. This paper presents a plane strain finite element analysis for the evaluation of localized bottom bulges in aboveground oil storage tanks. Load-incremental, elastic-plastic large deformation analysis is carried out considering the bottom plate contact with the foundation. The relationship of the plastic strain at the bulged bottom plate to the liquid pressure is discussed together with the deformation of the bulge. As a result, the bottom plate thickness has a significant effect on the deformation, but the bulged height does not. After the bulged center makes contact with the foundation, the stress and strain do not increase with increasing liquid pressure. In addition, the permissible bulged profile specified by API Standard 653 elastically deforms to make contact with the foundation under low liquid pressure.

Behavior of Localized Bottom Depression in Aboveground Oil Storage Tanks Under Liquid Pressure

2004 ◽  
Author(s):  
Shoichi Yoshida
Keyword(s):  
Finite Element Analysis ◽  
Deformation Analysis ◽  
Bottom Plate ◽  
Storage Tanks ◽  
Liquid Pressure ◽  
Element Analysis ◽  
Large Deformation Analysis ◽  
Oil Storage ◽  
Relationship Of ◽  
The Relationship

When constructing the bottom of aboveground oil storage tanks, the bottom plates are first laid out on the flat foundation, and they then are joined by welding the joints in sequence. As the foundation is difficult to be made completely homogeneous over the bottom area, the settlement of the bottom plates is not uniform under liquid pressure. The depressions of the bottom plates are sometimes found at the first internal inspection which is usually made about 10 years after the oil storage. This paper presents plane strain finite element analysis for the localized bottom depression in aboveground oil storage tanks. Load-incremental, elastic-plastic large deformation analysis is carried out considering contact with the foundation. The relationship of the stress at the depressed bottom plate to the liquid pressure is discussed together with the deformation of the depression.

Buckling of Ring Stiffened Pontoons of Floating Roofs in Aboveground Oil Storage Tanks

2007 ◽  
Author(s):  
Shoichi Yoshida ◽  
Kazuhiro Kitamura
Keyword(s):  
Large Diameter ◽  
Bending Moment ◽  
Bottom Plate ◽  
Storage Tanks ◽  
Element Analysis ◽  
Linear Elastic ◽  
Structural Problems ◽  
Oil Storage ◽  
Bifurcation Buckling ◽  
Shell Finite Element

The 2003 Tokachi-Oki earthquake caused severe damage to oil storage tanks due to liquid sloshing. Six single-deck floating roofs had experienced structural problems as evidenced by sinking failure in large diameter tanks at the refinery in Tomakomai, Japan. The pontoon of floating roof 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 might be caused in the lap-welded joints or in the stress concentrated parts of the pontoon bottom plate by the buckling. Then the floating roof began to lose buoyancy and submerged into the content slowly. The failure of the roof expanded gradually in the sinking process. It is presumed that the initial small failures were caused by the elastic buckling of the pontoon due to circumferential bending moment. In this paper, the buckling strength of the pontoon is presented using axisymmetric shell finite element analysis. Linear elastic bifurcation buckling analyses are carried out and the buckling characteristics of ring stiffened pontoons are investigated.

A Study of Formularization of Uplift Behavior at the Bottom Plate of Large LNG Storage Tanks During Earthquake

2012 ◽  
Author(s):  
Shoichiro Hayashi ◽  
Tomoyo Taniguchi
Keyword(s):  
Plate Thickness ◽  
Bottom Plate ◽  
Parameter Study ◽  
Plate Model ◽  
Storage Tanks ◽  
Liquid Pressure ◽  
Design Standards ◽  
Proposed Model ◽  
Present Design ◽  
Dynamic Liquid Pressure

In recent years, it has been found that seismic demand tends to be higher for LNG storage tanks and it requires detail estimations about the tank uplift. Generally FE analysis is performed for this aim, since the most of present design standards do not specify the design formula to calculate the stress of the bottom plate. In the case of establishing the bottom plate model with the uplift, several properties have to be considered, such as tank dimension and plate thickness, magnitude and distribution of dynamic liquid pressure that is affected by width and height of the uplift, elasticity of the bottom insulation, and bulging displacement of the tank sidewall. As an another approach for detail estimations including these properties, this study presents the mathematical solution of the bottom plate for estimating uplift height and stress distribution based on a theory of elastic bearing beam. To increase accuracy but maintain practicality, the thin cylindrical theory is also coupled to the bottom plate model for considering the influence of bulging displacement of the tank sidewall on the bottom plate. From the parameter study by the proposed model, it is found that the bulging displacement of the sidewall has significant effect to the uplift height of the bottom plate.

scholarly journals Perancangan Tangki Stainless Steel untuk Penyimpanan Minyak Kelapa Murni Kapasitas 75 m3

2018 ◽  
Vol 3 (1) ◽  
pp. 39 ◽  
Author(s):  
Pekik Mahardhika ◽  
Ayu Ratnasari
Keyword(s):  
Stainless Steel ◽  
Storage Tank ◽  
Raw Materials ◽  
Plate Thickness ◽  
Coconut Oil ◽  
Bottom Plate ◽  
Storage Tanks ◽  
Virgin Coconut Oil ◽  
Storage Container ◽  
Oil Storage

Tangki merupakan wadah penyimpanan yang sering dipakai di berbagai industriseperti petrokimia, pengilangan, dan perminyakan. Tangki penyimpanan tidak hanya menjadi tempat penyimpanan untuk produk dan bahan baku tetapi juga menjaga kelancaran ketersediaan produk dan bahan baku. Selain itu, tangki juga dapat menjaga produk atau bahan baku dari kontaminan. Minyak kelapa murni adalah minyak yang dibuat dari bahan baku kelapa segar. Minyak kelapa murni memiliki daya simpan lebih dari 12 bulan sehingga diperlukan tangki penyimpanan yang memadai demi menjaga produk dari kontaminasi. ASTM 304, ASTM 316L, dan S32304 merupakan stainless steel yang digunakan untuk material plat tangki penyimpanan minyak kelapa murni. Stainless steel merupakan baja tahan korosi sehingga diharapkan dapat menjaga kualitas produk minyak kelapa murni. Penelitian ini bertujuan untuk merancang tangki penyimpanan minyak kelapa murni menggunakan stainless steel. Tangki penyimpanan dirancang memiliki kapasitas 75 m3. Tangki dirancang dengan membandingkan antara API 650 dengan BS 2654. Hasil perhitungan didapatkan ketebalan plat shell aktual 6 mm, ketebalan plat dasar aktual 6 mm, ketebalan plat dasar annular aktual 8 mm, dan ketebalan atap aktual 6 mm. Berdasarkan hasil perhitungan, tegangan pada tangki masih memenuhi syarat karena tegangan ijin tangki lebih besar dari tegangan akibat beban statis, tegangan circumferensial, dan tegangan longitudinal. Dengan demikian, desain tangki penyimpanan dapat dikatakan aman.Kata kunci: API 650, BS 2654, minyak kelapa murni, stainless steel, tangki penyimpananTank is a storage container that is often used by various industries such as petrochemical, refining, and petroleum. Storage tanks isnot only a storage for products and raw materials but also maintain the fluency availability of products and raw materials. Furthermore, the tank can also keep products or raw materials from contaminants. Virgin coconut oil is oil made from fresh coconut. Virgin coconut oil has storability of more than 12 months, so that adequate storage tanks are required to keep the product from contamination. ASTM 304, ASTM 316L, and S32304 are stainless steels used for the material of the virgin coconut oil storage tank. Stainless steel is corrosion resistant steel so it is expected to maintain the quality of virgin coconut oil product. This research aims to design storage tank of virgin coconut oil using stainless steel material. The storage tank is designed to have a capacity of 75 m3. The tank is designed by comparing between API 650 and BS 2654. The calculation results obtained the actual thickness of the shell plate is 6 mm, the actual bottom plate thickness is 6 mm, the actual annular bottom plate thickness is 8 mm, and the actual roof thickness is 6 mm. Based on the calculation, tank stress is still accepted because the allowable stress of tank is larger than the stress due static load, circumferential stress, and longitudinal stress. Thus, the design of storage tank is safe.Keywords: API 650, BS 2654, stainless steel, storage tank, virgin coconut oil 

Buckling of Single-Deck Floating Roofs in Aboveground Oil Storage Tanks Due to Circumferential Bending Load

2006 ◽  
Author(s):  
Shoichi Yoshida ◽  
Kazuhiro Kitamura
Keyword(s):  
Large Diameter ◽  
Bending Moment ◽  
Bottom Plate ◽  
Storage Tanks ◽  
Element Analysis ◽  
Buckling Strength ◽  
Structural Problems ◽  
Oil Storage ◽  
Bending Load ◽  
Shell Finite Element

The 2003 Tokachi-Oki earthquake caused severe damage to oil storage tanks due to liquid sloshing. Six single-deck floating roofs had experienced structural problems as evidenced by sinking failure in large diameter tanks at the refinery at Tomakomai, Japan. The pontoon of floating roof 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 in the rap welding joints of pontoon bottom plate by the buckling. Then the floating roof began to lose buoyancy and submerged into the content slowly. The failure of the roof expanded gradually in the sinking process. It is presumed that the initial small failures were caused by the elastic buckling of the pontoon due to circumferential bending moment. This paper presents the buckling strength of the pontoon using axisymmetric shell finite element analysis. Linear elastic bifurcation buckling analysis is carried out and the buckling characteristics of the pontoon are investigated. The result shows that the thickness of both pontoon roof and bottom plates have significantly affect the buckling strength.

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.

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.

Axisymmetric Finite Element Analysis for Floating Roofs of Aboveground Storage Tanks Under Accumulated Rain Water Condition

2011 ◽  
Author(s):  
Shoichi Yoshida
Keyword(s):  
Finite Element ◽  
Load Condition ◽  
Rain Water ◽  
Water Volume ◽  
Deformation Analysis ◽  
Storage Tanks ◽  
Element Analysis ◽  
Water Condition ◽  
Incremental Method ◽  
Shell Finite Element

The floating roofs are used in large aboveground storage tanks to prevent evaporation of the content. The single-deck floating roof, which is considered herein, consists of a thin circular plate called a deck attached to a buoyant ring of box-shaped cross section called a pontoon. Under the accumulated rain water condition, the deck is deflected largely, and both its edge part and the pontoon are compressed circumferentially. Since the load condition due to the rain water depends on the deflected deck shape, it is difficult to find the unique equilibrium condition. This paper describes the deformation analysis for the single-deck floating roofs under the accumulated rain water condition using the geometrically nonlinear axisymmetric shell finite element method. The load incremental method, in which the equivalent nodal forces due to the rain water converges to coincide with the rain water load derived from both the current rain water volume and the deflected deck shape, is used.

Experimental Research on Concrete Filled Thin-Walled Steel Tube Long Columns

2008 ◽  
Vol 400-402 ◽  
pp. 551-557 ◽  
Author(s):  
Bao Zhu Cao ◽  
Yao Chun Zhang ◽  
Yue Ming Zhao
Keyword(s):  
Experimental Research ◽  
Local Buckling ◽  
Steel Tube ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Global Buckling ◽  
Thin Walled ◽  
Relationship Of ◽  
The Relationship ◽  
Theoretical Results

Experimental research on square and octagonal concrete filled thin-walled steel tube long columns of 6 specimens in axial compression and 8 specimens in eccentric compression is undertaken. The relationship of global buckling bearing capacity of the columns and local buckling of the steel tubes is obtained. The test indicates that local buckling occurs in steel tube of each column before it reaches ultimate capacity, and has little effect on global buckling performance. The ultimate load decreases obviously with the increase of slender ratio and eccentricity. The ductility of columns increases with the increase of steel ratio in composite sections. Composite beam element of ANSYS is adopted in the finite element analysis. The theoretical results are agreed well with test..

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