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.

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.

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 

Bending and free vibration analyses of functionally graded material nanoplates via a novel nonlocal single variable shear deformation plate theory

2020 ◽  
pp. 095440622096452
Author(s):  
Le Kha Hoa ◽  
Pham Van Vinh ◽  
Nguyen Dinh Duc ◽  
Nguyen Thoi Trung ◽  
Le Truong Son ◽  
...  
Keyword(s):  
Shear Deformation ◽  
Functionally Graded Material ◽  
Numerical Solutions ◽  
Scale Effects ◽  
Plate Thickness ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Small Scale ◽  
Parameter Study ◽  
Graded Material

A novel nonlocal shear deformation theory is established to investigate functionally graded nanoplates. The significant benefit of this theory is that it consists of only one unknown variable in its displacement formula and governing differential equation, but it can take into account both the quadratic distribution of the shear strains and stresses through the plate thickness as well as the small-scale effects on nanostructures. The numerical solutions of simply supported rectangular functionally graded material nanoplates are carried out by applying the Navier procedure. To indicate the accuracy and convergence of this theory, the present solutions have been compared with other published results. Furthermore, a deep parameter study is also carried out to exhibit the influence of some parameters on the response of the functionally graded material nanoplates.

A Physically-Based Anisotropic Discrete Fiber Model for Fibrous Soft Tissues

2010 ◽  
Author(s):  
C. Flynn ◽  
M. B. Rubin ◽  
P. M. F. Nielsen
Keyword(s):  
Soft Tissues ◽  
Mechanical Response ◽  
Continuous Distribution ◽  
Collagen Fibers ◽  
Fiber Bundles ◽  
Parameter Study ◽  
Rabbit Skin ◽  
Pig Skin ◽  
Proposed Model ◽  
Physically Based

Physically-based fibrous soft tissue models often consider the tissue to be a collection of fibers with a continuous distribution function to represent their orientations. This study proposes a simple model for the response of fibrous connective tissues in terms of a discrete number of fiber bundles. The proposed model consists of six weighted fiber bundles orientated such that they pass through opposing vertices of an icosahedron. A novel aspect of the proposed model is the use of a simple analytical function to represent the undulation distribution of the collagen fibers. The mechanical response of the elastin fiber is represented by a neo-Hookean hyperelastic equation. A parameter study was performed to analyze the effect of each parameter on the overall response of the model. The proposed model accurately simulated the uniaxial stretching of pig skin with an 8% error-of-fit for stretch ratios up to 1.8. The model also accurately simulated the biaxial stretching of rabbit skin with a 10% error-of-fit for stretch ratios up to 1.9. The stiffness of the collagen fibers determined by the model was about 100 MPa for the rabbit skin and 900 MPa for the pig skin, which are comparable with values reported in the literature. The stiffness of the elastin fibers in the model was about 2 kPa.

Advanced joint slip model for single-angle bolted connections considering various effects

2020 ◽  
Vol 23 (10) ◽  
pp. 2121-2135
Author(s):  
Ahmed Hussain Ali Abdelrahman ◽  
Yao-Peng Liu ◽  
Siu-Lai Chan
Keyword(s):  
Plate Thickness ◽  
Direct Analysis ◽  
Element Model ◽  
Fe Model ◽  
Slip Model ◽  
Transmission Towers ◽  
Slip Effects ◽  
Proposed Model ◽  
Full Scale Tests ◽  
The Cost

Latticed structures are commonly used in transmission towers due to lightweight, fast fabrication, and easy installation, but they generally experience more complicated structural behaviors. The full-scale tests on transmission towers have revealed large discrepancies between the numerical simulation and experimental results because the significant joint slip effects have not well considered in the former. The existing joint slip models were so simple that many key parameters had not been taken into account. Thus, a comprehensive joint slip model is proposed in this article for better prediction and design of tower structures. First, a full-detailed finite element model based on ABAQUS incorporating more realistic parameters for a typical joint is developed and calibrated by the experimental data from the literature. Furthermore, the proposed FE model is used for parametric study of joint behaviors with considerations of bolt pretension, friction at contact face, angle sizes and plate thickness, steel and bolt grades, number of bolts, and hole tolerance. Finally, an advanced joint slip model is provided for further incorporation in the second-order direct analysis of transmission towers. This work is limited in the literature and will significantly improve safety and enhance the cost-efficiency of tower design. The proposed model shows high accuracy and can be simply determined by joint details in line with the component method specified in Eurocode 3-1-8.

Evaluating Large Aboveground Storage Tanks Subject to Seismic Loading: Part I — Closed-Form Solutions and Equivalent Static Analysis

2018 ◽  
Author(s):  
Phillip E. Prueter ◽  
Seetha Ramudu Kummari
Keyword(s):  
Closed Form ◽  
Static Analysis ◽  
Storage Tank ◽  
Fluid Structure Interaction ◽  
Seismic Loading ◽  
Storage Tanks ◽  
Design Standards ◽  
Closed Form Solutions ◽  
Structure Interaction ◽  
Explicit Dynamic

Evaluating the dynamic response of large, aboveground storage tanks exposed to seismic loading is multifaceted. There are foundation-structure and fluid-structure interaction effects that can influence the overall tank behavior and likely failure modes. Additionally, local stresses at anchor bolt support chair attachments and the shell-to-floor junction can be difficult to quantify without detailed finite element analysis (FEA). Often times, performing explicit dynamic analysis with liquid sloshing effects can be time consuming, expensive, and even impractical. The intent of this paper is to summarize simplified analysis techniques that can be leveraged to evaluate aboveground storage tanks subject to seismic loading. Closed-form calculations to establish a recommended design for a tank, including seismic considerations, are available in storage tank design standards, including API 650 [1] (Appendix E). Seismic design standards have evolved significantly in recent years. Furthermore, for many vintage, in-service storage tanks, explicit seismic considerations were not incorporated into the original design. In Part I of this study, these design equations and other closed-form solutions are used to evaluate the structural integrity of a large, in-service, mechanically-anchored storage tank. The design equations in API 650 [1] are used to form the basis of simplified, equivalent static analysis, where seismic loads are applied to a three-dimensional FEA model via equivalent lateral body forces. These practical results are then compared to explicit dynamic seismic behavior of the same tank with fluid-structure interaction effects considered (in Part II of this study [2]). These comparisons offer insight into the appropriateness of using simplified hand-calculations and equivalent static analysis (and their relative conservatism) in lieu of more rigorous explicit dynamic and fluid sloshing simulations.

Effect of Annular Plate Projection Length on the Stresses in the Above Ground Steel Storage Tanks on Rigid Ring Wall Foundations

2011 ◽  
Author(s):  
Sridhar Sathyanarayanan ◽  
Seshu M. R. Adluri
Keyword(s):  
Life Cycle ◽  
Elevated Temperature ◽  
Theoretical Model ◽  
Annular Plate ◽  
Bottom Plate ◽  
Storage Tanks ◽  
Plastic Hinges ◽  
Rigid Ring ◽  
Design Life ◽  
Projection Length

The paper examines the effect of increased bottom plate projection for tanks with rigid ring wall foundations. A theoretical model, based on the existing model from Denham is proposed to determine the maximum projection length. The behavior of the tank, specifically near the bottom is studied till failure using FEA. The formation of plastic hinges in the bottom plate on the inside and outside of this joint is discussed in detail. The validity of the assumptions made by Karcher with regard to plastic hinges for obtaining the expression for the design life cycle in elevated temperature tanks is briefly analyzed.

Sex Differences in Joint Mobility

1984 ◽  
Vol 28 (11) ◽  
pp. 1006-1006 ◽  
Author(s):  
K. Rene'
Keyword(s):  
Sex Differences ◽  
Study Data ◽  
The Body ◽  
Joint Mobility ◽  
Joint Movement ◽  
Design Standards ◽  
College Female ◽  
Current Design ◽  
Female Data ◽  
Present Design

The primary purpose of this study was to provide a contemporary comparison of college female and male voluntary range of joint mobility. This was achieved by comparing the data collected in this study with that collected in an identical study in which male participants were used. Data were gathered from college females to determine their voluntary range of joint movement. One hundred female students at Texas ASM University participated in the study. The instruments used to take the measures were two hand-held bubble level electrogoniometers. Thirty-two movements of eight different joints of the body were measured. A second goal was to update and broaden the data base of female voluntary flexibility. This goal was met by reporting the data gathered from the female college sample and providing pertinent design information. In addition, the current female data were compared against present design standards. Finally, the present study data and that of the identical male study were combined to allow a comparison with an earlier study of sex differences in joint mobility. Results of this study indicate that females are generally more flexible than males. Significant differences were found to exist in twenty-six of the thiry-two comparisons made between this study and the corresponding male study. In twenty-four of these comparisons, females were found to have greater flexibility. The differences in joint mobility reported were attributed to real differences between the sexes since the methodologies were identical and the samples were drawn from equivalent populations. Comparisons between this study and the current design standards yielded conflicting results due to differences in methodologies and samples. Significant differences were found to exist in the comparisons made between the present data combined with the current male data and an earlier study concerning sex differences in flexibility. These differences were also attributed to differences in methodologies. Both comparisons drew the same conclusion, however: females are generally more flexible than males.

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