scholarly journals Flaw Stability in Mild Steel Tanks in the Upper-Shelf Ductile Range—Part II: J-Integral-Based Fracture Analysis

1999 ◽  
Vol 122 (2) ◽  
pp. 169-173 ◽  
Author(s):  
Poh-Sang Lam ◽  
Robert L. Sindelar

The J-integral fracture methodology was applied to evaluate the stability of postulated flaws in mild steel storage tanks. The material properties and the J-resistance JR curve were obtained from the archival A285 Grade B carbon steel test data. The J-integral calculation was based on the center-cracked panel (CCP) solution of Shih and Hutchinson (1976, ASME J. Eng. Mater. Technol. 98, pp. 289–295). A curvature correction was applied to account for the cylindrical shell configuration. A finite element analysis of an arbitrary flaw in the storage tank demonstrated that the curvature-corrected CCP solution is a close approximation. The maximum storage tank fluid level for a postulated flaw size can be established based on the J-integral flaw stability methodology. [S0094-9930(00)00502-3]

1999 ◽  
Vol 122 (2) ◽  
pp. 162-168 ◽  
Author(s):  
Robert L. Sindelar ◽  
Poh-Sang Lam ◽  
George R. Caskey, ◽  
Leta Y. Woo

Mechanical properties of 1950’s vintage, A285 Grade B carbon steels have been compiled for elastic-plastic fracture mechanics analysis of storage tanks (Lam and Sindelar, 2000). The properties are from standard Charpy V-notch (CVN), 0.4T planform compact tension (C(T)), and tensile (T) specimens machined from archival steel from large water piping. The piping and storage tanks were constructed in the 1950s from semi-killed, hot-rolled carbon steel plate specified as A285 Grade B. Evaluation of potential aging mechanisms at both service conditions shows no loss in fracture resistance of the steel in either case. Site and literature data show that the A285, Grade B steel, at and above approximately 70°F (21°C), is in the upper transition to upper shelf region for absorbed energy and is not subject to cleavage cracking or a brittle fracture mode. Furthermore, the tank sidewalls are 1/2 or 5/8-in. (12.7 or 15.875 mm) thick, and therefore, the J-resistance JR curve that characterizes material resistance to stable crack extension under elastic-plastic deformation best defines the material fracture toughness. The JR, curves for several heats of A285, Grade B steel tested at 40°F (4.4°C), a temperature near the average ductile-to-brittle (DBTT) transition temperature (CVN at 15 ft-lb or 20.3 J), are presented. This data is applicable to evaluate flaw stability of the storage tanks that are operated above 70°F (21°C) since, even at 40°F (4.4°C), crack advance is observed to proceed by ductile tearing. [S0094-9930(00)00402-9]


Author(s):  
Mohamed R. Chebaro ◽  
Nader Yoosef-Ghodsi ◽  
Howard K. Yue

API Standard 653 addresses issues related to the inspection, repair, alteration and reconstruction of steel storage tanks built according to API Standard 650 or API 12C to help maintain tank integrity. Although the standard covers three types of tank settlement, namely edge, bottom and shell, this paper focuses on the assessment of shell settlement. It also provides a comparison between an analytical model based on API Standard 653 and a finite element analysis (FEA) model that replicates field operating loading and settlement conditions of storage tanks. A basis for comparison between both models was established from the maximum allowable settlement and strain values. Several scenarios were generated using actual field data collected from steel storage tanks located in Alberta to illustrate the correlation between the two models. Specific information on the storage tanks under consideration cannot be disclosed for confidentiality reasons.


2021 ◽  
Vol 261 ◽  
pp. 01017
Author(s):  
Haoran Hu ◽  
Jian Guo ◽  
Bingyuan Hong ◽  
Yan Yan ◽  
Xu Yang ◽  
...  

Due to the thin-walled wind-sensitive structures of large crude oil storage tanks, it is necessary to consider the wind load failure of oil storage tanks in coastal areas under strong wind conditions during the design process. Based on the finite element analysis software ANSYS\Workbench, the static structure analysis and buckling analysis of the 100, 000 cubic crude oil storage tanks are carried out. In order to solve the buckling failure phenomenon, a wind-resistant ring structure was optimal designed for the crude oil storage tank according to standards, so that the storage tank can withstand hurricanes and typhoons above level 12 with a wind speed of 137 km/h.


Author(s):  
Shen Wang ◽  
Necip O. Akinci ◽  
William H. Johnson ◽  
Luis M. Moreschi

Diesel fuel oil storage tanks are critical components for safety of nuclear power plants. Proper functioning of the emergency diesel generators during an earthquake depends on the fuel oil supplied from the storage tank. Failure of the tank, nozzles or fuel pipes can result in contamination and/or leakage of the fuel. The allowable stress limits and design charts for above ground tanks, which are provided in the ASME Boiler and Pressure Vessel Code for a pressure vessel, are occasionally adopted in the design of underground tanks. However, the analytical methodology for evaluation of stresses in the buried tanks requires detailed analysis different from that for a typical pressure vessel. Soil-structure and fluid-structure interaction effects need to be considered in the analysis for simulation of the actual static and seismic loads. Therefore, advanced simulation techniques and finite element analysis tools have been used by several researchers to evaluate buried tanks. Simple, but acceptably accurate techniques for comprehensive evaluation of underground storage tanks have not been established. This study presents simplified evaluation techniques for a diesel fuel storage tank using fundamental concepts. The diesel fuel oil storage tanks considered here are cylindrical and oriented with their axes in the horizontal direction. The static overburden and seismic pressures cause ovaling of the tank and generate significant bending stresses, which are not addressed in the pressure vessel design approach. The simplified tank evaluation proposed here includes the ovaling effect under static overburden, seismic and sloshing loads. Earthquake induced stresses in hoop and longitudinal directions are calculated using the free field approach and the classical Housner Method is employed in the sloshing analysis. Allowable stress and buckling of the tank wall are checked against corresponding criteria.


2020 ◽  
Vol 20 (6) ◽  
pp. 2069-2081
Author(s):  
Huifeng Li ◽  
Lijun Lu ◽  
Xiangfeng Huang ◽  
Haidong Shangguan ◽  
Zhongqing Wei

Abstract In recent years, frequent non-point source pollution has raised serious challenges for urban water environmental management. The efficiency and cost of water quality storage tanks, which can prevent and control urban pollution effectively, are significantly affected by their locations. However, few studies have determined the location of decentralized storage tanks with consideration of the characteristics of initial rainwater quality, which has led to unsatisfactory or extravagant design. Therefore, a new design strategy is proposed to optimize the locations of water quality storage tanks using the InfoWorks ICM model in this study. It includes two basic steps. Firstly, the pollution severity of each node in the corresponding subcatchment is evaluated and ranked through the matter element analysis method and analytic hierarchy process. Secondly, all the nodes are precisely sorted by their excessive multiples using the single factor index method. Its application in the design of the decentralized storage tank locations in Fuzhou, China, proved that the proposed strategy can reduce the total volume of decentralized storage tanks to 0.38 times that of a terminal tank. The strategy presented in this study may also be useful in other research on storage tank design in urban pollution prevention and control systems.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7100
Author(s):  
Ahmad Mahamad Al-Yacouby ◽  
Lo Jia Hao ◽  
M. S. Liew ◽  
R. M. Chandima Ratnayake ◽  
Samindi M. K. Samarakoon

Thin-walled cylindrical shell storage tanks are pressure vessels in which the walls of the vessel have a thickness that is much smaller than the overall size of the vessel. These types of structures have global applications in various industries, including oil refineries and petrochemical plants. However, these storage tanks are vulnerable to fire and explosions. Therefore, a parametric study using numerical simulation was carried out, considering the internal liquid level, wall thickness, material yield strength, constraint conditions, and blast intensity, with a diameter of 100 m and height of 22.5 m under different blast loads using the finite element analysis method. The thickness of the tank wall is varied as 10 mm, 20 mm, 30 mm, and 40 mm, while the fill level of internal fluid is varied as 25, 50, 75, and 100%. The blast simulation was conducted using LS-DYNA software. The numerical results are then compared with analytical results. The effects of blast intensity, standoff distance, wall thickness, and fill level of internal fluid on the structural behaviour of the storage tank were investigated and discussed.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Musa Manga ◽  
Timothy G. Ngobi ◽  
Lawrence Okeny ◽  
Pamela Acheng ◽  
Hidaya Namakula ◽  
...  

Abstract Background Household water storage remains a necessity in many communities worldwide, especially in the developing countries. Water storage often using tanks/vessels is envisaged to be a source of water contamination, along with related user practices. Several studies have investigated this phenomenon, albeit in isolation. This study aimed at developing a systematic review, focusing on the impacts of water storage tank/vessel features and user practices on water quality. Methods Database searches for relevant peer-reviewed papers and grey literature were done. A systematic criterion was set for the selection of publications and after scrutinizing 1106 records, 24 were selected. These were further subjected to a quality appraisal, and data was extracted from them to complete the review. Results and discussion Microbiological and physicochemical parameters were the basis for measuring water quality in storage tanks or vessels. Water storage tank/vessel material and retention time had the highest effect on stored water quality along with age, colour, design, and location. Water storage tank/vessel cleaning and hygiene practices like tank/vessel covering were the user practices most investigated by researchers in the literature reviewed and they were seen to have an impact on stored water quality. Conclusions There is evidence in the literature that storage tanks/vessels, and user practices affect water quality. Little is known about the optimal tank/vessel cleaning frequency to ensure safe drinking water quality. More research is required to conclusively determine the best matrix of tank/vessel features and user practices to ensure good water quality.


2021 ◽  
Vol 11 (9) ◽  
pp. 3770
Author(s):  
Monica Tatarciuc ◽  
George Alexandru Maftei ◽  
Anca Vitalariu ◽  
Ionut Luchian ◽  
Ioana Martu ◽  
...  

Inlay-retained dental bridges can be a viable minimally invasive alternative when patients reject the idea of implant therapy or conventional retained full-coverage fixed dental prostheses, which require more tooth preparation. Inlay-retained dental bridges are indicated in patients with good oral hygiene, low susceptibility to caries, and a minimum coronal tooth height of 5 mm. The present study aims to evaluate, through the finite element method (FEM), the stability of these types of dental bridges and the stresses on the supporting teeth, under the action of masticatory forces. The analysis revealed the distribution of the load on the bridge elements and on the retainers, highlighting the areas of maximum pressure. The results of our study demonstrate that the stress determined by the loading force cannot cause damage to the prosthetic device or to abutment teeth. Thus, it can be considered an optimal economical solution for treating class III Kennedy edentation in young patients or as a provisional pre-implant rehabilitation option. However, special attention must be paid to its design, especially in the connection area between the bridge elements, because the connectors and the retainers represent the weakest parts.


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