Numerical analysis of stress-strain state of vertical cylindrical oil tanks with dents

Authors

S. N. Buganova, JSC “Kazakh Leading Architecture and Civil Engineering Academy” (28, Ryskulbekov St., Almaty, 050043, Kazakhstan), e-mail: snb_kazgasa@mail.ru
K. V. Avramov, A. Podgorny Institute of Mechanical Engineering Problems of NASU (2/10, Pozharsky str., Kharkiv, 61046, Ukraine), e-mail: kvavramov@gmail.com, ORCID: 0000-0002-8740-693X

Abstract

The destruction of vertical cylindrical tanks results in both human and economic losses. Despite constant improvement of the manufacturing technology of cylindrical tanks, a complete analysis of the influence of various dents on stress-strain states was not performed. Dents are the most dangerous, unpredictable zones that are studied a little. It should be specially emphasized that there is no system to assess the stress concentrations in the dent zone, and the regulatory documents for the construction and operation of oil tanks do not take into account the stress-strain state in the dent. The paper presents the results of a finite element analysis of the stress-strain states of the cylindrical tanks with spherical dents. On the basis of the finite element analysis, approximate relationships are derived for stress concentration coefficients that can be used to calculate various sized cylindrical tanks with different dents. A cylindrical tank with a spherical dent is investigated. The reasons for dent formation are not considered. It is assumed that there are no residual stresses in the dent area. Simulating the stress-strain state of the tank, the conclusion is made that the greatest stresses are observed in the lower part of the dent. As in the lower part of the dent, the internal pressure of fuel oil is greater. At high values of the relative depth of the dent the maximum stresses are observed only at the lower boundary of the dent. An approximation technique for calculating the stress concentration factor in the dent is proposed. An approximate model of the stress concentration factor due to the dent size parameters is built for an example tank.

Keywords: stress-strain; spherical dents; dimensionless parameters; equivalent stresses

Full text: Download in PDF

References

1. Likhman, V. V., Kopysitskaya, L. N., & Muratov, V. M. (1992). The Concentration of Stresses in Reservoirs with Local Imperfections of Form. Chemical and Petroleum Eng., vol. 6. pp. 22–24. https://doi.org/10.1007/BF01148986
2. Kuznetsov, V. V. & Kandakov, G. P. (2005). Problems of Domestic Reservoir Construction. Industrial and Civil Construction, vol. 5, pp. 17–19 (in Russian).
3. Prokhorov, V. A. (1999). Assessment of Risk Parameters for the Operation of Reservoirs for Storage of Petroleum Products in Conditions of the North. Moscow: Nedra, 144 p. (in Russian).
4. SN RK 3.05-24-2004. (2004). The Instruction on Designing, Manufacturing and Installation of Vertical Cylindrical Steel Tanks for Oil and Oil products. Enter. 2005-01-01. Astana.
5. VBN B.2.2-58.2-94. (1994). Vertical Steel Tanks for Storage of Oil and Oil Products with Saturated Vapor Pressure not Higher than 93.3 kPa. Kiyev: Goskomneftegaz.
6. PB 03-605-03. (2002). Rules for the Construction of Vertical Cylindrical Steel Tanks for Oil and Oil products. Enter. 2003.06.19. Moscow: Gosgortekhnadzor of Russia (in Russian).
7. Timoshenko, S. P. & Voinovsky-Krieger, S. (1963). Plates and Shells. Trans. With the English. Ed. G. S. Shapiro. Moscow: Fizmatgiz (in Russian).

Received 02 February 2018

Published 30 March 2018