Analysis of a Stress-Strain State of a Cylindrical Tank Wall Vertical Field Joint Zone

Abstract

In the study, experimental and theoretical studies were carried out to assess the influence of the vertical mounting joint zone of the tank on the stress-strain state of the defect zone. Thus, experimental tests of models of a tank wall fragment with an imperfection of the mounting joint evaluated the stress-strain state of the mounting joint zone and established the dependence of the stress concentration in the joint zone on the deflection, the width of the zone and the thickness of the tank wall. It is shown that with a 50 mm bending boom, the annular stresses increase by 1.3 times than with a 30 mm bending boom and the meridional stresses increase by 1.16 times. The same nature of the increase is observed with the stress concentration indicator. By numerical analysis of the stress-strain state of tanks with joint imperfections in the ANSYS medium, the stress-strain state of the tank is estimated for various values of the joint bending parameters ς and ξ. The dependences of the stress concentration coefficient on the geometric dimensions of the imperfection, radius and thickness of the tank wall are also obtained. From the results of calculating the stress concentration coefficient, with an increase in the dimensionless parameters ς and ξ, the values of the stress concentration coefficient Kσ increase by 1.35 times. As a result of the calculations, an interpolation polynomial (5), approximating the stress concentration coefficient Kσ, is obtained, which can be used to estimate the strength, durability and residual resource of the tank. In addition, the obtained results can be used to normalize the limiting dimensions of the imperfection of the joint and to establish the values of the coefficient, taking into account the peculiarities of the work of structures at stress concentrations.

Technological Analysis of the Production of Nickel-Containing Composite Materials

“…It should be noted that the reliability of the kinetic analysis carried out in this work, first of all, requires increased measurement accuracy and correct statistical processing of the results obtained. The literature describes various methods by which, after processing these curves (TG or DTA), the activation energy of processes can be determined [16][17][18][19][20][21][22][23][24][25][26].…”

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“…8, b and c allow us to conclude that both αand β-phase in the MMC layer have predominant (001) orientation. At the interface where the 3D-printed MMC layer was fused with the Ti-6Al-4V alloy base layer, there is a rather gradual local change of (001) orientation towards (120) and (111) for the α (Fig. 8, b) and β (Fig.…”

“…As a rule, the main criteria for determining the possibility of using a particular biocoating is the morphology of the coating surface, its structure, phase composition, and crystallinity, since these parameters are responsible for one of the essential indicators, namely, the intensity of bioresorption of the coating. In this paper, the possibility of controlling the structure of high-frequency magnetron coatings using: a) changes in the parameters of the spraying process (supply of positive/negative displacement to the substrate and the use of reaction gas); b) changes in the substrate temperature (in the range from 100 to 400 °C); c) changes in the plasma composition (using targets with different contents of hydroxyapatite and tricalcium phosphate phases) [118][119][120][121][122][123].…”

Oscillation frequencies of the reinforced wall of a steel vertical cylindrical tank for petroleum products depending on winding pre-tension

“…This leads to the need for additional research into the development of scientific foundations for assessing the strength, stability, and durability of vertical cylindrical tanks, taking into account actual operating conditions [4,5]. When designing reservoirs operated in seismically hazardous areas, research is carried out in the field of structural vibrations [6][7][8][9][10][11][12][13]. As a result of seismic load, there is a possibility of structural failure of the tank in the areas of bolted joints, dents [6,7], welds [8,9], and in other places of stress concentration [10][11][12][13].…”

“…When designing reservoirs operated in seismically hazardous areas, research is carried out in the field of structural vibrations [6][7][8][9][10][11][12][13]. As a result of seismic load, there is a possibility of structural failure of the tank in the areas of bolted joints, dents [6,7], welds [8,9], and in other places of stress concentration [10][11][12][13].…”