The Key Parts Of Stress Analysis Based On FEA In The Design Of20×10~4m~3Storage Tank

Crude oil storage tank is the development of big specification, the design of large oilstorage tanks have done a lot of research work, but the20×10~4m~3storage tank to achieve thepractical engineering application, also needs to make the analysis more detailed calculationsof the storage tank, and to provide theoretical basis for the optimization design.20×10~4m~3storage tank model analysis is performed with the finite element analysissoftware ANSYS in this dissertation, as far as possible it is realistic simulation that the stresscondition of shell and double-deck floating roof of storage tank are. Numerical calculationmethod is applied, through the ANSYS software analysis showed that the distribution law ofstress in the key parts of storage tank. And double-deck floating roof deformation andstrength are calculated, at the same time the unsinkability of floating roof checkingcalculation is also performed, in order to determine the optimum structure size of storagetank.For large storage tank shell, the maximum circumferential stress appears in the first ringtank shell or second ring, so the first ring tank shell width have great influence on the tankshell stress. The Calculation results by changing the range of the first ring wall width from2200mm to3800mm are carried on the comparative analysis, through the tank shell widthchange, found the change rule of stress in each part of the storage tank, it is of veryimportance to the first circle of tank wall width optimization and engineering application.Fillet weld is refers to the tank shell and annular bottom plates connected T shape insidefillet weld. The stress distribution of fillet weld is very complicated, and the area of stressconcentration. Aiming at the inside fillet weld grinding angle, the height and width size ofdifferent values,and annular bottom plate size extended length of different values, modelinganalysis, get the change regularity of stress peak value in fillet weld.Large shell openings of large storage tanks are usually arranged on the first ring tankshell. the stress distribution is more complex on the first ring tank shell, mainly from theheight distance of bottom plates with the variation of circumferential stress and the axialbending stress, mainly existing circumferential and axial bending stress with the variation ofthe height distance of bottom plates. Through the establishment of the tank shell openingreinforcement of three-dimensional entity model, analysis of stress status, checking openingreinforcement structure.For the three kinds of dangerous working conditions, is established using ANSYS beam, shell element coupled finite element model of double-deck floating roof, through thesimulation of equivalent hydrostatic pressure effect, stress intensity and displacement arecalculated, Limited by the maximum stress intensity, which makes the calculation resultsmore accurate and reliable.Finally, through the summary, the optimized design of the20×10~4m~3storage tank firstring shell, annular bottom plates, fillet weld and floating roof structure size, to reach thedomestic advanced level.