30m Dome Calculation Ver_D

SEDIMENTATION TANK OF PALOCH FPF DE-BOTTLENECKING PROJECT

Dia. 30m Steel Latticed Dome T-2302A/B

Calculation Report Rev No. D

Designed by: Lai sheng

Calibrated by: Xiao zhiyan

Reviewed by: Fang xiaofang

SHANGHAI BAOSHAN PETRO-MACHINERY PLANT

April 2015

上海宝山石油机械厂 SHANGHAI BAOSHAN PETRO-MACHINERY PLANT 中国上海宝山区罗店毛家路 368 号 (201908)

No.368 MaoJia Road, LuoDian BaoShan, ShangHai, China Tel & Fax：86 21 56860495,56869289

http：//www.dome-tank.cn E-mail：[email protected]

Dia. 30m Dome of Tank

Ⅰ. Design Specifications 1. API 650-11THED Welded Tanks for Oil Storage 2. ANSI/AISC 360-10 Specification for Structural Steel Buildings 3. IBC 2006 International Building Code Ⅱ. Design Parameters 1. Dead Load: Dome self-weight 250Pa

4~6mm Thickness Roof steel plate 540Pa 2. Live load: 1200 Pa 3. Wind load: 1200 Pa (Wind velocity 155km/h) 4. Snow load: 600 Pa 5. Design pressure: Positive pressure: +10000 Pa, Negative pressure: -500 Pa 6. Test pressure: Positive pressure: +10000 Pa, Negative pressure: -1200 Pa 7. Design Temperature: 95 ℃ 8. Seismic Important Factor: 1.25 9. Site Class: D 10. Exposure Category: C 11. Earthquake Zone: Zone 1 12.Nozle 14 Load: Fx=±2000N，Fy=±8000N，Fz=±1600N，

Mx=±900N.m，My=±1800N.m，Mz=±2200N.m Ⅲ. Load cases combination 1. Dead load+Live load 2. Dead load+Live load+Wind load 3. Dead load+Wind load+ Positive pressure 4. Dead load +Wind load+Negative pressure 5. Dead load+Snow load+ Positive pressure 6. Dead load+Snow load+ Negative pressure 7. Dead load +Wind load+ Positive pressure+Temperature 8. Dead load +Wind load+Negative pressure+Temperature 9. Dead load +Snow load+ Positive pressure+Temperature 10. Dead load +Snow load + Negative pressure+Temperature 11. Dead load + Live load of half span 12. Dead load + Live load of half span +Wind load 13. Dead load +Earthquake 14. Dead load +Earthquake+ Positive pressure 15. Dead load +Earthquake+ Negative pressure


Ⅳ. Lattice Classification of steel latticed dome on the tank The steel dome member is HN150x75 H-steel of ASTM A36. The design section properties are as follows： Dimensions：150x75x5x7 mm

Area：17.75 cm2 Radius of inertia：Rx＝6.01 cm； Ry＝1.66 cm Section modulus: Wx＝86.1 cm3； Wy＝13.2 cm3 Internal diameter for oil tank: D=30m Radius of curvature for steel latticed dome: Sr = 1.0D = 30 m Frequency for steel latticed mesh: 6 Total members are 330. Total Nodes have 121, Support Nodes have 30. The following is lattice classification for Steel latticed dome


Maximum length of member on steel latticed dome: 2929mm Slenderness Ratios for member bar: λ＝ 0.8×2929/16.6 ＝ 141 < [200]

The results conforms to the requirements for Clause 5.10.3.3 in the Criteria No. API 650

Ⅴ. Stress distribution analysis by Finite Element Software for steel Latticed Dome Structure Latticed dome structures on static force and buckling load stability intend to be analyzed by ANYSYS. According to Clause 5.10.6.2 in the criteria of API 650. Section area of Tension ring: A=pD2/(8Fatgθ) = 12990 mm2 Design Tension ring is made of steel plate ASTM A36: 500x30 & 90x30 Tension ring section area: 15000+2700 = 17700 mm2 Ⅵ. Calculations of stability and intensity on the members on the latticed dome The following is Axial Stress Diagram by the members on the latticed dome under Max. uniformly distributed load


The following is Buckling Stress Diagram for the members on the latticed dome under Max. uniformly distributed load

6.1. Checking of member bar on the latticed dome Checking of member bar on the latticed dome

Slenderness Ratio of member is λ＝ 89.1；ф＝0.627；

As has been obtained from resultants: Axial stress on the member bar: 39.715 MPa Bending stress of member for strong axis is 8.836 MPa.

Bending stress of member for feebleness axis is 2.625 MPa.

Therefore, Max.Stress on the member bar: σ＝ 39.715／0.627 +（8.836 + 2.625）＝ 75 MPa < [150]

6.2 Checking of bolts for nodes Each end of members have 12 blots of diameter 12mm of ASTM A193 Gr.B7. The top and bottom of each end of members have each 6 blots. Allowable shear stress of bolt: fb＝ 320 N/mm2

Max. Shear force of the top or bottom of each end of members N = 39.715x17.85e2/2 + 8.836x86.1e3/150 + 2.625x13.2e3/75


= 43900 N = 43.9 kN Shear capacity of 6 blots that top or bottom of each end of members NV ＝ 6x320x(122 π/4) = 217.1 kN > N = 43.9 kN OK! . 6.3 Checking of tension ring Max. Tension stess of tension ring is 63.722MPa by the calculation result. Max. Tension stress of tension ring: σ＝ 63.722 MPa < [140]

Therefore, tension ring is safe and reliable. Ⅶ. Calculations of stiffness and deformation on the latticed dome The following shows the deformation state on the latticed dome under the action of uniformly distributed load:


Deformation contour of the members under maximum unbalanced live load

The results are shown on the calculations: Max.vertical deformation on latticed dome should be 43.8 mm < [75] mm = D/400 Ⅷ. Calculations of overall latticed dome stability Overall stability analysis by ANSYS software is characterized with time increment by auto load and rapid convergence rate, considered all the preliminary defects on the tank shell. That is a good calculator for analyzing non-linear structures as well as overall stability. 8.1. Requirements relating to design specifications The whole process of preliminary geometric defects on dome structure can be analyzed for obtaining load values at the 1st critical point and considered as ultimate bearing capacity of structure. Allowable bearing capacity (normalized value) can be determined on the basis of latticed dome stability after ultimate bearing capacity divided by coefficient K. Coefficient value can be taken as 4.2. 8.2 Calculation principles


The stability on the latticed dome can be calculated in consideration of the analysis method of geometrical non-linearity finite element (Load-displacement whole process analysis), in the analysis the materials are assumed as linear elasticity. The following iterative equation can be used in load-displacement whole process analysis:

)1()( i

tttti

t NFUK

Where: tK —— t Tangent stiffness matrix in time structure；

)(iU ——Iterative increment at current displacement；

ttF —— tt Node load vector applied from outside at tt ； )1(

i

ttN —— tt Internal force vector on node point for member bar corresponding to tt .

8.3 Determination of preliminary defects distribution modality The dome installation tolerance on the preliminary curved surface should be focused when analyzed stability in the whole latticed dome; Min. buckling modality in the non-linearity buckling analysis in structural geometry can be used for preliminary defects distribution. Therefore, taken the 1st phase instability modality as overall instability modality in vertical direction in the middle of steel latticed dome, the structure can be analyzed by geometric non-linear buckling mode. The following is latticed dome modality figure at the 1st phase instability.


8.4. Determination of Max. Value of calculation for the preliminary defects Maximum Value of calculation for preliminary defects can be taken as 1/300 dome span. Normally, Max. value of defects can be Max. allowable installation tolerance in application, generally, this value will be determined in the specification mainly on the ground that an influence can be fully shown when the defects attain to 1/300 span or so. Max. span in this engineering is 30000mm, according to the requirements stipulated in the specification, Max. calculated value for preliminary defects has been determined as 100mm. Preliminary defects distribution modality can be determined according to the 1st phase modality. 8.5. Calculated results Stress-strain curve on the top node at the latticed dome:

As has been analyzed from the results at ANASYS non-linearity analysis, the load point is 63094N at the whole instability of latticed dome. Therefore, an safety factor resulted in dome stability should be:

K＝63094/10394＝6.1 > [4.2]

Vertically deformation value

on the top of latticed dome

Node loads

on the latticed

dome

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30m Dome Calculation Ver_D