1. Topology optimization of Oil Tanker Structures in Cargo Tank Region
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Topology optimization of Oil Tanker Structures in Cargo Tank Region
Speaker: GAO Chu
October 2016
QIU Weiqiang, GAO Chu, SUN Li, LUO Renjie

2. Content Proposal for a VLCC with one center line longitudinal bulkhead
Introduction to structure optimization techniques
Definition of Structural Model, boundary conditions and load patterns FEA
Topology results discussion
Conclusions
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3. Hull structure of VLCC and Suezmax size oil tanker
Typical transverse section of a Suezmax size oil tanker
Typical transverse section of a VLCC
VLCC with one C.L. BHD
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4. Tank arrangements of proposed VLCC and traditional one
Traditional VLCC
VLCC with one C.L. BHD
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5. Important issues to be aware of
Shear Strength
Stringer Design
Local Strength
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6. 7.3m 37.02m The “GREAT STONE BRIDGE” An Chi Ch'iao
An Chi Ch'iao the Great Stone Bridge
Chao Hsien, Hobei, China
Sui Dynasty ,AD ,
Li Chun Master Builder

7. Structure Optimization Design
Hull Structure Optimization Design
Hull
Structure Optimization
Design
Topology Optimization
Shape Optimization
Size Optimization
Structure Optimization Design
Production
Cost
Structure Capability
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8. Continuum Topology Optimization Methods
Homogenization method
SIMP （Solid Isotropic Microstructure with Penalty) method
ESO/BESO (Evolutionary /Bi-directional Evolutionary Structural Optimization) method
ICM (Independent Continuous Mapping) method
Level Set method
“Killed” element
Perimeter Method …
SIMP
BESO
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9. Basic Topology Optimization Procedure
START
FEA
Sensitivity
Filter Scheme
Construct a new design No
Yes
Converged?
END
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10. Structures to be optimized
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11. 45 Load Cases Loading Patterns and model constraints MARIC Location
Translation
Rotation δx δy δz θx θy θz
Aft End
Cross section -
Rigid Link
Independent point
Fix
End beam
Fore End
Crosssection
Intersection of CL&IB
Where: - no constraint applied (free)
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12. Problem Statement
“Killed” element
Empty
Solid
SIMP
BESO
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13. Structures to be optimized
Transverse frames
Horizontal Stringers
Non-designable
Designable
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14. Structures to be optimized
Separated
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15. Resulting topology of all loading patterns
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16. Resulting topology of typical transverse frame (all loading patterns)
SIMP
BESO
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17. Resulting topology of B3 by SIMP method
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18. Iteration steps in SIMP process without loading patterns B3 & B11
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19. Iteration steps in SIMP process without loading patterns B3 & B11
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20. Iteration steps in SIMP process without loading patterns B3 & B11
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21. Iteration steps in SIMP process without loading patterns B3 & B11
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22. Final solution (Iteration 67)
Topology Optimized Trans. Frames & H. Stringers
Final solution (Iteration 67)
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23. Optimum topology by SIMP
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24. Optimum topology by BESO
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25. Optimum topology of typical transverse frame by SIMP method
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26. Optimum topology of typical transverse frame by BESO method
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27. Optimum topology of typical transverse frame
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28. Optimum topology of typical horizontal stringers by SIMP & BESO method
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29. Optimized topology & new designs
SIMP 01
BESO 02
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30. Optimized topology & new designs
SIMP
BESO
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31. Web Height Optimization
Shape/size optimization
Vertical Girder
Web Height Optimization
Horizontal Stringer
Web Height
Optimization
Deck Transverse
Web Height
Optimization
Size Optimization 01 02
Rule Check
Nonlinear FEA
Elastic column buckling
Elastic torsional buckling
Elastic column / torsional buckling
Elasto-plastic behavior of the primary support member

32. BESO/SIMP optimum topology comparisons
Compared subjects
SIMP
BESO
Traditional VLCC
Comparison(%)
Surface areas of typical transverse frames (m2)
575.8
643.3
731.8
78.7%
87.9%
Averaged weight of typical transverse webs (ton, except for wash BHD)
100.8
111.3
143.1
70.4%
77.8%
Structural weight per meter in cargo hold (ton)
111.75
112.55
127.3
87.8%
88.4%
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33. Comparison between VLCC with one C.L.BHD and traditional one
Transverse section arrangements of VLCC with one C.L.BHD
Transverse section arrangements of Traditional VLCC
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34. Comparison between VLCC with one C.L.BHD and traditional one
Horizontal stringer arrangements of VLCC with one C.L.BHD
Horizontal stringer arrangements of Traditional VLCC
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35. Topology optimization with 3D elements
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36. Topology optimization with 3D elements
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37. Topology optimization with 3D elements
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38. Application on other tankers
New/Old transverse section design of Suezmax oil tanker
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39. Application on other tankers
New/Old transverse section design of Aframax oil tanker
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40. Vertical web end of a Aframax size oil tanker
Applications
Vertical web end of a Aframax size oil tanker
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41. Conclusions New structural design of a VLCC is proposed
Optimum topology of the VLCC with one C.L. BHD calculated and discussed
Problems encountered during the optimization procedure
Limitations of present optimization tools
Issues to be resolved in the future
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42. THANKS 中 国 船 舶 及 海 洋 工 程 设 计 研 究 院
MARINE DESIGN & RESEARCH INSTITUTE OF CHINA