Nonlinear Structural Mechanics in Association With Limit States and Risk-Based Approaches - On-Going...

8/8/2019 Nonlinear Structural Mechanics in Association With Limit States and Risk-Based Approaches - On-Going Research Projects by Prof. Jeom Kee Paik

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Nonlinear Structural Mechanics in Association withNonlinear Structural Mechanics in Association with

Limit States and RiskLimit States and Risk --based Approaches:based Approaches:

OnOn --Going Research ProjectsGoing Research Projects

Prof.Prof. JeomJeom KeeKee Paik, DirectorPaik, Director

LRET Research Centre of Excellenceat Pusan National University


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List of OnList of On --going Projectsgoing Projects ALPS (Analysis of Large PlatedALPS (Analysis of Large Plated --Structures)Structures) JIPJIP -- Explosion and fire engineering of Explosion and fire engineering of FPSOsFPSOs (EFEF)(EFEF) Impact pressureImpact pressure ChangeableChangeable --die systemdie system Dropped objectsDropped objects Friction stir welding (FSW)Friction stir welding (FSW) Arctic engineeringArctic engineering CFD simulations on gas explosion (Prof. J.C. Park)CFD simulations on gas explosion (Prof. J.C. Park) Risk based design of FPSO topsides against gas explosionRisk based design of FPSO topsides against gas explosion

(Dr. Z.(Dr. Z. CzujkoCzujko , Norway), Norway) Hybrid welding (Prof. H.S. Bang)Hybrid welding (Prof. H.S. Bang) Collision with iceberg (Prof. S.G. Lee)Collision with iceberg (Prof. S.G. Lee) Hazard identification methods (Prof. S.C. Shin)Hazard identification methods (Prof. S.C. Shin) Corrosion under dynamic flexing (Prof. R.E.Corrosion under dynamic flexing (Prof. R.E. MelchersMelchers , Australia), Australia) Nonlinear matrix equation solver (Prof. H.M. Kim)Nonlinear matrix equation solver (Prof. H.M. Kim) Strategic risk management (Prof. S.H.Strategic risk management (Prof. S.H. ChoiChoi ))


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Various Ocean Environmental PhenomenaVarious Ocean Environmental Phenomena WavesWaves Freak wavesFreak waves WindsWinds HurricaneHurricane Impact pressure actionsImpact pressure actions slamming, slamming,slamming, slamming,

green watergreen water CurrentsCurrents

UltraUltra -- low temperaturelow temperature LNG tanksLNG tanks Arctic environmentArctic environment Low temperatureLow temperature Accidental floodingAccidental flooding Dropped objectsDropped objects Collisions, groundingCollisions, grounding Fire, gas explosionFire, gas explosion Corrosion attackCorrosion attack


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Linear vs. Nonlinear Structural MechanicsLinear vs. Nonlinear Structural MechanicsFactors of nonlinear structural mechanics:Factors of nonlinear structural mechanics: Geometrical factors associated with buckling, large deflection,Geometrical factors associated with buckling, large deflection,

crushing / foldingcrushing / folding Material factors associated with yielding / plasticity, rupturMaterial factors associated with yielding / plasticity, ruptur e,e,

brittle fracture, damagebrittle fracture, damage Fabrication related initial imperfections such as initial distoFabrication related initial imperfections such as initial disto rtion,rtion,

residual stress, and softeningresidual stress, and softening Temperature factors such as low temperature associated withTemperature factors such as low temperature associated with

operation in arctic area or with low temperature cargo, and hoperation in arctic area or with low temperature cargo, and h ighightemperature due to fire and explosiontemperature due to fire and explosion

Dynamic factors (strain rate sensitivity, inertia effect) assocDynamic factors (strain rate sensitivity, inertia effect) assoc iatediated

with freak waves, impact pressure arising from sloshing, slammwith freak waves, impact pressure arising from sloshing, slamm ing oring orgreen water, and overpressure arising from explosion, impactsgreen water, and overpressure arising from explosion, impacts fromfromcollision and dropped objectscollision and dropped objects

AgeAge --related deterioration such as corrosion and fatigue crackingrelated deterioration such as corrosion and fatigue cracking


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Nonlinear Structural MechanicsNonlinear Structural MechanicsLimit states and risk based approachesLimit states and risk based approaches


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Limit States BasedLimit States Based ApproachesApproaches Limit state is a condition where the structure fails to perform

its intended function designed beforehand. Serviceability limit states (SLS) permanent set, stability,

station-keeping, vessel weathervaning, vessel motionexceedance, vibration and noise, mooring line vortexinduced resonance oscillation

Ultimate limit states (ULS) buckling and plastic collapse Fatigue limit states (FLS) fatigue cracking, fracture, crackpropagation

Accidental limit states (ALS) collisions, fire, gas explosion,

dropped objects

TodayToday s trends trend fusion technologyfusion technology


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Hazardidentification (Step1)

Risk assessment (Step2)

Decision makingrecommendations (Step5)

Risk control options(Step3)

Cost benefit assessment(Step4)

Risk = Frequency Consequence ALARP

Risk Based ApproachesRisk Based Approaches

ALARPALARP As Low As Reasonably PracticableAs Low As Reasonably Practicable


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ALPS Project (1/3)ALPS Project (1/3) Aim: ULS design technology in association with MAESTROAim: ULS design technology in association with MAESTRO Work scope: ULS analysis for stiffened panels and hull girdersWork scope: ULS analysis for stiffened panels and hull girders

Deliverables: ALPS/ULSAP, ALPS/HULLDeliverables: ALPS/ULSAP, ALPS/HULL

Longitudinal edge

T r a n s . f l o o r


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DRS C3 Advanced Technology Center (ATC), USA Code development and integration lead Worldwide distribution

Worldwide technical support Virginia Tech, USA

Professor Owen Hughes MAESTRO Intellectual Property Owner MAESTRO overall development strategy

University of Zagreb, Croatia Professor Vedran Zanic Optimization methods and code development European Union R&D Projects Applications to ship design and construction projects

Pusan National University, Korea Professor Jeom Kee Paik Ultimate and accidental limit states assessment

(ALPS project) Applications to ships and offshore installations

ALPS ProjectALPS Project MAESTRO Development Team (2/3)MAESTRO Development Team (2/3)


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HullformHullform

SubSub --divisiondivisionGeneralGeneral

ArrangementArrangement

ShipShipStructureStructureSurfaceSurfaceModelModel

FiniteElementModels

MAESTRO 2008MAESTRO 2008

TEMPEST TEMPEST Seakeeping &Hydro Loads HighPerformance Computers

StructuralEvaluation

LoadsModels

FESolvers

StructuralOptimizationI T E R AT E

I T E R AT E

Smart Product Model ArchitectureSmart Product Model Architecture

AcousticsAnalysis

CostAnalysis

ShipSignatures

HydrostaticsAnalysis

Resistance &Powering

ALPS/ULSAP, ALPS/HULL, ALPS/SCOLALPS/ULSAP, ALPS/HULL, ALPS/SCOL


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EFEF Joint IndustryEFEF Joint Industry ProjectProject Aim:Aim: EExplosion andxplosion and FFireire EEngineering of ngineering of FFPSOsPSOs (Phases I, II, III)(Phases I, II, III) Work scope: Quantified risk assessment and management forWork scope: Quantified risk assessment and management for

gas explosion and fire ongas explosion and fire on FPSOsFPSOs Deliverables: Quantitative risk based design procedure andDeliverables: Quantitative risk based design procedure and

guidanceguidance Partners:Partners: NowatecNowatec AS (Norway), ABS (USA), DSME (Korea),AS (Norway), ABS (USA), DSME (Korea),

HHI (Korea), HSE (UK), SHI (Korea)HHI (Korea), HSE (UK), SHI (Korea)


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Impact Pressure Project (1/3)Impact Pressure Project (1/3) Aim: Serviceability limit state design technology of stiffenedAim: Serviceability limit state design technology of stiffened

plate structures under impact pressure actions arising fromplate structures under impact pressure actions arising from

sloshing, slamming and green watersloshing, slamming and green water Work scope: Development of permanent deflection designWork scope: Development of permanent deflection design

formulationsformulations Deliverables: SLS design procedure and guidance againstDeliverables: SLS design procedure and guidance against

impact pressure actionsimpact pressure actions


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QuasiQuasi --static domain: 3static domain: 3 /T/T Dynamic / impact domain: 0.3Dynamic / impact domain: 0.3 /T


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0 2 4 6 8 10

Peak Pressure (P o/Pc)

0

1

2

3

4

5

6

Permanent Deflection (w

p/t)

FEM (LS-DYNA3D)ALPS/ULSAP

= 2.5 ms

= 1 ms

0 1 2 3 4 5Duration Time (ms)

0

10

20

30

40

Permanet Deflection (w

p/t)

FEM (LS-DYNA3D)ALPS/ULSAP

Po/Pc = 10

Po/Pc = 5

Impact Pressure Project (3/3)Impact Pressure Project (3/3)


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ChangeableChangeable --Die System Project (1/5)Die System Project (1/5) Aim: 3DAim: 3D --curved plate forming technologycurved plate forming technology Work scope: Changeable die systemWork scope: Changeable die system

Deliverables: Prototype machine for 3DDeliverables: Prototype machine for 3D --curved plate formingcurved plate forming Partners:Partners: KukdongKukdong Industrial Engineering (Korea), Small &Industrial Engineering (Korea), Small &

Medium Business Administration (Korea)Medium Business Administration (Korea)


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Line heating technologyLine heating technology

ChangeableChangeable --Die System Project (2/5)Die System Project (2/5)


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Controller

Stop

Measurement of

formed surface

CAD/CAE/CAMsystem

Tolerable?

Y

N

Punch

Press

Target sheet

Controller

Stop

Measurement of

formed surface

CAD/CAE/CAMsystem

Tolerable?

Y

N

Punch

Press

Target sheet


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A B E

DC

O

Deflection at each punch

Result of Elastic-plastic

large deflectionanalysis

Displacementof target surface

Loading

Unloading

Reationforce at each punch


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Dropped Object Project (1/3)Dropped Object Project (1/3) Aim: Accidental limit state design technologyAim: Accidental limit state design technology Work scope: Structural consequence of stiffened panels underWork scope: Structural consequence of stiffened panels under

impact arising from dropped objectsimpact arising from dropped objects Deliverables: Experimental database and limit state designDeliverables: Experimental database and limit state design

procedureprocedure Partner: SHI (Korea)Partner: SHI (Korea)

PlywoodPlywood

PUF PanelPUF Panel

Primary barrier (304SS)Primary barrier (304SS)Secondary barrierSecondary barrier

Inner HullInner Hull

PlywoodPlywood

PUF PanelPUF Panel



Drill Collar


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Dropped Object Project (2/3)Dropped Object Project (2/3)

Force (kN)

Time (sec)

869.49kN (time=0.77999s)

110.77kN (time=1.215s)

177.03kN (time=2.18499s)

Deflection (mm)

Time (sec)

Max: 16.15mm (time=0.96998s)

Average (4.40mm)Average(2.25mm)


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Dropped Object Project (3/3)Dropped Object Project (3/3)

PlywoodPlywood

PUF PanelPUF Panel



PlywoodPlywood

PUF PanelPUF Panel



80 mm

30 mm

80 mm

30 mm

166 mm

66 mm60 mm

166 mm

66 mm60 mm

B03

B02 B01

B06 B04

B05

S01

S02B03

B02 B01

B06 B04

B05

S01

S02


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Friction Stir Welding Project (1/7)Friction Stir Welding Project (1/7) Aim: Ultimate limit state design technology of friction stirAim: Ultimate limit state design technology of friction stir

welded aluminum structureswelded aluminum structures

Work scope: Buckling collapse testing and nonlinear FE analysisWork scope: Buckling collapse testing and nonlinear FE analysisfor friction stir welded aluminum stiffened panelsfor friction stir welded aluminum stiffened panels Deliverables: Experimental database and limit state designDeliverables: Experimental database and limit state design

procedureprocedure Partners: Ship Structure Committee (USA), ABS (USA)Partners: Ship Structure Committee (USA), ABS (USA)


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Friction Stir Welding Project (2/7)Friction Stir Welding Project (2/7)

MIG weldingMIG welding Friction stir welding (FSW)Friction stir welding (FSW)


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19A19A--MIGWMIGW 19C19C --FSWFSW


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++

++

Weld line

Weld line

++

Weld line

Unweld (extruded)Flange

b t b t b t b t b t b t b t b t

rtx=165.3 N/mm2

rcx=-34 N/mm2

: Measured

: Idealized

: Tensile stress

: Compressive stress

Material:

Plate 5083-H112

t = 6mm

Stiffener 6082-T6

hw = 66.1 mm

tw = 4 mm

b f = 40 mm

tf = 5.7 mm

b t = 25.6 mm

-100 0 100 200 300 400 500 600 700 800 900 1000b(mm)

-50

0

50

100

150

200

Residual Stress (N/mm

2)

b t b t b t b t b t b t b t b t

rtx=165.3 N/mm2

rcx=-34 N/mm2

: Measured

: Idealized

: Tensile stress

: Compressive stress

Material:

Plate 5083-H112

t = 6mm

Stiffener 6082-T6

hw = 66.1 mm

tw = 4 mm

b f = 40 mm

tf = 5.7 mm

b t = 25.6 mm

-100 0 100 200 300 400 500 600 700 800 900 1000b(mm)

-50

0

50

100

150

200

Residual Stress (N/mm

2)


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Loading capacity: 2000kNLoading capacity: 2000kN TestTest --bed length: 9.2mbed length: 9.2m TestTest --bed breadth: 2.4mbed breadth: 2.4m

Frame height: 4.42mFrame height: 4.42m Buckling collapse testingBuckling collapse testing


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Nonlinear FEANonlinear FEA

T r a n s . f r a m e s

1414

142 8

5 6

2 8

x

y

z

6

4

2

T r a n s . f r a m e s

1414

142 8

5 6

2 8

x

y

z

x

y

z

6

4

2

6

4

2

Axial compressive stress (MPa)

Strain

0 0.002 0.004 0.006 0.008

0

20

40

60

80

100

120

140

160

A

B

Axial compressive stress (MPa)

Strain

0 0.002 0.004 0.006 0.008

0

20

40

60

80

100

120

140

160

A

B


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Arctic Project (1/3)Arctic Project (1/3)

Aim: Structural design technology in arctic areaAim: Structural design technology in arctic area Work scope: Structural failure in low temperatureWork scope: Structural failure in low temperature

Deliverables: Experimental database and limit state designDeliverables: Experimental database and limit state designprocedure in low temperatureprocedure in low temperature


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Arctic Project (2/3)Arctic Project (2/3)

Original source: The Kansai Society of Naval Architects (1983)Original source: The Kansai Society of Naval Architects (1983)


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ArcticArctic

Project (3/3)Project (3/3)

Axial shortening

Pm

P Pm = Mean crushing load

Effect of low temperatureEffect of low temperature


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OtherOther

Joint ProjectsJoint Projects

CFD simulations on gas explosion (Prof. J.C. Park, PNU)CFD simulations on gas explosion (Prof. J.C. Park, PNU) Risk based design of FPSO topsides against gas explosionRisk based design of FPSO topsides against gas explosion

(Dr. Z.(Dr. Z. CzujkoCzujko ,, NowatecNowatec AS, Norway)AS, Norway) Hybrid welding (Prof. H.S. Bang,Hybrid welding (Prof. H.S. Bang, ChosunChosun Univ.)Univ.) Collision with iceberg (Prof. S.G. Lee, Korea MaritimeCollision with iceberg (Prof. S.G. Lee, Korea Maritime

Univ.)Univ.) Hazard identification methods (Prof. S.C. Shin, PNU)Hazard identification methods (Prof. S.C. Shin, PNU) Corrosion under dynamic flexing (Prof. R.E.Corrosion under dynamic flexing (Prof. R.E. MelchersMelchers ,,

Univ. of Newcastle, Australia)Univ. of Newcastle, Australia) Nonlinear matrix equation solver (Prof. H.M. Kim, PNU)Nonlinear matrix equation solver (Prof. H.M. Kim, PNU) Strategic risk management (Prof. S.H.Strategic risk management (Prof. S.H. ChoiChoi , PNU), PNU)


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International SymposiumInternational Symposium

Limit States and Risk Based ApproachesLimit States and Risk Based Approaches 88 --13 April 2009,13 April 2009, PhuketPhuket , Thailand, Thailand OrganizersOrganizers Prof.Prof. JeomJeom KeeKee Paik (At Sea)Paik (At Sea)Director, LRET Research Centre of ExcellenceDirector, LRET Research Centre of Excellence

at Pusan National University, Koreaat Pusan National University, Korea Prof. Robert E. Melchers (On Land)Prof. Robert E. Melchers (On Land)Director, Centre for InfrastructureDirector, Centre for Infrastructure PerformancePerformance&& Reliability, University of Newcastle, AustraliaReliability, University of Newcastle, Australia Prof.Prof. SatyaSatya N.N. AtluriAtluri (In the Air)(In the Air)Director. Center for Aerospace Research & Education,Director. Center for Aerospace Research & Education,University of California at Irvine, USAUniversity of California at Irvine, USA

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