PowerPoint Presentation

SIM SBO DeMoPreCI-MDT27/10/2015Steel degradation in Offshore from model to prediction

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QueDeDevelopmentMo MonitoringPre Prediction

CICoupled Interactions

MDTMaterial Durability Testing2

The concept3 damage modesAbrasionCorrosion (dissolution / H embrittlement)Fatigue

1 forming processWelding3

Industrial cases45

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Starting pointDo often occur simultaneously offshoreAll have their state of the art

But: interaction not well understood over-estimation in real applications12

Marry + further develop understandingCorrosion (H embrittlement) + fatigueAbrasion + corrosion (material dissolution)Fatigue + abrasion

First attempt to corrosion + fatigue + abrasion13

For each damage modeGenerate a numerical modelTo understand behaviorTo predict behavior

Experiments: improve understanding + generate input to build the models

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Industrial parties15

16Abrasion - corrosionDredging MaterialHigh Cr IronLC high tensile structural steelAbrasive type (2B/3B)Two-bodyTwo-bodyDry or wetWetWetDominant MechanismErosionAbrasion - corrosionParticle typeDepends on soil conditionsDepends on soil conditionParticle size4mm max Typical sea sandImpact velocity22 30 m/s (speed of the impeller)8-20 m/s (Wind speed)Operational hours40 60 hours20 25 years (design life)SourceLehigh Univeristy/Jan De NulM. Damgard et. al., Engineering Structures, 2014

Offshore wind

17Design of abrasion testerConfigurations realized in this design Single asperityMultiple asperityAbrasion-corrosion

Configurations not realized in this designImpact abrasion/erosion

FN

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Resonant Bending Fatigue Test Setup Corrosion fatigue instrumentationMTS universal test machine

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Environmental controlled chamberCorrosion fatigue instrumentation

20Scripting in ABAQUS with PythonParameterized Model3D solid single-edge notch in a specimen along an arbitrary path.Fixed load cyclic load in environment

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Cathodic cellAnodic cellHydrogen diffusionHydrogen diffusion coefficientHydrogen provided from the cathodic cellHydrogen diffusion through the sampleOxidation Hads at surface in the anodic cell generating an anodic current

Permeation cell

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j/jExperimentalTheoreticalPermeation results

t23H evolution and transport experiments

(*Ref 1): A.V. Uluc, F.D. Tichelaar, H. Terryn, A.J. Bottger: Journal of Electroanalytical Chemistry 739 (2015) 130-136

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H evolution and transport experiments

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Governing equation for each species:Domain 1: metalDomain 2: interfaceNa+OH-Fe2+H2O + e- Hads + OH- Fe Fe2+ + 2e-HadsH diffusionDomain 3: solutionH evolution and transport model

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H evolution and transport model27Interaction with heat transfer analysisProduction of ferrite at initial transformation temperatureWeight percentage:C% -- 0.39 Si% -- 2.05Ni% -- 4.08 Ae3 = 660 C Th = 460 CMs = 319 CTest with JMAK modelf = 1 - exp( -btn )

660 C

SDV1 = volume fraction of ferrite and pearliteSDV2 = volume fraction of Bainite and W-ferriteTemperature distribution where temperature initially falls below 660 C

Welds: thermal analysis

28Heat sourceheat transfer analysisMetallurgical analysisf, carbon diffusionHETVALOutput: Moving heat sourceHETVAL

Simulation of heat source of double ellipsoidal distributionInput: Ae3, Th, Ms , iUSDFLDChemical compositionGrain sizeWelds: thermal analysis

29Questions?:

More information: posters 23 28 at the poster session