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Tobias LooseIngenieurbüro Tobias Loose, Herdweg 13, D- 75045 Wössingen,loose@tl-ing.de www.tl-ing.eu

Efficient Setup and Documentation of Simulations for

Welding and Heat Treatment with DynaWeld

Simulationsforum Weimar08.11.16 till 10.11.16

Foto: ISF

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HeatingThermal HeatingInductive Heating

Quenching

Carburisation

Tempering

Quenching

Case Hardening

Inductive hardening

Press hardening

Heat treatment overview

Typeof heat treatment

Single process steps

Design of properties by local change of material properties and microstructure

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ClampingPredeformations

Cooling

Heating

ReheatingTempering

Weld Process Type- Arc Welding- GMAW, SAW, TIG- Laser- Electron Beam- GMAW-Laser-Hybrid- Resistive Welding, RSW

single or multi layered welds,

tack welds

Dimension10 µm .. 500 mm

Welding overviewwelding structure analysis

Type of Welding Single process steps

Distortion - Residual Stress - Material Properties after Welding

Grinding and Rewelding

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Substructuring of models for welding and heat treatment

SIMULATION

MODEL

GeometryMeshing or import

mesh from prior steps

Heat Source

Heating Carburization

MaterialData, and parameter

calibration

ProcessClamps and Boundarys

Quenching Media

Trajectories

FEMadditional settings:

load, contact, cinematics...

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Benefit of sub structuring

Complex simulation

task with many disciplines

Materialspecialist

Meshspecialist

FEMspecialisteasy to mange by task sharing

Weldingspecialist

Heat Treatmentspecialistoutsourcing single tasks

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Definition of simulation steps

SIMULATION

MODEL

POST

FILE OUTPUT

RESULT

REALITY

Mesher

Pre-Processsor

Solver Post-Processsor

DynaWeld LS-DYNA LS-Pre-Post

DynaWeld repesents a simulation environment with special preprocessors

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DynaWeldenvironment and preprocessor

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DynaWeldenvironment and preprocessor

DynaWeld is not an Island-Solution!

Customer definedEnvironment:

•Mesher•PreProcessor•PostProcessor•Auxilary Software

Process Chain

Linux and WindowsExcel and Libre Calc

Plug In for existing Software environmentas well as stand alone

Heat Treatment and Welding

relatedauxilary Tools

Interface•Material Simulation•Welding Process Simulation

User defined Keyword→ no limitation in modeling

Supports LS-DYNA FE-Code one Code - many Solvers - one License Fee

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MaterialFoto: Edyta Łopatecka

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Phase transformation during coolingCCT-diagram

Quelle: Bernd Hochholdinger, DYNAmore Swiss

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Phase kinetic models

Law:Koinstinen-Marburger

Parameter:Tstart: Start Temperature MSa: kinetic faktor KM

Use:f(temperature)diffusionless transformation

Austenit → Martensit

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Phase kinetic models

Law:generalized JMAK

Jonhson-Mehl-Avrami-Kolmogorov

Parameter:xeq: Proprotion at equilibrium (T) PEQn: form parameter (T) Nt: kinetic faktor (T) TAUf,f': Leblond factor (dT/dt) F, F'

Use:f(temperature, temperture gradient, time)diffusion-driven transformation

Austinitisation, TemperingAustenite → Ferite, Perlite, Bainitephase transformation Aluminium

Advantage:no limitation on material type nor chemical composition. Fitting according:temperatur(T) and temperature rate(dT/dt)

Disadvantage:needs calibration on existing CCT or TT

based on Avrami equitationextended by Leblond

,

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Materials with phase kinetic models in LS-DYNA

*MAT_254 / *MAT_GENERALIZED_PHASE_CHANGE

Heat treatmentWelding all materials

Laws:Koinstinen MarburgerOddyKirkaldygeneralized JMAKTime criteriumlist might be extended

userdefined assignment of laws

Features:24 PhasesShells, Solids, 2D-shellsWelding featuresPhase transformation strainTransformation induced plasticity (TRIP)Subcycling for phase transformationTemperingHardeness computation

Simulation of PROCESS-CHAIN feasible

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Selected features: DTEMP

Phase transformation calculation temperature requires limit on tempearature stepPhase transformation shall not reduce time step of mechanical solverDTEMP = maximum allowed temperature step drives subcycle for phase transformation:

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*MAT_254 calibration of phase transformation law

given CCT Data

LS-DYNA calculation

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Selected features: phase transformation strain

If Phase A and B have different densityin case of phase transformationadditional strain arises due to volume change:Phase Transformation Strain.

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Simplified approach for single phase model *MAT_270

Heating

Cooling

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Validation Nitschke-Pagel test

Distortion w:Experiment: 0,34 mmSysweld: 0,32 mmLS-DYNA: 0,34 mm

Loose, T.: Einfluß des transienten Schweißvorganges auf Verzug, Eigenspannungen und Stabiltiätsverhalten axial gedrückter Kreiszylinderschalenaus Stahl, Diss, Karlsruhe, 2008

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DynaWeld – Management forhigh sofisticated welding and heat treatment materials

Material DynaWeld Material User defined

Import and extensions:Base material phaseLiquid material phaseTempering phaseFlowcurve adjustmentWelding settings

JMatPro

WeldWare

other material simulation software

LS-DYNAMaterial keyword-file

multi phase *MAT_254

LS-DYNAMaterial keyword-filesingel phase *MAT_270

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DynaWeld Material - Import

Interfaces

Settings and Extensions

single phase multi phase

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DynaWeld Material – Documentationspreadsheet DynaWeld-Material-Check

Graph for each material parameter

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DynaWeldHeat Treatment

Foto: Edyta Łopatecka

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DynaWeld – Management for high sofisticated heat treatment simulation setup

Model Setup DynaWeldHeat TreatmentOven curve

HT-ProcessHT-ParameterHT-Solver Settings

Carburization

Quenching media

Diving

LS-DYNA Keyword-files

Dokumentationin spreadsheed format

LS-DYNA solver run

LS-DYNAMesh keyword-file

LS-DYNAMaterial keyword-file

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DynaWeld Heat Treatment - Process

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DynaWeld Heat Treatment - Parameter

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Foto: Edyta Łopatecka

DynaWeldWelding

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Laser welded sheet with tensile test

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DynaWeld – Management for high sofisticated welding simulation setup

Model Setup DynaWeldWelding Trajectory

ProcessTimestep adjustmentBoundary and ClampsParts, Material assignmentContactSolver Settings

Heat Source

Clamp Kinetic

LS-DYNA Keyword-files

Dokumentationin spreadsheed format

LS-DYNA solver run

LS-DYNAMesh keyword-file

LS-DYNAMaterial keyword-file

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DynaWeld Process

Types of heat sourcesurface heat sourcevolumetric heat sourcepart heating

Geometric shapeselipsoid – double elipsoidcylinderconus – double conus

Heat input onshell, shell 2Dsolidsegment

Start, end, intermediate time

Multi robots simultaneous

Multiple heat source

Reverse option

Reorder of sequence

Multi layered weldsauto deactivation of not yet deposit material

SimWeld interface

supports the newLS-DYNA heat source- on shells and solids- shell thickness distribution- engergy input control- sub cycling- mesh independent- time step independent

auto fill or copy option

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Weldpath definition - trajectory and reference

Trajek

tory No

deSet

Refere

nce No

deSet

Rotation of reference

Global coordinate system

Local coordinate systemheat source

uv

ww-offset

v-offset

u: Trajektory directionv: Torch directionw: Lateral direction

xz

y

Definition with one Nodesetauto detection of reference

normal on surface*BOUNDARY_THERMAL_WELD_TRAJECTORY

Local adjustment:- rotation- v-offset reference direction- w-offset lateral

automatic calculation of thelength of trajectory

Display of trajectory,reference, startpoint

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DynaWeld Boundary

time

forcedisp

Clamping

Clampedforce driven or

displacement driven

Unclamping

Single point constraints (SPC)

Symetry surfaces

Force on Nodes or Node Sets

Displacement on Nodes or Node Sets

Force or Displacement:•user defined ramp at start and end•local coordinate system•Predeformation•Prestress

Force or displacement driven clamps

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DynaWeld Contact

Welding contactchange friction → tied by temperature

Friction contact

Tied contact

Shell edge to surface or solidfriction or tied contact

Node to surfaceauto-correct of large penetration

mechanical only

Special featuressmooth option for curved sheets

mortar option for implicit analysisshell thickness considered automatically

mechanical and thermal

mechanical

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DynaWeld-Welding Input file generator

Analysis Options

Generate Input•one file•structured input•single task creation

Clean Work Directory

Check options

Run and Kill

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DynaWeld Tools

Create Variants

Heat iput check

Automatisation for results along path

or time history at nodes

Launch postprocessing file with

DynaWeld temperature scale

Performance analyse

Midpoint by 3 Points

Conversion utilities

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Check of heat input and final adjustment

right energy inputright results

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Conclusion

LS-DYNA

DynaWeld

from Process parameter to solver

keyword input

Material Models representing physics within phase kinetics

Succes in industrial applied

simulation for manufacturing

processes with high sophisticated

phiysical phenomena like

Heat Treatmentand Welding

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DynaWeld GmbH & Co. KG in GründungSchweißstruktursimulationSchweißprozessimulationWärmebehandlungsimulationWerkstoffsimulationProzesskettensimulation

www.dynaweld.de # www.dynaweld.eu

39Foto: Martin Loose