DYNAmore GmbH. Efficient Setup and Documentation. of Simulations for Welding and Heat Treatment with DynaWeld

Transcription

1 Foto: ISF Efficient Setup and Documentation Tobias Loose of Simulations for Welding and Heat Treatment with DynaWeld LS-Dyna Forum Bamberg till Ingenieurbüro Tobias Loose, Herdweg 13, D Wössingen, 1

2 Type of heat treatment Quenching Case Hardening Inductive hardening Press hardening Heat treatment overview Single process steps Heating Thermal Heating Inductive Heating Carburisation Quenching Tempering Design of properties by local change of material properties and microstructure 2

3 Type of Welding Weld Process Type - Arc Welding - GMAW, SAW, TIG - Laser - Electron Beam - GMAW-Laser-Hybrid - Resistive Welding, RSW single or multi layered welds, tack welds Dimension 10 µm mm Welding overview welding structure analysis Single process steps Clamping Predeformations Heating Cooling Reheating Tempering Grinding and Rewelding Distortion - Residual Stress - Material Properties after Welding 3

4 Trajectories Heat Source Clamps and Boundarys Heating Carburization Quenching Media Substructuring of models for welding and heat treatment Geometry Meshing or import mesh from prior steps Material Data, and parameter calibration Process FEM additional settings: load, contact, cinematics... S I M U L A T I O N M O DE L 4

5 Complex simulation task with many disciplines Benefit of sub structuring easy to mange by task sharing outsourcing single tasks Material specialist Mesh specialist FEM specialist Welding specialist Heat Treatment specialist 5

6 R E A L I T Y Definition of simulation steps S I M U L A F Mesher T I I L Post- O Solver E Processsor Pre- N Processsor O M UT O DE P DynaWeld LS-DYNA U LS-Pre-Post L T DynaWeld repesents a simulation environment with special preprocessors P O ST R ES U LT 6

7 DynaWeld environment and preprocessor 7

8 Customer defined Environment: Mesher PreProcessor PostProcessor Auxilary Software Linux and Windows Excel and Libre Calc Plug In for existing Software environment as well as stand alone DynaWeld environment and preprocessor DynaWeld is not an Island-Solution! Process Chain Interface Material Simulation Welding Process Simulation User defined Keyword no limitation in modeling Heat Treatment and Welding related auxilary Tools Supports LS-DYNA FE-Code one Code - many Solvers - one License Fee 8

9 Foto: Edyta Łopatecka Material 9

10 Quelle: Bernd Hochholdinger, DYNAmore Swiss Phase transformation during cooling CCT-diagram 10

11 Law: Koinstinen-Marburger Parameter: T start : Start Temperature MS a: kinetic faktor KM Phase kinetic models Use: f(temperature) diffusionless transformation Austenit Martensit 11

12 Law: generalized JMAK Jonhson-Mehl-Avrami-Kolmogorov Parameter: x eq : Proprotion at equilibrium (T) PEQ n: form parameter (T) N t: kinetic faktor (T) TAU f,f': Leblond factor (dt/dt) F, F' Advantage: no limitation on material type nor chemical composition. Fitting according: temperatur(t) and temperature rate(dt/dt) Phase kinetic models, based on Avrami equitation extended by Leblond Use: f(temperature, temperture gradient, time) diffusion-driven transformation Austinitisation, Tempering Austenite Ferite, Perlite, Bainite phase transformation Aluminium Disadvantage: needs calibration on existing CCT or TT 12

13 Materials with phase kinetic models in LS-DYNA *MAT_254 / *MAT_GENERALIZED_PHASE_CHANGE Heat treatment Welding Laws: Koinstinen Marburger Oddy Kirkaldy generalized JMAK Time criterium list might be extended userdefined assignment of laws all materials Simulation of PROCESS-CHAIN feasible Features: 24 Phases Shells, Solids, 2D-shells Welding features Phase transformation strain Transformation induced plasticity (TRIP) Subcycling for phase transformation Tempering Hardeness computation 13

14 Selected features: DTEMP Phase transformation calculation temperature requires limit on tempearature step Phase transformation shall not reduce time step of mechanical solver DTEMP = maximum allowed temperature step drives subcycle for phase transformation: 14

15 *MAT_254 calibration of phase transformation law given CCT Data LS-DYNA calculation 15

16 Selected features: phase transformation strain If Phase A and B have different density in case of phase transformation additional strain arises due to volume change: Phase Transformation Strain. 16

17 Simplified approach for single phase model *MAT_270 Cooling Heating 17

18 Validation Nitschke-Pagel test Distortion w: Experiment: 0,34 mm Sysweld: 0,32 mm LS-DYNA: 0,34 mm Loose, T.: Einfluß des transienten Schweißvorganges auf Verzug, Eigenspannungen und Stabiltiätsverhalten axial gedrückter Kreiszylinderschalen aus Stahl, Diss, Karlsruhe,

19 Material DynaWeld Management for high sofisticated welding and heat treatment materials LS-DYNA Material keyword-file multi phase *MAT_254 DynaWeld Material Import and extensions: Base material phase Liquid material phase Tempering phase Flowcurve adjustment Welding settings LS-DYNA Material keyword-file singel phase *MAT_270 User defined JMatPro WeldWare other material simulation software 19

20 Interfaces DynaWeld Material - Import single phase Settings and Extensions multi phase 20

21 DynaWeld Material Documentation spreadsheet DynaWeld-Material-Check Graph for each material parameter 21

22 Foto: Edyta Łopatecka DynaWeld Heat Treatment 22

23 Model Setup LS-DYNA Mesh keyword-file LS-DYNA Material keyword-file Dokumentation in spreadsheed format DynaWeld Management for high sofisticated heat treatment simulation setup DynaWeld Heat Treatment HT-Process HT-Parameter HT-Solver Settings LS-DYNA Keyword-files Oven curve Carburization Quenching media Diving LS-DYNA solver run 23

24 DynaWeld Heat Treatment - Process 24

25 DynaWeld Heat Treatment - Parameter 25

26 Foto: Edyta Łopatecka DynaWeld Welding 26

27 Laser welded sheet with tensile test 27

28 Model Setup LS-DYNA Mesh keyword-file LS-DYNA Material keyword-file Dokumentation in spreadsheed format DynaWeld Management for high sofisticated welding simulation setup DynaWeld Welding Process Timestep adjustment Boundary and Clamps Parts, Material assignment Contact Solver Settings LS-DYNA Keyword-files Trajectory Heat Source Clamp Kinetic LS-DYNA solver run 28

29 Types of heat source surface heat source volumetric heat source part heating Geometric shapes elipsoid double elipsoid cylinder conus double conus Heat input on shell, shell 2D solid segment DynaWeld Process Start, end, intermediate time Multi robots simultaneous Multiple heat source auto fill or copy option Reverse option Reorder of sequence Multi layered welds auto deactivation of not yet deposit material SimWeld interface supports the new LS-DYNA heat source - on shells and solids - shell thickness distribution - engergy input control - sub cycling - mesh independent - time step independent 29

30 Definition with one Nodeset auto detection of reference normal on surface *BOUNDARY_THERMAL_WELD_TRAJECTORY x Local adjustment: - rotation - v-offset reference direction - w-offset lateral automatic calculation of the length of trajectory Display of trajectory, reference, startpoint z Global coordinate system y Weldpath definition - trajectory and reference Reference NodeSet Rotation of reference v-offset Trajektory NodeSet v w-offset u Local coordinate system heat source w u: Trajektory direction v: Torch direction w: Lateral direction 30

31 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 DynaWeld Boundary Force or displacement driven clamps force disp Clamping Clamped force driven or displacement driven time Unclamping 31

32 DynaWeld Contact Welding contact change friction tied by temperature Friction contact Tied contact Shell edge to surface or solid friction or tied contact Node to surface auto-correct of large penetration mechanical only Special features smooth option for curved sheets mortar option for implicit analysis shell thickness considered automatically mechanical and thermal mechanical 32

33 Analysis Options Run and Kill Generate Input one file structured input single task creation DynaWeld-Welding Input file generator Clean Work Directory Check options 33

34 Create Variants Heat iput check Automatisation for results along path or time history at nodes Performance analyse Midpoint by 3 Points Conversion utilities Launch postprocessing file with DynaWeld temperature scale DynaWeld Tools 34

35 Check of heat input and final adjustment right energy input right results 35

36 LS-DYNA Material Models representing physics within phase kinetics from Process parameter to solver keyword input DynaWeld Conclusion Succes in industrial applied simulation for manufacturing processes with high sophisticated phiysical phenomena like Heat Treatment and Welding 36

37 Foto: Martin Loose 37