LS dyna

2. LS dyna Introduction

3. Alex Matei Student VT10 Backgorund : Mechanical engineering Master thesis: Deep drawing processes Thanks to: Karl Brian Nielsen Benny Endelt LS Dyna Introduction METCH - AALBORG UNIVERSITET

4. LS Dyna General purpose FEM software capable of simulating real world situations. High nonlinearity Material Boundary Transient dynamic FEM High speed Short duration LS Dyna Introduction METCH - AALBORG UNIVERSITET

5. Agenda I Geometry generation II FEM in Pre Post III Running LS Dyna IV Post processing V Conclusions Showcase of a deep drawing process, where the basics are going to be given and explain at a summary level. LS Dyna Introduction METCH - AALBORG UNIVERSITET

6. Unit system and file organization LS Dyna Introduction METCH - AALBORG UNIVERSITET

7. Geometry – basic sketch LS Dyna Introduction METCH - AALBORG UNIVERSITET

8. Geometry – LS Dyna Interface F11 to toggle between LS Dyna Introduction METCH - AALBORG UNIVERSITET

9. Geometry - options Design each component in individual files and then import them Easier to make individual adjustments Better debugging process Extra attention to the reference system TIP: make a small sketch on a piece of paper Generate your geometry 2D plane sketch Surface Volume Meshed geometry* *this option handles the discretization but can be used for geometry generation as well LS Dyna Introduction METCH - AALBORG UNIVERSITET

10. Geometry – sketch generation Surface geometry based on 2D sketch After generating the surface a shell property is asiged Generate 2 sketch based on coordinates Lines very simple, keep in plane Arc experiment in order to understand how the options Normal and Start Direction affect your arc, circle, ellipse etc. LS Dyna Introduction METCH - AALBORG UNIVERSITET

11. Geometry – surface generation Create the desired shape using surface operations – revolve Profile shape- click on the sketch Define the revolve axis and hit create select each line individually select it as a wire pay attention to the angle LS Dyna Introduction METCH - AALBORG UNIVERSITET

12. FEM – Preparing the model Discretization Defining material and thickness of the parts Define the process Define behavior between the components Define the behavior of the components at an individual level Verifying the final model LS Dyna Introduction METCH - AALBORG UNIVERSITET

13. FEM - Discretization Discretization should be made individually at part level Use Element and Mesh option Multiple options, chose auto mesher option Choose size methoid Mesh type, keep it mixed Compute or input size Mesh Reject Accept Done LS Dyna Introduction METCH - AALBORG UNIVERSITET

14. FEM - Insert components In a new file or the current one Click File>Import>LS Dyna Keyword file or press Ctrl +I After importing the second part you will be asked if you want to offset the ID Choose offset settings Start the part ID count from 100 000 for each part Click Set Click import Nodes ID will not overlap Easy to visualize problems Gives enough space for remeshing LS Dyna Introduction METCH - AALBORG UNIVERSITET

15. FEM – Define material and section Select Keyword manager from Model and Part Select all Scroll down and search Material Click the + button and all the list of materials will open. Search for a material type RIGID POWER LAW PLASTICITY Open each one to edit them LS Dyna Introduction METCH - AALBORG UNIVERSITET

16. FEM - Material Click accept New ID for a new material Research material properties that are needed Use software to extract material properties and import material Dynaform Select a title – sensitive name Input material properties (just by hovering you can see what is required from a section) LS Dyna Introduction METCH - AALBORG UNIVERSITET

17. FEM Material LS Dyna Introduction METCH - AALBORG UNIVERSITET

18. FEM Section In Keyword Manager select Section>Shell Give it a title ELFORM 2 is default but there are multiple options Shear Factor, SHRF default NIP default T1 thickness in node 1 If T1=1 the shell will have the thickness value of 1 Click accept and done LS Dyna Introduction METCH - AALBORG UNIVERSITET

19. FEM – Assign section and material Click on Part Data Choose assign button to activate the function Select a part Click on SECID and MID to choose section and material. Choose material and press done Click apply Verify LS Dyna Introduction METCH - AALBORG UNIVERSITET

20. FEM – Define process Punch moves and bends the blank Pressure is applied on the top die Blank is free but has pressure on the inside. The bottom die is rigid and cannot move LS Dyna Introduction METCH - AALBORG UNIVERSITET

21. FEM – Define process Appling pressure load on the blank and top die. Load curve- how it should be applied Keyword Manager>Define> Curve A1 abscissa (time input) O1 ordinate (value) After each AO pair press insert LS Dyna Introduction METCH - AALBORG UNIVERSITET

22. FEM – Define process Define the load Model and Part > Load> Shell (Shell set) Select CRE (create) Select SHELL_SET Choose loading curve Choose a scale factor Select PICK By Part Click on the part Apply For the Upper die is similar LS Dyna Introduction METCH - AALBORG UNIVERSITET

23. FEM - establish movement The movement is established in Keyword manager>Prescribed Motion Rigid Choose part Select the axis for movement DOF 3 for z VAD Select the type of movement Velocity Acceleration Displacement Select the load curve and scale factor LS Dyna Introduction METCH - AALBORG UNIVERSITET

24. FEM - Boundary conditions Model and Part>Entity creation >SPC Select CRE Set or node Degrees of freedom X,Y,Z, RX,RY,RZ Pick/Area Node/Element/Part Constrain the lower die completely Allow movement on z axis For punch and die LS Dyna Introduction METCH - AALBORG UNIVERSITET

25. FEM – Boundary conditions Constrain the blank on the edges using are pick of nodes LS Dyna Introduction METCH - AALBORG UNIVERSITET

26. FEM – Define the behavior between the parts Keyword > Contact> Automatic_One_Way_Surface_To_Surface SSTYP 3 MSTYP 3 Select slave SSID blank Select Master MSID punch Similar conditions for upper die and bottom one LS Dyna Introduction METCH - AALBORG UNIVERSITET

27. FEM – Define the behavior of the components Material behavior Thinning behavior Keyword manager>Control >shell>ISTUPD 1 material thinning Other requirements Energy options on what energy to compute Termination 0.002s Keyword>Database > Binary D3Plot DT 0.0002 ASCII> RC Force DT 0.0001 LS Dyna Introduction METCH - AALBORG UNIVERSITET

28. LS Dyna on cluster Use software MobaXterm Start a new terminal Input user and password Upload files Run LS Dyna Retrieve the results from the cluster and analyze them LS Dyna Introduction METCH - AALBORG UNIVERSITET

29. Post processing In LS DYNA open binary d3plot file. Open Post>Fringe component LS Dyna Introduction METCH - AALBORG UNIVERSITET

30. Change between interfaces Press F11 to change between the two LS PrePost interfaces Click on SelPar and select the blank. Click Fcomp and select Forming and Thickness Range select User and put range from 0.9 to 1.1 Visualize the thickness in the blank If something is wrong Use common sense LS Dyna Introduction METCH - AALBORG UNIVERSITET

31. Conclusion Pay attention to the units system Take each step carefully Double check your work in the beginning Explore different options so you can become better at it LS Dyna Introduction METCH - AALBORG UNIVERSITET