1. ISEA Summer School – Prato 3 rd June 2005 # Marco Pierini Marco Pierini – Università di Firenze – Italy marco.pierini@unifi.it FEM and Multibody Modelling of Luge Sled

2. ISEA Summer School – Prato 3 rd June 2005 # Cooperation UNIFI – FISI (Italian Federation for Winter Sports) Started in 2000Started in 2000 Aim: Make the Sled easier to driveAim: Make the Sled easier to drive FASTER

3. ISEA Summer School – Prato 3 rd June 2005 #Objective Short period (Salt Lake City Olimpic games: 2002)Short period (Salt Lake City Olimpic games: 2002) Small improvement Small improvement Longer period (Torino Olimpic Games: 2006)Longer period (Torino Olimpic Games: 2006) FEM and MB Modelling FEM and MB Modelling

4. ISEA Summer School – Prato 3 rd June 2005 # Open problems Very small know-how No publications on previous work No previous experience in Italy Translate in engineering sense the athlete sensation/feeling It has no sense to build a sled that the athlete dos not like!!!!

5. ISEA Summer School – Prato 3 rd June 2005 # International Luge Federation natural track natural track artificial track artificial track

6. ISEA Summer School – Prato 3 rd June 2005 #Descent

7. Some rules 21-25 kg for a single sled21-25 kg for a single sled ControlsControls – Temperature of the blades – Weight of the sled – Overall weight of the athlete TrackTrack –Minimum length 1000 m –Maximum length 1300 m

8. ISEA Summer School – Prato 3 rd June 2005 # More Interesting Facts Competitions may be held in extreme weather conditions with a temperature as low as – 25°C Competitions may be held in extreme weather conditions with a temperature as low as – 25°C If an athlete loses any item during a run he/she will be disqualified If an athlete loses any item during a run he/she will be disqualified The time is measured with an accuracy of 1000th of a second The time is measured with an accuracy of 1000th of a second In case of snowfall the track is swept after a certain number of athletes In case of snowfall the track is swept after a certain number of athletes The athlete has to pass the finish line in contact with his/her sled The athlete has to pass the finish line in contact with his/her sled In order to participate in a competition the athletes require a valid license (medical check-up, valid insurance) In order to participate in a competition the athletes require a valid license (medical check-up, valid insurance) The athlete must wear the FIL safety helmet The athlete must wear the FIL safety helmet

9. ISEA Summer School – Prato 3 rd June 2005 # The Sled Ruuners Seat Bridges Blades

10. ISEA Summer School – Prato 3 rd June 2005 # Seat (also called Pod Seat)

11. ISEA Summer School – Prato 3 rd June 2005 # Front bridge

12. ISEA Summer School – Prato 3 rd June 2005 # M8 Ruuners and Blades

13. ISEA Summer School – Prato 3 rd June 2005 # Driving technique

14. ISEA Summer School – Prato 3 rd June 2005 # Max Acceleration 6g Driving technique Max Speed 140 km/h

15. ISEA Summer School – Prato 3 rd June 2005 # Vertical & Transversal Stiffness Front View Vertical Stiffness Rear View Transversal Stiffness

16. ISEA Summer School – Prato 3 rd June 2005 # Short period improvement Possible variationPossible variation in the sled in the sled Keeping in mind the rules!!!! Modify the stiffness to fulfill the requirement of different tracks Screw torqueScrew torque Silent-BlockSilent-Block Steel pull Steel pull Reduction of vibration transmitted to the athlete Increase transversal stiffness

17. ISEA Summer School – Prato 3 rd June 2005 # Position of the Bridges Different tickness of the bridges Aim Change of the stiffness due to: Different Sled configuration (FEM) Force Weight

18. ISEA Summer School – Prato 3 rd June 2005 # Different Sled configuration (results)

19. ISEA Summer School – Prato 3 rd June 2005 # Different Sled configuration (results)

20. ISEA Summer School – Prato 3 rd June 2005 # Steel Pull Aim Increase transversal Stiffness

21. ISEA Summer School – Prato 3 rd June 2005 # Traction test Ultimate force 8000 N Calculate (FEM) max Force 800 N

22. ISEA Summer School – Prato 3 rd June 2005 # Steel pull

23. ISEA Summer School – Prato 3 rd June 2005 # Control of the torque M 1 =14 Nm M 2 =19 Nm M 3 =24 Nm

24. ISEA Summer School – Prato 3 rd June 2005 # Control of the torque (results) Torque M 2 Torque M 1

25. ISEA Summer School – Prato 3 rd June 2005 #Silent-block

26. Silent-block

27. Silent-block Mass Max Acceleration FEM Force acting on the Silent-block

28. ISEA Summer School – Prato 3 rd June 2005 # Silent-block (results)

29. ISEA Summer School – Prato 3 rd June 2005 # Short period improvement Reverse engineering of the SledReverse engineering of the Sled Development of the MB-FEMDevelopment of the MB-FEM Aim: development of MB-FEM model able to simulate the descent Steps

30. ISEA Summer School – Prato 3 rd June 2005 # CAD Model Reverse Engineering Phisical Model

31. ISEA Summer School – Prato 3 rd June 2005 # Reverse Engineering Instruments FARO Arm CAD Software Anthrocam

32. ISEA Summer School – Prato 3 rd June 2005 # Reverse Engineering Very important to use the same reference system

33. ISEA Summer School – Prato 3 rd June 2005 # Scanning ModeScanning Mode Reverse Engineering Point ModePoint Mode Acquisition Techniques CAD Model

34. ISEA Summer School – Prato 3 rd June 2005 # MB-FE Modeling MSC AdamsMSC Adams Simplied model Accurate model

35. ISEA Summer School – Prato 3 rd June 2005 # MB-FE Modeling Simplied model Made with rigid body element Ruuner + Blade Bridges Center of gravity of athlete

36. ISEA Summer School – Prato 3 rd June 2005 # MB-FE Modeling Interaction between solid Function Contact Simplied model Simulation of contact and friction

37. ISEA Summer School – Prato 3 rd June 2005 # MB-FE Modeling Simplied model Use of spheres for the contact

38. ISEA Summer School – Prato 3 rd June 2005 # MB-FE Modeling Simplied model F Seconda configuration - - No DOF - - No Friction - Lateral Forces First configuration - - 1 DOF - - Friction

39. ISEA Summer School – Prato 3 rd June 2005 # MB-FE Modeling Simplied model General Force: (Lateral Force)

40. ISEA Summer School – Prato 3 rd June 2005 # No lateral forces MB-FE Modeling Simplied model

41. ISEA Summer School – Prato 3 rd June 2005 # MB-FE Modeling Simplied model With lateral Forces

42. ISEA Summer School – Prato 3 rd June 2005 # MB-FE Modeling Accurate model Common characteristics Inertial properties Silent-block are also modeled All parts are geometrically correct and flexible Spheres to simulate the contact Main differerences Lateral Forces

43. ISEA Summer School – Prato 3 rd June 2005 # MB-FE Modeling Accurate model CAD Model Parasolid FEM model Flexible parts

44. ISEA Summer School – Prato 3 rd June 2005 # MB-FE Modeling Accurate model Adams model

45. ISEA Summer School – Prato 3 rd June 2005 # MB-FE Modeling Accurate model First Simulation Entrance in the labyrinth

46. ISEA Summer School – Prato 3 rd June 2005 # Second Simulation MB-FE Modeling Accurate model Turn constant radius

47. ISEA Summer School – Prato 3 rd June 2005 # Salt Lake City Olympic Games 2002 Armin Zoeggeler. IV Run

48. ISEA Summer School – Prato 3 rd June 2005 # Armin Zoeggeler Gold Medal Salt Lake City Olympic Games 2002