KC-135: Particle Damping

1. KC-135: Particle Damping Bill Tandy Tim Allison Rob Ross John Hatlelid

2. Introduction • Team Overview • Project Description • Theory • Design • Budget • Schedule

3. The Team-Bill Tandy • Internship Experiences Lead to the Concept • Became the ‘de Facto’ Leader • Overall Responsibility for the Project • Point Man for NASA • Attends Department Meetings & Events

4. The Team-Tim Allison • Hard Working and Diligent • Responsible for Funding • Arranged Hotel and Travel • Theoretical Background

5. The Team-Rob Ross • Aptitude for Design and Construction • Given Responsibility for Construction • Cabinet Design and Construction • Experiment Materials and Setup • Volunteered to Write Weekly Memos

6. The Team-John Hatlelid • Dedicated and Thorough • Determined Components of the Experiment • Responsibility for Applying for Donations • Worked with Rob on Construction

7. KC-135 Program • Annual opportunity for undergraduate student research • KC-135 Aircraft flies parabolic trajectory to create microgravity environment • Microgravity environment available for 20-30 seconds

8. Goals for this Semester • Understand the underlying concepts of vibrating cantilever beams • Devise an experiment to test the impact of particle damping • Gather data on the ground • Gather data in flight • Compare the two sets of data

9. Project Background • Ball Aerospace Needed Unique Solutions to Damping Vibrations in Space Structures • Particle Damping was Investigated, but Discarded Due to Lack of Data • NASA’s Student Flight Program Provided the Perfect Platform for Data Acquisition

10. Experiment Basics • Vibrating Cantilever Beam Filled with Particles of Different Material Properties

11. Particle Variations • Twelve Pre-Filled Beams • Three Materials of Different Density • Each Material Will Have Two Sizes • Each Size Will Fill the Beam 50% & 75%

12. Data Reduction • Accelerometer will acquire acceleration at the tip of beam • Peak acceleration amplitude will be plotted vs. time • We will compare the duration & amplitude of transient, steady-state, and decay period vibrations for each sample

13. Theory Overview • Viscoelastic Damping • Frictional Damping • Beam Response • Problems

14. Theory – Viscoelastic Damping • Particles collide with other particles and with the cavity wall • Energy only conserved for perfectly elastic collisions, where particles are undeformed • Particles may be represented with Maxwell model: • Dashpot in Maxwell model represents viscoelastic damping within material Source: University of Texas

15. Theory – Frictional Damping • Friction forces act on particles as they scrape against each other and cavity walls, converting kinetic energy to thermal energy: • Particle-Particle: • Particle-Cavity: • Particle-Cavity Equations are only useful in a gravitational field Source: Olson & Drake, University of Dayton

16. Theory – Beam Response • System is a cantilever beam with sinusoidal base excitation: • Differential EOM is: • Solution is an infinite sum: y(t)=Y0sin(t) u(x,t) Algebraic Eigensolutions Solutions to Modal ODEs

17. Theory - Problems • Theoretical solution possible for hollow rod, but with added particles the problem becomes extremely complex • A theoretical prediction of the beam’s motion will not be attempted • The effect of particles will be analyzed experimentally on the KC-135

18. Test Bay Design • Some factors influencing the design • Requirements • Size • Procedures • Materials

19. Test Bay Design • Some factors influencing the design • Requirements • Size • Procedures • Materials

20. Test Bay Design • Some factors influencing the design • Requirements • Size • Procedures • Materials

21. Test Bay Design • Some factors influencing the design • Requirements • Size • Procedures • Materials

22. Test Bay Design • Some factors influencing the design • Requirements • Size • Procedures • Materials

23. Test Bay Design • Some factors influencing the design • Requirements • Size • Procedures • Materials

24. Test Bay Design: Requirements • Structurally sound (withstand 9 G’s) • Secure to Aircraft • Test equipment security • Test equipment containment • Weight per spacer • Non-hazardous

25. Test Bay Design: Requirements • Structurally sound (withstand 9 G’s) • Secure to Aircraft • Test equipment security • Test equipment containment • Weight per spacer • Non-hazardous

26. Test Bay Design: Requirements • Structurally sound (withstand 9 G’s) • Secure to Aircraft • Test equipment security • Test equipment containment • Weight per spacer • Non-hazardous

27. Test Bay Design: Requirements • Structurally sound (withstand 9 G’s) • Secure to Aircraft • Test equipment security • Test equipment containment • Weight per spacer • Non-hazardous

28. Test Bay Design: Requirements • Structurally sound (withstand 9 G’s) • Secure to Aircraft • Test equipment security • Test equipment containment • Weight per spacer • Non-hazardous

29. Test Bay Design: Requirements • Structurally sound (withstand 9 G’s) • Secure to Aircraft • Test equipment security • Test equipment containment • Weight per spacer • Non-hazardous

30. Test Bay Design: Requirements • Structurally sound (withstand 9 G’s) • Secure to Aircraft • Test equipment security • Test equipment containment • Weight per spacer • Non-hazardous

31. Test Bay Design: Size • Layout • Spacing • Weight • Timing

32. Test Bay Design: Size • Layout • Spacing • Weight • Timing

33. Test Bay Design: Size • Layout • Spacing • Weight • Timing

34. Test Bay Design: Size • Layout • Spacing • Weight • Timing

35. Test Bay Design: Size • Layout • Spacing • Weight • Timing

36. Test Bay Design: Size / Layout • KC-135 cross-section • KC-135 floor spacers

37. Test Bay Design: Size / Layout • KC-135 cross-section • KC-135 floor spacers

38. Test Bay Design: Size / Layout • KC-135 cross-section • KC-135 floorspacers

39. Test Bay Design: Size / Spacing • Ample room for test operation • Specimens laid end to end • Function generator, Line conditioner, Surge protector • Computer, Work space

40. Test Bay Design: Size / Spacing • Ample room for test operation • Specimens laid end to end • Function generator, Line conditioner, Surge protector • Computer, Work space

41. Test Bay Design: Size / Spacing • Ample room for test operation • Specimens laid end to end • Function generator, Line conditioner, Surge protector • Computer, Work space

42. Test Bay Design: Size / Spacing • Ample room for test operation • Specimens laid end to end • Function generator, Line conditioner, Surge protector • Computer, Work space

43. Test Bay Design: Size / Spacing • Ample room for test operation • Specimens laid end to end • Function generator, Line conditioner, Surge protector • Computer, Work space

44. Test Bay Design: Size / Weight • 200 lbs per spacer used • 6 spacers required • 300 lbs max weight • Our weight approximately 280 lbs

45. Test Bay Design: Size / Weight • 200 lbs per spacer used • 6 spacers required • 300 lbs max weight • Our weight approximately 280 lbs

46. Test Bay Design: Size / Weight • 200 lbs per spacer used • 6 spacers required • 300 lbs max weight • Our weight approximately 280 lbs

47. Test Bay Design: Size / Weight • 200 lbs per spacer used • 6 spacers required • 300 lbs max weight • Our weight approximately 280 lbs

48. Test Bay Design: Size / Weight • 200 lbs per spacer used • 6 spacers required • 300 lbs max weight • Our weight approximately 280 lbs

49. Test Bay Design: Size / Timing • 30 second zero G maneuver • 40 seconds for test specimen swap and test setup • Requires that test areas be uncluttered

50. Test Bay Design: Size / Timing • 30 second zero G maneuver • 40 seconds for test specimen swap and test setup • Requires that test areas be uncluttered