P14042: Una -Crutch

1. P14042: Una-Crutch Right Move, Right Place, Right Time Systems Design Review Day 2 Ana Allen Joanna Dzionara-Norsen Beverly Liriano Dan Sawicki

2. Agenda

3. Concept and Architecture development

4. Concepts

5. Initial Concepts Rev 1Pugh Chart

6. Initial Concepts Rev 1 Pugh Chart (Continued) Continued

7. Initial Concepts Rev 2Pugh Chart

8. Initial Concepts Rev 2 Pugh Chart (Continued) Continued

9. New Concepts Rev 3Pugh Chart

10. Connective Mechanism Terms

11. Concept NA • Pros: • Springs relax user tension • Large surface area on single crutch • Hinge is simple to use • Cons: • Expensive • Many components • Too many steps to assemble Pin Hinge

12. Concept NB • Pros: • Easy connection • Aesthetically pleasing • Innovative design • Minimal components • Spring base • Cons: • Bulky • Potentially expensive • Magnetic Connection Male/female mold Male/female mold and/or pin Magnetic

13. Concept NC Male/female mold • Pros: • Adjustable handle • Spring base • Male/female mold is an easy connection • Innovative design • Cons: • Stability • Thickness Male/female mold Clamp

14. Concept ND • Pros: • Lightweight • Revolutionary handle design • Cons: • Base connection is inconvenient if user is on one leg • Similar to axilla crutch Guide track Male/female mold Snap

15. Concept NE Male/female mold • Pros: • Foldable into a cane • Lightweight • Stable • Cons: • Two separate bases • Not aesthetically pleasing • Pad is in contact with the ground Pin

16. Concept NF • Pros: • Largest surface area for connection • No axillary component • Spring base • Minimal components • Cons: • Not aesthetically pleasing • Stability compromised Male/female mold for elbows

17. New Concepts Rev 4Pugh Chart

18. System Architecture

19. Engineering analysis

20. Engineering Analysis Overview

21. Loads: Statics Analysis of Axilla Crutch

22. High μs value to low μs value Ice will result in slip the quickest! Concrete is least likely to slip!

23. Cantilevered Beam Analysis • Crutch handle modeled as a cantilevered beam with a distributed load and external moment: • Cross-sections considered: circular, square, hollow circular, I-beam, T-beam • Maximum stress from bending: = 25 MPa = 27.6 MPa L = 0.39in OD = 0.47 in = 12 mm Smallest dimensions at which the maximum stress from bending does not exceed the yield strength of aluminum L = 0.39in = 10 mm

24. Static Analysis ASSUMPTIONS: P ΣFy=ma=0 Σfy=-P+Nf=0 P=Nf Nf

25. Static Analysis ASSUMPTIONS: ΣFy=ma=0 ΣFy=Nf-Cy=0 Nf=Cy=P Dx Cx Cy Dy Nf

26. Static Analysis P BX BX By By ΣFy=ma=0 ΣFy=2By-P=0 By=P/2

27. Statics Analysis Ax Ax

28. Static Analysis ASSUMPTIONS: Ax Bx By unknown: 3 unknowns Ax,BX,Cx Equations: 3 equations ΣFy=ma=0 ΣFx=ma=0 ΣM=0 Dy Cx Cy Dx

29. Prototype Test Plan

30. Risk Assessment

31. Action Items for Subsystem Design Phase

32. THANK YOU AND WE ARE NOW OPEN FOR QUESTIONS!

33. Backup slide

34. Detailed Project Plan (Week 7)

35. Detailed Project Plan (Week 8-9)

36. Bill of Materials

37. Final Product Test Plan

38. Questions?