1. The Great Team1 Week 8 : Engineering Analysis Bunk Bed Converter Adam Brown Blaine Gardner Sarah Gleaton Jimmy Jiang Addisu Lemlem Lee Tschaepe 7/12/2006

2. The Great Team2 Locking Mechanism

3. The Great Team3 Locking Mechanism

4. The Great Team4 Pin Analysis

5. The Great Team5 Bed Positions Up Position- 0 degrees rotation Down Position- 90 degrees rotation

6. The Great Team6 Free Body Diagram Force from mattress and mattress frame Force due to weight of arm Torque to be generated by spring *Maximum Torque is required in the vertical position

7. The Great Team7 Pivot Arm Arm is 2” x 2” mild steel square tubing Each arm is 41” long Each arm weighs 10.905 lbs Torque generated @ 90 by each arm= T= F(lbs) x L/2(in) => 10.905 x 41/2= 223.45 lb-in

8. The Great Team8 Frame and Mattress Frame weighs 25 lbs Mattress weighs 50 lbs This force is distributed over 4 arms; each arm must support ¼ of this force.

9. The Great Team9 Calculations -Torque due to mattress and frame: (50/4)*41+(25/4)*41=768.755 -Torque due to weight of Pivot Arm: 10.905*(41/2)=223.45 lb-in Total Torque generated for one arm: 992.25lb-in

10. The Great Team10 Results If a torque of 850 lb-in is applied using a torsion spring, the user must lift 3.47 lbs per arm Total user required force to upper bunk assembly is 13.88 lbs

11. The Great Team11 Bed Frame Analysis

12. Secondary Moment of Inertia c = center of mass = 0.85 in

13. Frame Analysis – Long Side Bending Stress Long Side of Bed FrameMaximum Bending Stress Material: Carbon Steel 1040 CR, Yield Strength = 71kpsi

14. Frame Analysis – Short Side Bending Stress Short Side of Bed FrameMaximum Bending Stress Material: Carbon Steel 1040 CR, Yield Strength = 71kpsi

15. Frame Analysis – Bearing Stress LONG SIDESHORT SIDE Bolt: D = 1/4”, Carbon Steel 1010 CR, Yield Strength = 44 kpsi

16. Frame Analysis – Shear Stress LONG SIDESHORT SIDE Bolt: D = 1/4”, Carbon Steel 1010 CR, Yield Strength = 44 kpsi