Ceiling-mounted bicycle lift structural analysis

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{| class="wikitable" border="0"  
{| class="wikitable" border="0"  
|- align="left"
|- align="left"
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! Images !! Calculations !!  
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! ''Images'' !! ''Calculations'' !!  
|-  align="left"
|-  align="left"
| [[Image:Team1-Bracket.jpg|300px]] || '''Material''': Carbon steel<br />
| [[Image:Team1-Bracket.jpg|300px]] || '''Material''': Carbon steel<br />
E = 202,700 N/mm<sup>2</sup><br />
E = 202,700 N/mm<sup>2</sup><br />
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Yield strength = 350 Mpa<br />
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Yield strength = 220 Mpa<br />
<br />
<br />
'''Loads'''<br />
'''Loads'''<br />
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K = 1.7  -  From table A-15-12 of (Shigley, Mechanical Engineering Design)<br />
K = 1.7  -  From table A-15-12 of (Shigley, Mechanical Engineering Design)<br />
<br />
<br />
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'''<big>Actual Maximum Stress = 17.1 Mpa<br /></big>'''<br />
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'''<big>Actual Maximum Stress = 17.1 Mpa<br /></big>'''
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'''<big>Safety Factor = 12.9 Mpa<br /></big>'''
<br />
<br />
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{| class="wikitable" border="0"  
{| class="wikitable" border="0"  
|- align="left"
|- align="left"
-
! Images !! Calculations !!  
+
! ''Images'' !! ''Calculations'' !!  
|-  align="left"
|-  align="left"
| [[Image:Team1-UPulley.jpg|300px]] || '''Material''': Carbon steel<br />
| [[Image:Team1-UPulley.jpg|300px]] || '''Material''': Carbon steel<br />
E = 202,700 N/mm<sup>2</sup><br />
E = 202,700 N/mm<sup>2</sup><br />
-
Yield strength = 350 Mpa<br />
+
Yield strength = 220 Mpa<br />
<br />
<br />
'''Loads'''<br />
'''Loads'''<br />
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<br />
<br />
'''<big>Actual Maximum Stress = 20.6 Mpa<br /></big>'''
'''<big>Actual Maximum Stress = 20.6 Mpa<br /></big>'''
 +
'''<big>Safety Factor = 10.7 Mpa<br /></big>'''
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|}
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 +
 +
==Part # 003: Pulley Wheel==
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{| class="wikitable" border="0"
 +
|- align="left"
 +
! ''Images'' !! ''Calculations'' !!
 +
|-  align="left"
 +
| [[Image:Team1-Pulley.jpg|300px]] || '''Material''': Injection molded plastic<br />
 +
E = 3,500 N/mm<sup>2</sup><br />
 +
v = .4
 +
Yield strength = 103 Mpa<br />
 +
<br />
 +
'''Loads'''<br />
 +
P/2 = 111.2 N<br />
 +
P/4 = 55.6 N<br />
 +
<br />
 +
(P = 50 lbs)<br />
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|-  align="left"
 +
| [[Image:Team1-FBD-Pulley.JPG|300px]] || '''Contact Stress'''<br />
 +
Diameter 1: 5.3 mm<br />
 +
Diameter 2: 4.9 mm<br />
 +
Contact length = 13.5mm<br />
 +
Half-width of contact surface = 2 mm<br />
 +
 +
<big>'''Maximum Compressive Stress = 4.2 Mpa<br />'''</big>
 +
<big>'''Safety Factor = 24.5<br />'''</big>
|}
|}

Revision as of 01:54, 8 March 2007

Part # 001: Ceiling Bracket

Images Calculations
Material: Carbon steel

E = 202,700 N/mm2
Yield strength = 220 Mpa

Loads
P/2 = 111.2 N
P/4 = 55.6 N

(P = 50 lbs)

Bending along X-axis

Distance between support forces: 200 mm
Vertical centroid: -7.57 mm (measure from top surface)
Second moment of area about centroidal axis: 3510 mm4
Maximum bending moment: 5,560 N*mm2

Maximum x-bending stress: 9.47 N/mm2 = 9.47 Mpa

Bending along Z-axis

Distance between support forces: 70 mm
Vertical centroid: -.66 mm (measure from top surface)
Second moment of area about centroidal axis: 37.8 mm4
Maximum bending moment: 1,946 N*mm2

Maximum z-bending stress: 3.4 N/mm2 = 3.4 Mpa

Maximum net bending stress: 10.1 Mpa

Stress Concentration Factor
h = 1.22 mm (sheet thickness)
w = 50 mm (section width)
d = 6 mm (hole size)

d/w = .12 d/h = 5
K = 1.7 - From table A-15-12 of (Shigley, Mechanical Engineering Design)

Actual Maximum Stress = 17.1 Mpa
 Safety Factor = 12.9 Mpa

Part # 002: U-Pulley Mount

Images Calculations
Material: Carbon steel

E = 202,700 N/mm2
Yield strength = 220 Mpa

Loads
P/2 = 111.2 N
P/4 = 55.6 N

(P = 50 lbs)

Bending along X-axis

Distance between support forces: 20 mm
Vertical centroid: -.66 mm (measure from top surface)
Second moment of area about centroidal axis: 3.03 mm4
Maximum bending moment: 556 N*mm2

Maximum x-bending stress: 12.1 N/mm2 = 12.1 Mpa

Stress Concentration Factor

h = 1.22 mm (sheet thickness)
w = 48 mm (section width)
d = 6 mm (hole size)

d/w = .13 d/h = 5
K = 1.7 - From table A-15-12 of (Shigley, Mechanical Engineering Design)

Actual Maximum Stress = 20.6 Mpa
 Safety Factor = 10.7 Mpa


Part # 003: Pulley Wheel

Images Calculations
Material: Injection molded plastic

E = 3,500 N/mm2
v = .4 Yield strength = 103 Mpa

Loads
P/2 = 111.2 N
P/4 = 55.6 N

(P = 50 lbs)

Contact Stress

Diameter 1: 5.3 mm
Diameter 2: 4.9 mm
Contact length = 13.5mm
Half-width of contact surface = 2 mm

Maximum Compressive Stress = 4.2 Mpa
 Safety Factor = 24.5

Retrieved from "http://wiki.ece.cmu.edu/ddl/index.php/Ceiling-mounted_bicycle_lift_structural_analysis"
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