Ceiling-mounted bicycle lift structural analysis

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P/2 = 111.2 N<br />
P/2 = 111.2 N<br />
P/4 = 55.6 N<br />
P/4 = 55.6 N<br />
 +
<br />
 +
(P = 50 lbs)<br />
|-  align="left"
|-  align="left"
| [[Image:Team1-FBD-Bracket.JPG|300px]] || '''Bending along X-axis'''<br />
| [[Image:Team1-FBD-Bracket.JPG|300px]] || '''Bending along X-axis'''<br />
Line 22: Line 24:
| [[Image:Team1-Stress-Bracket.JPG|300px]] || '''Bending along Z-axis'''<br />
| [[Image:Team1-Stress-Bracket.JPG|300px]] || '''Bending along Z-axis'''<br />
Distance between support forces: 70 mm<br />
Distance between support forces: 70 mm<br />
-
Vertical centroid: -.066 mm (measure from top surface)<br />
+
Vertical centroid: -.66 mm (measure from top surface)<br />
Second moment of area about centroidal axis: 37.8 mm<sup>4</sup><br />
Second moment of area about centroidal axis: 37.8 mm<sup>4</sup><br />
Maximum bending moment:  1,946 N*mm<sup>2</sup><br />
Maximum bending moment:  1,946 N*mm<sup>2</sup><br />
Line 53: Line 55:
P/2 = 111.2 N<br />
P/2 = 111.2 N<br />
P/4 = 55.6 N<br />
P/4 = 55.6 N<br />
 +
<br />
 +
(P = 50 lbs)<br />
|-  align="left"
|-  align="left"
| [[Image:Team1-FBD-UPulley.JPG|300px]] || '''Bending along X-axis'''<br />
| [[Image:Team1-FBD-UPulley.JPG|300px]] || '''Bending along X-axis'''<br />
-
Distance between support forces: 200 mm<br />
+
Distance between support forces: 20 mm<br />
-
Vertical centroid: -7.57 mm (measure from top surface)<br />
+
Vertical centroid: -.66 mm (measure from top surface)<br />
-
Second moment of area about centroidal axis: 3510 mm<sup>4</sup><br />
+
Second moment of area about centroidal axis: 3.03 mm<sup>4</sup><br />
-
Maximum bending moment:  5,560 N*mm<sup>2</sup><br />
+
Maximum bending moment:  556 N*mm<sup>2</sup><br />
<br />
<br />
-
Maximum x-bending stress: 9.47 N/mm<sup>2</sup> = 9.47 Mpa<br />
+
Maximum x-bending stress: 12.1 N/mm<sup>2</sup> = 12.1 Mpa<br />
|-  align="left"
|-  align="left"
-
| [[Image:Team1-Stress-UPulley.JPG|300px]] || '''Bending along Z-axis'''<br />
+
| [[Image:Team1-Stress-UPulley.JPG|300px]] || '''Stress Concentration Factor'''<br />
-
Distance between support forces: 70 mm<br />
+
-
Vertical centroid: -.066 mm (measure from top surface)<br />
+
-
Second moment of area about centroidal axis: 37.8 mm<sup>4</sup><br />
+
-
Maximum bending moment:  1,946 N*mm<sup>2</sup><br />
+
-
<br />
+
-
Maximum z-bending stress: 3.4 N/mm<sup>2</sup> = 3.4 Mpa<br />
+
-
<br />
+
-
'''Maximum net bending stress: 10.1 Mpa'''<br />
+
-
|}
+
-
'''Stress Concentration Factor'''<br />
+
h = 1.22 mm (sheet thickness)<br />
h = 1.22 mm (sheet thickness)<br />
-
w = 50 mm (section width)<br />
+
w = 48 mm (section width)<br />
d = 6 mm (hole size)<br />
d = 6 mm (hole size)<br />
<br />
<br />
-
d/w = .12     d/h = 5<br />
+
d/w = .13     d/h = 5<br />
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 />
-
'''<big>Actual Maximum Stress = 17.1 Mpa<br /></big>'''
+
'''<big>Actual Maximum Stress = 20.6 Mpa<br /></big>'''
 +
|}

Revision as of 00:47, 8 March 2007

Part # 001: Ceiling Bracket

Images Calculations
Material: Carbon steel

E = 202,700 N/mm2
Yield strength = 350 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


Part # 002: U-Pulley Mount

Images Calculations
Material: Carbon steel

E = 202,700 N/mm2
Yield strength = 350 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

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