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TORSION LAB REPORT Essay Example
 Category:Engineering and Construction
 Document type:Assignment
 Level:Undergraduate
 Page:1
 Words:394
Lab report 4
Figure 1: Graph of torsion against angular deflection.
Discussion
The graph of torsion against angular deflection is a linear graph starting from the origin. This shows that there is a linear relationship between torsion and angular deflection. According to the graph, as torsion is increased, the angle of deflection also increases.
Situations where torsional deflection would be undesirable.

Engine crank shafts.

In shafts connecting pump and motor.

Excessive torsional deflection in beams.
Force (N) 
Torque (T) (N.m) 
Angular deflection at 3 mm 
Angular deflection at 4 mm 
J at D = 3mm 
J at D = 4mm 
0 
7.95319E12 
2.5136E11 

Table 1: Table of calculated angular deflections at diameters of 3mm and 4mm.
As shown in the results above, the angular deflections at 3mm diameter is greater than the angular deflection at 4mm diameter. The reduction in angular deflection with an increase in diameter is as a result of stiffness. Stiffness in the rod increases with an increase in thickness or diameter of the rod.
Table 2: Comparison of Torsion against angular deflection graphs for steel and brass.
The graph of Torsion against angular deflection for both brass and steel are as shown above. Brass experiences more angular deflection as compared to steel when subjected to equivalent torsion.
Diameter of the steel rod (d) 

Polar moment of Inertia (J) 
1.02957E11 

Length (L) 

Torque (Nm) 
Angular deflection (Rads) 
TL (N.m^2) 
JƟ*10^13) 
0 
0 
0 

0.000532777 
5.48531E14 

0.001065553 
1.09706E13 

0.00159833 
1.64559E13 

0.002131107 
2.19412E13 

0.002663884 
2.74266E13 
Table 3: Summary of the calculated parameters from the experiment results.
From the data, the graph of TL against I_{p}Ɵ was plotted.
Figure 2: The graph below shows the relationship between TL and JƟ.
Form the graph, it is evident that there is a linear relationship between TL and JƟ. This is evidenced by the straight linear line starting from the origin.
Gradient of the graph
From the gradient formula, =
, the graph is TL against JƟ thus, meaning that the gradient of the graph represents inverse of the value of modulus of rigidity of the material (G). The value of modulus of rigidity obtained from the inverse of the gradient of the graph is slightly lower than the actual value. This difference can be attributed to errors.
References
Bores, A. P., & Schmidt, R. J. (2003). Advanced mechanics of materials. John Wiley & Sons, Inc., New York.