Equipment: WP500 Torsion Tester
Title: Torsion Testing of Cast Iron
Location: GF-051, MATERIALS LAB
Torsion Testing of Cast Iron
ENGINEERING MATERIALS LAB-III
A. Theory
In solid mechanics, torsion refers to the twisting action caused by a pair of externally applied equal and
oppositely directed force couples acting on parallel planes or by a single external couple applied to a
member that has one end fixed against rotation. It is expressed in newton meters (N.m) or foot-pound
force (ft.lbf). In sections perpendicular to the torque axis, the resultant shear stress in this section is
perpendicular to the radius.
B. Equipment
The Torsion Tester, 30Nm WP 500 is used for torsion testing of metal test bars loaded to destruction. The
test moment and torsion angle are measured.
C. Assumptions
1. The apparatus is error free in measurement of the force value.
D. Procedure
For Information
Specimen Head: 17 mm Hexagon Head
Permissible Specimen Length: 750 mm (Max)
Specimen Drawing for Experiment
General Procedure
1. Insert sockets into square connections.
2. Release clamping lever on torque measurement unit and push it backwards.
3. Place the specimen in the sockets and slide the torque measurement unit forwards again. Make sure
the moving device is located in the center of its range of movement.
4. Fix the torque measurement unit in place with the clamping levers.
5. Carefully pre-tension the specimen until there is no more slack and the torque display begins to move.
6. Set the torque to display to zero using the tare function.
7. Set the pointers on the two angle scales to zero.
8. Set the dial gauge on the compensation device to zero by rotating the scale ring.
9. Reset the revolution counter.
10. Begin the experiment and complete the table as under.
Equipment: WP500 Torsion Tester
Title: Torsion Testing of Cast Iron
Location: GF-051, MATERIALS LAB
D. Observations
S.
No
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
Input
Angle
Turns
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
125
130
135
140
145
150
155
160
165
Torque, T
(Nm)
Angle of twist
ɸ (°)
Shearing
Angle, ɼ (rad)
Shear
Stress, Ʈ
(N/𝒎𝒎𝟐)
Equipment: WP500 Torsion Tester
Title: Torsion Testing of Cast Iron
Location: GF-051, MATERIALS LAB
E. Lab Discussion
1. Using the values, make the following graphs:
a. Torque (Nm) against Specimen Torsion Angle (°)
b. Shear Stress (N/𝑚𝑚2) against Shearing Angle (rad)
c. Calculate the value of Modulus of Rigidity using the graph in part (b).
2. Discuss the breaking behavior being exhibited by the specimen.
Please Note: Grace Marks would be awarded for cleanliness, finesse of handling lab equipment and
presentation of work.