MECN2010/A
Class Test
19 April 2021
Question 1:
Total: 19 Marks
The following load displacement data was recorded for a tensile test conducted on a dumbell tensile
sample with a test length of 50 mm and a 12.63 mm diameter. On failure, the final length of the
specimen was measured to be 54.935 mm.
Point
Load (N)
Length
(mm)
Displacement (mm)
Strain
Stress
(MPa)
0
0
50
0
0
0
50.025
0.025000
0.000500
35.519
0.075000
0.001500
106.558
1
2
13350
3
22240
50.125
0.125000
0.002500
177.516
4
31150
50.255
0.255000
0.005100
248.635
5
33360
50.75
0.750000
6
35140
52
2.000000
7
35580
53
8
33800
55.125
5.125
0.102500
Failure
Failure
Failure
Failure
266.274
0.040000
280.482
0.060000
283.994
Failure
Question 1A
Calculate the values of the missing data points in the table above (highlighted yellow). Label each piece
of missing data clearly i.e. Point 2 Length = x mm.
(5 Marks)
Question 1B
Calculate the elastic modulus of the material. Show all working.
(4 Marks)
Question 1C
How much elastic strain is recovered at failure? Show all working
(4 Marks)
Question 1D
Calculate the 0.2% offset yield value of this specimen? Show all working
(4 Marks)
Question 1E
Would you say that this material behaves in a ductile or brittle manner? Motivate your answer.
(2 Marks)