PS: Answer only four questions!
1. (a) Define stress and strain obtained from tension test.
(b) Using the stress ($\sigma$)- strain ($\varepsilon$) curves of a steel seen in Figure 1 below, determine the
following:
(i) Yield strength.
(ii) Tensile strength.
(iii) Fracture elongation.
(iv) Young's modulus (Modulus of elasticity)
(c) Would a 10 mm diameter tie-rod machined from this steel support a load of 7 tons (70
kN) without fracture? Calculate it.
600
500
400
500
Stress
400
(MPa)
300
Stress
300
(MPa) 200
200
100
100
0
0,000
0,002 0,004 0.006
Strain
0
0,00
0,04
0,08
0,12
0,16
0,20
Strain
Figure 1: Stress - strain curves of a steel.