A tensile test is conducted on a mild steel bar. The following data was obtained from the test : diameter of the steel bar= 3cm, Gauge Length of the bar = 20cm, Load at Elastic limit= 250kN, Extension at a load of 150kN= 0.21 mm, Maximum Load = 380kN, Total Extension= 60mm, Diameter of the rod at failure=2.25cm, determine young's modulus?
Detailed Solution:
from the data given Area of bar = 0.785 x 30 x 30 =706.5 sq(mm), now,, within elastic limit load is 150kN, stress = 150000/706.5= 212.314N/sq(mm) strain = 0.21/200 = 0.00105 young modulus = stress/strain = 212.314/0.00105 = 2.02 x 10^5 N/sq(mm) =2.02x 10^11 N/sq(m) = 202 x 10^9 N/sq(m) = 202GN/Sq(m)