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 the percentage decrease in Area?
Detailed Solution:
Percentage decrease in Area = ((Original Area - Area at failure)/(original Area)) x 100 = ((0.785 x 30 x 30 - 0.785 x 22.5 x 22.5)/(0.785 x 30 x 30)) x 100 = 43.75%