Learning unit 3: Exercise 2
Question 1
During tensile testing of a steel alloy, the strain hardening exponent and true yield strength
were found to be 0.2 and 450 MPa respectively. Calculate the UTS of the steel alloy
Question 2:
A 5cm long circular rod of the AISI 1020 hot rolled steel with a diameter of 1.25 cm is subjected
to tensile loading till fracture. The tensile test results after testing are shown in the table below:
Mechanical property
Measured values
Yield strength
315 MPa
Ultimate tensile strength (UTS)
420 MPa
Elongation at fracture
39%
% Reduction in area
51%
Suppose you have observed that 45% of the total elongation was uniform in nature prior the
point of instability, Determine the power law expression of the steel.
Question 3
A particular alloy that was subjected to tensile testing till fracture follows a Ludwik equation
according to: 𝝈𝒕 = 𝝈𝒐 +640ɛ𝟎.𝟏𝟓 . Suppose the modulus of resilience for the alloy is given as
128.69 kJ/mᶟ, calculate the length of the sample at the point of instability, given the initial
gage length of 50mm.