GATE 2022 PI – Question 50
A 30 mm diameter, 40 mm high cylinder is open-die forged between platens. Assume perfect plasticity, flow stress 300 MPa. Find ideal load at 30% height reduction in kN, nearest integer.
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: 300 to 306
Explanation
Final height is 0.7×40 = 28 mm. Volume conservation gives $A_f=A_0h_0/h_f=(\pi30^2/4)/0.7=1009.80$ mm². Ideal frictionless load is flow stress × current area = 300×1009.80 = 302940 N ≈ **303 kN**.