A solid round bar, 25 mm in diameter, has a groove 2

Mechanical Engineering Jan 28, 2021

A solid round bar, 25 mm in diameter, has a groove 2.5-mm deep with a 2.5-mm radius machined into it. The bar is made of AISI 1018 CD steel and is subjected to a purely reversing torque of 200 N · m. For the S-Ncurve of this material, let f = 0.9.

(a) Estimate the number of cycles to failure.

(b) If the bar is also placed in an environment with a temperature of 450?C, estimate the number of cycles to failure.