A1-in-diameter solid round bar has a groove 0.1-in deep with a 0.1-in radius machined into it. the bar is made of aisi 1020 cd steel and is subjected to a purely reversing torque of 1800 lbf ? in. for the s-n curve of this material, let f 5 0.9. (a) estimate the number of cycles to failure. (b) if the bar is also placed in an environment with a temperature of 750°f, estimate the num- ber of cycles to failure.

If you were designing a bumper for a car, would you prefer it to exhibit elastic or plastic deformation? why? consider the functions of a bumper in both a minor "fender-bender" and a major collision.

Adouble-strand no. 60 roller chain is used to transmit power between a 13-tooth driving sprocket rotating at 300 rev/min and a 52-tooth driven sprocket. a) what is the allowable horsepower of this drive? b) estimate the center-to-center distance if the chain length is 82 pitches. c) estimate the torque and bending force on the driving shaft by the chain if the actual horsepower transmitted is 30 percent less than the corrected (allowable) power.

Shafts are machine elements that are used to a) carry axial loads b) direct shear loads c) transmit power d) rotate at constant speed e) none of the above circular and square shafts subjected to the same torque under the same circum behave a) the same way b) almost the same way