King Fahd U niversity of Petroleum & M inerals
College of Engineering Sciences
Mechanical Engineering Department
First Semester (2007-2008) (071)
ME 307: MACHINE DESIGN I
HW #4
Chapter 7: Fatigue Failure Resulting from
Variable Loading
DUE DATE:
Sat. 01-12-2007
Problem 1
Corresponding to a reliability of 90 %, find the endurance limit and the number of cycles-tofailure of a 1-in round UNS G-10150 cold-drawn steel bar. The bar is subjected to a purely
reversing torque of 250 N.m, and is placed in an environment with T = 500°C.
Solution
ME 307: Machine Design I
1/5
HW 4: Chapter 7
Problem 2
Determine the fatigue strength of a rotating beam made of AISI 1020, hot-rolled steel
corresponding to a life of 2 × 103 cycles of stress reversal. Also, determine the life of the
specimen corresponding to a stress amplitude of 42 kpsi. The known properties are: σo =
120 kpsi, m = 0.20 and εf = 0.88.
Solution
Solution
Problem 3
Solve Problem 7-12 of the textbook.
Solution
Problem 4
Solve Problem 7-17 of the textbook.
ME 307: Machine Design I
2/5
HW 4: Chapter 7
ME 307: Machine Design I
3/5
HW 4: Chapter 7
Solution
Problem 5
ME 307: Machine Design I
Solve Problem 7-23 of the textbook.
4/5
HW 4: Chapter 7
Solution
Problem 6
ME 307: Machine Design I
Solve Problem 7-26 of the textbook.
5/5
HW 4: Chapter 7