King Fahd University of Petroleum and Minerals
Mechanical Engineering Department
(Semester 062)
ME 307 Machine Design I
HW # 3
(Assigned: Monday, 02 April 2007
Due: Monday, 09 April 2007)
PROBLEM # 1
The rod shown in the sketch has two 90o bends. The diameter of the rod is 50 mm.
Neglect any transverse shear effects. Determine the factor of safety at the most critical
section of the rod if the member is made from :
1. AISI 1040 cold drawn carbon steel.
Employ the following failure theories:
a. Distortion Energy
b. Maximum Shear Stress
2. Gray cast iron ASTM 30
Employ the following failure theories:
a. Coulomb Mohr
b. Modified I-Mohr
PROBLEM # 2
The following state of stress at a critical point in a part fabricated from class 20 gray cast iron
x = 50 MPa, xy = 30 MPa (ccw)
Determine the static factor of safety based on the state of stress at this point using
(a) MNS (b) BCM (c) M1M and (d) M2M theories
PROBLEM # 3
Solve Problem # 6-14 of the textbook (show all the steps including free body diagram, shear and
moment diagrams, stress analysis etc.)
PROBLEM # 4
Solve Problem # 6-21 of the textbook (show all the steps including free body diagram, shear and
moment diagrams, stress analysis etc.)