School of Engineering
Mechanical Engineering Department
Bachelor of Science in Mechanical Engineering
Subject: Mechanics of Materials-II ME 323
Assignment 1
Maximum marks: 10
Submission date: 17th May 2019
Topics covered:
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Combined bending and torsion of the shaft
Stresses on plane inclined to the direction of loading
Principal stresses and principal planes
Question:
A marine propeller shaft of 250 mm diameter is subjected to a torque of T = 150 kN.m and pure bending moment of
M = 180 kN.m. During inspection, a small surface crack is observed at 500 to longitudinal axis of the shaft ad shown
in the Figure Q1. Determine:
a.
b.
c.
The normal and shear stresses at the crack as it passes position A, B, C during the rotation of the shaft.
Express the bending and shear stresses as biaxial stress systems for positions A, B and C.
Determine principal stresses and princial planes for position A, B and C indicated on the shaft.
Figure Q1