Strength of Materials

6.7 POLAR MODULUS

Polar modulus is defined as the ratio of the polar moment of inertia to the radius of the shaft. It is also called as torsional section modulus. It is denoted by Z_p.

 

 

1. For solid shaft

 

 

2. For hollow shaft

 

SOLVED PROBLEM 6.1

Determine the diameter of a solid shaft which transmits 300 kW at 250 rpm. The maximum shear stress must not exceed 30 N/mm² and the twist should not be more than 1° in a shaft length of 2 m. ...