GD2 and polar moment of inertia

[Jolilechat]

Please, what is GD2?
Is this quantity related to the polar moment of inertia?

Thank you.

 

[rob768]

GD^2 is the (old) unit of rotational (polar) inertia, in which the D = Diameter. The current unit is J, which is dependant on form. For a cylinder or a massive disk, it is the product of mass X radius^2

best
rob

 

[rob768]

OOps, I have to correct myself here. It is ½ * M * r²