What Is the Radius of Gyration?

The radius of gyration is the distance from the center of the hypothetical differential mass of the object to the axis of rotation, and its size is equal to the moment of inertia divided by the total area of the section and then squared.

Section turning radius

Right!

The radius of gyration is the distance from the center of the hypothetical differential mass of the object to the axis of rotation, and its size is equal to the moment of inertia divided by the total area of the section and then squared.

Radius of slewing

Physically, the mass of a rigid body distributed according to a certain law is equivalent to the mass of a mass centered on a certain point during rotation. The vertical distance from this point to an axis is k. Therefore, the inertia of the rigid body with respect to a certain axis and The equivalent mass point has the same moment of inertia for the same axis, that is, I = mk2. Then k is called the radius of rotation for the axis.

The size of the turning radius is related to the centroid axis of the section. The minimum radius of gyration generally refers to the smaller of the radius of gyration for two centroid shafts in asymmetrical sections (such as unequal angle steel). When calculating the slenderness ratio of a component, for example, if the calculated lengths of the component in-plane and out-of-plane are equal, its slenderness ratio is calculated using the minimum turning radius.