Calculating the radius of gyration

To calculate the radius of gyration for the cross-section of the beam in the diagram, start with the values of I that were calculated earlier.

Ixx = 33.3 x 106 mm4Beam with the x and y axes marked. The breath of the beam is 50 mm and the depth of the beam is 200 mm.

Iyy = 2.08 x 106 mm4

Refer to the diagram for the values of b and d that are used in the calculation of A.

A = Area of cross-section = 50 mm x 200 mm = 10,000 mm2

Substitute I and A into the formula for r to give:

An equation: rxx square root of I divided by A equals to the square root of (33.3 x 106 mm4) divided by (10,000 mm2), which equals 57.7 mm.

This is the value of the radius of gyration about the x-x axis.

Calculating r