Radius of Gyration in Structural Engineering
Radius of gyration is used to describe the distribution of cross sectional area in a column around its centroidal axis
In structural engineering the Radius of Gyration is used to describe the distribution of cross sectional area in a column around its centroidal axis.
The structural engineering radius of gyration can be expressed as
r = (I / A)1/2 (1)
where
r = radius of gyration (m, mm, ft, in...)
I = Area Moment Of Inertia (m4, mm4, ft4, in4 ..)
A = cross sectional area (m2, mm2, ft2, in2...)
Some typical Sections and their Radius of Gyration
Rectangle - with axis in center
Radius of Gyration for a rectangle with axis in center can be calculated as
r = 0.289 h (1)
Rectangle - with excentric axis
Radius of Gyration for a rectangle with excentric axis can be calculated as
r = 0.577 h (2)
Rectangle - with tilted axis
Radius of Gyration for a rectangle with tilted axis can be calculated as
r = b h / (6 (b2 + h2))1/2 (3)
Rectangle - with tilted axis II
Radius of Gyration for a rectangle with tilted axis can be calculated as
r = (((h2 + cos2a) + (b2 sin2a)) / 12)1/2 (4)
Hollow Square
Radius of Gyration for a hollow square can be calculated as
r = ((H2 + h2) / 12)1/2 (5)
Hollow Square - with tilted axis
Radius of Gyration for a hollow square with tilted axis can be calculated as
r = ((H2 + h2) / 12)1/2 (6)
Equilateral Triangle with excentric axis
Radius of Gyration for a equilateral triangle can be calculated as
r = h / (18)1/2 (7)
Triangle
Radius of Gyration for a equilateral triangle can be calculated as
r = h / (6)1/2 (8)
