Geometrical Properties of Double Tee Section

Dimensions

h =   m, t_w =   m

b_f1 =   m, t_f1 =   m

b_f2 =   m, t_f2 =   m

Area

A_w = h·t_w m²

A_f1 = (b_f1 – t_w)·t_f1 m²

A_f2 = (b_f2 – t_w)·t_f2 m²

A = A_w + A_f1 + A_f2 m²

Centroid

y_c = max(b_f1; b_f2)2 m

S_y = A_w·h2 + A_f1·t_f12 + A_f2·(h – t_f22) m³

z_c = S_yA m

Perimeter

P = 2·(h + b_f1 + b_f2 – t_w) m

Second moments of area

I_{y_w} = A_w·(h²12 + (z_c – h2)²) m⁴

I_{y_f1} = A_f1·(t_f1²12 + (z_c – t_f12)²) m⁴

I_{y_f2} = A_f2·(t_f2²12 + (h – z_c – t_f22)²) m⁴

I_y = I_{y_w} + I_{y_f1} + I_{y_f2} m⁴

I_z = t_f1·b_f1³ + t_f2·b_f2³ + (h – t_f1 – t_f2)·t_w³12 m⁴

Polar moment of area

I_x = I_y + I_z m⁴

Radii of gyration

r_y =  I_yA m

r_z =  I_zA m

r_x =  I_xA m