This chapter covers the theory behind reduction of the cross-section.

Rectangular cross-section

b_red = b - (δ_V + δ_H) a

h_red = h - (δ_T + δ_B) a

Plate section and hollowcore

h_red = h - (δ_T + δ_B) a

Circular cross-section

d_red = d - 2a

T-type cross-section and F-type cross-section

h_f,red = h_f - (δ_T + δ_B) a_flange

b_f,red = b_f - (δ_L + δ_R) a_flange

As an approximation, b_f increases/decreases according to the strength parameters between the flange and the body.

L-type cross-section

b_red = b - (δ_L + δ_B) a_body

h_red = h - δ_T a_body - δ_B a_flange

b_f,red = b_f - (δ_L a_body + δ_R a_flange)

As an approximation, b_f increases/decreases according to the strength parameters between the flange and the body.

For the entire cross-section the reduced parameters of the body are used.

f_cd(θ_M) = k_c(θ_M,body) f_cd

E_cd(θ_M) = k_c(θ_M,body)² E_cd(θ_M)