transfer the load from the top flange to the bottom one

prevent buckling of web

decrease the effective depth of web

prevent excessive deflection

axial forces

shear and axial forces

shear and bending forces

axial and bending forces

lateral loads

longitudinal loads and vertical loads

lateral, longitudinal and vertical loads

lateral and longitudinal loads

d/4

d/3

d/2

2d/3

only (i)

both (i) and (ii)

both (i) and (iii)

(i), (ii) and (iii)