The interaction of axial load, bending moment and shear force is checked at the center of each cell. Whereas the SCI P-100 approach (see Clause 7.2.3) ignores the shear effects for V< 0.5Pv, BS 5950-1:2000 and the Westok approach raises that limit to 0.6, and incorporates a different equation for the reduced effective web thickness, t_e.When applicable, the effective section properties in bending, tension and compression are then recalculated using t_e.