Effective Widths of Unstiffened Elements

Uniformly Compressed Unstiffened Elements

The effective widths for uniformly compressed unstiffened elements are calculated in the same manner as for stiffened elements (Art. 10.8.1), except that k in Eq. 10.4 is taken as 0.43. Figure 10.6 illustrates the location of the effective width on the cross section.

Unstiffened Elements and Edge Stiffeners with Stress Gradient

The effective width for unstiffened elements (including edge stiffeners) with a stress gradient is calculated in the same manner as for uniformly loaded stiffened elements (Art. 10.9.1) except that (1) k in Eq. 10.4 is taken as 0.43, and (2) the stress ƒ3 is taken as the maximum compressive stress in the element. Figure 10.7 shows the location of ƒ3 and the effective width for an edge stiffener consisting of an inclined lip. (Such lips are more structurally efficient when bent at 90 , but inclined lips allow nesting of certain sections.)