effective-width

Four square steel boxes holding the same 0.0040 m2 of steel at four widths. Widening the box thins its wall, and past a computable width the widest box becomes the weakest.

Diseño de acero conformado en frío (ancho efectivo Winter, EN 1993-1-5, AISI S100 DSM y pandeo distorsional) / Cold-formed steel design (Winter effective width, EN 1993-1-5, AISI S100 DSM, and distortional buckling)