The effects of rounded corners in cold bent thin profiles

The issue presented below concerns a not insignificant aspect in defining the geometric characteristics of thin cold-bent steel sheet profiles with regard to how to consider the presence of curved connections (bends) between flat elements of the same section.

EN 1993-1-3 states verbatim that "the influence of curved fittings should be taken into account when calculating the geometric characteristics of a section by considering reduced lengths of the flat parts (bp) with reference to the midpoint (P) of the curvature thus identifying a nominal geometry of the section."

The Italian standard makes no mention of the "nominal section" to be referred to when calculating geometric characteristics based on effective lengths of compressed parts and effective lengths of tensioned parts; on the other hand, the European standard does not give a clear definition of "nominal section."

In the article a proposed reasoned approach used in automatic calculation.

The effects of rounded corners in cold bent thin profiles.