ABSTRACT

From the experimental tests it could be shown that the moment-rotation behaviour of coldand hot-formed SHS beams differs significantly as presented in Figures 3 and 4. Though

Buckling of structural hollow sections 221 all sections investigated were class 1 sections according to EC 3, only the cold-formed sections exceed their nominal plastic moment capacity and are, consequently, useable for plastic design. All hot-formed sections hardly reach their plastic moment level and are without larger rotations. Therefore, they behave like class 2 sections according to EC 3 and are not applicable for plastic design. Another observation can be made regarding the shape of the moment-rotation (m-<p) curve ofboth section types. Whereas hot-formed SHS reach their maximum moment capacity directly after leaving the elastic path, cold-formed SHS reach their maximum moment with significant plateau deformations. The slope of the descending branch of the m-<p curve is similar for both section types.