Theoretical and Experimental Studies of Steel Profiles

Abstract

The main purpose of the tests is the checking of the stiffness characteristics of steel sheets at several load levels.
The tests were carried out in collaboration with INCERC, Iaşi Branch. The testing stand was built inside the Laboratory of the Structural Mechanics Department from the Faculty of Civil Engineering and Architecture, Technical University „Gh. Asachi†of Iaşi.
The testing of the elements was carried out according to EC3, chap.9, “Testing Procedure†because the elements are classified as cold-rolled thin-gauge profiles as stated in Romanian Norm NP 012-92 (EC 3 parts 1-3).
The testing procedure consisted of several repeated loading-unloading cycles. Finally, one specimen from each class was loaded until collapsed. The local buckling of the edge ribs caused the collapse of the profiles (in reality this is impossible because the steel sheets are coupled).
The ultimate deflections are limited according to several Norms between L/100 and L/200. The loading-unloading cycles pointed out the lack of permanent strains for maximum displacements below the L/200 limit. Out of this limit the permanent strains appear i.e. the rib folding in the support areas.