Estabilidade estrutural de colunas treliçadas espaciais constituídas de perfis de aço formados a frio

Abstract

The present thesis includes the results of the structural stability of laced built-up cold-formed steel (CFS) columns, subjected to axial compression. The objective is to analyze the behavior of these spatial laced columns through full scale experimental tests, in which the collapse is caused by the interaction between local and global buckling in the compressed chord members. The spatial columns, composed of four plane-trussed members designed with lipped channel CFS and fully connected with self-drilling screws, were tested with 6200, 12200 and 16200 mm length, 0.8 or 1.25mm plate thickness. In addition to these tests, it was also carried out experimental tests of columns´ chord members to obtain the collapse loads and comparison with the analytical DSM equations (direct strength method). The results showed that the DSM can be applied to obtain the collapse loads of the chord built-up members, composed of two lipped channels connected with self-drilling screws. The final results of the investigation indicate the adopted methodology, including the column global buckling nonlinear behavior combined with the collapse mode of the double lipped channel CFS chord members connected by self-drilling screws, is able to be applied for regular structural design of the CFS spatial trussed arrangement.