BEHAVIOR AND STRENGTH OF DISTORTIONAL-GLOBAL INTERACTION IN COLD FORMED STEEL LIPPED CHANNEL COLUMNS

Resumo

The cold formed steel members (CFS) are light steel options widely applied in the civil
construction. Furthermore, the CFS is a very slender option that allows the buckling behavior to develop
on local, distortional and global modes. In this away, it is expected that a greater attention over this
structural solution is necessary to guarantee the reliability and safety of the structure. On recent studies,
it has been shown that when the local, distortional and global modes occur with similar critical loads,
the strength capacity of the structural member is reduced due to a coupled phenomenon. The proposed
paper will discuss the distortional-global (D-G) buckling interaction of CFS lipped channels columns
under axial load. Additionally, it is developed a computer program (FStr) for elastic buckling analysis,
based on Finite Strip Method (FSM), in order to find CFS columns experiencing D-G interaction. The
program is developed on MATLAB with an easy graphical user interface. After settled the profiles under
strong interaction, a non-linear analysis using Finite Element Method (FEM) is used to find the strength
of the columns. Additional analysis and comments are discussed in order to understand the behavior and
the strength capacity of the CFS lipped channel columns under the proposed buckling interaction.