NUMERICAL ANALYSIS OF LOCAL-GLOBAL BUCKLING INTERACTION IN LAMINATED COMPOSITE CHANNEL COLUMNS

Resumo

The study of buckling in thin-walled structures is essential to ensure safety, efficiency, and economic viability in structural design, as these systems are particularly prone to instability phenomena. Channel, widely used in structural applications, can exhibit various buckling modes: local (plate-type), global (flexural and flexural-torsional), or through interactions between these modes. Accurate design must account for such interactions to ensure sufficient structural capacity, as understanding these mechanisms is crucial for reliably predicting the behavior of compressed columns and preventing premature failure. These stability problems become even more complex when advanced materials, such as fiber-reinforced composites, are employed. These materials have attracted significant attention due to their high specific strength, corrosion resistance, and tailorability. In thin-walled members, fiber-reinforced composites enable the optimization of mechanical performance through controlled ply orientations and stacking sequences. Nonetheless, their anisotropic behavior introduces significant complexity in accurately predicting structural buckling responses. Therefore, this work aims to develop a numerical model using the Finite Element Method to investigate the interaction between local and global buckling in simply supported fiber-reinforced composite channel columns under axial compression, and to assess the influence of initial geometric imperfections on the load-carrying capacity of these structural elements.