Analysis of Critical Buckling in Composite Structures Under Thermo-Mechanical Loads: FE Approach

This study investigates the buckling behavior of thin-walled composite C-section channels with and without cut-outs subjected to thermo-mechanical loading. Finite element analysis was performed in ANSYS Workbench using glass fiber-reinforced polymer (GFRP) laminates. Three key design parameters: hole shape, spacing ratio, and opening ratio were systematically varied to evaluate their effects on critical buckling capacity. The results revealed that the intact structure exhibited the highest stability, while perforated models experienced reduced resistance. Among hole geometries, hexagonal cut-outs demonstrated the best performance, followed by circular holes, whereas square holes showed the lowest resistance due to corner-induced stress concentrations. The effect of spacing ratio indicated that excessively large spacing reduced stability by creating longer unsupported regions, while moderate values performed better. Similarly, increasing the opening ratio weakened all configurations, with square cut-outs most affected. These findings provide valuable insights for optimizing lightweight composite designs by balancing geometric efficiency and buckling stability.