Performance and stability assessment of small square steel tubes under axial tension and compression

Steel tubes with small cross-sectional dimensions have extensive applications in civil engineering. This study focuses on understanding the effect of the unsupported length-to-width (L/B) ratio on the structural stability of square steel tubes with small cross-sectional dimensions (small square steel tubes) subjected to axial compression and tension. Sixty-three small square steel tube specimens with three different cross-sectional dimensions (25 mm × 25 mm, 30 mm × 30 mm, and 35 mm × 35 mm) were tested under compression and tension. Specimens with varying L/B ratios ranging from 2 to 12 were tested under axial compression. The ultimate compressive strength of the specimens was compared with the ultimate tensile strength of the corresponding specimens. The experimental findings revealed that the L/B ratio significantly influenced the failure mechanism, stress-strain behaviour, stability, and ultimate to yield stress ratios of small square steel tubes. The results also highlighted the importance of using controlled length and cross-sectional dimensions of the small square steel tubes to ensure stability in engineering applications.<p></p>