Experimental Study on the Influence of Stress Concentration on the Flexural Stability of Aluminum Hollow Tube

Abstract

The hollow sections gradually replace solid sections in most structural applications in various engineering fields due to their attractive features, such as lightweight and high specific strength. In this research, one such attempt was made to investigate the flexural capability of aluminum hollow tubes (AHT) with a square cross-section. The research's objective was to study the influence of stress concentration on the flexural behavior of the hollow tube. The role of stress concentration in a structural member was crucial as it may hamper the balance of the entire system and its function. The type of stress concentration considered in the research was through the hole cross-section and quantities. Three-point bending test with concentrated load was conducted on the specimens of a hollow tube with different stress concentrations, such as a circular hole, a square hole, and perforations. The load was applied manually during the bending test. The bending test was carried out on all specimens for various support spans of 110, 130, 170, and 200 mm. The output measures of the study were maximum bending load, deflection, and flexural stiffness. The maximum bending load capacity of around 5.7 kN was observed for AHT with a circular hole with a support span of 110 mm. The maximum deflection measured at the beam mid-span increased rapidly as the aspect ratio increased from 73.33 to 93.33. After that point, the deflection variation was marginal for the increased aspect ratio from 113.33 to 133.33. This was due to the effect spring back effect, which dominated more on the bending behavior at a shorter span between the supports.