Experimental investigation of bitubal circular energy absorbers under quasi-static axial load

• Experimental study of axial quasi-static crushing of bitubal circular absorbers.
• Investigating the influence of different variables on crashworthiness parameters.
• Bitubal specimens are more efficient than the equivalent monotubal specimens.
• Introducing two solutions to reduce the maximum crushing load of bitubal absorbers.
• Cutting groove on the upper portion of tube decreases peak loads significantly.

In this article, bitubal circular energy absorbers consist of two AL-6063-O tubes with unequal diameters placed coaxially and compressed under quasi-static axial load are studied experimentally. The effects of diameter and wall-thickness of each tube and the interaction between two tubes on the crashworthiness parameters are investigated in detail. In order to reduce the high value of peak load induced in the bitubal absorbers, two worthwhile solutions are proposed. The first one is to use two tubes with different lengths and the other one is to cut groove at the end portion of one of the tubes.