On the crashworthiness performance of thin-walled circular tubes: Effect of diameter and thickness

Abstract

Thin-walled metal structures are known as an effective solution in absorbing impact energy and reducing the resulting reaction forces. The design of energy absorbers with higher energy absorption capability, lower weight and reaction forces, as well as lower manufacturing cost, has always been of interest. In this study, the effects of diameter and thickness of thin-walled Aluminum tubes on different crashworthiness criteria were investigated. To this end, different geometries were examined by simulating the uniaxial compressive test applying the finite element method. The results revealed that the optimal diameter for a simple circular tube (SCT), assuming constant length and thickness, is the smallest diameter in terms of resistance to global buckling. The SCT with an optimal diameter has the highest specific energy absorption (SEA), the lowest maximum crushing force (${\mathrm{F}}_{\max }$), and the highest crushing force efficiency (CFE). Moreover, in this study, the effect of thickness on the tubular absorber performance was numerically investigated according to four criteria: SEA, ${\mathrm{F}}_{\max },$ CFE, and energy absorption (EA), and the optimal dimensions were obtained. Based on the results, increasing the thickness increases CFE, and increasing the ratio of thickness to diameter (t/D) increases SEA and CFE. Eventually, by applying the regression analysis, two equations were presented to calculate ${\mathrm{F}}_{\max }$ and CFE, which can be used to predict the performance of thin-walled metal tubes.

Graphical Abstract

Highlights

• Reducing the tube diameter reduces the force fluctuations during crushing.

• SEA increases by increasing the tube thickness specially for small diameters.

• As thickness-to-diameter ratio (t/D) increases, SEA and CFE increase.

• Three different objective functions were carried out to find the optimum tube.

• Obtained fitted equations predict the maximum crushing force and force efficiency.

Keywords:

• Crashworthiness
• thin-walled metal structures
• aluminum circular tubes
• crushing force efficiency
• specific energy absorption
• peak crushing force