A Study On The Energy Absorption Capability Of Thin-walled Tubes Under Axial Crushing

As an energy-absorbing material and structure, thin-walled tubes are extensively applied asenergy-absorbing members in automobile, airplane and ship industry, because of their relativelylow density, stable deform mode and excellent energy absorption ability. Therefore, how toimprove the energy absorption ability of the tube is an important research subject. This paperstudied the energy absorption capability of the thin-walled tubes under axial crushing, the majorworks having:1) Firstly, the energy absorption efficiency f is adopted to uniformly characterize the energyabsorption property of a tubular element. With the maximum value of the energy absorptionefficiency, every tube structure achieves the optimum energy absorption ability, then can make acomparison for these different tubes with different materials and structures. In addition, this paperbased on the experiment proposes a simple and effective method to reduce the initial crushing peakforce，without making an effect to the compressive capacity of the whole structure.2) Using the concept of the energy absorption efficiency, the paper studied the energyabsorption of the tubes experimentally, calculating the SAE and the average crushing force andcomparing with the results, given by theoretical model. The comparison shows that the results ofexperiment are able to correlate to the results of Singace’s model. For further study of the results ofexperiment, the paper discusses the relation between the energy absorption of tube with itsgeometric dimensioning t/D, and deduces the dimensionless parameter, which characterizes theenergy absorption property of tube. The discussion shows that the about(t/D)0.5is quadraticfunction, and a downward parabola. Namely, there is a(t/D)0.5critical value, which makes theability of energy absorption of tube achieve the maximum.3) The energy absorption capability in foam-filled tube, sandwich tube, double tube areinvestigated based on the experiment. The study finds that the sandwich tube had higher SAE valuethan empty tube about20%, also higher than that of foam-filled tube. The paper specificallyanalyses the mechanism of sandwich tube with higher energy absorption ability. It found that ismainly because of the neatly diamond deform mode of outside tube, which originally deformed inEuler buckling mode, becoming to an excellent energy absorption member. Consequently, through reasonable design a low density thin-walled tube, which acts as an outside tube to the main energy-absorbing member, it can largely improve the energy absorption ability of the whole structure.