Impact Experimental Study and Theoretical Analysis on Energy Absorbing Capability of Splitting and Curling of Tubes

A Steel tube is one of the most important of energy absorbing elements. The quasi-static and impact experiments were performed. DHR9401 drop hammer rig, TDS420A digital recorder and force sensor were used in the tests. All specimens have been split and curled by pressing axially against a conical dies with semi-angles 45⁰. Six groups steel circular tube with internal diameter 54.4 mm and thickness 0.43 mm~3.00 mm were used. To obtain a regular deformation mode and reduce the initiated spike, by pre-cutting six 4 mm slits which were contributed evenly at the lower end of each tube. The deformation modes of the specimen are obtained and load-time curves in the impact experiments are given. Theoretical analysis based on the theory of energy balance is carried and the ratio of every kind of energy to total energy is obtained. Energy analysis indicates that tearing energy is the main component of the total energy. The result from energy analysis agrees well with impact experiments.