Axial splitting of circular metal tubes

A novel mode of deformation of circular tubes axially compressed on to a die is examined experimentally with regard to its energy absorbing capacity. The tube splits as a number of axial cracks are produced and the strips so formed are bent into curls. The major part of the deformation takes place at a nearly constant load which can be increased by preventing the formation of the curls. A simple upper bound approach is used to estimate this operating load. Compared with axial buckling and the inversion mode, the operating load for a splitting tube is somewhat lower. However, the fact that the stroke is of the order of 90% of the tube length means that the performance as measured by the total energy absorbed is often as good as these two efficient modes of deformation.