Abstract
A new method has been developed for separating dispersive waves in elastic and viscoelastic rods from multi-point strain and velocity measurements. Knowing the basic waves, the stress, the strain, the displacement and the particle velocity can be calculated at any point of the bar. The method is based on the assumption of one dimensional and single mode dispersive wave propagation and it takes account of the wave dispersion. It is shown that the method is stable with respect to noise, so that the measuring time is increased considerably. Subsequently, the maximum strain which can be measured in a material tested with a classical SHPB (Split Hopkinson Pressure Bar) set-up is also increased and is no longer limited by the length of the bars. The method is illustrated here by applying it successfully to the analysis of a real test of aluminum honeycomb. It can also be applied to other kinds of one-dimensional and single-mode dispersive waves such as flexural waves in beams and acoustic waves in wave-guides.