Séparation et reconstruction des ondes dans les barres élastiques et viscoélastiques à partir de mesures redondantes

When using a classical SHPB (Split Hopkinson Pressure Bar) set-up, the useful measuring time is limited by the need of separating the waves propagating in opposite directions. A new method for separating and rebuilding waves in finite bars was developed, with no time limit, from $\text{N}$ strain measurements and $\text{P}$ particle velocity measurements $\text{(N+P⩾2)}$. It takes account of the wave dispersion in elastic and viscoelastic bars. The method is illustrated with the loading of a free bar where the measured displacement is 30 times longer than the displacement that would be obtained with the classical method.