Understanding and Interpreting of the Measured Wave Signals in Impact Dynamics Studies

The significance and difficulty of the multi-position measuring were analyzed when understanding and interpreting the wave signals measured in impact dynamic experiments. By combining the Lagrange inverse analysis with the Hopkinson pressure bar technique, a new method was proposed, which substantially resolves the problem of measuring simultaneously both stress wave and particle velocity at a Lagrange position in impact tests. When the particle velocity wave signals at n (n3) Lagrange positions are measured, by using this new method, the dynamic stress-strain curves at n Lagrange positions of specimen can be determined and interpreted. The feasibility and validity of this new method was consistently confirmed by numerical tests for two viscoelastic materials (PMMA and cement mortar).