Propagation of Plastic Wave in Lead Bar

An experimental study on the plastic wave propagation in a cylindrical lead bar was made using a Hopkinson bar system under the conditions of several constant end velocities and a constant duration time. The stress history as well as the strain history at several locations along the length of the bar were measured. The unloading wave and the secondary wave generated in the bar were observed clearly. On the other hand, compression tests in a wide range of strain-rates were carried out to determine the strain-rate dependency of the material.It was found that a plateau, the region of constant stress and strain, exists but the results predicted from the rate-independent theory based on the static stress-strain relation do not agree well with the experimental results.