Split Hopkinson pressure bar measurements of polymer energy dissipation and identification of the glass transition condition

We explore the idea of using a split Hopkinson pressure bar to measure polymer energy dissipation. For an elastic specimen the sum of the mechanical energies within the transmitted and reflected pressure pulses ought to be equal to mechanical energy in the incident pressure wave. Any deficit is due to inelastic dissipation by the specimen. The amount of energy dissipated can be plotted as a function of temperature and will be greatest at the glass transition condition. Our results are discussed in the context of dynamic mechanical analysis data taken on the same polymer and the use of Group Interaction Modelling as a physical framework of understanding.