Energy balances and uniaxial damage of highly filled elastomers

A propellant sample undergoes internal damage while it is tested at finite deformation. The damage consists of broken molecular chains and void spaces which form around the filler particles and contribute to failure of the propellant. Attempts were made to determine the amount of this damage from the viewpoint of energy dissipations. Mechanical energy losses, called damage energy, were computed from energy changes during tension cycling experiments carried out at different temperatures and straining rates. Shift procedures were applied to the experimental results, and a double-reduced master curve for damage energies was obtained by using time–temperature and strain shift factors. The reduced master curve can be used to predict the extent of damage accumulated in a propellant sample during tensile tests at different straining rates and temperatures.