This report describes an experimental effort to characterize the viscoelastic properties of polyurea and the failure of ductile materials at high strain rates. The viscoelastic properties of cast polyurea were determined under monotonic loading conditions, both in the confined compression and Arcan shear configurations. The nonlinear viscoelastic properties have been determined and validated by predicting the large deformation compression behavior. Expanding ring experiments were performed on Al 6061-O, Al 1100-H14 ...