Polyurea is a special type of elastomer that features fast setting time as well as good chemical and fire resistance. It has also good mechanical properties such as its high toughness-to-density ratio and high strain rate-sensitivity, so its application is recently extended to structural purpose to form sandwich-type or multi-layered plates. Those structures can be used for retrofitting of military vehicles and historic buildings, absorbing energy during structural crash. In order to investigate its behavior of hysteresis as well as rate-sensitivity, three different testing systems are used to cover a wide range of strain rates up to strain of 100%. In view of impact and blast events, the virgin state of polyurea is considered throughout the experiments. First, a hydraulic universal testing machine is used to perform uniaxial compressive loading/unloading tests in order to investigate its hysteresis behavior at low strain rates (0.001/s to 10/s). Second, two distinct gas-gun split Hopkinson pressure bar [SHPB] systems are employed to cover high strain rates: a nylon bar system (700/s to 1200/s) and an aluminum bar system (2300/s to 3700/s). Lastly, the rate-sensitivity for intermediate strain rates (10/s to 1000/s) is characterized using a modified SHPB system.
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