Investigating the dynamic mechanical behaviors of polyurea through experimentation and modeling

Polyurea is widely employed as a protective coating in many fields because of its superior ability to improve the anti-blast and anti-impact capability of structures. In this study, the mechanical properties of polyurea XS-350 were investigated via systematic experimentation over a wide range of strain rates (0.001–7000 s⁻¹) by using an MTS, Instron VHS, and split-Hopkinson bars. The stress-strain behavior of polyurea was obtained for various strain rates, and the effects of strain rate on the primary mechanical properties were analyzed. Additionally, a modified rate-dependent constitutive model is proposed based on the nine-parameter Mooney-Rivlin model. The results show that the stress-strain curves can be divided into three distinct regions: the linear-elastic stage, the highly elastic stage, and an approximate linear region terminating in fracture. The mechanical properties of the polyurea material were found to be highly dependent on the strain rate. Furthermore, a comparison between model predictions and the experimental stress-strain curves demonstrated that the proposed model can characterize the mechanical properties of polyurea over a wide range of strain rates.