Experimental investigation and modeling of mechanical behaviors of polyurea over wide ranges of strain rates and temperatures

Theoretical and experimental studies on the compressive mechanical behavior of two formulations of polyurea under uniaxial stress state and quasi-one dimensional strain state are conducted over the temperature range of −40°C-+20 °C and the strain rate range of 0.001/s-12000/s. The stress-strain behavior of polyurea samples is established at different strain rates and temperatures, and key mechanical properties of the materials are determined. The experimental results show the significant sensitivity of compressive stress-strain curves of polyurea to strain rate and temperature within and beyond linear viscoelastic regime. In addition, the mechanical properties of PU605 (Versalink P-650 reacted with 105% molar equivalent Isonate 143L) are compared to those of PU105 (Versalink P-1000 reacted with 105% molar equivalent Isonate 143L). Based on the experimental results with confined pressure, a calculation method is presented which is available to study the bulk modulus of polyurea. Finally, a visco-hyperelastic constitutive model is developed to describe the nonlinear mechanical behavior of polyurea over a wide range of strain rates and temperatures.