Strain rate dependent constitutive model for predicting the material behaviour of polyurea under high strain rate tensile loading

A strain rate dependent constitutive material model to predict the high strain rate behaviour of polyurea has been proposed. The well-known nine parameter Mooney–Rivlin constitutive material model was considered as the base model in deriving the rate dependent material model. A rate dependent term was introduced into the original Mooney–Rivlin model and was validated using high strain material data for polyurea. Due to its simplified formation and extensive use in finite element codes such as LS-DYNA® and ANSYS®, improvement of the original model shows a higher significance in terms of constitutive model development for hyper-elastic materials. High strain rate tensile tests program has been conducted to obtained the material model parameters. Experimental and model prediction for both stress–strain and energy behaviour of the material indicates close agreement. Stress–strain non-linearity and high strain rate sensitivity of polyurea is also highlighted in this paper.