ABSTRAKT

The mechanical response of poly-methyl-methacrylate (PMMA) acrylic polymer was numerically investigated under conditions of increased temperature and strain rate. PMMA is a highly strain rate- and temperature-sensitive polymer that can behave quite differently under different loading conditions. A temperature- and strain rate-dependent viscoelastic material model was employed to predict the quasi-static and dynamic behavior of this polymer at different temperatures and loading rates. The material model was implemented in an explicit finite element (FE) solver LS-DYNA by establishing a user defined material subroutine (UMAT). Finite-element models for low-strain rate uniaxial tensile test and high-strain rate split Hopkinson pressure bar (SHPB) compression test were built to verify the accuracy of the material subroutine. The results of simulations were compared with experimental results in terms of stress strain curves. Numerical results showed that the model successfully predicted the stress−strain behavior of PMMA at low and high strain rates as well as at elevated temperatures.