Dynamic constitutive model of PMMA at room temperature

The split Hopkinson pressure bar (SHPB) experiments were conducted to investigate the dynamic characteristics of the organic polymer glass, polymethyl methacrylate (PMMA) at room temperature. The experimental results display that PMMA at room temperature and high strain rates may undergo failure in the elastic stage and cannot enter the plastic stage, which exhibits a brittle behavior rather than a ductile one. And the elastic module of PMMA seems not to be obviously rate-dependent. Based on the above, the mechanical properties of PMMA were described by using a viscoelastic constitutive model and the relevant constitutive parameters were determined by the fitting methods. The fitted results further validated the conclusion obtained by the experiments.