Dynamic Constitutive Model of High-Strength Graphite Material

Impact compression tests of high-strength graphite SMF-800 were carried out using a split Hopkinson pressure bar(SHPB) testing system,and the stress and strain curves at strain rates of 618,868 s-1and 1 185 s-1 were obtained.And the stress-strain curves were fitted by the damage ZWT viscoelastic constitutive model and the one dimensional elastic brittle damage constitutive model,and fitting results were compared.The results show that the destruction stress and strain increase with the increase of strain rate.The damage ZWT viscoelastic constitutive model is more effective than the one dimensional elastic brittle damage constitutive model to describe the dynamic mechanical properties of the high-strength graphite material.Moreover,the fitting related indexes of the damage ZWT viscoelastic constitutive model were up to 0.992 15,0.999 52 and 0.972 15,respectively,at strain rates of 618,868 s-1and 1 185 s-1.