Abstract: In order to study the constitutive behaviour of high density polyethylene, uniaxial tension experiments were performed to obtain stress-strain curves. The experimental results indicated that the mechanical properties of PE-HD was strain-rate-dependent, the yield strength increased obviously with increasing strain rate, and the relationship between yield strength and logarithm of strain rate was linear. Considering the strain-rate-dependent mechanical properties of PE-HD, the Sherwood-Frost constitutive model was used to study the mechanical behaviour of high density polyethylene. Comparison of the model-predicted curves with the experimental ones showed that the Sherwood-Frost model could well predict the mechanical properties of PE-HD.

Key words: high density polyethylene, Sherwood-Frost constitutive model, stress, strain, uniaxial tension, yield strength