Constitutive Model and Failure Criterion Analysis of High-Density Polyethylene Pipe Under Thermal-Mechanical Load

As a typical viscoelastic material, high-density polyethylene (HDPE) properties are sensitive to service temperature and strain rate. In order to establish a new constitutive model and failure criterion equation for HDPE pipes at different service temperatures and strain rates, tensile tests of HDPE pipes at different temperatures and strain rates were carried out, and then a constitutive model of PE pipe considering the influence of temperature and strain rate was proposed by modifying the Suleiman’s hyperbolic constitutive equation. Finally, a ductile failure criterion of HDPE material was established based on the strength theory.