Mechanical Characterization and Numerical Modeling of High Density Polyethylene Pipes

The worldwide plastic pipe industry is predicted to experience a dramatic grow over the next decade. As a group of plastic pipes, high density polyethylene (HDPE) pipes are often employed because of their low-cost production, easy installation, and excellent long-term performance. However, due to their complicated semi-crystalline microstructure and nonlinear time-temperature dependent mechanical behavior, the mechanical characterization of HDPE pipes is very challenging and time consuming. In addition, during the manufacturing of HDPE pipes, the processing conditions (such as molecular orientation, cooling rate, and extrusion injection pressure) can introduce different complex microstructures into the material which yield different material properties. In this study, a robust mechanical characterization approach is developed to support numerical modeling of HDPE pipes. The mechanical tests are performed directly on as-manufactured pipe segments. The simulation results are compared with the experimental data for tensile and internal pressurization (burst) tests and a good agreement is observed.