Thermo-mechanical behavior of polyethylene under mechanical loads at cryogenic and elevated temperatures

For the design of a polymer liner in a high-pressure vessel, experimental and numerical analyses of high-density polyethylene (HDPE) are conducted under tensile and compressive loads. The effect of temperature on the mechanical behavior of the HDPE is investigated experimentally in a range of 223K to 373K. For tensile and compression tests, specimens are cut out of a prototype polymer liner, which is to be developed for automobile high-pressure hydrogen tanks. The specimens include manufacturing influences of the future used liner. Investigating the effect of temperature numerically in a finite element analysis, two different material models are taken into consideration to represent the thermo-mechanical behavior of the HDPE: an elastic-plastic material model with isotropic hardening and a hyperelastic material model. The results of the finite element analyses are compared with the experimental results in the entire temperature range. Temperature-dependent impacts of the tension-compression asymmetry are quantified experimentally and numerically for the mechanical behavior of polyethylene.