Mechanical characterization of notched high density polyethylene (HDPE) pipe: Testing and prediction

Abstract

The mechanical performances of traditional notched HDPE pipe (NHP) with various groove depths and shapes, including U-type, V-type and L-type (linear type), are critical for the safety assessment. However, some important mechanical performances, such as the limit load, creep, low cycle fatigue or high cycle fatigue may be not convenient to test by the NHP specimen. A novel notched HDPE ring (NHR) specimen was designed to test the mechanical performances of NHP, and the tested results were compared with those data obtained by NHP specimens, finite element simulation and theoretical prediction. Results show that the simulated and predicted ultimate loads of NHR specimens with various groove shapes and depths are in good agreement with experimental data. Additionally, the strength reduction factors of NHP and NHR specimens are very close to each other when the depth ratio is less than 0.4 for various grooves. It is of interest that the static creep lives of NHR specimens with U-type and V-type notches are relatively shorter than that of the specimens with the L-type groove. Therefore, the NHP specimen can be replaced by the proposed NHR specimen to test mechanical properties for convenience.