Fatigue Fracture Behavior of Single-Edge-Notched Specimens Prepared From Polyethylene Pipes

摘要

This paper presents a comparative analysis of crack propagation behavior of single-edge-notched (SEN) specimens prepared from high density polyethylene (HDPE) and medium density polyethylene (MDPE) gas grade pipes tested under fatigue loading conditions. The rate of crack growth was found to be influenced by the morphology in the pipe. The crack propagation behavior was governed by the plasticity at the crack tip which in turn was linked to the sample crystallinity. The effect of oven aging on fatigue life was also addressed. Oven aging was found to increase the crystallinity which resulted in lowering the fatigue life.