An experimental study was conducted to reproduce running crack in $N_2$ gas pressurized polyethylene pipes.
The experiment was conducted in a laboratory at the ambient temperature ranging from 4℃ to 25℃. Brittle running crack occurred more easily in larger diameter sizes and lower molecular weight grade materials. Cracks in smaller diameter pipes and higher molecular weight grade materials were arrested by ductile yielding after 5~250mm of crack extension.
Brittle cracks propagated in sinusoidal shape with average crack speed of 510~510 m/sec.