HDPE pipe failure analysis under overpressure in presence of defect

Abstract

Pipe failure and leaks are frequent phenomena in urban areas. In order to minimize the risk of long-term leakage, nearly 60% of drinking water systems are renewed with third-generation polyethylene pipes, PE100. Due to its characteristics, it is a material of choice for water supply networks. However, the presence of a defect can lead the pipe failure under the effect of transient flow. In order to examine this problem, the cracking behavior of PE100 pipes with a defect has been studied. Using burst tests and finite element modeling, we have demonstrated that the concept of elastic-plastic fracture mechanics, the J-integral, can define with acceptable precision the crack initiation and the failure behavior of PE100 pipe. The J-integral value at the time of appearance of the damage zone, plastic strain-hardening, is considered numerically to be the value of the toughness. This allowed us to define the pressure leading to the crack initiation. The results are compared with the experimental burst pressures.