Andreas Frank, Gerald Pinter, Mridula Kapur, E. Nezbedová
Papers # 2012 Barcelona
Results from cracked round bar tests (CRB) and pennsylvania notch tests (PENT) for several polyethylene (PE) pipe grades are compared. The CRB tests were conducted at 23 °C and 80 °C, the PENT tests only at 80 °C. A material ranking based on the CRB tests was in good accordance to PENT failure times, although a slight temperature dependence of the ranking could be identified. If using adequate instruments for measuring the crack opening displacement the clear detection of the crack initiation in the CRB tests opens the possibility of partitioning the total failure time into time for crack initiation and time for slow crack growth which potentially may be interesting for material development or conservative lifetime assessment of pressurized PE pipes.