Failure prediction analysis for polyethylene flawed pipes

Through this paper limit load analysis and the EPRI/GE procedure were applied to predict instability conditions for medium density polyethylene flawed pipes. Predicted values for internally pressurized cylinders with axial cracks and cylinders with circumferential cracks under remote tension were compared to experimental results obtained from tests conducted on full scale structures. For the pipes under internal pressure, both schemes led to critical pressure values in agreement with actual burst pressures, despite plastic collapse having been observed in the failure of these structures. For the pipes with circumferential internal cracks subjected to remote tension, the predicted loads from the EPRI procedure do not agree with experimental values whereas limit load predictions are quite satisfactory. On the other hand, for the circumferentially externally cracked pipes both predictions reasonable agree with experimental data.