Determination of material fracture toughness by a computational/experimental approach for rapid crack propagation in PE pipe

Based on an investigation of the Small Scale Steady State (S4) test, an int egrated computational/ experimental approach has been developed in order to assess the fracture behaviour of polyethylene (PE) gas distribution pipe m aterial during rapid crack propagation (RCP). This paper describes the use of the results obtained from the S4 test and program modified from PFRAC (P ipeline Fracture Analysis Code) to evaluate the fracture toughness of the m aterial, G(d), which could not be directly obtained from the test, and to p redict critical pressure, p(c), for RCP in a full scale PE pipe. The contac t algorithms are developed to consider the opening pipe wall impact against a series of containment rings and the capabilities of PFRAC are also exten ded. Since G(d) is evaluated, the investigations are made on it to the effe ct of temperature and wall thickness. In addition, procedures to evaluate t he critical pressure for the S4 test pipe are also discussed.