Full History Burst Test Through Finite Element Analysis

Ductile Fracture propagation phenomena have been widely investigated by researchers in the last years, with particular regard to large metallic structures such as pressurized vessels or gas pipelines. A large number of burst tests have been carried out by Centro Sviluppo Materiali S.p.A. (C.S.M.) in the last decades to identify a set of significant parameters characterizing fracture propagation conditions; the aim is to foresee the behavior (speed and its derivatives) of longitudinal running cracks. The optimal choice of these parameters is strongly helped by appropriate use of Finite Element analysis. To this goal a Finite Element software has been developed, it allows the correct computing of some particular aspects of fracture propagation and the behavior of pressured real gases during decompression. In the present paper a pipeline burst test, carried out on a X100 grade pipeline, and all laboratory tests and data manipulations necessary to build up the whole procedure have been discussed. One of the main objectives is the setting of a procedure able to identify the fracture parameters, when a ductile propagation occurs, avoiding any scatter due to transient effects.