Ductile tearing analyses of cracked TP304 pipes using the multiaxial fracture strain energy model and the Gurson-Tvergaard-Needleman model

Abstract

Ductile crack growth behaviours of TP304 pipes containing different circumferential defects were investigated in the study. Finite element (FE) damage analysis of the ductile fracture was carried out based on an uncoupled multiaxial fracture strain energy (MFSE) model with only two model parameters, which can be calibrated by data from tensile tests and fracture toughness tests. For the purpose of comparison, the Gurson-Tvergaard-Needleman (GTN) model was also employed in the FE damage analysis. It is observed that the MFSE model can reproduce the ductile tearing experiments as excellently as the GTN model does. Despite its simplicity, the MFSE model can reasonably predict the magnitudes of the crack initiation load and maximum load, the load-line displacement, the crack mouth opening displacement, the crack extension and the crack profiles in the full-scale cracked pipe tests.