Effect Analysis of Gurson Model Parameters on Crack Extension of Pipeline

Leakage-before-break technique is widely used in high energy pipeline of nuclear plant, for which crack stability of pipeline under complex loading condition is a key issue, and crack growth resistance curve of pipeline material is the important foundation for crack stability analysis. In this paper, ferritic steel A533B is studied, Gurson damage model is used to simulate crack process of contact tension specimen under unitension, and effect of Gurson model parameter on simulation result is discussed. The following results are found during simulation: initial porosity factor is the main parameter, when it increases gradually, unstable crack extension will be observed; however, only initial J toughness is affected by critical porosity factor; the minor parameter is load step control, when it increases, stable and convergent result is obtained. All results in this paper can be used to determine parameters in Gurson mode, which will be foundation for crack extension analysis of pipeline.