Numerical model for unstable ductile crack propagation and arrest in pipelines using finite difference method

•A numerical model to predict unstable ductile crack propagation/arrest is proposed.•The model is based on finite difference method.•Gas decompression, pipe deformation and crack propagation are formulated.•Effect of soil backfill depth is formulated in the model.•The model predicts experimental results reasonably well.

Prevention of unstable ductile crack propagation has been a great issue in pipeline industry. For appropriate pipe design, the authors developed a numerical model to predict unstable ductile crack propagation/arrest using finite difference method. The features of the model are as follows: (1) pipe deformation and gas decompression are formulated based on one-dimensional partial differential equations; (2) the interaction among pipe deformation, gas decompression and crack propagation is considered; (3) soil backfill effect, which constrains pipe deformation, is considered as added density. In this paper, the model is described in detail, and applied to full-scale natural gas pipe burst tests.