Predicting the crack open displacements of a partially debonded pipeline in rock mass under SH waves

To avoid the in-service crack growth of pipelines, a fundamentally based mathematical model of a partially debonded pipeline embedded in the rock mass is proposed, and the dynamic crack open displacement under anti-plane shear waves is theoretical derived. The debonding region around the pipeline is modeled as an interface crack with noncontacting faces. The wave fields in different regions are expressed by wave function expansion method. The crack opening displacement in the debonding region is represented by Chebyshev polynomials. Some examples are illustrated, and the results are figured. The results show that the crack open displacement increases with increasing wave frequency. Due to the increase of pipeline thickness, the crack open displacement also increases. In the region of high frequency, the value of crack open displacement is more sensitive to the crack size. Comparison with existing results is given to validate this dynamic model.