Theoretical analysis of local indentation by the wedge indenter for pressurised pipeline

External impact is one of the potential hazards for in-service subsea pipelines. The stress concentration by external impact can create a dent that affects the pipeline's ultimate bearing capacity. In this paper, a theoretical model based on the string-on-plastic foundation is established to model the local indentation of pressurised pipelines by a wedge indenter. The effects of internal pressure and boundary conditions on the denting process are investigated. With this model, the relationship between the indenting force and the dented depth is obtained under a set of two boundary conditions. The accuracy of the new analytical models is validated by comparing them with the specification and numerical simulation model. It is believed that the new analytical models will provide theoretical guidance for maintaining the reliability and integrity of in-service pressurised pipelines.