On the Collapse Failure of Dented Pipes Under Bending Moment and External Pressure

This paper presents the numerical research on the collapse failure of dented subsea pipelines under bending moment and external pressure. Firstly, the case of pure bending moment is studied and shows that the increase of initial denting displacement and ratio of diameter to thickness leads to decreased critical moment. Then the external pressure is imposed, and it is concluded that the non-dimensionalized critical bending moment decreases with the increase of the pre-applied external pressure and the initial denting displacement. If the bending moment is applied to the dented pipe before the external pressure, the collapse pressure would decrease to some extent. This paper is expected to provide the security guidelines to dented pipes under bending moment and external pressure.