The latest research progress on residual ultimate strength of metallic pipelines with structural damage is presented through literature survey. The investigated pipe diameter-to-thickness ratios majorly lie between 20 and 50, which are typically applicable in deep water. Influential parameters in terms of pipe load, installation process and material that affect the ultimate strength of pipes are categorised. Structural damage including dent, metal loss and crack is identified and efforts are made to summarise critical damage factors such as dent length and crack depth. Furthermore, research and prediction methods on pipe residual ultimate strength in terms of experimental tests, numerical simulations and analytical predictions are summarised and discussed. Specific details on how to introduce, simplify and simulate structural damage are presented and discussed. It is expected that the mechanism of residual ultimate strength of metallic pipes with structural damage can be clarified through this study so that guidance will be provided for researchers in this field.

The surface crack, also known as the partly through-thickness crack, is a serious threat to the structural integrity of offshore metallic pipes. In this paper, we review the research progress in regard to surface crack growth in metallic pipes subjected to cyclic loads from the fracture mechanics perspective. The purpose is to provide state-of-the-art investigations, as well as indicate the remaining challenges. First, the available studies on surface cracked metallic pipes are overviewed from experimental, numerical, and analytical perspectives, respectively. Then, we analyse state-of-the-art research and discuss the insufficiencies of the available literature from different perspectives, such as surface cracks and pipe configurations, environmental influential parameters, the girth welding effect, and numerical and analytical evaluation methods. Building on these surveys and discussions, we identify various remaining challenges and possible further research topics that are anticipated to be of significant value both for academics and practitioners.