DOI

Flexible risers are one kind of flexible pipes that transport fluid between subsea facilities and topside structures. This pipelike structure consists of multiple layers and its innermost carcass layer is designed for external hydrostatic pressure resistance. For the flexible risers used in ultra-deep water fields, the critical collapse pressure of the carcass layers is one of the dominant factors in their safety design. However, the complexity of the interlocked carcass design introduces significant difficulties and constraints into the engineering analysis. To facilitate the anti-collapse analysis, equivalent layer methods are demanded to help construct an equivalent pipe that performs a similar collapse behavior of the carcass. This paper proposes a strain energy based equivalent layer method which trying to bridge the equivalence between those two structures by considering equivalent geometric and material properties for the equivalent layer. Those properties are determined through strain energy equivalence and membrane stiffness equivalence. The strain energy of the carcass is obtained through numerical models and is then used in a derived equation set to calculate the equivalent properties for the equivalent layer. After all the equivalent properties have been determined, an equivalent layer FE model is built and used to predict the critical pressure of the carcass. The prediction result is compared to that of the full 3D carcass model as well as the equivalent models that built based on other existing equivalent methods, which shows that the proposed equivalent layer method gives a better performance on predicting the critical pressure of the carcass.

Original languageEnglish
Title of host publicationProceedings ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering
Subtitle of host publicationVolume 5: Pipelines, Risers, and Subsea Systems
Place of PublicationNew York, NY, USA
PublisherASME
Number of pages9
ISBN (Electronic)978-0-7918-5124-1
DOIs
Publication statusPublished - 2018
EventASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering, OMAE 2018 - Madrid, Spain
Duration: 17 Jun 201822 Jun 2018

Conference

ConferenceASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering, OMAE 2018
CountrySpain
CityMadrid
Period17/06/1822/06/18

    Research areas

  • Carcass, Collapse failure, Equivalent layer, Flexible riser, Strain energy

ID: 50240795