Reeled pipelines are submitted to cyclic deformation during reeling and unreeling operations. The behaviour of the plastic deformed pipe needed assessment. The customer furthermore provided a pipe for testing of its plastic behaviour.
The reeling process was modelled using finite element simulations. Pipe material was sampled and cyclically deformed, eventually followed by a second deformation step in another direction. The test matrix was elaborated in order to determine the evolution of the shape and the location of the yield locus in function of the pre-deformation steps.
A pipe was bent several times in different directions against a former in the MSC’s purpose-built reeling simulator. Ovality / HiLo was measured and the pipe was tested on its buckling resistance.
The information provided gives insight about the risk of ovalisation of the pipe after reeling and unreeling. The obtained results are implemented in a model for further simulation of the reeling installation process.
The ultra-low cycle fatigue characteristics of the pipe were determined as well as the feasibility of the pipe to multiple bending cycles.
Strain mappings in the pre-straining direction
Dedicated ultra-low cycle fatigue test set-up