Radial Buckling of Tensile Armor Wires in Subsea Flexible Pipe—Numerical Assessment of Key Factors
Bibliographic record
Abstract
Flexible pipes can be used as risers, jumpers, and flowlines that may be subject to axial forces and out-of-plane bending motion due to operational and environmental loading conditions. The tensile armor wires provide axial stiffness to resist these loads. Antibirdcaging tape is used to provide circumferential support and prevent a loss of stability for the tension armor wires, in the radial direction. The antibirdcaging tape may be damaged where a condition known as “wet annulus” occurs that may result in the radial buckling (i.e., birdcaging mechanism) of the tensile armor wires. A three-dimensional continuum finite element (FE) model of a 4 in. flexible pipe is developed using abaqus/implicit software package. As a verification case, the radial buckling response is compared with similar but limited experimental work available in the public domain. The modeling procedures represent an improvement over past studies through the increased number of layers and elements to model contact interactions and failure mechanisms. A limited parameter study highlighted the importance of key factors influencing the radial buckling mechanism that includes external pressure, internal pressure, and damage, related to the percentage of wet annulus. The importance of radial contact pressure and shear stress between layers was also identified. The outcomes may be used to improve guidance in the engineering analysis and design of flexible pipelines and to support the improvement of recommended practices.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".