Random fatigue analysis of drill-pipe threaded connection
Bibliographic record
Abstract
Threaded connections are widely used in connecting drill pipes into a drill string. During drilling operations, the threaded connections are subjected to various external loads, including the load from the unevenness of rock formation at the bottom, impact from the well bore and axial hook load etc. These loads are primarily random, and will cause fatigue damage to the connections during drilling operation. In this paper, a standard 4.5" API line pipe threaded connection is analysed to investigate the fatigue effect of the random loads. A static stress analysis is first conducted considering 'make-up' and 'tensile load' steps. Then modal analysis and random vibration analysis are carried out, with the excitation considered as random. The fatigue damage is predicted using the so called three-band technique based on the stress results obtained. Effects of parameters, such as the random excitation, location of the connection, and friction coefficient, on the fatigue are discussed.
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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) | 0.000 | 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) | 0.001 | 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".