A Method to Reduce the Number of Assembly Tightening Passes in Bolted Flange Joints
Why this work is in the frame
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Bibliographic record
Abstract
Abstract Bolted flange joints are extensively used in pressure vessels and piping equipment and rotating machinery. Achieving a uniform bolt preload during the assembly process is particularly important to satisfy tightness in applications such as oil, gas, fossil, and nuclear industries. However, this task becomes very difficult due to the need of retightening the bolts because of elastic interaction and bolt cross talk. The risk of leakage failure under service loading is consequently increased because of the scatter of the bolt preload. This article presents an analytical model based on the theory of circular beams on the linear elastic foundation that simulates the elastic interaction present during the tightening of bolted flange joints to reduce the number of passes while achieving bolt load uniformity. As such, a novel methodology that optimizes tightening sequence strategies is suggested to obtain uniform bolt tension while avoiding yield under a minimum number of tightening passes. In this regard, based on the target preload, the load applied to each bolt in each pass is suggested. The developed approach is validated both numerically using finite element method and experimentally on a NPS 4 class 900 welding neck flange joint using the criss-cross tightening and sequential patterns.
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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 | 0.002 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| 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 it