Numerical Analysis of Intermittent Stick-Slip Behaviour of Tube-Support Interaction in Heat-Exchangers
Bibliographic record
Abstract
Flow induced excitation forces in heat exchangers cause tube-support interactions. The long-term interaction is an important phenomenon which may cause fretting-wear of the tubes. Experimental tests of the interaction show the occurrence of stick-slip intermittent behavior in the tube response. Many factors are involved to precisely predict the interaction behavior including flow excitation forces, impact and friction forces. One of the explanations behind the intermittent stick-slip behavior may be interpreted by refinements in the conceptual choice of friction model and coefficient of friction. Therefore, among the factors above, the incorporated friction model plays an important role in the determination of the level of fretting-wear in the system. The friction model should satisfy two important criteria: the first important aspect is the strategy of the friction model to detect the cessation of sticking, the beginning of partial slipping and establishment of the sliding region. The second important aspect is defining a friction coefficient function for the entire system response to precisely represent the transient stick-slip regions. In the present work, the velocity limited friction model was compared with the LuGre model which is a rate dependent friction model. The effect of varying the break-away force and Stribeck effect on the stick-slip region was also investigated. Furthermore, the criteria to demarcate the stick-slip region in the LuGre model are discussed and a different method to incorporate the Stribeck effect and presliding damping in the Dahl friction model are proposed. Finally, a new hybrid spring-damper friction model inspired by the Cattaneo-Mindlin stress distribution in the contact region is proposed.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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 source (direct Gemma or distilled Codex), 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".