A novel viscoplastic model of high-density polyethylene pipe material
Bibliographic record
Abstract
ABSTRACT: A nonlinear three-component elastic viscoplastic strain-rate-dependent model was developed for a high-density polyethylene pipe material. In this model, the stress at any point is assumed to be a unique function of the instantaneous irreversible strain, its rate and acceleration, irrespective of any intermediate stress and strain history. However, a reference strain rate was assumed and below this the response was independent of the strain rate. Parameters of the model were determined using published data on strain-rate-dependent material responses. The model was developed within the elasto-viscoplastic framework so that it could be used in solving boundary value problems. The return mapping algorithm of strain-rate-dependent elasto-plastic material is described with the detailed derivation of the consistent tangent operator for quadratic convergence. The model was successfully implemented in an existing finite-element code. Finite-element analyses using this model were capable of simulating the strain-rate-dependent stress–strain relation, the response to a jump in the strain rate and an unloading–reloading response for a high-density polyethylene pipe material published in the literature.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".