Nonisothermal finite‐element analysis of thermoforming of polyethylene terephthalate sheet: Incomplete effect of the forming stage
Bibliographic record
Abstract
Abstract In this work, we consider a nonisothermal finite‐element analysis approach using an explicit dynamic procedure for the forming of a polyethylene terephthalate (PET) sheet subjected to air‐flow loading. The dynamic pressure load is thus deduced from the van der Waals equation of state. The effect of the radiative‐conduction heat transfer during the reheating stage, the stress‐deformation behavior during the incomplete forming stage, and the solidification during the cooling stage are simulated. The viscohyperelastic behavior of the Christensen–Yang‐like model is considered. The Lagrangian formulation, together with the assumption of the membrane shell theory, is used. The viscohyperelastic model is validated with the equibiaxial stretching tests. Also, temperature validation is performed by comparing the computed, the theoretical, and the experimental temperature profiles obtained from measuring the inside and outside PET sheet surface. An example of thermoforming a PET part is presented. In this example, the influence of the air‐flow on the thickness and the stress distribution is presented. POLYM. ENG. SCI., 47:2129–2144, 2007. © 2007 Society of Plastics Engineers
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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 | 0.001 |
| 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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 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 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".