A comparative numerical study of motorcoach rollover resistance under ECE R66 and proposed NHTSA regulation conditions
Bibliographic record
Abstract
Under increasing public concern for the safety of passengers in large passenger vehicles such as buses and motorcoaches, legislative regulations are enforced and continuously updated worldwide. Recently, a new federal regulation was proposed in North America to enhance the safety level of motorcoach passengers under the rollover condition, based on regulation No. 66 of the Economic Commission for Europe (ECE R66), but with more severe loading conditions in the form of the full passenger mass ballasted to all seats. This article presents the results of a comparative study on rollover resistance and energy absorption distribution of a motorcoach structure for loadings of both zero and full passenger mass. Two test conditions are numerically simulated using a complete validated finite element model of a typical motorcoach. The results of the comparison indicate that the test conditions of the proposed regulation with full passenger mass lead to a 4.7 times greater penetration of the surviving space of the passenger compartment than the ECE R66 conditions with zero passenger mass. The distribution of the energy absorption suggests that pillar loops rank first in absorbing energy. Owing to the coupled passenger mass, the National Highway Traffic Safety Administration (NHTSA) proposed regulation places higher requirements on the rollover resistance of the wall beams and seat-wall joints, as their energy absorption ratio at the end of impact increases by 27%. Overall, the results of the study can provide a data basis for the manufacturers to improve the rollover resistance of motorcoaches.
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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) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| 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".