Impact simulation of bird strike on semi-spherical transparencies: application to observation bubbles in the C-295 aircraft
Bibliographic record
Abstract
Conflicts between birds and aircraft have increased in the last years since traffic volume and bird population have spread. Although it seems an \ninsignificant event,up to 2009, EASA sets in 242 fatalities and 90 hull losses because of these incidents and this is why Canadian customers are concerned \nby this increment and have demanded a specific certification for the spotter windows bubbles of C-295 aircraft. This concern has motivated the aim of this \nresearch promoted by Airbus Defence and Space. The purpose of this research is the numerical simulation of bird impact on semi-spherical transparencies similar to observation bubbles in the C-295 aircraft in order to obtain a rst approach of the structural behaviour under this fact. \nThe study is divided into three stages: - Firstly, the characterization of the bird is performed against rigid \nat metallic targets. Experimental data coming from CRAVHI project and analytical interpretation based on Willbeck's theory have been used to validate the results. \n- Secondly, the characterization of the transparency is achieved, and although the lack of experimental results complicated the labour, some researches and analytical results have been used to find a suitable model.Two analyses on \nat transparencies have been carried out in parallel, a monolithic transparency and a laminated model (similar to \nspotter windows and cabin windshields respectively). \n- Finally, the semi-spherical bubble has been modelled. The explicit numerical simulation code \\Visual Environment", formerly PAM-CRASH, has been used for the simulation of these impacts. \nThe results show the high dependence of acrylic materials on strain rates and the need to take it into consideration in the modelization of the finite element model. \nMoreover, the results expressed in terms of ballistic limits show that the current spotter window monolithic design would not fail in case of a bird striking \nthe bubble until speeds about 50 m/s, making the advantages of laminated model (in terms of weight reduction and limit speed increment) of interest for further works.
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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 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| 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".