On Electromagnetic Shielding in Composite Aircraft: An Applied Electromagnetic Approach
Bibliographic record
Abstract
Effectiveness of current electromagnetic shielding techniques in composite aircraft has been called into question several times before and is a subject of interest and research in the aerospace industry. We present an analytical approach to understand the issues in detail. It was found using first order approximations that a panel with Aluminum expanded metallic foil (ExMF) along with carbon fiber plies used on composite aircraft provides fair albeit lower electromagnetic shielding from source frequencies of a few KHz until well into MHz range when compared to an aluminum panel used on metallic aircraft. This was primarily attributed to relatively large skin depth value at low frequencies which was due to: a) low electrical conductivity of aluminum ExMF when compared to bulk aluminum; b) low electrical conductivity of resin impregnated carbon fiber layers and; c) very thin layer of aluminum ExMF used. It was also found that as source frequency goes higher (between 800 MHz to 18 GHz range), fields penetrate through the aluminum ExMF and although they may get attenuated by the CFRP plies however, shielding effectiveness at higher frequencies still remains lower for composite aircraft when compared to metallic aircraft.
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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 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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) | 0.004 | 0.002 |
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".