Why airliner windows have no corners: stress piles up at the tightest curve
30seconds
Cut a hole in a stretched plate and the force has to squeeze past it, so the metal beside the hole carries far more stress than the rest. For a round hole in a large plate the peak is exactly three times the average; for a sharp-cornered one it is much worse.
Reshape a hole yourself and watch the stress peak climb as the tip gets tighter. It is why the first jet airliner, the de Havilland Comet, cracked at the corners of its squarish windows, and why airliner windows have been rounded ever since.
Deep dive · 5 min
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