Definition
Thin sheet metal that has been formed into a series of parallel ridges and grooves to increase its rigidity and resistance to bending across the direction of the corrugations. Used in aircraft construction where stiffness must be added without significantly increasing weight.
Plain English
Flat metal that has been pressed into a wavy pattern so it becomes much stiffer and harder to bend, while still being light.
Context Anchor
Seen in aircraft structures, especially when discussing skins, panels, control surfaces, or older aircraft construction methods.
Derivation
From the Latin 'corrugare', meaning 'to wrinkle' (from 'ruga', a wrinkle or fold). The wrinkles in the metal are exactly what give it its added stiffness.
Why Pilots Care
The ridges give lightweight parts the strength needed to handle flight loads without adding heavy reinforcements.
Analogy
Take a flat piece of paper and try to hold it out flat — it sags. Fold it into a fan shape and it stays rigid. The folds do the same job in metal.
Intuition Check
Do not assume the ridges mean the metal is damaged or wrinkled by accident. In this term, the ridges are intentionally formed to add stiffness.
Example Sentence 1
The aileron's internal ribs were reinforced with corrugated sheet metal to keep the surface rigid in flight.
Example Sentence 2
Early aircraft often used corrugated sheet metal on the wings to keep them light yet rigid.