Definition
A structural property describing how strongly a material or part resists bending when a load is applied across it. Bending stiffness depends on both the material itself and the shape and thickness of the part. In composite aircraft structures, it is a key reason thicker sandwich panels and certain layups are used: they resist flexing far more than a thin sheet of the same weight.
Plain English
How hard it is to bend something. A part with high bending stiffness flexes very little under load; a part with low bending stiffness flexes more easily.
Context Anchor
Seen in discussions of composite aircraft structures, especially how layers, cores, and skins are arranged to make a part light but resistant to bending.
Derivation
From 'bending' (to flex or curve under load) and 'stiffness' (resistance to deformation). The combined term simply means 'resistance to being bent.'
Why Pilots Care
Determines whether a wing or control surface holds its shape under flight loads, directly affecting structural safety and performance.
Analogy
Think of a thin ruler versus a thick wooden board of the same length. Both are 'wood,' but the board barely flexes when you push on it. That difference is bending stiffness.
Intuition Check
Bending stiffness is not the same as strength. Strength is about how much load a part can take before it breaks; bending stiffness is about how much it resists flexing before that point.
Example Sentence 1
The honeycomb core in the composite floor panel gives it high bending stiffness without adding much weight.
Example Sentence 2
Engineers chose a thicker layup schedule because the original design lacked sufficient bending stiffness in the tailplane.