Theory 34/Aerospace Structures

Panel Buckling Is a Thickness Ratio

The claim

Stiffened panel buckling is set by the ratio of skin thickness to stiffener spacing rather than by skin thickness alone.

01Mechanism

The skin buckles between stiffeners; the span it must carry scales with spacing while its resistance scales with thickness cubed, so the ratio governs.

02Predictions

P1Buckling load should collapse onto the ratio.
P2Thickness alone should mispredict.

03Refutation

Buckling tracking thickness would remove the spacing.