Notions of "plate" and "veiling
Structural instabilities of plates

Simplistically, a plate can be defined as a structural component in which one of the three dimensions, known as "thickness", is small in relation to the other two. In principle, it is a flat structural being, meaning that the mid-plane, the surface at mid-thickness, is initially assumed to be perfectly flat.

To avoid unnecessary mathematical complications, we limit ourselves here to considering only plates for which both :

• the thickness t is constant ;

• the shape is rectangular and defined by length a and width b ;

• the constituent material – for structural steels, in this case –, is assumed to be homogeneous and isotropic.

Strictly speaking, these conditions do not constitute restrictions,...