Buckling Equations for Laminated Plates

A plate buckles when the in-plane compressive load gets so large that the originally flat equilibrium state is no longer stable, and the plate deflects into a nonflat (wavy) configuration. The load at which the departure from the flat state takes place is called the buckling load. The flat equilibrium state has only in-plane forces and undergoes only ex- 

Bending, Buckling, and Vibration of Laminated r. ies 287 The variations in force and moment resultants are 

The boundary conditions could be different for each edge of a plate, so the number of combinations of possible boundary conditions is quite large as it was with equilibrium problems. 

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