Acta Scientiarum Polonorum

The present paper analyses the boundary effect in the plate theory. We considered a plate half-band and rectangular plates loaded at the free edge with twisting moments and lateral load  (Fig. 1). Such load does not cause displacements or stress resultants in plates calculated according to the thin plate theory. The boundary effect occurs when we analyze plates of medium thickness. The paper obtains solutions according to the Hencky-Boole theory and it presents the boundary effect in a plate band and rectangular plates. We studied the scope of disturbances caused by the edge load in the half-band as well as the influence of homogenous boundary conditions, given on the opposite edges of rectangular plates, on the scope of the boundary effect. It was shown that the solutions of the half-band and rectangular plates at the η₀=b/a=1 quotient (Fig. 1) do not differ significantly, and at η₀=b/a=2 the differences disappear, which means that at a distance of two plate widths displacements and stress resultants disappear.