Here we investigate the limits and the boundary layers of the three-dimensi
onal displacement in thin elastic plates as the thickness tends to zero in
each of the eight main types of lateral boundary conditions on their edges:
hard and soft clamped, hard and soft simple support, friction conditions,
sliding edge, and free plates. Relying on construction algorithms [M. Dauge
and I. Gruais, Asymptotic Anal., 13 (1996), pp. 167-197], we establish an
asymptotics of the displacement combining inner and outer expansions. We de
scribe the two first terms in the outer expansion: these are Kirchhoff-Love
displacements satisfying prescribed boundary conditions that we exhibit. W
e also study the first boundary layer term: when the transverse component i
s clamped, it has generically nonzero transverse and normal components, whe
reas when the transverse component is free, the first boundary layer term i
s of bending type and has only its nonzero in-plane tangential component.