Patent ID: 8061966

Claim:
A composite containment casing, including a fan casing for a gas turbine engine fan assembly that includes at least one fan blade, the fan casing having a radial thickness, the containment casing comprising: a body having an interior; an abradable system integrally joined to the interior of the body of the containment casing wherein the abradable system comprises: a sandwich structure including: a first facesheet and a second facesheet positioned about at least one core layer; and at least one abradable layer applied to the sandwich structure, the sandwich structure defining a circumferential pocket positioned between opposed ends of the body, the sandwich structure comprising a width of from about one to about three times an axial chord length of the at least one fan blade and a depth of from about one to about five times the radial thickness of the fan casing, wherein the at least one core layer comprises any of a cell configuration, a columnar configuration, or a truss configuration and wherein the sandwich structure is strong radially and weak circumferentially.