A vessel, such as a wing-integrated aircraft fuel tank. The vessel can include
a first surface portion, a second surface portion spaced apart from the first surface
portion, and a core positioned between the first and second surface portions. The
core can be sealably connected to the first and second surface portions and can
be positioned to carry a load from at least one of the first and second surface
portions to the other. The core can include a plurality of cells separated by cell
walls, at least some of which have wall openings positioned to provide liquid communication
between adjacent cells.
