Abstract: The invention relates to a monolithic structure in composite material manufactured starting from a fiber-reinforced prepreg material and comprises two walls facing each other and at least one interconnection element extending transversely between the walls, connected to them and delimiting with the latter respective elongated cavities; wherein the walls extend symmetrically at opposite sides of a direction; the interconnection element is a rib extending transversely to the aforesaid direction; at least one wall has a sandwich configuration and comprises two panels facing each other and at least one spar member, which extends transversely between the panels, is connected to them, delimits with the latter respective elongated cavities and extends transversally to the rib.

Abstract: A hollow body closed at its lower end by means of a bottom wall is provided and the body includes an upper filler opening for introducing a selected fluent material into the body. A false bottom wall is disposed in surface-to-surface engagement with and underlies the bottom wall and is oscillatably supported from the latter for shifting between first and second positions. The bottom wall and false bottom wall have openings formed therethrough which are disposed out of registry with each other when the false bottom wall is in its first position and registered with each other when the false bottom wall is disposed in the second position thereof, whereby fluent material within the hollow body may flow, by gravity, downwardly through the openings formed in the bottom wall and the false bottom wall.