A modular mold for producing a panel including a panel of fiber reinforced material. The panel is configured to form hollow cells having an undulated trapezoidal cross-section. The mold includes at least three molding bars for forming each hollow cell. One of the molding bars has a trapezoidal cross shape. The other two molding bars have a triangular cross shape. The trapezoidal molding bar is located between the two triangular molding bars. The three molding bars when put together its cross-section forms the shape of the trapezoidal cross-section of the hollow cell.

A floor panel for installation in an aircraft includes a plurality of thermoplastic C-shaped stringers, a consolidated thermoplastic deltoid filler, a thermoplastic upper facing sheet, and a thermoplastic lower facing sheet. The stringers are disposed in a parallel arrangement with one another. The deltoid filler is disposed within a longitudinally-extending notch defined by a pair of adjacent stringers. The upper facing sheet covers an upper surface of the stringers and the deltoid filler. The lower facing sheet covers a lower surface of the stringers and the deltoid filler. The stringers, the deltoid filler, and the upper and lower facing sheets are integrally consolidated forming a unitary construction.

In a method for manufacturing a honeycomb core by a domed bonding layer, a bonding sheet is, upon bonding of each cell, heated with hot air to form a uniform bonding layer on an end surface of each honeycomb cell, thereby providing a lightweight honeycomb core having stable strength. In the method for manufacturing the honeycomb core, a technique including the doming step of pumping, when bonding molding is performed for a core in which multiple ribs are connected to form an assembly of cells by means of a flat thermally-weldable bonding sheet laid on an upper surface of the core, upward hot air upwardly into the cells to form a dome-shaped bonding layer at the bonding sheet on an upper surface of each cell, the rupturing step of pumping downward hot air from above to the vicinity of the top of the dome-shaped bonding layer to rupture the bonding layer, and the thermal welding step of forming a uniform bonding layer on upper edge portions of the cells by means of meltability and surface tension.

Apparatus and associated methods relate to using an additive (material deposition) process to incrementally form a closed-cell lattice structure formed as a unitary body in the shape of a marine hull cavity, the unit cells of the closed-cell lattice structure are substantially hollow. In an illustrative example, a method may include (a) forming a closed-cell lattice structure through additive manufacture, the hull cavity material may be bonded to an upper manufactured liner and a lower manufactured liner through lamination or mechanical connection. Unit cells of the closed-cell lattice structure may include hollow voids filled with gases. Providing the additive manufactured closed-cell lattice structure with a unitary body and hollow voids to trap gases may further advantageously promote the buoyancy and reduce the degeneration of a marine hull.

A process for manufacturing a composite structure includes: providing first mandrels, each first mandrel including a base and a plurality of projections arranged longitudinally along and projecting vertically out from the base; providing second mandrels; providing first ribbon plies, each first ribbon ply including a sheet of fibrous material; arranging each first ribbon ply with a respective first mandrel, the arranging of each first ribbon ply including substantially covering each surface of each of the projections of one of the first mandrels with a respective first ribbon ply; mating each second mandrel with a respective first mandrel such that each first ribbon ply is sandwiched between a respective first mandrel and a respective second mandrel; and curing resin disposed with the first ribbon plies to consolidate the first ribbon plies together and form a fiber-reinforced composite core structure of an acoustic panel.

An object of the present invention is to provide a fiber-reinforced composite material achieving both lightweight properties and mechanical properties, a laminate thereof, and a prepreg capable of easily molding a sandwich structure thereof. The present invention is a prepreg comprising a reinforced fiber substrate (B) impregnated with a resin (A), wherein the reinforced fiber substrate (B) exists in a folded state having a plurality of folds with a fold angle of 0 or more and less than 90 in the prepreg.

A method for forming a fiber-reinforced thermoplastic control surface includes forming first and second skins from a fiber-reinforced thermoplastic resin. The method further includes overmolding fiber-reinforced thermoplastic features onto the first skin and/or second skin, including stiffener structures, sidewalls, and/or hinges. The method further comprises welding or consolidating the first and second skins together, along with the associated internal features overmolded thereon to form a single-piece, stiffened, fiber-reinforced thermoplastic control surface.

A method for producing a composite tank is disclosed. The tank has a continuous fiber reinforcement, a prismatic shape, and a thickness e for the storage of a pressurized gas in an internal cavity of the tank. The tank comprises fibers extending between two non-contiguous faces of the tank through the internal cavity. The method includes: (i) obtaining a prismatic fibrous preform having a thickness e comprising three-dimensional continuous reinforcements throughout its thickness; (ii) impregnating an outer layer of the preform with a polymer over a thickness of less than of the thickness e so as to constitute a composite outer shell extending over all faces of the prism; and (iii) forming a sealed layer constituting an inner lining, having a thickness of less than 1/10th of the thickness e between the outer shell and the fibrous network contained in the cavity of the tank.

A floor panel for installation in an aircraft includes a plurality of thermoplastic C-shaped stringers, a consolidated thermoplastic deltoid filler, a thermoplastic upper facing sheet, and a thermoplastic lower facing sheet. The stringers are disposed in a parallel arrangement with one another. The deltoid filler is disposed within a longitudinally-extending notch defined by a pair of adjacent stringers. The upper facing sheet covers an upper surface of the stringers and the deltoid filler. The lower facing sheet covers a lower surface of the stringers and the deltoid filler. The stringers, the deltoid filler, and the upper and lower facing sheets are integrally consolidated forming a unitary construction.

The invention relates to a method for manufacturing a box-shaped monolithic structure with a cavity by curing a fiber-reinforced prepreg material. The method comprises using two or more elongated and internally hollow support tools which have a complementary form to that of the cavities to be manufactured, and a composition based on reinforcement material and polymer suitable to allow the passage from a rigid state to a flexible elastomeric state and vice versa in response to heating/cooling down. In the rigid state, the support tools allow the direct lamination of the prepreg material on their external walls and are configured to set the flexible elastomeric state at a temperature lower than the curing temperature and higher than 50? C. During the curing operation, the curing pressure is applied both outside the structure being formed and inside the support tools, whose walls have become flexible, to push on the prepreg material to be cured.