The present invention relates to a skin/bulkhead structure comprising a barrel-shaped skin made of a fiber-reinforced composite and a pressure bulkhead connected to an opening of the barrel-shaped skin.
Pressure bulkheads, which are installed in front and back of a pressurized cabin of aircrafts, etc., are classified to spherical panels and flat panels. In large aircrafts, the spherical panels are often used as an aft pressure bulkhead. The spherical panels are generally composed of a stiffened spherical plate, and a pressure is applied thereto as membrane force. The spherical panels are advantageous in high structural efficiency and small weight penalty, however, it necessitates high production cost and useless, excessive spaces. On the other hand, in small aircrafts, the flat panels are desirably used as the pressure bulkhead from the viewpoint of space-saving. The flat panels are generally composed of a flat plate stiffened by thick beams, and they receive an applied pressure as bending moment. The flat panels have a remarkably simple composition and high space efficiency.
The pressure bulkhead is demanded to be connected to a barrel-shaped skin with high reliability. In a small aircraft body made of a fiber-reinforced composite, conventionally, the pressure bulkhead has been connected to the barrel-shaped skin by such a method that comprises the steps of: connecting marginal portion of the pressure bulkhead to the barrel-shaped skin by a rivet, adhesion, etc.; and providing complicated sealing to prevent the body from airleaking. However, this method has suffered disadvantages of increased production cost and heavy weight.
An object of the present invention is to provide a light, reliable skin/bulkhead structure comprising a barrel-shaped skin and a pressure bulkhead, which is excellent in space efficiency and can be produced with reduced production cost.
As a result of intensive research in view of the above object, the inventor has found that a light, reliable skin/bulkhead structure comprising a barrel-shaped skin and a pressure bulkhead can be produced with excellent space efficiency and reduced production cost if the pressure bulkhead is connected to the barrel-shaped skin by a combination of mechanical connection and adhesive connection. The present invention has been accomplished by the finding.
Thus, a skin/bulkhead structure of the present invention comprises a barrel-shaped skin and a pressure bulkhead composed of a stiffening member and a bulkhead skin, wherein an end of the stiffening member is mechanically connected to an opening of the barrel-shaped skin through a first connecting member and marginal portion of the bulkhead skin is adhesive-connected to the opening through a second connecting member, the barrel-shaped skin, the stiffening member, the bulkhead skin, the first connecting member and the second connecting member being each made of a fiber-reinforced composite.
According to the skin/bulkhead structure of the present invention, it is preferable that the opening of the barrel-shaped skin has edge portion expanded over the pressure bulkhead, and the end of the stiffening member is mechanically connected to the edge portion. The bulkhead skin is preferably a flat plate in shape, and the stiffening member preferably has an I-shaped cross section. Further, the second connecting member is preferably a ring in shape, and a cross section thereof is preferably in L-shape.