Patent ID: 8337740

Claim:
A method of making a composite structure, the method comprising: obtaining at least two pressurizable members having sufficient rigidity for supporting fiber plies thereon, each of the pressurizable members having a desired shape before pressurization that includes an outer surface and an inner surface defining a volumetric region, the desired shape of each pressurizable member being different from a final shape of the composite structure, each of the pressurizable members further having an opening to permit internal pressurization thereof; arranging fiber plies wetted with a resin to form at least one structural member located between the at least two pressurizable members, wherein each of the pressurizable members substantially maintains its respective, desired shape after being loaded with the fiber plies, yet before pressurization thereof; positioning at least one stiffener adjacent the structural member and further positioning the at least one stiffener between and in contact with one of the pressurizable members and the wetted fiber plies, the at least one stiffener having a modulus of elasticity that is substantially larger than a modulus of elasticity of the resin; placing a composite assembly into a mold, wherein the composite assembly includes an arrangement of the pressurizable members, the fiber plies and the stiffener; pressurizing an outer surface of the composite assembly with a first pressure; and simultaneously pressurizing the inner surface of the pressurizable members with a second pressure, wherein the first pressure and the second pressure operate to compress the fiber plies while the at least one stiffener maintains a desired shape of the web structure during pressurization.