Abstract: A composite structure is provided. The structure is based upon a three-dimensional woven fabric structure. The three-dimensional woven fabric has a first fabric layer and a second fabric layer spaced apart from the first fabric layer, with the layers connected by threads which form a portion of the three-dimensional woven fabric structure. The threads define voids in the space between the first and second layers. A first resinous material is coated onto and allowed to penetrate the first layer of the woven fabric structure. Next a second resinous material is coated onto and allowed to penetrate the second layer of the woven fabric structure. The voids are filled with a third resinous material. In order to complete the formation of the composite structure, the resins are fully cured. Using this method it is possible for the resinous materials to be chemically incompatible, yet mechanically attached by the cloth material.

Abstract: A composite structure is provided. The structure is based upon a three-dimensional woven fabric structure. The three-dimensional woven fabric has a first fabric layer and a second fabric layer spaced apart from the first fabric layer, with the layers connected by threads which form a portion of the three-dimensional woven fabric structure. The threads define voids in the space between the first and second layers. A first resinous material is coated onto and allowed to penetrate the first layer of the woven fabric structure. Next a second resinous material is coated onto and allowed to penetrate the second layer of the woven fabric structure. Following the application of the resins, the voids remain substantially empty. In order to complete the formation of the composite structure, the resins are fully cured. Using this method it is possible for the first resinous material and the second resinous material to be chemically incompatible, yet mechanically attached by the cloth material.

Abstract: A fuel tank for aircraft includes a rigid securement for securing the tank to the aircraft, a skin connected to the securement, and a liner inside the skin. The skin includes an elastic fiber and a tensile fiber embedded in a flexible matrix. In one embodiment, the elastic fiber and the tensile fiber are wound in layers within the flexible matrix, and the elastic fiber is wrapped spirally about the tensile fiber. The elastic fiber is preferably an elastomeric fiber such as an elastic, segmented polyurethane fiber. The tensile fiber is preferably an aramid polymer fiber such as an aromatic polycarbonamide fiber. The flexible matrix may be formed of natural rubber or neoprene rubber. When the tank is filled, the elastic fiber lengthens until the tensile fiber resists further stretching. The elastic fiber tends to contract as the tank is emptied, substantially reducing the storage space required by the tank. The tank is nestable when empty, but is nonetheless substantially ready to receive fuel.