# US 8,540,921 B2 · Method of forming a reinforced foam-filled composite stringer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,540,921 B2 - Document ID: US8540921B2 - Status: Granted - Kind: B2 - Application number: 12/277,483 - Filed: 2008-11-25 - Published: 2010-05-27 - Granted: 2013-09-24 - Earliest claimed: 2008-11-25 - Assignees: The Boeing Company - Applicants: Simon D. Senibi; Barry P. Van West; Juan Carlos Guzman; Douglas A. McCarville; Daniel M. Rotter - Inventors: Simon D. Senibi; Barry P. Van West; Juan Carlos Guzman; Douglas A. McCarville; Daniel M. Rotter - Web page: https://patentgrep.com/patent/US8540921B2 ## CPC - B32B 5/18: characterised by features of a layer {of} foamed material - B32B 1/08: Tubular products - B32B 3/26: characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids {(foam layer B32B5/18; layer of synthetic resin characterised by fillers that create voids or cavities B32B27/205); characterised by an apertured layer} - B32B 3/28: characterised by a layer comprising a deformed thin sheet {, i.e. the layer having its entire thickness deformed out of the plane}, e.g. corrugated, crumpled (B32B29/08 takes precedence) - B32B 9/005: {comprising one layer of ceramic material, e.g. porcelain, ceramic tile (layered products with at least two ceramic layers composed mainly of ceramic B32B18/00)} - B32B 9/007: {comprising carbon, e.g. graphite, composite carbon} - B32B 15/046: {of foam} - B32B 15/18: comprising iron or steel {(B32B15/011, B32B15/012 and B32B15/013 take precedence)} - B32B 15/20: comprising aluminium or copper {(B32B15/016 and B32B15/017 take precedence)} - B32B 27/00: Layered products comprising {a layer of} synthetic resin {(fibrous or filamentary layer made of a synthetic resin B32B5/02; particulate layer made of a synthetic resin B32B5/16; foamed layer made of a synthetic resin B32B5/18)} - B64C 1/064: {Stringers; Longerons} - B32B 2266/08: Closed cell foam - B32B 2307/558: Impact strength, toughness - B32B 2605/18: Aircraft - Y10T 428/233: Foamed or expanded material encased - Y10T 428/24504: Component comprises a polymer [e.g., rubber, etc.] - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - B64C: AEROPLANES; HELICOPTERS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A method and apparatus for manufacturing a composite stringer. A composite material and foam are laid up onto a tool in the form of a stringer. The foam has a plurality of structural members within the foam. The plurality of structural members has a number of orientations to resist a number of loads. The composite material, the foam in the form of the stringer, and the plurality of structural members are cured to form the composite stringer. ## Claims ### Claim 1 A method for manufacturing a composite stringer, the method comprising: placing a plurality of structural members within a foam, the plurality of structural members comprising at least one of a number of pins, a number of tubes, and a number of rods; laying up a composite material and the foam with the plurality of structural members within the foam onto a tool in the form of a stringer, wherein the plurality of structural members has at least a first orientation and a second orientation, the first orientation and the second orientation being different from each other, the plurality of structural members configured to resist a number of loads on the stringer including at least compressive loads; placing the foam and the composite material onto a skin ply such that the plurality of structural members within the foam do not substantially pierce the skin ply; wherein the structural members extend from the skin ply to a first and a second wall of the composite stringer and wherein the structural members are positioned substantially within the foam; and curing the composite material, the foam in the form of the stringer, and the plurality of structural members to form the composite stringer. ### Claim 2 (depends on 1) The method of claim 1 further comprising: placing the plurality of structural members within the foam; shaping the foam for the composite stringer with the plurality of structural members within the foam. ### Claim 3 (depends on 1) The method of claim 1, wherein the laying up step comprises: laying up the composite material onto an inside mold line; and placing the foam onto the composite material. ### Claim 4 (depends on 3) The method of claim 3, wherein the laying up step further comprises: placing a skin ply over the foam and the composite material. ### Claim 5 (depends on 4) The method of claim 4 wherein the laying up step is performed using an outside mold line. ### Claim 6 (depends on 1) The method of claim 1, wherein the composite stringer has a shape selected from one of a trapezoid shape, a hat shape, a solid shape, and a hollow shape. ### Claim 7 (depends on 1) The method of claim 1, wherein the plurality of structural members is comprised of a material selected from one of aluminum, steel, carbon-reinforced material, graphite-reinforced material, titanium, a metal alloy, and a ceramic material. ### Claim 8 (depends on 1) The method of claim 1, wherein the plurality of structural members has a first density in a first area and a second density in a second area. ### Claim 9 (depends on 1) The method of claim 1, wherein the composite stringer is located in an aircraft. ### Claim 10 (depends on 1) The method of claim 1, wherein the first orientation and the second orientation are selected so as to be substantially normal to each other. ### Claim 11 A method for forming a composite part, the method comprising: laying up a composite material and a foam core onto a tool in a form of the composite part, the foam core having a plurality of structural members, wherein the plurality of structural members has at least a first orientation and a second orientation, the first orientation and the second orientation being different from each other, the plurality of structural members configured to resist a number of loads including at least compressive forces on the composite part, the plurality of structural members comprising at least one of a number of pins, a number of tubes, and a number of rods; placing the foam core and the composite material onto a skin ply; curing the composite material and the foam core in the form of the composite part such that the plurality of structural members do not substantially pierce the skin ply; wherein the structural members extend from the skin ply to a first and a second wall of the composite part stringer and wherein the structural members are positioned substantially within the foam; and forming the composite part with a channel in which the foam core is located. ### Claim 12 (depends on 11) The method of claim 11, wherein the laying up step comprises: laying up the composite material onto an inside mold line; and placing the foam core onto the composite material. ### Claim 13 (depends on 11) The method of claim 11, wherein the plurality of structural members has a first density in a first area and a second density in a second area, the first density and second density being different. ### Claim 14 (depends on 11) The method of claim 11, wherein the composite part is a composite stringer. ### Claim 15 (depends on 14) The method of claim 14, wherein the composite stringer has a shape selected from one of a trapezoid shape, a hat shape, a solid shape, and a hollow shape. ### Claim 16 (depends on 11) The method of claim 11, wherein the plurality of structural members is comprised of a material selected from one of aluminum, steel, carbon-reinforced material, graphite-reinforced material, titanium, a metal alloy, and a ceramic material. ### Claim 17 (depends on 11) The method of claim 11, wherein the first orientation and the second orientation are selected so as to be substantially normal to each other. ### Claim 18 A method for manufacturing a plurality of composite stringers, the method comprising: laying up composite material and foam with a plurality of z-pins within the foam onto a plurality of tools to form a plurality of composite stringers, wherein the plurality of z-pins has at least a first orientation, the plurality of z-pins configured to resist a number of loads including compressive loads on the composite stringers, and the plurality of z-pins comprising at least one of a number of pins, a number of tubes, and a number of rods; placing the plurality of composite stringers on a single tool; placing a skin ply over the plurality of composite stringers to form a structure; wherein the plurality of z-pins extends from the skin ply to a first and a second wall of the composite stringers and wherein the structural members are positioned substantially within the foam; and curing the structure such that the plurality of z-pins do not substantially extend past the first and the second wall of the composite stringer.