# US 11,027,521 B2 · Splice joint in laminate composite structure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,027,521 B2 - Document ID: US11027521B2 - Status: Granted - Kind: B2 - Application number: 16/004,371 - Filed: 2018-06-09 - Published: 2019-12-12 - Granted: 2021-06-08 - Earliest claimed: 2018-06-09 - Assignees: Textron Innovations Inc. - Applicants: Bell Helicopter Textron Inc. - Inventors: Sebastien Duval - Web page: https://patentgrep.com/patent/US11027521B2 ## CPC - B32B 5/02: characterised by structural features of a {fibrous or filamentary} layer {(layer formed of metallic wires B32B15/02; layer formed of natural mineral fibres B32B19/02; layer formed of wood fibres B32B21/02)} - B29C 70/304: {In-plane lamination by juxtaposing or interleaving of plies, e.g. scarf joining} - B29C 70/382: {Automated fiber placement [AFP]} - B29D 99/001: {Producing wall or panel-like structures, e.g. for hulls, fuselages, or buildings (articles with hollow walls B29D24/00)} - B29D 99/0028: {hollow blades} - B32B 1/00: Layered products having a non-planar shape - B32B 5/12: characterised by the relative arrangement of fibres or filaments of {different layers, e.g. the fibres or filaments being parallel or perpendicular to each other} - B32B 7/03: with respect to the orientation of features (direction of fibres or filaments B32B5/12) - B32B 27/08: of synthetic resin - B29K 2105/0881: {unidirectional} - B29L 2031/3076: {Aircrafts (blades, propellers B29L2031/08)} - B29L 2031/3088: {Helicopters} - B32B 5/26: another layer {next to it} also being fibrous or filamentary {(relative arrangement of fibres or filaments of different layers B32B5/12)} - B32B 2250/20: All layers being fibrous or filamentary - B32B 2260/023: Two or more layers - B32B 2260/04: Impregnation, embedding, or binder material - B32B 2605/18: Aircraft - Y02T 50/40: Weight reduction - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00) - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract Layers of plies of composite material are laid on a convex tool surface. A first layer is placed with a first ply of a first section having a gap edge adjacent a gap edge of a first ply of a second section, the edges being parallel and a contraction distance from each other. A second layer is placed with a second ply of the first section having a gap edge adjacent a gap edge of a second ply of the second section, the edges being parallel and a contraction distance from each other, the second ply of the second section overlapping onto the first ply of the first section by a splice distance. Consolidation and curing cause contraction of the layers toward the tool, allowing the adjacent gap edges of each layer to be in close proximity or in contact after moving toward each other during the contraction. ## Claims ### Claim 1 A method for forming a composite structure of first and second sections joined by a splice joint, each section being formed from uncured layers of plies of composite material, each ply being formed from fibers and a volume of uncured matrix material and having a gap edge, the method comprising: (a) placing a first ply of the first section on a convex surface of a tool; (b) placing a first ply of the second section on the surface of the tool, a gap edge of the first ply of the second section being spaced by a selected first contraction distance from and generally parallel to a gap edge of the first ply of the first section, the first plies forming a first layer; (c) placing a second ply of the first section on the first ply of the first section, a gap edge of the second ply of the first section being spaced by a selected splice distance plus a selected second contraction distance from the gap edge of the first ply of the first section; (d) placing a second ply of the second section on the first ply of the second section, a gap edge of the second ply of the second section being spaced by the selected second contraction distance from and generally parallel to the gap edge of the second ply of the first section, a portion of the second ply of the second section overlapping the first ply of the first section by the splice distance, the second plies forming a second layer, the first and second layers forming a splice joint; (e) consolidating the layers and curing the matrix material, thereby causing contraction of the layers toward the tool, the first and second contraction distances being selected so that adjacent gap edges of the plies of each layer are in close proximity or in contact after moving toward each other during the contraction, the second contraction distance being larger than the first contraction distance. ### Claim 2 (depends on 1) The method of claim 1, further comprising: repeating steps (c) and (d) to place additional layers prior to step (e), a contraction distance for each additional layer being larger than a contraction distance in an adjacent previous layer. ### Claim 3 (depends on 1) The method of claim 1, further comprising: repeating steps (c) and (d) to place additional layers prior to step (e), a contraction distance for each additional layer being larger than a contraction distance in an adjacent previous layer, the additional layers being arranged to form a stack of layers symmetric about a thickness of the stack. ### Claim 4 (depends on 1) The method of claim 1, further comprising: forming a second splice joint in the layers to join a third section to the first and second sections. ### Claim 5 (depends on 1) The method of claim 1, wherein the tool has a closed shape. ### Claim 6 (depends on 1) The method of claim 1, wherein the tool has an open shape. ### Claim 7 (depends on 1) The method of claim 1, wherein the plies are formed from unidirectional fibers. ### Claim 8 (depends on 1) The method of claim 1, wherein the plies are formed from unidirectional fibers, and steps (c) and (d) comprise orienting the fibers of the second layer at an angle to the fibers of the first layer. ### Claim 9 (depends on 1) The method of claim 1, wherein the fibers of the first ply of the first section and of the second ply of the second section are oriented in the same direction. ### Claim 10 (depends on 1) The method of claim 1, wherein the gap edges of the second plies are generally parallel to the gap edges of the first plies. ### Claim 11 (depends on 1) The method of claim 1, further comprising: repeating steps (c) and (d) to place additional layers prior to step (e), the additional layers being arranged so that gaps formed between gap edges of each layer form a V-shaped pattern through the thickness of the structure. ### Claim 12 A method for forming a closed-shape composite structure of first and second sections joined by a splice joint, each section being formed from uncured layers of plies of composite material, each ply being formed from fibers and a volume of uncured matrix material and having a gap edge, the method comprising: (a) forming a first layer by placing a first ply of each of the first and second sections on a convex surface of a mandrel, gap edges of the first plies being spaced by a selected first contraction distance from each other, thereby forming a gap between the gap edges of the first plies; (b) placing a second ply of the first section on the first ply of the first section, a gap edge of the second ply of the first section being spaced by a selected splice distance plus a selected second contraction distance from the gap edge of the first ply of the first section; (c) placing a second ply of the second section on the first ply of the second section, a gap edge of the second ply of the second section being spaced by the selected second contraction distance from and generally parallel to the gap edge of the second ply of the first section, thereby forming a gap between the gap edges of the second plies, a portion of the second ply of the second section overlapping the first ply of the first section by the splice distance, the second plies forming a second layer, the first and second layers forming a splice joint; (d) consolidating the layers and curing the matrix material, thereby causing contraction of the layers toward the mandrel, the first and second contraction distances being selected so that adjacent gap edges of the plies of each layer are in close proximity or in contact after moving toward each other during the contraction, the second contraction distance being larger than the first contraction distance. ### Claim 13 (depends on 12) The method of claim 12, further comprising: repeating steps (b) and (c) to place additional layers prior to step (d), a contraction distance for each additional layer being larger than a contraction distance in an adjacent previous layer. ### Claim 14 (depends on 12) The method of claim 12, further comprising: repeating steps (b) and (c) to place additional layers prior to step (d), a contraction distance for each additional layer being larger than a contraction distance in an adjacent previous layer, the additional layers being arranged to form a stack of layers symmetric about a thickness of the stack. ### Claim 15 (depends on 12) The method of claim 12, further comprising: repeating steps (b) and (c) to place additional layers prior to step (d), a contraction distance for each additional layer being larger than a contraction distance in an adjacent previous layer, the additional layers being arranged so that the gaps form a V-shaped pattern through the thickness of the structure. ### Claim 16 (depends on 12) The method of claim 12, further comprising: forming a second splice joint in the layers to join a third section to the first and second sections. ### Claim 17 (depends on 12) The method of claim 12, wherein the plies are formed from unidirectional fibers. ### Claim 18 (depends on 12) The method of claim 12, wherein the plies are formed from unidirectional fibers, and steps (b) and (c) comprise orienting the fibers of the second layer at an angle to the fibers of the first layer. ### Claim 19 (depends on 12) The method of claim 12, wherein the fibers of the first ply of the first section and of the second ply of the second section are oriented in the same direction. ### Claim 20 (depends on 12) The method of claim 12, wherein the gap edges of the second plies are generally parallel to the gap edges of the first plies.