# US 9,517,594 B2 · Composite structure having a stabilizing element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,517,594 B2 - Document ID: US9517594B2 - Status: Granted - Kind: B2 - Application number: 13/644,628 - Filed: 2012-10-04 - Published: 2014-04-10 - Granted: 2016-12-13 - Earliest claimed: 2012-10-04 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Marc R. Matsen; Mark A. Negley - Web page: https://patentgrep.com/patent/US9517594B2 ## CPC - B29C 70/34: and shaping or impregnating by compression {, i.e. combined with compressing after the lay-up operation} - B29C 70/543: {Fixing the position or configuration of fibrous reinforcements before or during moulding (for non-woven fabrics D04H3/08)} - Y02T 50/40: Weight reduction - Y10T 156/10: Methods of surface bonding and/or assembly therefor - Y10T 428/24562: Interlaminar spaces - 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) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A composite structure may include a laminate and a stabilizing element. The laminate may have a plurality of composite plies. The composite structure may include a geometric discontinuity that may be associated with the laminate. The stabilizing element may be included with the composite plies and may be located proximate the geometric discontinuity. ## Claims ### Claim 1 A composite structure, comprising: a laminate having a plurality of composite plies and a laminate surface; a compression discontinuity associated with the laminate; a stabilizing element included with the composite plies below the laminate surface and being located proximate the compression discontinuity for preventing localized out-of-plane fiber distortion of the composite plies at the compression discontinuity; and the stabilizing element having stabilizing element edges and being located in a common plane with at least one composite ply having ply edges, the stabilizing element and the at least one composite ply arranged in one of the following configurations: the stabilizing element edges disposed in opposing relation to the ply edges; the at least one composite ply extending up and over the stabilizing element edges and overlapping the stabilizing element edges. ### Claim 2 (depends on 1) The composite structure of claim 1, wherein: the laminate comprises a panel formed of the plurality of the composite plies; the compression discontinuity comprises a region of low compaction pressure located proximate a structural member edge of a structural member mounted to the panel; and the stabilizing element being included with the composite plies and being located proximate the structural member edge. ### Claim 3 (depends on 1) The composite structure of claim 1, wherein: the laminate comprises a panel formed of the plurality of the composite plies; the compression discontinuity comprises a caul plate gap located between a pair of caul plates removably positioned against the panel; and the stabilizing element being included with the composite plies and being located proximate the caul plate gap. ### Claim 4 (depends on 1) The composite structure of claim 1, wherein: the stabilizing element has a stabilizing element coefficient of thermal expansion that is substantially equivalent to a laminate coefficient of thermal expansion. ### Claim 5 (depends on 1) The composite structure of claim 1, wherein: the stabilizing element has a stabilizing element stiffness in a range of from approximately 15 MSI to approximately 80 MSI. ### Claim 6 (depends on 1) The composite structure of claim 1, wherein: the stabilizing element is formed of stabilizing element material comprising at least one of cured composite material, ceramic material, and metallic material. ### Claim 7 (depends on 1) The composite structure of claim 1, wherein: the stabilizing element has a stabilizing element thickness that is approximately equivalent to one of the following: a ply thickness of a composite ply, a multiple of the ply thickness. ### Claim 8 (depends on 1) The composite structure of claim 1, wherein: the composite structure comprises a composite structure of an aircraft. ### Claim 9 A composite structure, comprising: a structural member having a plurality of composite plies and a laminate surface; a geometric discontinuity associated with the structural member; a stabilizing element included with the composite plies below the laminate surface and being located proximate the geometric discontinuity for preventing localized out-of-plane fiber distortion at the geometric discontinuity; and the stabilizing element having stabilizing element edges and being located in a common plane with at least one composite ply having ply edges, the stabilizing element and the at least one composite ply arranged in one of the following configurations: the stabilizing element edges disposed in opposing relation to the ply edges; the at least one composite ply extending up and over the stabilizing element edges and overlapping the stabilizing element edges. ### Claim 10 (depends on 9) The composite structure of claim 9 wherein: the geometric discontinuity comprises a cross-sectional shape-change in the structural member; and the stabilizing element being included with the composite plies and being located proximate the cross-sectional shape-change. ### Claim 11 (depends on 10) The composite structure of claim 10 wherein: the cross-sectional shape-change comprises a structural member radius formed in a structural member cross-section. ### Claim 12 (depends on 10) The composite structure of claim 10 wherein: the structural member is comprised of a plurality of sub-laminates; the cross-sectional shape-change comprising a radius filler located at a juncture of the sub-laminates; and the stabilizing element being located proximate the radius filler. ### Claim 13 A ply stabilizer, comprising: a stabilizing element for a laminate having a plurality of composite plies and a laminate surface; the laminate having a compression discontinuity associated therewith; the stabilizing element being included with the composite plies below the laminate surface and being located proximate the compression discontinuity for preventing localized out-of-plane fiber distortion at the compression discontinuity; and the stabilizing element having stabilizing element edges and being located in a common plane with at least one composite ply having ply edges, the stabilizing element and the at least one composite ply arranged in one of the following configurations: the stabilizing element edges disposed in opposing relation to the ply edges; the at least one composite ply extending up and over the stabilizing element edges and overlapping the stabilizing element edges. ### Claim 14 (depends on 13) The ply stabilizer of claim 13, wherein: the laminate comprises a panel formed of the plurality of the composite plies; the compression discontinuity comprises a region of low compaction pressure located proximate a structural member edge of a structural member mounted to the panel; and the stabilizing element being included with the composite plies and being located proximate the structural member edge. ### Claim 15 (depends on 13) The ply stabilizer of claim 13, wherein: the laminate comprises a panel formed of the plurality of the composite plies; the compression discontinuity comprises a caul plate gap located between a pair of caul plates removably positioned against the panel; and the stabilizing element being included with the composite plies and being located proximate the caul plate gap. ### Claim 16 (depends on 13) The ply stabilizer of claim 13, wherein: the stabilizing element has a stabilizing element coefficient of thermal expansion that is substantially equivalent to a laminate coefficient of thermal expansion. ### Claim 17 (depends on 13) The ply stabilizer of claim 13, wherein: the stabilizing element has a stabilizing element stiffness in a range of from approximately 15 MSI to approximately 80 MSI. ### Claim 18 (depends on 13) The ply stabilizer of claim 13, wherein: the stabilizing element is formed of stabilizing element material comprising at least one of cured composite, ceramic, and metal. ### Claim 19 A method of making a composite structure, comprising the steps of: laying up a laminate with a plurality of composite plies, the laminate having a laminate surface and at least one of a compression discontinuity and a geometric discontinuity associated with the laminate; applying a stabilizing element with the composite plies below the laminate surface; locating the stabilizing element proximate the at least one of the compression discontinuity and the geometric discontinuity, the stabilizing element having stabilizing element edges and being located in a common plane with at least one composite ply having ply edges, the stabilizing element and the at least one composite ply arranged in one of the following configurations: the stabilizing element edges disposed in opposing relation to the ply edges; the at least one composite ply extending up and over the stabilizing element edges and overlapping the stabilizing element edges; and preventing, using the stabilizing element, localized out-of-plane fiber distortion at the at least one of the compression discontinuity and the geometric discontinuity. ### Claim 20 (depends on 19) The method of claim 19, further comprising the step of: laying up the laminate as a panel formed of the plurality of the composite plies and having a structural member mounted thereto; and locating the stabilizing element proximate a structural member edge. ### Claim 21 (depends on 20) The method of claim 20, further comprising the steps of: applying compaction pressure to the laminate; generating the compression discontinuity comprising a region of low compaction pressure associated with the structural member edge; and mitigating, using the stabilizing element, fiber distortion in the composite plies. ### Claim 22 (depends on 19) The method of claim 19, further comprising the step of: laying up the laminate as a structural member formed of the plurality of the composite plies. ### Claim 23 (depends on 22) The method of claim 22, further comprising the step of: locating the stabilizing element proximate the geometric discontinuity in a structural member cross-section. ### Claim 24 (depends on 22) The method of claim 22, further comprising the step of: locating the stabilizing element proximate the geometric discontinuity comprising a cross-sectional shape-change of a structural member cross-section. ### Claim 25 (depends on 22) The method of claim 22, further comprising the step of: locating the stabilizing element proximate the geometric discontinuity comprising a structural member radius of a structural member cross-section. ### Claim 26 (depends on 22) The method of claim 22, further comprising the step of: locating the stabilizing element proximate the geometric discontinuity comprising a radius filler at a juncture of a plurality of sub-laminates of the structural member.