Sandwich structure having arrestment feature

• US 8,955,290 B2
• Filed: 12/17/2012
• Issued: 02/17/2015
• Est. Priority Date: 12/04/2009
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Saff, Charles R., Fogarty, John H., Gu, Haozhong, Richardson, Terry D., Retz, Kevin M.
• Primary Examiner(s): A, Phi
• Assistant Examiner(s): HIJAZ, OMAR F
• Application Number:
  US13/716,593
• Publication Number:
  US 20130129970A1
• Time in Patent Office: 792 Days
• Field of Search: 527/831, 527/831.4, 527/831.8, 527/831.9, 527/841.4, 527/841.5, 527/901, 527/931, 527/931.1, 527/941, 524/042, 524/043, 524/045, 524/70, 524/66, 524/68, 524/65
• US Class Current: 52/783.1
• CPC Class Codes: B23B 3/04 Turning-machines in which the workpiece is rotated by means at a distance from the headstock
• CPC Class Codes: B29C 65/00 Joining or sealing of preformed parts , e.g. welding of plastics materials; Apparatus therefor general aspects of processes or apparatus for joining preformed parts B29C66/00; using porous material formed by internal pressure generated therein for joining preformed parts B29C44/1228, B29C44/326
• CPC Class Codes: B29C 66/01 General aspects dealing with the joint area or with the area to be joined B29C65/76, B29C65/82 take precedence
• CPC Class Codes: B29C 66/05 Particular design of joint configurations
• CPC Class Codes: B29C 66/10 particular design of the joint cross-sections
• CPC Class Codes: B29C 66/11 Joint cross-sections comprising a single joint-segment, i.e. one of the parts to be joined comprising a single joint-segment in the joint cross-section B29C66/12 and subgroups take precedence
• CPC Class Codes: B29C 66/112 Single lapped joints
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/114 Single butt joints
• CPC Class Codes: B29C 66/1142 Single butt to butt joints
• CPC Class Codes: B29C 66/118 Single monotone curved joints
• CPC Class Codes: B29C 66/1182 the joint being C-shaped
• CPC Class Codes: B29C 66/122 Joint cross-sections combining only two joint-segments, i.e. one of the parts to be joined comprising only two joint-segments in the joint cross-section B29C66/124 takes precedence
• CPC Class Codes: B29C 66/128 Stepped joint cross-sections
• CPC Class Codes: B32B 2250/03 3 layers
• CPC Class Codes: B32B 2307/718 Weight, e.g. weight per square meter
• CPC Class Codes: B32B 2605/18 Aircraft blades, propellers B32B2603/00
• CPC Class Codes: B32B 3/04 characterised by at least one layer folded at the edge, e.g. over another layer ; characterised by at least one layer enveloping or enclosing a material
• CPC Class Codes: B32B 3/06 for securing layers together; for attaching the product to another member, e.g. to a support , or to another product, e.g. groove/tongue, interlocking
• CPC Class Codes: B32B 3/12 characterised by a layer of regularly- arranged cells, e.g. a honeycomb structure
• CPC Class Codes: B32B 3/14 : characterised by a face layer formed of separate pieces of material which are juxtaposed side-by-side B32B5/02 takes precedence
• CPC Class Codes: B32B 3/18 : characterised by an internal layer formed of separate pieces of material which are juxtaposed side-by-side B32B5/02 takes precedence
• CPC Class Codes: Y10T 156/10 : Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 156/1002 : with permanent bending or reshaping or surface deformation of self sustaining lamina
• CPC Class Codes: Y10T 156/1034 : Overedge bending of lamina about edges of sheetlike base
• CPC Class Codes: Y10T 156/1093 : with covering of discrete laminae with additional lamina
• CPC Class Codes: Y10T 29/49622 : Vehicular structural member making
• CPC Class Codes: Y10T 29/49982 : Coating
• CPC Class Codes: Y10T 428/239 : Complete cover or casing
• CPC Class Codes: Y10T 428/24174 : including sheet or component perpendicular to plane of web or sheet
• CPC Class Codes: Y10T 428/24752 : Laterally noncoextensive components
• CPC Class Codes: Y10T 428/24777 : Edge feature
• CPC Class Codes: Y10T 428/249923 : Including interlaminar mechanical fastener

Abstract

A composite sandwich structure comprises a core sandwiched between composite laminate facesheets. The core includes a plurality of core sections spliced together at joints that incorporate integral features for arresting the propagation of irregularities in the facesheets.

Claims

1. An aircraft structure comprising:

a first facesheet and a second facesheet, each comprising a composite laminate;

a core comprising a first core segment and a second core segment, the core being joined to and sandwiched between the first facesheet and the second facesheet, a joint being between the first core segment and the second core segment, the joint being sandwiched between the first facesheet and the second facesheet; and

an arrestment feature configured to arrest propagation of an inconsistency, the arrestment feature wrapping at least partially around two sides of at least one of the first core segment and the second core segment at about the joint, and the first face sheet and the second facesheet each extending over the arrestment feature, wherein the arrestment feature wraps around two sides of the first core segment and two sides of the second core segment such that the first facesheet and the second facesheet are both in contact with portions of the arrestment feature, wherein the arrestment feature comprises a first wrap and a second wrap, wherein the first wrap and the second wrap both are generally C-shaped in cross section, wherein the first wrap covers three sides of the first core segment, and wherein the second wrap covers three sides of the second core segment;

wherein at least one of a first composite strap overlies the joint, wherein the first composite strap is sandwiched between the first facesheet and both the first wrap and the second wrap and wherein at least one of a second composite strap overlies the joint, wherein the second composite strap is sandwiched between the second facesheet and both the first wrap and the second wrap; and

wherein at least the first composite strap is placed in a first recess in contiguous first outer faces of the first core segment and the second core segment facing the first facesheet and the second composite strap is placed in a second recess in contiguous second outer faces of the first core segment and the second core segment facing the second facesheet.

2. The structure of claim 1, wherein:

the first core segment and the second core segment are further joined by at least one composite strap.

3. The structure of claim 2, wherein the arrestment feature includes a layer of adhesive joining the first wrap and the second wrap at the joint.

4. A vehicular structure comprising:

a first facesheet and a second facesheet, each comprising multiple plies of a composite material;

a segmented core sandwiched between and joined to the first facesheet and second facesheet, the segmented core including a plurality of core segments spliced together along corresponding joints between mutual edges of the plurality of core segments; and

a plurality of arrestment features, wherein ones of the plurality of arrestment features extend along ones of the corresponding joints, wherein all of the plurality of arrestment features are sandwiched between the first facesheet and the second facesheet, and wherein all of the plurality of arrestment features are configured to arrest propagation of an inconsistency in the structure, wherein the plurality of arrestment features include;

corresponding composite wraps covering corresponding edges of the plurality of core segments along ones of the corresponding joints, the corresponding composite wraps forming corresponding back-to-back C-shape cross sections along ones of the corresponding joints, and

corresponding composite straps respectively covering ones of the corresponding joints and correspondingly sandwiched between the corresponding composite wraps and one of the first facesheet and the second facesheet wherein the corresponding composite straps are placed at the corresponding joints into recesses in outer faces of the core segments.

5. The structure of claim 4, further comprising:

corresponding layers of adhesive adhesively joining the corresponding composite wraps on each side of each of the corresponding joints.

6. The structure of claim 4, wherein:

each of the corresponding composite wraps and the corresponding composite straps comprise a fiber reinforced resin.

7. A vehicular structure, comprising:

a first facesheet and a second facesheet, each comprising multiple plies of a composite material;

a core including a plurality of core segments sandwiched between the first facesheet and the second facesheet; and

corresponding joints connecting ones of the plurality of core segments together along edges of the plurality of core segments, the corresponding joints including arrestment features including corresponding pairs of composite wraps respectively wrapped around edges of adjacent core segments, and corresponding pairs of composite straps respectively engaging the first facesheet and the second facesheet, the corresponding pairs of composite wraps forming corresponding back-to-back C-shape cross sections along ones of the corresponding joints, and

the arrestment features further including corresponding composite straps respectively covering ones of the corresponding joints and correspondingly sandwiched between the corresponding composite wraps and one of the first facesheet and the second facesheet wherein the corresponding composite straps are placed at the corresponding joints into recesses in outer faces of the core segments.

8. The structure of claim 7, wherein:

the corresponding pairs of composite wraps overlie at least corresponding portions of each of three sides of corresponding ones of the plurality of core segments.

9. The structure of claim 7, wherein portions of the corresponding pairs of composite wraps engage the first facesheet and the second facesheet.

10. The structure of claim 7, wherein the arrestment features are preassembled as an uncured layup.