CA2314678C - Sandwich structure and method of repairing the same - Google Patents

Sandwich structure and method of repairing the same Download PDF

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Publication number
CA2314678C
CA2314678C CA002314678A CA2314678A CA2314678C CA 2314678 C CA2314678 C CA 2314678C CA 002314678 A CA002314678 A CA 002314678A CA 2314678 A CA2314678 A CA 2314678A CA 2314678 C CA2314678 C CA 2314678C
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CA
Canada
Prior art keywords
core
surface plate
opening
sandwich structure
plate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
CA002314678A
Other languages
French (fr)
Other versions
CA2314678A1 (en
Inventor
Toru Itoh
Shunichi Bandoh
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kawasaki Motors Ltd
Original Assignee
Kawasaki Jukogyo KK
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kawasaki Jukogyo KK filed Critical Kawasaki Jukogyo KK
Publication of CA2314678A1 publication Critical patent/CA2314678A1/en
Application granted granted Critical
Publication of CA2314678C publication Critical patent/CA2314678C/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/065—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of foam
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • 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
    • B29C73/00—Repairing of articles made from plastics or substances in a plastic state, e.g. of articles shaped or produced by using techniques covered by this subclass or subclass B29D
    • B29C73/04—Repairing of articles made from plastics or substances in a plastic state, e.g. of articles shaped or produced by using techniques covered by this subclass or subclass B29D using preformed elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • 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
    • B29C73/00—Repairing of articles made from plastics or substances in a plastic state, e.g. of articles shaped or produced by using techniques covered by this subclass or subclass B29D
    • B29C73/24—Apparatus or accessories not otherwise provided for
    • B29C73/26—Apparatus or accessories not otherwise provided for for mechanical pretreatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
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    • B32B3/02—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form characterised by features of form at particular places, e.g. in edge regions
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    • B32B3/10—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form characterised by a discontinuous layer, i.e. formed of separate pieces of material
    • B32B3/12—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form characterised by a discontinuous layer, i.e. formed of separate pieces of material characterised by a layer of regularly- arranged cells, e.g. a honeycomb structure
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y10T428/24512—Polyurethane
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y10T428/24521—Structurally defined web or sheet [e.g., overall dimension, etc.] including variation in thickness with component conforming to contour of nonplanar surface
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y10T428/249982—With component specified as adhesive or bonding agent

Abstract

A sandwich structure does not permit the permeation of water and a sandwich structure repairing method is capable of easily repairing the sandwich structure. A sandwich structure (1) includes a core (4) formed of a closed-cell foam plastic material, and surface plates (2, 3) formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and bonded to the opposite surfaces of the core (4). Water is unable to permeate the sandwich structure. When the outer surface plate (2) of the sandwich structure (1) is damaged, a damaged portion of the outer surface plate (2) is removed to form a circular opening (10) in the outer surface plate (2), a portion of the core (4) in the vicinity of the circular opening (10) is removed by shot blasting work, a support plate (16) provided with radial arms (18) is fastened to the inner surface of the outer surface plate (2) with rivets (25) at a position corresponding to the circular opening (10), a circular cover plate (40) is fitted in the opening (10) so as to be seated on the support plate (16) and is fastened to the support plate (16) with rivets (25). A cavity formed by removing the portion of the core (4) is filled up with a filling material (43).

Description

SANDWICH STRUCTURE AND METHOD OF REPAIRING THE SAME
BACKGROUND OF THE INVENTION
Field of the Invention The present invention relates to a sandwich structure to be used as a structural member of aircraft, rolling stock, automobiles and ships, and a method of repairing such a sandwich structure.
Description of the Related Art Lightweight, reinforced metal plates of aluminum alloys have been used for forming structural members of aircraft and the like. Recently, reinforced, plate structures of a composite material and sandwich structures formed by laminating a honeycomb core between surface plates of a composite material have been prevalently used. The surface plates of a composite material are bonded to the honeycomb core with adhesive films. Usually, cell elements of a honeycomb core are bonded together with a foaming adhesive that foams in a hot pressure molding process.
When a surface plate of a composite material is damaged and needs repairing, it is general to repair the damaged surface plate by scraping off a damaged part of the surface plate, laminating adhesive layers and prepreg sheets formed by impregnating a fiber structure with a resin in a recess formed by scraping off the damaged part so as to fill up the recess, and applying heat and pressure to the layers of the prepreg sheets and the adhesive to set the layers of the prepreg sheets.
When a sandwich structure having a honeycomb core sandwiched between surface plates is damaged, it sometimes occurs that water leaks into the sandwich structure through the periphery of the sandwich structure or cracks formed in the surface plate and water collects in the sandwich structure. The water collected in the honeycomb structure diffuses throughout the sandwich structure through the foam adhesive layers bonding together the cell elements of the honeycomb core. The adhesive film used for bonding together the surface plates and the honeycomb core includes a glass fabric, a cotton fabric or a meshed carrier of synthetic fibers. Therefore, small gaps are formed between the surface plates and the honeycomb core and it is possible that the water spreads through the gaps. If water collects in the honeycomb core and the honeycomb core is made of a metal, such as an aluminum alloy, the honeycomb core will be corroded and the surface plates will separate from the honeycomb core.
Even if the honeycomb core is made of a nonmetallic material, water collected in the honeycomb core repeats freezing and evaporation according to the variation of the ambient condition of the sandwich structure to deteriorate the adhesive bonding together the surface plates and the honeycomb core and to reduce the bonding strength of the adhesive and, consequently, the surface plates separates from the honeycomb core.
The water collected in the honeycomb core increases the weight of the sandwich structure, changes the position of the center of gravity of the sandwich structure adversely affecting the dynamic characteristic of the sandwich structure. In some cases, the sandwich structure is heated at a temperature not lower than 100 C when repairing the damaged sandwich structure. If the honeycomb core contains water, the water evaporates to increase the pressure in the sandwich structure when the sandwich structure is heated and, in the worst case, the sandwich structure will burst.
If it is known that the honeycomb core contains water, small holes are formed in the surface plate and the water is drained through the small holes or the sandwich structure is unfastened and the water is removed by suction, which, however, needs time and costs.
When fabricating a sandwich structure having portions of different thicknesses, a honeycomb core must be machined, which requires troublesome work.
when repairing a damaged portion of a sandwich structure by laminating prepreg sheets, heat and pressure must be applied to the laminated prepreg sheets to set the prepreg sheets, which needs special devices. When setting prepreg sheets by applying heat and pressure thereto, pressure and temperature must be strictly controlled, which requires very troublesome work.
After completing the repair of the damaged part of the sandwich structure by setting the prepreg sheets, the adhesive bonding the laminated prepreg sheets covering the damaged part to the mother structure of the repaired part must be inspected. Thus, the repair of the damaged sandwich structure needs special devices and much time and work.

SUMNLARy OF THE INVENTION
Accordingly, it is an object of the present invention to provide a sandwich structure capable of inhibiting the penetration of water therein and having a core that can be easily processed and to provide a method of repairing a sandwich structure by simple work.
According to a first aspect of the present invention, a sandwich structure includes a core having foam plastic core members formed of a closed-cell foam plastic material, and surface plates formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and covering the opposite surfaces of the core, wherein the foam plastic core members are bonded together with adhesive films that do not foam, and the surface plates are bonded to the core with adhesive films not containing any carrier or a component resin of the fiber-reinforced composite material forming the surface plates.
Since the sandwich structure is provided with the foam plastic core members of a closed-cell foam plastic material,water is unable to collect in the sandwich structure. Since the foam plastic core members are bonded together with an adhesive film that does not foam and the composite surface plates are bonded to the core with an adhesive film not having any carrier or a component resin of the fiber-reinforced composite material forming the composite surface plates, any passages through which water penetrates and diffuses into the sandwich structure are not formed at all. Consequently, the sandwich structure is free from troubles due to the penetration of water into the sandwich structure.
According to a second aspect of the present invention, a sandwich structure includes a core having foam plastic core members of a closed-cell foam plastic material and honeycomb core members, and surface plates formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and covering the opposite surfaces of the core, wherein a peripheral part of the core is formed of the foam plastic core members arranged so as to surround the honeycomb core members, the foam plastic core members are bonded together with adhesive films that do not foam, and the surface plates are bonded to the core with adhesive films not containing any carrier or a component resin of the fiber-reinforced composite material forming the surface plates.
Since the peripheral part of the sandwich structure through which water is most liable to leak into the sandwich structure is formed of the foam plastic core members, the foam plastic core members are bonded together with an adhesive film that does not foam, and the surface plates are bonded to the core with adhesive films not containing any carrier or a component resin of the fiber-reinforced composite material forming the surface plates, the sandwich structure is free from troubles due to the penetration of water into the sandwich structure. Since the core has the honeycomb core members having strength and rigidity which are generally higher than those of the foam plastic core members, the sandwich structure has a high strength and a high rigidity.
According to a third aspect of the present invention, a sandwich structure includes a core having foam plastic core members formed of a closed-cell foam plastic material and honeycomb core members, and surface plates formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and covering the opposite surfaces of the core, wherein the core is formed by sandwiching the honeycomb core members between the foam plastic core members and bonding the foam plastic core members to the honeycomb core members with adhesive films not containing any carrier.
Since the core is formed by sandwiching the honeycomb cores between the foam plastic core members and bonding the foam plastic core members to the honeycomb core members with an adhesive film not containing any carrier, water is unable to penetrate into the honeycomb core members and the sandwich structure even if the surface plate is fissured or broken. Since the core has the honeycomb core members having strength and rigidity which are generally higher than those of the foam plastic core members, the sandwich structure has a high strength and a high rigidity.
Since the foam plastic core members capable of readily absorbing shocks are contiguous with the surface plates, the sandwich structure is resistant to damaging actions.
According to a fourth aspect of the present invention, a sandwich structure includes a core having foam plastic core members formed of a closed-cell foam plastic material and honeycomb core members, and surface plates formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and covering the opposite surfaces of the core, wherein portions of the core corresponding to portions of the sandwich structure where thickness varies sharply are formed of the foam plastic core members, portions of the core corresponding to portions of the sandwich structure where thickness varies gradually are formed of the honeycomb core members, and the composite surface plates are bonded to the core with adhesive films not containing any carrier or a component resin of the fiber-reinforced composite material forming the surface plates.
Since the portions of the core corresponding to portions of the sandwich structure where thickness varies sharply are formed of the foam plastic core members capable of being easily processed and of being smoothly processed according to the variation of the thickness, the core can be easily processed and the composite surface plates can be easily bonded to the core.
According to a fifth aspect of the present invention, a sandwich structure repairing method of repairing a sandwich structure including a core having foam plastic core members formed of a closed-cell foam plastic material, and outer and inner surface plates of a fiber-reinforced composite material and bonded to the opposite surfaces of the core with an adhesive film not containing any carrier or a component resin of the composite surface plates includes the step of attaching a support plate to the inner surface of a damaged portion of the outer surface plate with rivets.
Since the support plate is attached to the inner surface of the outer surface plate, the repaired portion of the outer composite surface plate has a smooth surface. Since the support plate is attached to the outer composite surface plate by riveting work using rivets for repair instead of bonding work using an adhesive that requires time and labor, time and labor necessary for repairing the sandwich structure can be greatly reduced.
According to a sixth aspect of the present invention, a sandwich structure repairing method of repairing a sandwich structure comprising a core having foam plastic core members formed of a closed-cell foam plastic material, and an outer surface plate and an inner surface plate formed of a fiber-reinforced plastic material and bonded to the opposite surfaces of the core with adhesive films not containing any carrier or a component resin of the fiber-reinforced composite material forming the surface plates, said sandwich structure repairing method comprising the steps of: putting an outer support plate to an inner surface of a damaged portion of the outer surface plate; and fastening the outer support plate to the outer surface plate with rivets.
When an operator is able to perform repairing work on the side of the inner surface of the sandwich structure and the damage in the outer surface plate is slight, the outer support plate can be attached to the inner surface of the outer surface plate from the inner side of the sandwich structure with the rivets, and the cavity can be filled up with the filling material, and the inner support plate can be easily attached to the inner surface plate.
Preferably, a portion of the inner surface plate and a portion of the core corresponding to the damaged portion of the outer surface plate are removed; the outer support plate is fastened to the inner surface of the damaged portion of the outer surface plate with rivets; a cavity formed by removing the portion of the core is filled up with a filling material; and an inner support plate of a size greater than that of an opening in the inner surface plate formed by removing the portion of the inner surface plate is fastened to the inner surface plate with rivets so as to cover the opening in the inner surface plate.
When an operator is able to perform repairing work on the side of the inner surface of the sandwich structure, the portion of the outer surface plate including the damaged portion is removed to form the opening, the outer support plate is attached to the inner surface of the outer surface plate, the space formed by removing the portion of the core is filled up with the filling material, and the cover plate of the size equal to that of the opening in the outer surface plate is fitted in the opening in the outer surface plate and the cover plate is fastened to the support plate with rivets. Thus, the outer surface of the outer surface plate can be finished in a smooth surface. Since the method employs riveting work using rivets, time and labor for the repair work can be reduced.
Preferably, an opening is formed in the damaged portion of the outer surface plate; a portion of the core and a portion of the inner surface plate corresponding to the opening and a region around an edge of the opening are removed;the outer support plate is fastened to the inner surface of a portion of the outer surface plate around an edge of the opening in the outer surface plate with rivets; a cover plate formed of the same material as that forming the outer surface plate and having a thickness equal to that of the outer surface plate is fitted in the opening and is fastened to the outer support plate with rivets;
a cavity formed in the core by removing the portion of the core is filled up with a filling material; and an inner support plate of a size greater than that of an opening in the inner surface plate formed by removing the portion of the inner surface plate is fastened to the inner surface plate with rivets so as to cover the opening in the inner surface plate.
Preferably, a portion of the outer surface plate including the damaged portion is removed to form an opening in the outer surface plate; a portion of the core corresponding to the opening in the outer surface plate and a portion of the core around an edge of the opening in the outer surface plate are removed; the outer support plate is expandable over a region greater than the opening in the outer surface plate; the outer support plate is inserted through the opening in the outer surface plate; the outer support plate is fastened to the inner surface of the outer surface plate with rivets; a cover plate of a size equal to that of the opening formed in the outer surface plate and of a thickness equal to that of the outer surface plate is fitted in the opening in the outer surface plate; the outer support plate is fastened to the support plate with rivets; and a cavity formed by removing the portions of the core is filled up with a filling material.
Since the expandable outer support plate is used, the outer surface of the outer surface plate can be finished in a smooth surface even if repairing work can be carried out only on the side of the outer surface of the sandwich structure.
Preferably, a plurality of the outer support plates are used; a portion of the outer surface plate including the damaged portion is removed to form an opening in the outer surface plate;
a portion of the core corresponding to the opening in the outer surface plate and a portion of the core around an edge of the opening in the outer surface plate are removed; the plurality of the outer support plates are inserted through the opening in the outer surface plate so as to be arranged on the inner surface of a portion of the outer surface plate around an edge of the opening in the outer surface plate; the plurality of the outer support plates are fastened to the inner surface of the outer surface plate with rivets; a cover plate of a size equal to that of the opening formed in the outer surface plate and of a thickness equal to that of the outer surface plate is fitted in the opening in the outer surface plate; the cover plate is fastened to the plurality of the outer support plates with rivets; and a cavity formed by removing the portions of the core is filled up with a filling material.
Since the plurality of the outer upport plates are used instead of the expandable outer support plate, complicated processing work for forming the expandable outer support plate is unnecessary and hence processing work can be reduced.

Preferably, the portions of the core of a foam plastic material corresponding to the opening in the outer surface plate and a region around the edge of the opening in the outer surface plate are removed by shot blasting work.
Since the sandwich structure has the core of a foam plastic material, the portions of the core can be easily removed by shot blasting work, which reduces time and labor necessary for repairing.
In one aspect, the present invention provides a sandwich structure comprising a core having foam plastic core members formed of a closed-cell foam plastic material;
and surface plates formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and covering the opposite surfaces of the core; wherein the foam plastic core members are bonded together with non-foaming adhesive films, and the surface plates are bonded to the core with carrier-free adhesive films or a component resin of the fiber-reinforced composite material forming the surface plates.
In another aspect, the present invention provides a sandwich structure comprising a core having foam plastic core members formed of a closed-cell foam plastic material and honeycomb core members; and surface plates formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and covering the opposite surfaces of the core; wherein a peripheral part of the core is formed of the foam plastic core members arranged so as to surround the honeycomb core members, the foam plastic core members are bonded together with non-foaming adhesive films, and the surface plates are bonded to the core with carrier-free adhesive films or a component resin of the fiber-reinforced composite material forming the surface plates.
In yet another aspect, the present invention provides a sandwich structure comprising a core having foam plastic core members formed of a closed-cell foam plastic material and honeycomb core members; and surface plates formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and covering the opposite surfaces of the core; wherein the core is formed 9a by sandwiching the honeycomb core members between the foam plastic core members and bonding the foam plastic core members to the honeycomb core members with carrier-free adhesive films.
In a further aspect, the present invention provides a sandwich structure comprising a core having foam plastic core members formed of a closed-cell foam plastic material and honeycomb core members; and surface plates formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and covering the opposite surfaces of the core; wherein portions of the core corresponding to portions of the sandwich structure where thickness varies sharply are formed of the foam plastic core members, portions of the core corresponding to portions of the sandwich structure where thickness varies gradually are formed of the honeycomb core members, and the surface plates are bonded to the core with carrier-free adhesive films or a component resin of the fiber-reinforced composite material forming the surface plates.
In yet a further aspect, the present invention provides a sandwich structure repairing method of repairing a sandwich structure comprising a core having foam plastic core members formed of a closed-cell foam plastic material, and an outer surface plate and an inner surface plate formed of a fiber-reinforced plastic material and bonded to the opposite surfaces of the core with carrier-free adhesive films or a component resin of the fiber-reinforced composite material forming the surface plates, said sandwich structure repairing method comprising the steps of: putting an outer support plate to an inner surface of a damaged portion of the outer surface plate; and fastening the outer support plate to the outer surface plate with rivets.
In yet a further aspect, the present invention resides in a sandwich structure comprising: a core having foam plastic core members formed of a closed-cell foam plastic material; and surface plates formed of a fiber-reinforced composite material covering the opposite surfaces of the core, said fiber-reinforced composite material having a 9b component resin and hydrophobic inorganic fibers as reinforcing fibers contained within the component resin;
wherein the foam plastic core members are bonded together on a side of the foam plastic core members facing each other with a first non-foaming adhesive film, and the surface plates are bonded to the core on sides of the foam plastic core members facing the surface plates with a second carrier-free adhesive film or the component resin of the fiber-reinforced composite material forming the surface plates, wherein the first adhesive film and the second adhesive film are different.
In yet a further aspect, the present invention resides in a sandwich structure repairing method of repairing a sandwich structure comprising a core having foam plastic core members formed of a closed-cell foam plastic material; and surface plates formed of a fiber-reinforced composite material covering the opposite surfaces of the core, said fiber-reinforced composite material having a component resin and hydrophobic inorganic fibers as reinforcing fibers contained within the component resin; wherein the foam plastic core members are bonded together on a side of the foam plastic core members facing each other with a first non-foaming adhesive film, and the surface plates are bonded to the core on sides of the foam plastic core members facing the surface plates with a second carrier-free adhesive film or the component resin of the fiber-reinforced composite material forming the surface plates, wherein the first adhesive film and the second adhesive film are different, said sandwich structure repairing method comprising the steps of: putting an outer support plate to an inner surface of a damaged portion of the outer surface plate; and fastening the outer support plate to the outer surface plate with rivets.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in connection with the accompanying drawings, in which:

9c Fig. 1 is an exploded perspective view of a sandwich structure 50 in a first embodiment according to the present invention;
Fig. 2 is an exploded perspective view of a sandwich structure 60 in a second embodiment according to the present invention;
Fig. 3 is a fragmentary sectional view of a sandwich structure 70 in a third embodiment according to the present invention;
Fig. 4 is a fragmentary sectional view of a sandwich structure 80 in a fourth embodiment according to the present invention;
Fig. 5 is a perspective view of a damaged sandwich structure 1;
Fig. 6 is a perspective view of assistance in explaining a method of cutting out a damaged portion in a sandwich structure when repairing the sandwich structure by a sandwich structure repairing method according to the present invention;
Fig. 7 is a perspective view of assistance in explaining a method of removing a portion of a core included in a sandwich structure;
Fig. 8 is a sectional view of assistance in explaining a method of removing a portion of a core included in a sandwich structure;

Fig. 9 is a fragmentary plan view of a sandwich structure with a support plate attached to an outer composite surface plate included therein;
Fig. 10 is a fragmentary sectional view of the sandwich structure shown in Fig. 9;
Fig. 11 is a sectional view of assistance in explaining a riveting method;
Fig. 12 is a perspective view of a repaired sandwich structure provided with a cover plate;
Fig. 13 is a fragmentary sectional view of a repaired sandwich structure having a hollow filled up with a filling material; and Fig. 14 is a fragmentary sectional view of assistance in explaining another sandwich structure repairing method according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Fig. 1 showing a sandwich structure 50 in a first embodiment according to the present invention to be used as a skin of an aircraft, the sandwich structure 50 has a core including core members 51 of a closed -cell foam plastic material, and surface plates 52 and 53 of a fiber-reinforced composite material covering the opposite surfaces of the core, respectively.
The closed-cell foam plastic material is , for example, a closed-cell foam polymethacrylimide (PMI) or a closed-cell foam polyvinyl chloride ( PVC ). The surface plates 52 and 53 are formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers, such as carbon fibers, as reinforcing fibers.
Each of the surface plates 52 and 53 is formed by laminating a plurality of prepreg sheets each formed by impregnating a sheet of the reinforcing fibers with an epoxy resin or the like.
The core members 51 are bonded together with an adhesive film 54 of an adhesive that does not foam, such as Cytec FM300K .
The surface plates 52 and 53 are bonded to the core members 51 with adhesive films 55 of an adhesive, such as Cytec FM300U , not containing any carrier. The surface plates 52 and 53 can be bonded to the core members 51 without forming any gaps between the surface plates 52 and 53 and the core members 51 by the adhesive films 55. Consequently, water is unable to leak into the sandwich structure 50. The surface plates 52 and 53 may be bonded to the core members 51 by using the resin of the composite material forming the surface plates 52 and 53 instead of using the adhesive films 55. Prepreg sheets for forming the surface plates 52 and 53 may be superposed on the opposite surfaces of the opposite surfaces of the core consisting of the core members 51, and heat and pressure may be applied to the prepreg sheets for setting to bond the surface plates 52 and 53 to the core members 51.
Water is unable to penetrate into the core members 51 because the core members 51 are formed of the closed-cell foam plastic material. Since the core members 51 are bonded together with the adhesive film 54 of an adhesive that does not foam, water is unable to spread inside the sandwich structure 50 through the joint of the core members 51 even if the surface plate 52 or 53 is fissured.
Referring to Fig. 2 showing a sandwich structure 60 in a second embodiment according to the present invention, the sandwich structure 60 has a core 67, and surface plates 62 and 63. The surface plates 62 and 63, similarly to the surface plates 52 and 53 of the sandwich structure 50 in the first embodiment, are formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers. The surface plates 62 and 63 are bonded to the opposite surfaces of the core 67 with adhesive films 64 not containing any carrier or with the resin of the fiber-reinforced composite material, respectively.
The core 67 has a honeycomb core member 66 and foam plastic core members 61 of a closed-cell plastic material surrounding the honeycomb core member 66 and bonded together with adhesive films 65 that do not foam. The honeycomb core member 66 has high strength and rigidity to withstand force that acts thereon in a direction along the thickness of the sandwich structure 60 and low strength and rigidity to withstand force that acts thereon in a direction perpendicular to the direction along the thickness of the sandwich structure 60. Therefore, when heating and pressing a sandwich structure provided with a honeycomb core, the sandwich structure must be placed in a metal locating jig having the shape of a frame or a peripheral part of the sandwich structure must be gently tapered to prevent the sandwich structure from being crushed by lateral pressure. Since the sandwich structure 60 is provided with the core 67 including the foam plastic core members 61 arranged in the shape of a frame so as to surround the honeycomb core member 66, the sandwich structure 60 has high strength to withstand lateral force, and a peripheral part of the sandwich structure 60 can be sharply tapered.
Referring to Fig. 3 showing a sandwich structure 70 in a third embodiment according to the present invention, the sandwich structure 70 has a core 77 including foam plastic core members 72 and 73 of a closed-cell foam plastic material and a honeycomb core member 71 sandwiched between the foam plastic core members 72 and 73, and surface plates 75 and 76 bonded to the opposite surfaces of the core 77, respectively. The foam plastic core members 72 and 73 are bonded to the honeycomb core member 71 with adhesive films 78 not containing any carrier. The surface plates 75 and 76 are bonded to the core 77 with adhesive films 79 not containing any carrier. The surface plates 75 and 76 are formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers.
Since the honeycomb core member 71 is sandwiched between the foam plastic core members 72 and 73, water is unable to leak into the sandwich structure 70 even if the surface plate 75 or 76 is fissured. Since the foam plastic core members 72 and 73 capable of absorbing shocks are contiguous with the surface plates 75 and 76, the sandwich structure 70 is resistant to damaging actions.
Referring to Fig. 4 showing a sandwich structure 80 in a fourth embodiment according to the present invention, the sandwich structure 80 has a core 86 including honeycomb core members 81 and a foam plastic core member 85, and surface plates 83 and 84. The honeycomb core members 81 are disposed in portions of the sandwich structure 80 in which the thickness of the sandwich structure 80 varies in a narrow range, and the foam plastic core member 85 is disposed in a portion of the sandwich structure 80 in which the thickness of the sandwich structure 80 varies in a wide range.
When forming a sandwich structure of varying thickness provided with a honeycomb core, the honeycomb core must be machined so as to conform to the varying thickness of the sandwich structure. The machining of the honeycomb core is a troublesome work. Therefore, the sandwich structure 80 in the fourth embodiment is provided with the core 86 including the honeycomb core members 81 disposed in portions of the sandwich structure 80 in which the thickness of the sandwich structure 80 varies in a narrow range, and the foam plastic core member 85 disposed in a portion of the sandwich structure 80 in which the thickness of the sandwich structure 80 varies in a wide range. The core 81 can be easily formed. The surface plates 83 and 84 are formed by laminating prepreg sheets on the core 86. The surface plates 83 and 84 are bonded to the core 86 with adhesive films 87 not containing any carrier. The surface plates 83 and 84 are formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers.
A sandwich structure repairing method in a fifth embodiment according to the present invention will be explained hereinafter.
Fig. 5 shows a damaged sandwich structure 1. The sandwich structure 1 is a composite structure and has a flat core 4 of 12.7 mm in thickness and surface plates 2 and 3 covering the opposite surfaces of the core 4. The core 4 is formed of a closed-cell foam plastic material. The surface plates 2 and 3 are formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers. The sandwich structure 1 is used as a skin of, for example, aircraft or rolling stock, such as a high-speed passenger car for a rapid train. The surface plates 2 and 3 serve as an outer surface plate and an inner surface plate, respectively.
The outer surface plate 2 is formed of a fiber-reinforced composite material formed by laminating eight prepreg sheets each formed by impregnating a sheet of reinforcing fibers with a resin.
The inner surface plate 3 is formed of a fiber-reinforced composite material formed by laminating four prepreg sheets and is thinner than the outer surface plate 2.
As shown in Fig. 5, a fissure 5 is formed in the outer surface plate 2 of the sandwich structure 1 and the outer surface plate 2 needs repair. A portion of the outer surface plate 2 having the fissure 5 is cut out with a hole saw 11 as shown in Fig. 6 to form a round opening 10 in the outer surface plate 2. The hole saw 11 has the shape of a hollow cylinder with cutting teeth 12 around its edge. The hole saw 11 is rotated at a high rotating speed about its axis to cut a round hole. The hole saw 11 has a diameter greater than that of a circular region including the fissure 5 in the outer surface plate 2. Since the portion including the fissure 5 of the outer surface plate 2 is cut out in a circular shape, the intensity of stress concentration can be limited to a low level. The diameter of the hole saw 11 is, for example, 50 mm. As shown in Fig. 6, a cylindrical portion of the core 4 underlying the outer surface plate 2 is cut out together with the round portion of the outer surface plate 2, so that the round opening 10 is formed in the outer surface plate 2.
Figs. 7 and 8 are views of assistance in explaining work for removing portions of the core 4. Portions of the core 4 corresponding to the opening 10 and around the edge of the opening are removed. Since the core 4 is formed of a closed-cell foam plastic material and the surface plates 2 and 3 are formed of a fiber-reinforced composite material, only the portions of the core 4 can be efficiently removed by shot blasting using shot, such as walnut power or particles of alumina or corn. The shot is blown through a nozzle 15 against the core 4 to scrape off portions of the core 4. An end portion of the nozzle 15 is bent substantially through an angle of 180 as shown in Fig. 8 to facilitate removing a portion of the core 4 around the edge of the opening 10 formed in the outer surface plate 2.
After the desired portions of the core 4 have been removed, a support plate 16 is inserted in a hole formed in the sandwich structure 1 as shown in Figs. 9 and 10. The support plate 16 is an expandable plate having a circular central part 17 and rectangular radial arms 18 (eight radial arms in this embodiment) like petals of a flower as shown in Fig. 9. The support plate 16 is made of, for example, a titanium alloy. The support plate 16 can be formed by punching a titanium alloy sheet. The diameter of the circular central part 17 is smaller than that of the opening 10. The diameter of an imaginary circle circumscribed about the support plate 16 is far greater than that of the opening 10.
The support plate 16 is inserted through the opening 10 in the space formed by removing the portions of the core 4. When inserting the support plate 16 in the space, the arms 18 are curved inward and the arms 18 are extended in the space after the support plate 16 has been entirely inserted into the space. Subsequently, through holes 24 for passing rivets 25 are formed through the outer surface plate 2 and the arms 18 with a drill. The through holes 24 may be formed in the outer surface plate 2 and the arms 18 before inserting the support plate 16 into the space. The arms 18 are fastened to the inner surface of a portion of the outer surface plate 2 around the edge of the opening 10 with the rivets as shown in Fig. 10.
Referring to Fig. 11, the rivets 25 are blind rivets that can be staked from one side thereof. Each rivet 25 has a countersunk flat head 26 that can be set flush with the outer surface of the outer surface plate 2. The rivet 25 has a hollow rod 27 and a draw bar 28 inserted in the hollow rod 27. A sleeve is put on an inner end portion of the draw bar 28 projecting from the hollow rod 27, and the inner end of the draw bar 28 is connected to a solid core bolt 31 formed at the extremity of the sleeve 30. A coiled washer 32 is disposed on the base end of the sleeve 30. An inner end portion of the hollow rod 27 is tapered.
As shown in Fig. 11(1) , the rivet 25 is inserted from the outside of the outer surface plate 2 in the through holes 24 formed in the outer surface plate 2 and the arm 18, and then the draw bar 28 is pulled outward by a tool. Then, the coiled washer 32 is uncoiled and expanded by the tapered inner end portion of the hollow rod 27 as shown in Fig. 11( 2). As the draw bar 28 is pulled further outward, the coiled washer 32 is brought into contact with the inner surface of the arm 18 of the support plate 16 and the sleeve 30 is fully staked. Then, a portion of the draw bar 28 projecting outward from the head 26 is cut off. Thus, the eight arms 18 of the support plate 16 are fastened to the outer surface plate 2 with the rivets 25.
Subsequently, a cover plate 40 is seated on the support plate 16 in the opening 10 as shown in Fig. 12. The cover plate 40 is a circular plate formed by cutting a plate of the same fiber-reinforced composite material as that forming the outer surface plate 2 with the hole saw 11. Since the circular central part 17 of the support plate 16 lies in the opening 10 and the arms 18 are fastened to the inner surface of the outer surface plate 2, the cover plate 40 is seated on the circular central part 17. Then, eight through holes are formed through the cover plate 40 and the support plate 16 with a drill at eight positions corresponding to the eight arms 18. Blind rivets 25 are inserted in the through holes and are staked by the same method as that mentioned above to fasten the cover plate 40 to the circular central part 17 with the rivets 25. Since the thickness of the cover plate 40 is equal to that of the outer surface plate 2, the outer surface of the cover plate 40 fastened to the support plate 16 is flush with the outer surface of the outer surface plate 2.
After the cover plate 40 has been thus fastened to the support plate 16 with the rivet 25, two through holes 41 and 42 are formed through the cover plate 40 and the support plate 16. A filling material 43 is injected through the through hole 41 into the space formed in the sandwich structure 1 by means of an injection gun. The filling material 43 is a liquid foaming resin containing minute bubbles. The space formed by removing the portions of the core 4 is filled up with the filling material 43 as shown in Fig. 13. After the space has been fully filled with the filling material 43, the filling material 43 overflows through the other through hole 42, which indicates that the space has been fully filled with the filling material 43. The filling material 43 injected into the space sets perfectly in a predetermined time. The filling material sets at an ordinary temperature.
Thus, the damaged sandwich structure 1 can be easily repaired by using the rivets 25 without requiring any special devices. The titanium alloy forming the support plate 16 has a coefficient of thermal expansion nearer to that of the fiber-reinforced composite material forming the surface plates 2 and 3 than those of aluminum alloys. Therefore, an excessively high thermal stress will not be induced in the support plate 16 while the sandwich structure 1 is in use even though the support plate 16 is fastened to the outer surface plate 2 with the rivets 25.
The sandwich structure repairing method may use a support means other than the support plate 16 having the radial arms 18.
For example, a plurality of support plates may be fastened to the inner surface of a portion of the outer surface plate 2 around the edge of the opening 10 with rivets so as to protrude into the opening 10, and the cover plate 40 may be placed on and fastened with rivets to the support plates.
When repairing work can be performed on the side of the inner surface plate 3, a cylindrical portion of the sandwich structure 1 including portions of the outer surface plate 2, the core 4 and the inner surface plate 3 may be removed with the hole saw 11 to form a cylindrical space extending through the sandwich structure 1. The cylindrical space permits the repairing work to be performed on both the outer and the inner side of the sandwich structure 1 and facilitates the work for removing a portion of the core 4 around the edge of the opening in the outer surface plate 2. Since the inner surface of the sandwich structure 1 is out of view and need not be entirely flat, a cover plate of a diameter greater than that of an opening formed in the back surface plate 3 may be fastened with rivets directly to the inner surface plate 3 so as to cover the opening in the inner surface plate 3.
A sandwich structure repairing method in a sixth embodiment according to the present invention will be explained hereinafter with reference to Fig. 14, in which parts like or corresponding to those shown in Figs. 5 to 13 are denoted by the same reference characters and the description thereof will be omitted.
The sandwich structure repairing method is used when repairing work can be performed on the side of an inner surface plate 3 of a sandwich structure 1. The sandwich structure 1 has a flaw 5 in an outer surface plate 2 thereof. A portion of the inner surface plate 3 corresponding to a portion of the outer surface plate 2 having the flaw 5 is removed with a hole saw 11 to form an opening, and a portion of a core 4 corresponding to the portion having the flaw 5 is removed by shot blasting as mentioned above. A mending plate (as an outer support plate)45 is put on the inner surface of the portion of the outer surface plate 2 having the flaw 5 and is fastened to the outer surface plate 2 with rivets 25. The mending plate 45 is formed of a titanium alloy or the same fiber-reinforced composite material as that forming the outer surface plate 2. Then, a space formed by removing a portion of the core 4 is filled up with a filling material 43 and a cover plate (as an inner support plate )46 is fastened to the inner surface plate 3 with rivets 25 so as to cover the opening formed in the inner surface plate 3. Thus, any opening does not need to be formed in the outer surface plate 2.
This sandwich structure repairing method is applicable not only to repairing a sandwich structure provided with only a foam plastic core, but also to repairing sandwich structures provided with a core consisting of honeycomb core members and foam plastic core members as those shown in Figs. 2 to 4.
According to the present invention, a sandwich structure includes a core having foam plastic core members of a closed-cell foam plastic material, and composite surface plates of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and covering the opposite surfaces of the core, wherein the foam plastic core members are bonded together with an adhesive film that does not foam, and the composite surface plates are bonded to the core with adhesive films not containing any carrier or a component resin of the fiber-reinforced composite material forming the surface plates.
Thus, the leakage of water into the sandwich structure can be prevented with reliability.
According to the present invention, a peripheral part of the core is formed of the foam plastic core members arranged so as to surround the honeycomb core members. Therefore, the sandwich structure has a high strength and a high rigidity.
According to the present invention, the core is formed by sandwiching the honeycomb core members between the foam plastic core members and bonding the foam plastic core members to the honeycomb core members with adhesive films not containing any carrier. Therefore, water is unable to penetrate into the sandwich structure and the sandwich structure has a high strength and a high rigidity.
According to the present invention, portions of the core corresponding to portions of the sandwich structure where thickness varies sharply are formed of the foam plastic core members and portions of the core corresponding to portions of the sandwich structure where thickness varies gradually are formed of the honeycomb core members. Therefore, the core can be easily processed and the composite surface plates can be easily bonded to the core.
According to the present invention, the sandwich structure repairing method puts the outer support plate to the inner surface of the outer surface plate and fastens the same to the outer surface plate with the rivets. Since the outer support plate is attached to the outer surface plate by riveting work using rivets for repair instead of bonding work using an adhesive that requires time and labor, time and labor necessary for repairing the sandwich structure can be greatly reduced.
According to the present invention, the sandwich structure repairing method removes a damaged portion of the outer surface plate to form an opening, attaches the outer support plate to the inner surface of a portion of the outer surface plate around the edge of the opening with the rivets, and fits the cover plate in the opening and fastens the same to the support plates. Thus, the sandwich structure can be repaired so that the outer surface thereof is flat and smooth.
According to the present invention, a portion of the foam plastic core member can be easily removed by shot blasting, which reduces repairing time greatly.
Although the invention has been described in its preferred embodiments with a certain degree of particularity, obviously many changes and variations are possible therein. It is therefore to be understood that the present invention may be practiced otherwise than as specifically described herein without departing from the scope and spirit thereof.

Claims (22)

1. A sandwich structure comprising:
a core having foam plastic core members formed of a closed-cell foam plastic material; and surface plates formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and covering the opposite surfaces of the core;
wherein the foam plastic core members are bonded together with non-foaming adhesive films, and the surface plates are bonded to the core with carrier-free adhesive films or a component resin of the fiber-reinforced composite material forming the surface plates.
2. A sandwich structure comprising:
a core having foam plastic core members formed of a closed-cell foam plastic material and honeycomb core members; and surface plates formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and covering the opposite surfaces of the core;
wherein a peripheral part of the core is formed of the foam plastic core members arranged so as to surround the honeycomb core members, the foam plastic core members are bonded together with non-foaming adhesive films, and the surface plates are bonded to the core with carrier-free adhesive films or a component resin of the fiber-reinforced composite material forming the surface plates.
3. A sandwich structure comprising:
a core having foam plastic core members formed of a closed-cell foam plastic material and honeycomb core members; and surface plates formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and covering the opposite surfaces of the core;
wherein the core is formed by sandwiching the honeycomb core members between the foam plastic core members and bonding the foam plastic core members to the honeycomb core members with carrier-free adhesive films.
4. A sandwich structure comprising:
a core having foam plastic core members formed of a closed-cell foam plastic material and honeycomb core members; and surface plates formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and covering the opposite surfaces of the core;
wherein portions of the core corresponding to portions of the sandwich structure where thickness varies sharply are formed of the foam plastic core members, portions of the core corresponding to portions of the sandwich structure where thickness varies gradually are formed of the honeycomb core members, and the surface plates are bonded to the core with carrier-free adhesive films or a component resin of the fiber-reinforced composite material forming the surface plates.
5. The sandwich structure according to any one of claims 1 to 4 to be used as a structural member of aircraft, rolling stock, an automobile or a ship.
6. A sandwich structure repairing method of repairing a sandwich structure comprising a core having foam plastic core members formed of a closed-cell foam plastic material, and an outer surface plate and an inner surface plate formed of a fiber-reinforced plastic material and bonded to the opposite surfaces of the core with carrier-free adhesive films or a component resin of the fiber-reinforced composite material forming the surface plates, said sandwich structure repairing method comprising the steps of:
putting an outer support plate to an inner surface of a damaged portion of the outer surface plate; and fastening the outer support plate to the outer surface plate with rivets.
7. The sandwich structure repairing method according to claim 6, wherein:
a portion of the inner surface plate and a portion of the core corresponding to the damaged portion of the outer surface plate are removed;

the outer support plate is fastened to the inner surface of the damaged portion of the outer surface plate with rivets;
a cavity formed by removing the portion of the core is filled up with a filling material; and an inner support plate of a size greater than that of an opening in the inner surface plate formed by removing the portion of the inner surface plate is fastened to the inner surface plate with rivets so as to cover the opening in the inner surface plate.
8. The sandwich structure repairing method according to claim 6, wherein:
an opening is formed in the damaged portion of the outer surface plate;
a portion of the core and a portion of the inner surface plate corresponding to the opening and a region around an edge of the opening are removed;
the outer support plate is fastened to the inner surface of a portion of the outer surface plate around an edge of the opening in the outer surface plate with rivets;
a cover plate formed of the same material as that forming the outer surface plate and having a thickness equal to that of the outer surface plate is fitted in the opening and is fastened to the outer support plate with rivets;
a cavity formed in the core by removing the portion of the core is filled up with a filling material; and an inner support plate of a size greater than that of an opening in the inner surface plate formed by removing the portion of the inner surface plate is fastened to the inner surface plate with rivets so as to cover the opening in the inner surface plate.
9. The sandwich structure repairing method according to claim 6, wherein:
a portion of the outer surface plate including the damaged portion is removed to form an opening in the outer surface plate;
a portion of the core corresponding to the opening in the outer surface plate and a portion of the core around an edge of the opening in the outer surface plate are removed;
the outer support plate is expandable over a region greater than the opening in the outer surface plate;

the outer support plate is inserted through the opening in the outer surface plate;

the outer support plate is fastened to the inner surface of the outer surface plate with rivets;

a cover plate of a size equal to that of the opening formed in the outer surface plate and of a thickness equal to that of the outer surface plate is fitted in the opening in the outer surface plate;

the outer support plate is fastened to the cover plate with rivets; and a cavity formed by removing the portions of the core is filled up with a filling material.
10. The sandwich structure repairing method according to claim 6, wherein:

a plurality of the outer support plates are used;
a portion of the outer surface plate including the damaged portion is removed to form an opening in the outer surface plate;

a portion of the core corresponding to the opening in the outer surface plate and a portion of the core around an edge of the opening in the outer surface plate are removed;

the plurality of the outer support plates are inserted through the opening in the outer surface plate so as to be arranged on the inner surface of a portion of the outer surface plate around an edge of the opening in the outer surface plate;

the plurality of the outer support plates are fastened to the inner surface of the outer surface plate with rivets;

a cover plate of a size equal to that of the opening formed in the outer surface plate and of a thickness equal to that of the outer surface plate is fitted in the opening in the outer surface plate;

the cover plate is fastened to the plurality of the outer support plates with rivets; and a cavity formed by removing the portions of the core is filled up with a filling material.
11. The sandwich structure repairing method according to any one of claims 6 to 10, wherein the portion of the core of a foam plastic material are removed by a shot blasting process.
12. A sandwich structure comprising:

a core having foam plastic core members formed of a closed-cell foam plastic material; and surface plates formed of a fiber-reinforced composite material covering the opposite surfaces of the core, said fiber-reinforced composite material having a component resin and hydrophobic inorganic fibers as reinforcing fibers contained within the component resin;

wherein the foam plastic core members are bonded together on a side of the foam plastic core members facing each other with a first non-foaming adhesive film, and the surface plates are bonded to the core on sides of the foam plastic core members facing the surface plates with a second carrier-free adhesive film or the component resin of the fiber-reinforced composite material forming the surface plates, wherein the first adhesive film and the second adhesive film are different.
13. The sandwich structure according to claim 12, wherein:

the core further has honeycomb core members, and a peripheral part of the core is formed of the foam plastic core members arranged so as to surround the honeycomb core members.
14. The sandwich structure according to claim 12, wherein:

the core further has honeycomb core members, and the core is formed by sandwiching the honeycomb core members between the foam plastic core members and bonding the foam plastic core members to the honeycomb core members with the second adhesive films.
15. The sandwich structure according to claim 12, wherein:

the core further has honeycomb core members; and portions of the core corresponding to portions of the sandwich structure where thickness varies sharply are formed of the foam plastic core members, portions of the core corresponding to portions of the sandwich structure where thickness varies gradually are formed of the honeycomb core members.
16. The sandwich structure according to any one of claims 12 to 15 to be used as a structural member of aircraft, rolling stock, an automobile or a ship.
17. A sandwich structure repairing method of repairing a sandwich structure comprising a core having foam plastic core members formed of a closed-cell foam plastic material; and surface plates formed of a fiber-reinforced composite material covering the opposite surfaces of the core, said fiber-reinforced composite material having a component resin and hydrophobic inorganic fibers as reinforcing fibers contained within the component resin;

wherein the foam plastic core members are bonded together on a side of the foam plastic core members facing each other with a first non-foaming adhesive film, and the surface plates are bonded to the core on sides of the foam plastic core members facing the surface plates with a second carrier-free adhesive film or the component resin of the fiber-reinforced composite material forming the surface plates, wherein the first adhesive film and the second adhesive film are different, said sandwich structure repairing method comprising the steps of:

putting an outer support plate to an inner surface of a damaged portion of the outer surface plate; and fastening the outer support plate to the outer surface plate with rivets.
18. The sandwich structure repairing method according to claim 17, wherein:

a portion of the inner surface plate and a portion of the core corresponding to the damaged portion of the outer surface plate are removed;

the outer support plate is fastened to the inner surface of the damaged portion of the outer surface plate with rivets;
a cavity formed by removing the portion of the core is filled up with a filling material; and an inner support plate of a size greater than that of an opening in the inner surface plate formed by removing the portion of the inner surface plate is fastened to the inner surface plate with rivets so as to cover the opening in the inner surface plate.
19. The sandwich structure repairing method according to claim 17, wherein:

an opening is formed in the damaged portion of the outer surface plate;

a portion of the core and a portion of the inner surface plate corresponding to the opening and a region around an edge of the opening are removed;

the outer support plate is fastened to the inner surface of a portion of the outer surface plate around an edge of the opening in the outer surface plate with rivets;

a cover plate formed of the same material as that forming the outer surface plate and having a thickness equal to that of the outer surface plate is fitted in the opening and is fastened to the outer support plate with rivets;

a cavity formed in the core by removing the portion of the core is filled up with a filling material; and an inner support plate of a size greater than that of an opening in the inner surface plate formed by removing the portion of the inner surface plate is fastened to the inner surface plate with rivets so as to cover the opening in the inner surface plate.
20. The sandwich structure repairing method according to claim 17, wherein:

a portion of the outer surface plate including the damaged portion is removed to form an opening in the outer surface plate;

a portion of the core corresponding to the opening in the outer surface plate and a portion of the core around an edge of the opening in the outer surface plate are removed;

the outer support plate is expandable over a region greater than the opening in the outer surface plate;

the outer support plate is inserted through the opening in the outer surface plate;

the outer support plate is fastened to the inner surface of the outer surface plate with rivets;

a cover plate of a size equal to that of the opening formed in the outer surface plate and of a thickness equal to that of the outer surface plate is fitted in the opening in the outer surface plate;

the outer support plate is fastened to the cover plate with rivets; and a cavity formed by removing the portions of the core is filled up with a filling material.
21. The sandwich structure repairing method according to claim 17, wherein:

a plurality of the outer support plates are used;
a portion of the outer surface plate including the damaged portion is removed to form an opening in the outer surface plate;

a portion of the core corresponding to the opening in the outer surface plate and a portion of the core around an edge of the opening in the outer surface plate are removed;

the plurality of the outer support plates are inserted through the openings in the outer surface plate so as to be arranged on the inner surface of a portion of the outer surface plate around an edge of the opening in the outer surface plate;

the plurality of the outer support plates are fastened to the inner surface of the outer surface plate with rivets;

a cover plate of a size equal to that of the opening formed in the outer surface plate and of a thickness equal to that of the outer surface plate is fitted in the opening in the outer surface plate;

the cover plate is fastened to the plurality of the outer support plates with rivets; and a cavity formed by removing the portions of the core is filled up with a filling material.
22. The sandwich repairing method according to any one of claims 17 to 21, wherein the portion of the core of a foam plastic material are removed by a shot blasting process.
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Families Citing this family (63)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6955167B2 (en) * 2002-03-18 2005-10-18 Electrolux Professional Outdoor Products, Inc. Pavement working apparatus and methods of making
US7757684B2 (en) 2002-03-18 2010-07-20 Electrolux Professional Outdoor Products, Inc. Movable machinery, including pavement working apparatus and methods of making
EP1688238A1 (en) * 2005-02-02 2006-08-09 Saab Ab Method for repair of composite articles
TWI353303B (en) * 2004-09-07 2011-12-01 Toray Industries Sandwich structure and integrated molding using th
JP2006198866A (en) * 2005-01-20 2006-08-03 Mitsubishi Rayon Co Ltd Core material for sandwich structural material and manufacturing method of sandwich structural material
US8367183B2 (en) 2005-06-08 2013-02-05 Kabushiki Kaisha Shizuka Sandwich panel including honeycomb structure body and method of producing the sandwich panel
US20080260992A1 (en) * 2005-06-08 2008-10-23 Kabushiki Kaisha Shizuka Sandwich Panel Including Honeycomb Structure Body and Method of Producing the Sandwich Panel
WO2007063145A1 (en) 2005-11-30 2007-06-07 Airbus España, S.L. Composite material structure with embedded optical fibre and method for repairing same
AU2005338589B2 (en) 2005-11-30 2013-01-31 Airbus Operations, S.L. Composite material structure having an embedded optical fibre in one of the surface layers thereof and method for connecting and repairing same
DE102007003273A1 (en) * 2007-01-23 2008-07-24 Airbus Deutschland Gmbh Localized processing of reinforced foam materials as well as composite core components
US7891096B2 (en) * 2007-01-23 2011-02-22 Airbus Deutschland Gmbh Method for reinforcing a foam material as well as a sandwich component
US7842147B2 (en) * 2007-01-31 2010-11-30 M.C. Gill Corporation Composite panel having in-situ thermoset foamed core
US8108979B2 (en) * 2007-04-24 2012-02-07 United Technologies Corporation Using a stiffener to repair a part for an aircraft engine
GB2448901A (en) * 2007-05-02 2008-11-05 Alderley Materials Ltd Thermal Insulation Structure
GB2455063A (en) * 2007-11-12 2009-06-03 Rolls Royce Plc Method of repairing a lined structure
US8371009B2 (en) * 2007-12-12 2013-02-12 General Electric Company Methods for repairing composite containment casings
US8403624B2 (en) * 2007-12-12 2013-03-26 General Electric Company Composite containment casings having an integral fragment catcher
US7981519B2 (en) * 2008-04-11 2011-07-19 United Technologies Corporation Metallic doubler for repair of a gas turbine engine part
US20090313931A1 (en) * 2008-06-24 2009-12-24 Porter William H Multilayered structural insulated panel
US20100014935A1 (en) * 2008-07-21 2010-01-21 Fred Jevaney Reinforced bulkheads and methods of making same
JP4860730B2 (en) * 2009-07-24 2012-01-25 株式会社イノアックコーポレーション Lightweight honeycomb panel
DE102009035108B4 (en) * 2009-07-29 2013-02-07 Airbus Operations Gmbh Method and spraying device for repairing a sandwich panel
US20120272592A1 (en) * 2009-10-28 2012-11-01 Carmen Bellavia Light weight molded roof tile with integrated solar capabilities
WO2011071318A2 (en) * 2009-12-10 2011-06-16 Cho Hyun-Chul Board having a built-in member, heat insulation structure, and ship in which the ingress of water is prevented
US9993983B2 (en) * 2010-02-26 2018-06-12 Mitsubishi Heavy Industries, Ltd. Repairing method for composite material and composite material using the same
EP2595878B1 (en) * 2010-07-20 2017-05-03 Airbus Operations GmbH Main-load-bearing planking shell and structural component and flow body comprising such a main-load-bearing planking shell
DE102010053569B4 (en) 2010-12-06 2012-07-26 Airbus Operations Gmbh Method for repairing an aircraft structural component
BR112013018293A2 (en) * 2011-01-18 2016-11-16 Leoni Kabel Holding Gmbh device for the automated supply of connection elements to a unit and connection processing as well as supply hose for connection elements
US8091229B2 (en) * 2011-03-08 2012-01-10 General Electric Company Method of repairing a subsurface void or damage for a wind turbine blade
US8844108B2 (en) * 2011-07-12 2014-09-30 The Boeing Company Large area repair of composite aircraft
JP5818700B2 (en) * 2012-01-19 2015-11-18 三菱航空機株式会社 Repair method and repair structure of honeycomb sandwich structure
US9333684B2 (en) 2012-10-30 2016-05-10 Bell Helicopter Textron Inc. Method of repairing, splicing, joining, machining, and stabilizing honeycomb core using pourable structural foam and a structure incorporating the same
US9015941B2 (en) * 2012-10-30 2015-04-28 Bell Helicopter Textron Inc. Method of repairing honeycomb core using pourable structural foam
US9597826B2 (en) 2012-10-30 2017-03-21 Bell Helicopter Textron Inc. Method of repairing, splicing, joining, machining, and stabilizing honeycomb core using pourable structural foam and a structure incorporating the same
US9149999B2 (en) 2012-10-30 2015-10-06 Bell Helicopter Textron Inc. Method of repairing, splicing, joining, machining, and stabilizing honeycomb core using pourable structural foam and a structure incorporating the same
EP2792630A1 (en) * 2013-04-16 2014-10-22 Kone Corporation An elevator car and an elevator
US9133626B2 (en) * 2013-05-02 2015-09-15 Tower Ipco Company Limited Multi-purpose tile
US8985513B2 (en) * 2013-06-17 2015-03-24 The Boeing Company Honeycomb cores with splice joints and methods of assembling honeycomb cores
DE102013018148B4 (en) * 2013-12-04 2015-07-30 Premium Aerotec Gmbh Process for the production of a fiber composite component, as well as semifinished assembly usable therefor
DE102013225730A1 (en) * 2013-12-12 2015-06-18 Bayerische Motoren Werke Aktiengesellschaft Honeycomb sandwich structure and method for producing a honeycomb sandwich structure
EP2930011A1 (en) * 2014-04-07 2015-10-14 AIRBUS HELICOPTERS DEUTSCHLAND GmbH A method of repairing a sandwich component having a honeycomb core with an associated core height
US10406789B2 (en) * 2014-06-04 2019-09-10 Bright Lite Structures Llc Multicomponent polymer resin, methods for applying the same, and composite laminate structure including the same
JP6215167B2 (en) * 2014-09-29 2017-10-18 積水化成品工業株式会社 Fiber reinforced composite and method for producing fiber reinforced composite
US10967583B2 (en) 2015-04-03 2021-04-06 Bright Lite Structures Llc Apparatus for controllably cutting fibers and related methods
US10828484B2 (en) * 2015-08-21 2020-11-10 Medline Industries, Inc. Disinfecting cap
CN106079675B (en) * 2016-06-30 2019-01-25 中铁伟业（北京）新技术有限公司 Composite board for train
CN106226393B (en) * 2016-07-05 2020-01-31 国营芜湖机械厂 layered damage repairing method for laminated composite material structure
EP4046783A1 (en) * 2016-10-25 2022-08-24 Rohr, Inc. Acoustic panel repair with retention of acoustic properties
DE102016222435B4 (en) 2016-11-15 2018-09-06 Deutsches Zentrum für Luft- und Raumfahrt e.V. Sandwich element, load-bearing structure and vehicle
FR3062806B1 (en) * 2017-02-15 2021-05-28 Safran Nacelles PROCESS FOR MACHINING A COMPOSITE MATERIAL, ESPECIALLY FOR THE REPAIR OF THE COMPOSITE MATERIAL
US10604226B2 (en) * 2017-04-14 2020-03-31 Textron Innovations Inc. Shielded structure for aircraft
NL2018851B1 (en) * 2017-05-05 2018-11-14 Johannes Franciscus Maria Van Veldhoven Mattheus Method for repairing damage to an insulated body of a vehicle and repaired vehicle.
US10946600B1 (en) * 2017-08-29 2021-03-16 Hrl Laboratories, Llc Composite structure repair methods incorporating a lattice core material
US11148375B1 (en) * 2017-08-29 2021-10-19 Hrl Laboratories, Llc Method of repairing sandwich structure and repaired sandwich structure
RU2664620C1 (en) * 2017-10-20 2018-08-21 Российская Федерация, От Имени Которой Выступает Министерство Промышленности И Торговли Российской Федерации Polymer composite materials three-layer panels repairing method
CN110962377A (en) * 2018-09-28 2020-04-07 成都飞机工业（集团）有限责任公司 Honeycomb sandwich structure part repairing method capable of reducing structure loss
CN109649679A (en) * 2018-10-15 2019-04-19 西北工业大学 Plate repair method
US11312507B2 (en) * 2019-09-03 2022-04-26 The Boeing Company Repair assembly to repair an area on a member of a vehicle
FR3100745B1 (en) * 2019-09-16 2021-08-06 Safran Nacelles Repair process for thermal protection of a nacelle structure
CN113370605A (en) * 2021-05-18 2021-09-10 上海市富力达科技股份有限公司 Carbon fiber composite material plate with sandwich structure and preparation process thereof
US20230011358A1 (en) * 2021-07-08 2023-01-12 The Boeing Company Method for repairing composite structures using foamable media
CN113478946A (en) * 2021-07-12 2021-10-08 重庆泛锐科技有限公司 Repairing method of sandwich composite material plate
CN114368173B (en) * 2021-11-24 2023-07-07 中国南方航空股份有限公司 Typical gradual change step type hyperbolic laminate structure penetrating damage repair process

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3619344A (en) * 1969-08-07 1971-11-09 Du Pont Oriented foam laminar structures
US4120712A (en) * 1975-03-17 1978-10-17 The Boeing Company Method of securing two non-metal surfaces together using a hot melt type fastener heatable by induction heating
GB2032843B (en) * 1978-10-31 1982-07-14 Coal Ind Foamed phenolic board laminate
US4351873A (en) * 1980-07-31 1982-09-28 Gaf Corporation Double faced insulating board
FR2525849B1 (en) * 1982-04-26 1985-08-09 Hutchinson PRINTED CIRCUIT SUBSTRATE
US4557961A (en) * 1983-05-27 1985-12-10 The Boeing Company Light-weight, fire-retardant structural panel
US4749601A (en) * 1985-04-25 1988-06-07 Hillinger Brad O Composite structure
WO1987003842A1 (en) * 1985-12-19 1987-07-02 Built-Rite Productions Pty. Limited Refurbishment of fibreglass panels
US4687691A (en) * 1986-04-28 1987-08-18 United Technologies Corporation Honeycomb spliced multilayer foam core aircraft composite parts and method for making same
US5328744A (en) * 1990-10-09 1994-07-12 E. I. Du Pont De Nemours And Company Panel having a core with thermoplastic resin facings
AU650769B2 (en) * 1991-08-05 1994-06-30 3A Technology & Management Ltd. Process for the production of a composite sheet comprising a cellular core and at least one outer layer
US5313034A (en) * 1992-01-15 1994-05-17 Edison Welding Institute, Inc. Thermoplastic welding
US5462623A (en) * 1992-05-04 1995-10-31 Webcore Technologies, Inc. Method of production of reinforced foam cores
JPH06173170A (en) 1992-12-04 1994-06-21 Sumika Hercules Kk Sizing agent composition for reinforcing fiber
US5589016A (en) * 1994-04-29 1996-12-31 The Boeing Company Prescored foam for panel fabrication
US5580502A (en) * 1995-03-23 1996-12-03 Sikorsky Aircraft Corporation Method of fabricating a composite article having an integral, co-cured composite stiffening member
IL114613A (en) * 1995-07-16 1999-09-22 Tat Ind Ltd Parallel flow condenser heat exchanger

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JP3243461B2 (en) 2002-01-07
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DE60028663D1 (en) 2006-07-27

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