CN-121989482-A - Repair method for debonding composite materials

CN121989482ACN 121989482 ACN121989482 ACN 121989482ACN-121989482-A

Abstract

The invention belongs to the technical field of composite material repair, and discloses a repair method for debonding a composite material. The method comprises the steps of determining the debonding positions of an upper skin and a sandwich, between the sandwich and an interlayer and between the sandwich and a lower skin of a composite material, defining a region to be repaired, processing a first injection hole and a first ventilation hole at the periphery of the region to be repaired, wherein the first injection hole and the first ventilation hole are communicated with a debonding gap, the first injection hole does not penetrate through a corresponding debonding interface layer, injecting resin glue through the first injection hole, curing after the resin glue overflows and fills the first ventilation hole, achieving debonding interface bonding, processing a first through hole penetrating through the upper skin in the region to be repaired, extending into the region to be repaired through an L-shaped workpiece to remove the sandwich and the interlayer in the region to be repaired to form a concave cavity, removing scraps, injecting potting glue into the concave cavity, curing, and expanding the first through hole into a second through hole penetrating through the upper skin, curing the potting glue and the lower skin, and fastening a wet installation fastening assembly at the gap to fill the adhesive. The comprehensive requirements of structure reinforcement, interface repair and sealing protection are met.

Inventors

ZHANG FAN
LI XIAOHUI
XIA CHUNWEI
ZHUANG HONGXING
GU LINGCONG
CHEN MO
YANG HUI
YUAN YUHUI

Assignees

上海飞机制造有限公司

Dates

Publication Date: 20260508
Application Date: 20260313

Claims (10)

1. A repairing method for debonding composite material, the composite material (10) comprises an upper skin (101), a lower skin (102), a plurality of sandwich cores (103) and a plurality of interlayer (104), wherein the upper skin (101) and the lower skin (102) are arranged at intervals up and down, a plurality of the sandwich cores (103) are clamped between the upper skin and the lower skin, the interlayer (104) is arranged between two adjacent sandwich cores (103), the upper skin (101) and the sandwich cores (103), the interlayer (104), the sandwich cores (103) and the lower skin (102) are mutually adhered and fixed, and the repairing method for the composite material debonding is characterized by comprising the following steps: step S100, detecting and determining debonding positions and debonding ranges among the upper skin (101) and the sandwich (103), the sandwich (103) and the interlayer (104), and between the sandwich (103) and the lower skin (102), and defining an area (11) to be repaired; step 200, positioning and processing a first injection hole (12) and a first ventilation hole (13) around the area (11) to be repaired, wherein the first injection hole (12) is communicated with a debonding gap (14) formed by debonding the first ventilation hole (13), the first injection hole (12) is opened to a position corresponding to a layer where a debonding interface is located and does not penetrate through the debonding interface layer, resin adhesive (21) is injected into the debonding gap (14) through the first injection hole (12), and after the resin adhesive (21) overflows from the first ventilation hole (13) and is fully filled, the resin adhesive (21) is solidified so as to bond and fix the debonding interface; Step S300, positioning a mechanical connection installation position in the area (11) to be repaired, machining a first through hole (15) penetrating through the upper skin (101) at the mechanical connection installation position, inserting an L-shaped workpiece (31) through the first through hole (15), removing the sandwich (103) and the interlayer (104) materials in the area (11) to be repaired, forming a concave cavity (16), and removing scraps; step 400, pouring sealant (23) into the concave cavity (16) through the first through hole (15), and curing the pouring sealant (23) after confirming full filling; And S500, reaming the first through hole (15) to a second through hole (17) at the mechanical connection installation position, wherein the second through hole (17) is smaller than the area (11) to be repaired in size, the second through hole (17) penetrates through the upper skin (101), the solidified pouring sealant (23) and the lower skin (102), a fastening component (32) for mechanical connection is mounted at the second through hole (17) in a wet mode, and an adhesive is filled in a gap between the fastening component (32) and the wall of the second through hole (17) and then the fastening component is fastened.
2. The repair method for debonding of composite materials according to claim 1, wherein the step S300 further comprises using a positioning template (33) having a smaller aperture than the first through hole (15) to be placed on the upper skin (101) to protect the upper skin (101), or using an elastic material to wrap a portion of the L-shaped work piece (31) in contact with the upper skin (101) to protect the upper skin (101).
3. A repair method for debonding of composite materials according to claim 1, characterized in that in step S300, the radial diameter of the cavity (16) is 20-50 mm.
4. The method for repairing the debonded composite material according to claim 1, wherein the step S400 further comprises uniformly distributing a plurality of second ventilation holes (18) communicated with the cavity (16) in the circumferential direction of the first through hole (15) on the upper skin (101), curing after the potting adhesive (23) overflows from all the second ventilation holes (18), wherein the diameter of the second ventilation holes (18) is less than or equal to 1.6mm, and the second ventilation holes (18) are positioned in a range of 0mm-6mm from the outer edge of the area (11) to be repaired.
5. The repairing method of the composite material debonding according to claim 1, wherein in the step S400, the potting adhesive (23) is a structural adhesive or a foaming adhesive having an adhesive bonding and reinforcing function.
6. The method according to claim 1, wherein in the step S500, the fastening assembly (32) includes a screw (321), a nut (322), a first spacer (323) and a second spacer (324), the first spacer (323) is disposed on the outer side of the upper skin (101), the second spacer (324) is disposed on the outer side of the lower skin (102), a shaft portion of the screw (321) sequentially penetrates through the first spacer (323), the second through hole (17) and the second spacer (324), a head portion of the screw (321) is abutted against the first spacer (323), and the nut (322) is in threaded connection with the shaft portion of the screw (321) and abutted against the second spacer (324).
7. The method for repairing a composite material debonding according to claim 6, further comprising step S600 after step S500, wherein the step S600 is to clean the outer periphery of the head of the screw (321) and seal-coat the head of the screw (321) with a sealant.
8. The repair method for debonding of composite materials according to any of the claims 1-7, characterized in that the curing means of the resin glue (21) and the potting glue (23) can each be cured independently by choosing different temperatures.
9. The method of repairing a composite material debonded according to any of claims 1-7, wherein step S100 is directly engaged with step S300, omitting step S200, further comprising step S301 after step S300; The step S301 includes injecting the resin adhesive (21) into a debonding interface in the cavity (16) through the first through hole (15) for local repair, reaming the first through hole (15) to the size of the second through hole (17) at the mechanical connection installation position, penetrating the second through hole (17) through the upper skin (101) and the lower skin (102), pre-installing the fastening component (32) in an untwisted state on the second through hole (17) and then injecting the pouring sealant (23) into the cavity (16), screwing the fastening component (32), conducting heat through the fastening component (32) made of metal through a heating device to solidify the pouring sealant (23), and synchronously solidifying the pouring sealant (23) and the resin adhesive (21) for local repair, and omitting the steps S400 to S500.
10. The method of repairing a composite material debonded according to any of claims 1-7, wherein steps S100 to S200 are performed normally, further comprising step S302 after step S300; The step S302 comprises reaming the first through hole (15) to the size of the second through hole (17) at the mechanical connection installation position, penetrating the second through hole (17) through the upper skin (101) and the lower skin (102), pre-installing the fastening component (32) on the second through hole (17) in an untwisted state, injecting the pouring sealant (23) into the cavity (16), screwing the fastening component (32), conducting heat through the fastening component (32) made of metal by a heating device to solidify the pouring sealant (23), and omitting the step S400 to the step S500.

Description

Repair method for debonding composite materials Technical Field The invention relates to the technical field of composite material repair, in particular to a repair method for debonding a composite material. Background The composite material comprises an upper skin, a lower skin and a plurality of sandwich structures, wherein the sandwich structures comprise sandwich cores and interlayer layers, the upper skin and the lower skin are arranged at intervals up and down, a plurality of sandwich cores are clamped between the upper skin and the lower skin, the interlayer layers are arranged between two adjacent sandwich cores, and the upper skin and the sandwich cores, the sandwich cores and the interlayer layers, and the sandwich cores and the lower skin are mutually adhered and fixed. The sandwich structure has wide application in composite material structure by virtue of the advantages of light weight, high bending rigidity, high material utilization rate and the like, and the multi-layer sandwich structure can further improve the bearing efficiency. However, in the process of manufacturing, assembling and using the composite material, the problems of skin and sandwich damage, interface debonding, separation among multiple layers of sandwich and the like are easy to occur, and large-area debonding defects can be formed when the problems are serious. In the range of the structure allowing maintenance, the debonding damage is reasonably repaired, so that the structure is ensured to be safe to use, and the replacement and maintenance cost of parts can be reduced. At present, the existing sandwich structure repairing technology still has obvious defects that in the traditional mechanical connection repairing technology, the tightening force of a fastener directly acts on a thin skin, skin pressure loss or loosening and failure of the fastener are easy to cause, water vapor is difficult to invade a sandwich layer to cause corrosion damage, a large bonding area is needed for simple cementing repairing, the risks of insufficient bonding strength and weak bonding failure exist, the comprehensive requirements of structure reinforcement, interface repairing and sealing protection are difficult to meet at the same time, and the high-efficiency and reliable repairing requirements of the debonding damage of the multi-layer sandwich composite material cannot be adapted. Thus, there is a need for repair methods for composite debonding to address the above problems. Disclosure of Invention The invention aims to provide a repairing method for debonding composite materials, which is suitable for efficiently and reliably repairing debonding damage of composite materials with a multi-layer sandwich, and can be used for realizing comprehensive requirements of structure reinforcement, interface repair and sealing protection, and recovering load transmission in the composite materials conveniently and reliably. To achieve the purpose, the invention adopts the following technical scheme: The repairing method for the debonding of the composite material comprises an upper skin, a lower skin, a plurality of sandwich cores and a plurality of interlayer, wherein the upper skin and the lower skin are arranged at intervals up and down, a plurality of sandwich cores are arranged between the upper skin and the lower skin, the interlayer is arranged between two adjacent sandwich cores, the upper skin and the sandwich cores, the sandwich cores and the interlayer, and the sandwich cores and the lower skin are mutually adhered and fixed, and the repairing method for the debonding of the composite material comprises the following steps: Step 100, detecting and determining the debonding position and debonding range between the upper skin and the sandwich, between the sandwich and the interlayer, and between the sandwich and the lower skin, and defining a region to be repaired; Step 200, positioning and processing a first injection hole and a first ventilation hole at the periphery of the area to be repaired, wherein the first injection hole is communicated with a debonding gap formed by debonding the first ventilation hole, the first injection hole is opened to the position of a layer corresponding to the debonding interface and does not penetrate through the debonding interface layer, resin glue is injected into the debonding gap through the first injection hole, and after the resin glue overflows from the first ventilation hole and is fully filled, the resin glue is solidified to bond and fix the debonding interface; Step 300, positioning a mechanical connection installation position in the area to be repaired, and processing a first through hole penetrating through the upper skin at the mechanical connection installation position; step S400, pouring sealant into the concave cavity through the first through hole, and curing the pouring sealant after confirming full filling; And S500, reaming the first through hole to a second through hole size at