CN110815877A - A repair method for penetration damage of thin-walled composite laminate structure with curvature - Google Patents

Abstract

The invention belongs to the technical field of composite material repair, and relates to a repair method for penetrating damage of a thin-walled composite material laminate structure with a curvature. As an auxiliary tool, filling the damaged area of the composite material with filler, including the following steps: a new foam backboard, the outer surface of the foam backing board has the same curvature as the inner surface of the damaged area of the composite material, and the size is 15mm larger than the circumference of the damaged area ‑20mm; fix the foam backboard on the inner surface of the damaged area of the composite material; fill the damaged area of the composite material with filler, and then lay a repair cloth on the outer surface, and the number of layers of repair cloth is at least one layer more than the number of layers in the damaged area , curing and forming; compared with the commonly used adhesive patch and wet laying repair methods, the repair method of the present invention does not require new composite patch forming tooling or sheet metal backing tooling, which effectively reduces the repair cost.

Description

A repair method for penetration damage of thin-walled composite laminate structure with curvature

technical field

The invention belongs to composite material repair technology, and relates to a repair method for penetration damage of thin-walled and curved composite material laminate structures.

Background technique

There are two common repair methods for penetrating damage of thin-walled composite laminate structures with curvature: the first is repair by adhesive patch, a new composite patch is made, and the patch is glued to the damaged area, as shown in Figure 1. As shown, this repair method requires a new forming tool for the composite patch. The second is wet-paving repair. A new sheet metal back plate is made as a repair cloth layer support and fixed on the inside of the damaged area, the repair cloth is laid on the outside of the damaged area, and the sheet metal back plate is removed after curing, as shown in the figure. 2, this repair method requires the tooling of a new sheet metal backing.

Due to the uncertainty of the location of the penetration damage, it is difficult to reuse the newly made tooling, so the use of these two repair methods will lead to high repair costs, time-consuming and low efficiency.

SUMMARY OF THE INVENTION

The purpose of the present invention is to propose a new repair method for penetrating damage of thin-walled composite laminate structure with curvature, so as to solve the technical problems of high maintenance cost and low efficiency caused by the need for new tooling in the current method.

In order to solve this technical problem, the technical scheme of the present invention is:

A method for repairing penetration damage of a thin-walled composite material laminate structure with curvature. Fill the filler.

A method for repairing penetration damage of a thin-walled composite laminate structure with curvature, the method comprising the following steps:

Step 1, make a new foam backboard, the outer surface of the foam backboard has the same curvature as the inner surface of the damaged area of the composite material, the inner surface curvature of the foam backboard is not required, and the size is 15mm-20mm larger than the circumference of the damaged area;

Step 2, fixing the foam backboard on the inner surface of the damaged area of the composite material;

Step 3: Filling the damaged area of the composite material with filler, and then laying a repair cloth on the outer surface. The number of layers of the repair cloth is at least one layer more than the number of layers in the damaged area, and then cured and formed.

The thickness requirement of the foam backboard in step 1: 5±1mm.

In the second step, the foam backing board is glued to the inner surface of the damaged area of the composite material.

In step 2, a layer of repair cloth is laid on the inner surface of the foam backboard, and the repair cloth is 15mm-20mm larger than the circumference of the foam backboard, and is cured and formed.

In the step 3, the first layer of repair cloth is 15mm-20mm larger than the circumference of the damaged area, and each subsequent layer of repair cloth is 15mm-20mm larger than the circumference of the previous layer.

Preferably, the repairing method further includes the step of stripping the damaged area of the composite material part before step 2.

Preferably, the material of the foam backboard is rigid foam.

The beneficial effects of the present invention are as follows: the repair method for the penetration damage of the thin-walled composite material laminate structure with curvature proposed by the present invention does not require a new composite material patch forming tool compared with the commonly used adhesive patch and wet laying repair methods Or sheet metal back plate tooling, effectively reducing the repair cost.

Description of drawings

In order to illustrate the technical solutions implemented by the present invention more clearly, the following will briefly explain the accompanying drawings that need to be used in the examples of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and for those skilled in the art, other drawings can also be obtained from these drawings without creative effort.

Fig. 1 is a schematic diagram of the repairing of adhesive patch in the prior art;

Fig. 2 is the wet paving repair schematic diagram of the prior art;

3 is a schematic diagram of the repair method of the present invention;

4 is a schematic diagram of damage to the front edge cover of the vertical stabilizer in the first embodiment;

5 is a schematic diagram of damage to the wingtip skin in Example 2;

Among them, 1-composite material patch, 2-composite material piece, 3-glue, 4-sheet metal backboard, 5-repair cloth, 6-foam backboard, 7-filler.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

The features of various aspects of the embodiments of the present invention will be described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that the present invention may be practiced without these specific details. The following description of the embodiments is only for a better understanding of the present invention by illustrating examples of the invention. The present invention is not limited to any specific arrangements and methods provided below, but covers all product structures, any improvements, substitutions, and the like of methods covered without departing from the spirit of the present invention.

In the various drawings and the following description, well-known structures and techniques have not been shown in order to avoid unnecessarily obscuring the present invention. The repair method for the penetration damage of the thin-walled composite material laminate structure with curvature proposed by the present invention is shown in FIG. 3 .

The specific implementation steps are as follows: the first step is to make a new foam backboard 6. The outer surface of the foam backboard 6 has the same curvature as the inner surface of the damaged area of the composite material part 2. The inner surface curvature of the foam backboard 6 is not required. 15mm-20mm larger than the circumference of the damaged area. In the second step, glue the foam backboard 6 to the inner surface of the damaged area of the composite material part 2 with glue 3, and lay a layer of repair cloth 5 outside the foam backboard 6. The repair cloth 5 is larger than the circumference of the foam backboard 6 by 15mm- 20mm, cured and formed. The third step is to fill the damaged area of the composite material 2 with filler 7, and then lay a repair cloth 5 on the outer surface. The number of layers of the repair cloth 5 is at least one layer more than the number of layers in the damaged area, and the first layer of repair cloth 5 is larger than the damaged area. The circumference is 15mm-20mm, and then each layer of repair cloth 5 is larger than the circumference of the previous layer by 15mm-20mm, and it is cured and formed.

Example 1:

The front edge cover of the vertical stabilizer of a certain type of machine is a composite laminated structure. As shown in Figure 4, there is a penetrating damage near the front end of the root, with an area of 22mm × 17mm, and the damage area is layered with two layers of fabric. The angle is ±45°.

Refer to Figure 3 for repair implementation: The first step is to open a Φ30mm hole in the damaged area of the composite material to remove the layer in the damaged area, and carry out paint stripping treatment within a Φ150mm range around the hole. The second step is to make a Φ60mm foam backboard with DHS261-113-15 foam. The outer surface of the foam backboard has the same curvature as the inner surface of the damaged area of the composite material. The foam backboard is glued with EA9396 glue on the composite material. On the inner surface of the damaged area, lay a layer of Φ90mm ECS0031.12 dry carbon cloth dipped in EA9396 adhesive repair cloth on the outside of the foam backboard. The laying direction is ±45°. The third step is to fill the damaged area of the composite material with 17# filler, and then lay three layers of repair cloth on the outer surface. The size of the first layer is Φ60mm, the size of the second layer is Φ90mm, and the size of the third layer is Φ120mm. It is ±45°, and it is cured under normal temperature and pressure. The fourth step is to smooth the repaired area and touch up the paint.

Embodiment 2:

A certain type of wingtip is a composite laminate structure. As shown in Figure 5, there are two gap damage areas A and B in the middle of the lower skin of the wingtip, with diameters of 50mm (number A) and 15mm × 10mm respectively. (No. B) size, the damaged area is two layers of fabric, and the layup angle is ±45°.

Refer to Figure 3 for repair implementation:

Repair of damaged area A: The first step is to remove the skin of the damaged area A on the outer surface of the lower skin of the right wingtip, and drill the damaged area A; the second step is to remove the area around the damaged area A on the outer surface of the lower skin of the right wingtip. For paint treatment, the radius of the peeling area is greater than the diameter of the hole by 60mm; the third step is to polish the Tedlar film around the inside of the damaged area A, and the radius of the grinding area is greater than the diameter of the hole by 40mm; the fourth step, use DHS261-113-15 foam to make a new Φ70mm foam back Glue the foam backboard to the inner surface of the wingtip damage area with EA9396 glue (3), and lay a layer of Φ90mm ECS0031.12 dry carbon cloth soaked in EA9396 glue repair cloth on the outside of the foam backboard. The laying direction is ±45°, pressurized and cured at room temperature; the fifth step is to fill the damaged area of the wing tip with 17# filler, and then lay three layers of ECS0031.12 dry carbon cloth soaked with EA9396 glue on the outer surface of the repair cloth, the size of the first layer is Φ70mm , The size of the second layer is Φ90mm, the size of the third layer is Φ110mm, the laying direction is ±45°, and the pressure is cured and formed at room temperature; the sixth step is to smooth the repair area and touch up the paint.

Repair of damaged area B: the size of repairing foam backboard, repair cloth and polishing and paint stripping is reduced accordingly, and the repair method is the same as that of damaged area A.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited to this. Various equivalent modifications or substitutions should be included within the protection scope of the present invention.

Claims (8)

1. a repair method for penetrating damage to a thin-walled composite material laminate structure with curvature, characterized in that: the method adopts a foam backboard whose outer surface is consistent with the inner surface curvature of the damaged area of the composite material as auxiliary tooling, Fill the damaged area of the composite part with filler. 2. The method for repairing the penetration damage of the thin-walled composite laminate structure with curvature according to claim 1, wherein the repair method comprises the following steps: Step 1, make a new foam backboard, the outer surface of the foam backboard has the same curvature as the inner surface of the damaged area of the composite material, and the size is 15mm-20mm larger than the circumference of the damaged area; Step 2, fixing the foam backboard on the inner surface of the damaged area of the composite material; Step 3: Filling the damaged area of the composite material with filler, and then laying a repair cloth on the outer surface. The number of layers of the repair cloth is at least one layer more than the number of layers in the damaged area, and then cured and formed. 3 . The method for repairing penetration damage of a thin-walled composite laminate structure with curvature according to claim 2 , wherein the thickness requirement of the foam backboard in step 1 is 5±1 mm. 4 . 4 . The method for repairing penetration damage of a thin-walled and curved composite laminate structure according to claim 2 , wherein in step 2, the foam backing plate is glued to the inner surface of the damaged area of the composite material. 5 . 5. The method for repairing the penetration damage of the thin-walled composite laminate structure with curvature according to claim 2, wherein in step 2, a layer of repair cloth is laid on the inner surface of the foam backing board, and the repairing The cloth is 15mm-20mm larger than the circumference of the foam backboard, and it is cured and formed. 6. The repair method for penetrating damage of thin-walled composite laminate structure with curvature according to claim 2, wherein the first layer of repair cloth is larger than the circumference of the damaged area by 15mm-20mm in the step 3, and then every The layer of repair cloth is 15mm-20mm larger than the circumference of the previous layer. 7. The method for repairing the penetration damage of the thin-walled composite material laminate structure with curvature according to any one of claims 2 to 6, characterized in that: it further comprises a method of stripping the damaged area of the composite material piece before step 2. step. 8 . The method for repairing penetration damage of a thin-walled composite laminate structure with curvature according to claim 7 , wherein the foam backing board is made of rigid foam. 9 .

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