阅读说明：本技术 组件、使组件的片材着色的方法及修复组件的面板的方法 (Assembly, method for colouring a sheet of an assembly and method for repairing a panel of an assembly ) 是由 安托尼·林斯 纪尧姆·费雷尔 弗兰克·多比容 朱利恩·查尔斯 于 2020-11-17 设计创作，主要内容包括：本发明涉及一种袋体(11)和复合面板(2)的组件、使组件的片材着色的方法及修复组件的面板的方法,所述复合面板呈现出通过使用所述袋体(11)对修复件聚合而修复的受损区域(8)。所述袋体包括旨在在所述面板(2)上铺设的片材(12)。当所述面板(2)和所述片材(12)铺设在彼此顶部时,所述片材(12)呈现出能够以取决于所述面板(2)的与其对应的区域所需的聚合温度的比例来吸收通过辐射而发射到所述片材上的热量的区域,所述辐射通过相关区域中的片材的适当着色而被部分吸收。能够确定面板中比其他区域辐射吸收较低的那些区域意味着在修复方面可以调整加热以适应聚合的需求,从而可以在整个受损区域上获得均匀的聚合,从而加固了修复。(The invention relates to an assembly of a pouch (11) and a composite panel (2) presenting a damaged area (8) repaired by polymerizing a repair using said pouch (11), a method of colouring a sheet of the assembly and a method of repairing a panel of the assembly. The bag body comprises a sheet (12) intended to be laid on the panel (2). When the panel (2) and the sheet (12) are laid on top of each other, the sheet (12) presents an area capable of absorbing the heat emitted onto the sheet by radiation, which is partially absorbed by a suitable colouring of the sheet in the relevant area, in a proportion depending on the polymerization temperature required by the area of the panel (2) corresponding to it. Being able to determine those areas of the panel that have lower radiation absorption than other areas means that the heating can be adjusted in terms of repair to suit the needs of polymerisation, so that a uniform polymerisation can be obtained over the whole damaged area, thus reinforcing the repair.)

1. An assembly of a bag (11) and a composite panel (2) presenting a damaged area (8) to be repaired by polymerizing a repair using the bag (11), the bag comprising a sheet (12) intended to be laid on the panel (2), characterized in that, when the panel (2) and the sheet (12) are laid on top of each other, the sheet (12) presents an area (18) capable of absorbing the heat emitted onto the sheet by radiation partially absorbed by a suitable coloration of the sheet in the relevant area (18) in a proportion dependent on the polymerization temperature required by the area of the panel (2) corresponding thereto.

2. The assembly according to claim 1, characterized in that said sheet is heat-sensitive or comprises a heat-sensitive film and, when subjected to a radiation heating means, exhibits zones of different color corresponding to corresponding zones of the panel requiring different polymerization temperatures.

3. Assembly according to one of claims 1 and 2, characterized in that the different colours comprise at least partially partial hues of black and white.

4. Assembly according to one of claims 1 to 3, characterized in that those areas (18) of the sheet (12) intended to be laid over corresponding areas of the panel requiring a lower polymerization temperature exhibit a lighter colour, whereas those areas of the sheet intended to be laid over areas of the panel requiring a higher polymerization temperature exhibit a darker colour.

5. Assembly according to one of claims 1 to 4, characterized in that the colour of the areas (18) of the sheet (12) has been obtained by applying pigments or colorants.

6. Assembly according to one of claims 1 to 5, characterized in that the colour of the areas (18) of the sheet (12) is obtained by printing.

7. Assembly according to one of claims 1 to 6, characterized in that the bag (11) comprises a white covering (22).

8. A method of colouring a sheet of said assembly according to one of claims 1 to 7, characterized in that it comprises the following steps: -temporarily heating the panel (2) by radiation; -detecting the temperature at least over the whole damaged area (8) to be repaired; -defining areas (18) of different colors depending on the measured temperature; -applying a color in said defined area (18).

9. A method of colouring a sheet of said assembly according to one of claims 1 to 7, characterized in that it comprises the following steps: -thermally simulating a damaged area (8) to be repaired; -detecting the temperature at least throughout the area to be repaired; -defining areas (18) of different colours according to the temperature obtained by the simulation; -applying a color in said defined area.

10. Method for colouring sheet material of said assembly according to one of claims 8 and 9, characterized in that the application of said colour uses pigments or colouring agents.

11. Method for colouring a sheet of said assembly according to one of claims 8 and 10, characterized in that the application of said colours is carried out using printing.

12. Method for repairing a panel of an assembly according to one of claims 1 to 7 using a sheet of said assembly, characterized in that it comprises a step of applying said sheet (12) to said panel (2) under vacuum and a step of heating said sheet by radiation using heating means (10).

13. Method according to claim 12, characterized in that a white covering (22) is inserted between the sheet (12) and the panel (2).

Technical Field

The present invention relates to a tool, and more particularly, to a sheet for repairing composite panels and a repair method using such a sheet. The invention also relates to a method for colouring said sheet and to a method for repairing a panel.

Background

During the course of operation, aircraft may present areas made of composite materials that have been damaged and need repair.

From patent application FR 3039452 a method is known for repairing composite panels using a heated covering to polymerize a repair, for example made of a new ply of composite material, to fix it to the composite panel. However, the heated covering provides a more or less uniform temperature over its entire surface. The temperature required for a suitable polymerization now depends on the geometry of the panel, for example on its thickness (which may not be the same over the whole extent of the area to be repaired), or again for example on reliefs, cavities or other geometrical configurations that cause dissipation or accumulation of heat (such as the presence of reinforcements with recesses that form heat sinks that accumulate heat, or else the presence of materials acting as heat sinks that accumulate heat in smaller spaces, for example cells of foam, honeycomb material or the like), or else on any other feature of the panel that makes the temperature different from one area to another. Due to the uniformity of the thermal power spread by the heated covering, the temperature difference at the level of the panel and due to the particular geometric configuration causes the polymerization to be non-uniform over the entire surface of the area to be repaired, and this results in a less robust repair.

Disclosure of Invention

The object of the present invention is to propose a tool that is able to alleviate these drawbacks and to distribute the panel heating temperature according to the polymerization needs in the heating area concerned.

To this end, the invention relates to an assembly of a bag and a composite panel presenting a damaged area to be repaired by polymerisation of the repair using the bag, the bag comprising a sheet intended to be laid on a panel, characterized in that, when the panel and the sheet are laid on top of each other, the sheet presents an area capable of absorbing the heat emitted by radiation onto the sheet, the proportion of radiation depending on the desired polymerisation temperature of the area of the panel corresponding thereto, the radiation being partially absorbed by appropriate colouring of the sheet in the relevant area.

In this way, the heating temperature is distributed over the surface of the panel as required and is no longer the same everywhere. The sheet exhibits differently colored regions corresponding to corresponding regions of the panel requiring different polymerization temperatures: this results in a more uniform polymerization.

The present invention contemplates at least one of the following optional features considered alone or in combination.

The sheet is heat-sensitive or comprises a heat-sensitive film, and, when subjected to a radiant heating device, exhibits areas of different color corresponding to corresponding areas of the panel requiring different polymerization temperatures.

The different colors at least partially comprise partial hues of black and white.

Those areas of the sheet intended to be laid over corresponding areas of the panel requiring a lower polymerization temperature exhibit a lighter color, whereas those areas of the sheet intended to be laid over areas of the panel requiring a higher polymerization temperature exhibit a darker color.

The color of the areas of the sheet has been obtained by applying pigments or colorants.

The color of the area of the sheet is obtained by printing.

The pouch comprises a white cover.

The invention also relates to a method for colouring a sheet of said assembly having the above characteristics, characterized in that it comprises the following steps: -temporarily heating the panel by radiation; -detecting the temperature at least over the whole damaged area to be repaired; -defining areas of different colors depending on the measured temperature; -applying a color in said defined area.

According to an alternative, the method of colouring the sheet of the assembly is characterized in that it comprises the following steps: -thermally simulating a damaged area to be repaired; -detecting the temperature at least throughout the area to be repaired; -defining areas of different colours according to the temperature obtained by the simulation; -applying a color in said defined area.

The present invention contemplates at least one of the following optional features considered alone or in combination.

The application of the color uses pigments or colorants.

The application of the color is performed using printing.

The invention also relates to a method for repairing a panel of an assembly exhibiting the above-mentioned characteristics, using a sheet of said assembly, characterized in that it comprises a step of applying said sheet to said panel under vacuum and a step of heating said sheet by radiation using heating means.

A white cover may be inserted between the sheet and the panel.

Drawings

Further objects, features and advantages will become apparent from the following description of the invention, given purely by way of non-limiting example with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a damaged panel outside the fuselage of an aircraft under repair, and a sheet laid over the panel;

fig. 2 is a view of a damaged panel of the fuselage interior of an aircraft under repair, on which panel a sheet is laid;

fig. 3 is a view of an example of an image obtained by a thermal camera exposed to a panel of a radiation heating device, the color of the image appearing in only a partial tone of black and white, the coldest temperature being generally blue in the image and gray in the figure, the hottest temperature being red in the image and black in the figure;

FIG. 4 is a view of a model of a colored region obtained from the thermal image of FIG. 3;

fig. 5 is a partial perspective view of a sheet laid on a panel under repair in a different area from fig. 2.

Detailed Description

The invention is explained below using an example of a damaged composite panel 2 of a fuselage 4 of an aircraft 6. However, it is not limited to the present application and may relate to any type of damaged composite panel of an aircraft or even a car, a ship, a train or another vehicle of another type or of any type of equipment in any type of field (such as, for example, wind energy, sports, leisure, etc.).

As illustrated in fig. 1, the fuselage 4 of an aircraft comprises a panel 2 formed by a composite skin, which panel is damaged over the entire area 8 (hereinafter referred to as damaged area). The area 8 is shown in solid lines in fig. 1 and 2 to make it more easily visible, but is normally not visible as it is below the sheet. The zone 8 may be just outside (fig. 1), inside (fig. 2) or on both sides when the damage is completely passed through. The term "panel" generally refers to any element that exhibits a damaged area and belongs to a broader system, which in the illustrated example is an aircraft fuselage. The panel 2 is made of a composite material formed of at least reinforcements (fibers, particles, etc.) and a matrix in which the reinforcements are embedded. The matrix involved in the illustrated example is an organic matrix, more particularly a polymer resin. Many methods for repairing damaged areas of composite panels, particularly in situ methods, are known and do not form the subject of the present invention. They involve polymerizing the repair with the damaged panel. The repair method of the invention uses a radiation heating device 10, such as for example an ultraviolet lamp or the use of infrared light. As demonstrated in the previously mentioned patents, most in situ repair methods employ a pocket 11 comprising a sheet 12 to hold the repair in place in the damaged area 8 of the panel during heating to secure the repair to the panel by polymerization of the resin. The pockets 11 are mounted on the panels (and maintenance pieces) under vacuum to enhance retention. In some embodiments, bag 11 is constrained to sheet 12. In other embodiments as will be seen later, pouch 11 may include other components.

The idea behind the tool according to the invention is to allow the heat to which the panel 2 is subjected to be distributed differently over the entire surface of this panel, according to the temperature required to obtain a reinforcement that is uniform in polymerizing the repair with the panel and thus reinforced. If the polymerization temperature is too low, polymerization is insufficient and the repair will not withstand the usual conditions to which an aircraft is subjected. If the polymerization temperature is too high, the resin may burn, not only must the entire body be repaired repeatedly, but damage may also be exacerbated.

As seen previously, the panel 2 is not generally shaped as a perfectly curved parallelepiped; typically, the thickness of the panel 2 varies according to environmental requirements (e.g., locally applied additional loads).

It may also be a specific requirement, such as increasing stiffness or strengthening the structure or filtering noise, that additional material, such as a honeycomb layer, be introduced to increase stiffness or filter out certain frequencies.

Other devices or systems may be added to the simple panel. Thus, to take one example, stiffeners 14 (visible in FIG. 2) may be attached to the skin of the fuselage. In the example illustrated in fig. 1 to 3, the panel 2 has a stiffener 14 (depicted in fig. 2). Because bag 11 (and sheet 12) is laid under vacuum on panel 2, it conforms to the shape of panel 2, and as shown in fig. 2, the relief such as that formed by stiffener 14 is clearly located below bag 11. The pockets 11 hide their exact shape in the figures, but they are hat section reinforcements. Inside the hat shape of the stiffener 14, heat accumulates and the temperature at the stiffener is higher in the area of the stiffener even if the stiffener 14 is applied uniformly to the entire surface of the panel. As a result, it is not necessary to spread as much heat in the area of the stiffener as on the rest of the panel surface, since otherwise the heat in the area of the stiffener may become excessive and lead to the above-mentioned disadvantages.

It is therefore advantageous to be able to regulate the temperature of the heat emitted by the radiation as required by the local configuration of the panel.

In order to distribute the heat in a controlled manner, the idea is to use a radiant heat that is uniform over the entire surface of the damaged area 8 and to filter said radiation in proportions determined according to the precise point on the panel to which it is applied.

It is known that some of the radiation received by the object is absorbed and converted into thermal energy. Depending on the material of the object, the appearance of its surface and depending on its colour, a greater or lesser proportion of the radiation is absorbed or reflected. Black is known to absorb received radiation and heat objects, while white is known to cause significant reflections.

The invention consists in using sheets 12 presenting different colours so that, depending on the colour concerned, only a determined proportion of the heat applied thereto by radiation is projected. The color chosen depends on the desired proportion of heat to be locally filtered out in order to obtain the temperature required for polymerization at a particular point of exposure on the panel. This results in a color model 16 of the sheet 12 that is specific to the panel 2 to be repaired. The colour zone 18 of the model 16 is entirely dependent on the panel 2 to be repaired, on its geometrical configuration and consequently on its requirements with respect to the polymerization temperature.

In the present specification, the term color refers to, for example, a hue (black, blue, red, etc.), but may also refer to a shade (i.e., light, dark). Thus, in one particular example, the sheet 12 has color regions 18 of various hues. Further, according to another example (as depicted in fig. 4), the sheet comprises only partial hues of black and white, i.e. no shades of grey of other colors: the dark or light of the area changes, so each color corresponds to a shade of gray (light gray, dark gray, etc.).

The model 16 is based on the reflection/absorption capabilities of the colors (hue or shade). Therefore, dark shades (i.e., shades close to black or dark gray) reflect less heat in the black and white partial tone range: they are therefore applied to the colder regions of the panel, which need to be heated to reach the polymerization temperature of the resin. Conversely, light shades (i.e., shades near light gray or white) reflect more heat and are applied to those areas of the panel that are hotter so that they are not heated to an unnecessary degree.

Black is considered the darkest shade and not necessarily the color most effective in heating the area. Thus, navy blue has proven to be more effective than black.

To determine the color zone 18 of the sheet 12, the polymers, pigments, or other elements that make up it and that are capable of withstanding temperature are considered appropriate. In other words, the color selected for the sheet must not increase its absorption capacity relative to the panel to be repaired, so as to reach a sheet temperature that may damage the sheet given its configuration.

The sheet is of the type known to those skilled in the art; it may be made of a plastic material very similar to nylon capable of withstanding thermal and chemical stresses, such as IPPLON (registered trademark), more particularly ipploncm 1300 or Capran (registered trademark) and more particularly Capran 980.

The remainder of the description will relate to a method for colouring a sheet and more particularly to the steps for creating the colour region 18.

A first method for creating the regions 18 first includes determining the regions and then creating the regions on the sheet once the regions are determined. The second method combines the steps into a single step, i.e. the step of creating the region while determining the region.

With respect to the first method, there are many possible embodiments for determining and creating regions.

A first embodiment for determining color regions comprises the steps of: when the panel 2 is subjected to the radiant heating device 10, the temperature at the panel is detected. Using a set of detected temperatures, a temperature map of the panel is created. From this figure, color regions can be designed onto the sheet.

According to one particular embodiment for detecting temperature, a thermal camera is used (other means such as a temperature probe may be sufficient). The panel 2 is heated by the radiant heating means 10 for a short period of time, which is long enough to establish the above-mentioned diagram.

According to the second embodiment, a temperature map can also be created using software means. Today, many tools exist for simulating the temperature behavior of composite panels. Therefore, all that is needed is to simulate the physical experiment described in the first embodiment, i.e., the heating of the panel, to obtain the desired map.

The color area 18 is derived from a temperature map obtained physically in the first embodiment or by simulation in the second embodiment. The thermal camera gives an image of the color area 18, as shown in fig. 3: the real image is in color, but has been depicted here in black and white. Therefore, the image with the lowest temperature is blue (gray in the figure), and the image with the highest temperature is red (black in the figure). As can be seen from fig. 3, the highest temperature is in the area of the stiffener, as previously described.

Once the color zone 18 is determined, a color zone is created on the sheet. In one embodiment, the color regions of the sheet may be obtained by applying pigments or colorants. Application is contemplated in a very general sense and includes deposition, impregnation, or any other action that allows for coloring of the sheet 12 with a pigment or colorant. Another application example given below is printing which can be analogized to deposition. Other examples include dyeing, painting, etc. It is also possible to directly design the sheet with different color areas. According to one embodiment, the definition of the model 16 (i.e., the color area 18) is captured in a black and white or color printer and the sheet is printed according to the color model depicted in FIG. 4.

The coloring of the sheet according to the determined color model may also be performed using a screen printing technique.

During printing, position reference marks 19 are provided to allow the sheet to be accurately superimposed on the panel so that the color areas correspond to the associated areas of the panel. These reference marks may be multiple reference marks such as windows, axes of stiffeners (e.g., axis 19 in fig. 2), ends of panels (edge 19 of another example of panel 2 in fig. 1), reference points, and the like.

FIG. 5 partially depicts a sheeting made from an image obtained by a thermal camera during use. All areas corresponding to those areas of the panel that are identified as hot relative to the rest of the panel, i.e., all areas having a temperature above the operator determined threshold S1, are colored white. In the example illustrated in fig. 5, this refers to the hollow structure of the reinforcement. All areas corresponding to those areas of the panel identified as cold relative to the rest of the panel, i.e., all areas having a temperature below the operator determined threshold S2, are colored in black. As seen previously, they can be colored in a deep blue color using a color printer. All those areas of the panel that are identified as neither hot nor cold, i.e., the areas with temperatures above the threshold S2 and below the threshold S1, are colored in gray shades compared to the rest of the panel. In the example illustrated in fig. 5, there are no areas colored gray, only black and white.

As seen above, a second method may be employed to determine the color zone 18 and simultaneously color the sheeting 12. The method of colouring the sheet comprises the use of a heat-sensitive film 20, the colour of which varies with the temperature and, in the case of interest herein, becomes lighter when the area is hotter and darker when the area is cooler. The amount of heat dissipated by the sheet 12 then varies depending on the color zone 18 obtained. The film is then used as the sheet 12 (if the film 20 has sufficient properties to perform the same role), or is laminated on said sheet 12. In the latter case, the film 20 constitutes an additional layer between the sheet 12 and the panel 2, and the film 20 and the sheet 12 are considered to constitute an assembly generically referred to in the description by the term sheet. Unlike previous methods, this method does not require any location indicators.

According to a particular embodiment of the invention, bag 11 comprises a white or light-coloured covering 22 superimposed on sheet 12 to improve the colour contrast between regions 18. The cover may be made, for example, using a glass repair fabric.

The repairing method comprises the following steps: a pouch body 11 comprising a sheet 12 colored as described above or capable of developing a color (with or without the addition of a heat-sensitive film 20, according to an embodiment) is fitted over at least the damaged area 8. The sheet 12 covers the repair and is connected to the panel in a fluid tight manner. The positioning reference 19 on the sheet 12 allows the sheet to be centred with respect to the panel, so that an area 18 of the sheet overlaps a corresponding area of the panel (more specifically in the area of the damaged area 8). The radiation heating device 10 is mounted to spread heat over the entire surface of the region 8. As shown in the example of fig. 1, the infrared lamps are mounted on the ground, supported by a tripod, and are raised to the height of the zone 8, so as to spread the heat over the entire surface of the zone. A vacuum application device of known type is activated to evacuate the pockets 11 and remove the gases present in the volume defined by the pockets and the panel, thus retaining the repair on the panel 2. Since the repair and the panel depend on the selected repair method, the repair and the panel will not be described in detail. As seen above, a cover 22 may be interposed between the sheet 12 and the panel 2. Thus, bag 11 includes sheet 12 and cover 22.

When the light 10 is switched on, the heat is diffused by radiation onto the pockets 11 and therefore onto the sheet 12. The radiation is reflected and absorbed in a proportion dependent on the colour zone 18 of the sheet and the resin polymerises uniformly over the entire surface of the damaged area 8. Since a better temperature distribution on the panel is obtained, the polymerization temperature is uniform over its entire surface and the resulting mechanical properties are better.

The heating devices are simple and quick to install, since they are limited to simple radiant heating devices, which sheets have been used in repair methods. The repair method does not require any level of expertise. It is no longer necessary to apply additional heating means (such as hot air) locally to the colder regions of the panel.