Fiber Composite Component Having An Integrated Structural Health Sensor Arrangement

Abstract

A fiber composite component having an integrated structural health sensor arrangement includes a plurality of layers of fibers embedded in a matrix material, at least two rupture sensing fibers arranged on or in at least one of the layers, wherein the rupture sensing fibers are carbon fibers having an electrically insulating coating, and two electrical connection devices, each being accessible from an outer delimiting surface or an outer edge of the component, wherein the electrical connection devices are connected to different ends of the rupture sensing fibers.

Claims

1. A fiber composite component having an integrated structural health sensor arrangement, the component comprising: a plurality of layers of fibers embedded in a matrix material; at least two rupture sensing fibers arranged on or in at least one of the plurality of layers, wherein the at least two rupture sensing fibers are carbon fibers having an electrically insulating coating, and two electrical connection devices, each being accessible from an outer delimiting surface or an outer edge of the component, wherein the electrical connection devices are connected to different ends of the at least two rupture sensing fibers.

2. The fiber composite component according to claim 1, wherein the at least two rupture sensing fibers are arranged at least in two different halves of a surface extension of the component.

3. The fiber composite component according to claim 1, wherein the plurality of layers comprises several layers of fibers arranged on top of each other, wherein on or in each of at least two of the layers at least one rupture sensing fiber is arranged.

4. The fiber composite component according to claim 1, wherein the plurality of layers comprises several layers of fibers arranged on top of each other, wherein at least two rupture sensing fibers are arranged in or on different layers and extend along the same direction.

5. The fiber composite component according to claim 1, wherein the plurality of layers comprises several layers of fibers arranged on top of each other, wherein two groups of rupture sensing fibers are arranged in at least one of the layers, wherein the rupture sensing fibers of each group extend along the same direction, and wherein the rupture sensing fibers of a first group and of a second group enclose an angle of at least 45.

6. The fiber composite component according to claim 5, wherein at least two layers of the plurality of layers each comprise at least one group of rupture sensing fibers.

7. The fiber composite component according to claim 1, wherein the two electrical connection devices arranged at diametrically opposed ends of the component.

8. The fiber composite component according to claim 1, wherein the at least two rupture sensing fibers comprise a solid polymer electrolyte coating.

9. The fiber composite component according to claim 1, wherein the component is a carbon fiber reinforced component.

10. A component system with integrated structural health monitoring, comprising: at least one fiber composite component according to claim 1, and at least one evaluation unit connected to the two electrical connection devices of the at least fiber composite component, wherein the evaluation unit is configured to measure the conductivity of the at least two rupture sensing fibers individually and to generate a warning signal if a conductivity of at least one of the at least two rupture sensing fibers is below a predetermined value.

11. An aircraft, comprising at least one component system according to claim 10.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Other characteristics, advantages and potential applications of the present invention result from the following description of the exemplary embodiments illustrated in the figures. In this respect, all described and/or graphically illustrated characteristics also form the object of the invention individually and in arbitrary combination regardless of their composition in the individual claims or their references to other claims. Furthermore, identical or similar objects are identified by the same reference symbols in the figures.

[0026] FIG. 1 shows a schematic view of a fiber composite component with a rupture sensing fiber integrated therein.

[0027] FIG. 2 shows the component 2 of FIG. 1 with a rupture.

[0028] FIG. 3 shows the component of FIGS. 1 and 2 with rupture sensing fibers arranged in a grid.

[0029] FIG. 4 shows the component in a spatial view having rupture sensing fibers arranged in a grid.

[0030] FIGS. 5 and 6 show multiple layers of the component with multiple grids of rupture sensing fibers.

[0031] FIG. 7 shows a possible process for integrating the rupture sensing fibers.

[0032] FIG. 8 shows an aircraft having at least one such component.

DETAILED DESCRIPTION

[0033] FIG. 1 shows a fiber composite component 2 in a very schematic view to explain an aspect of the present invention. Fibers 4 of the component 2 can be recognized in a first lateral delimiting surface 6 on the left-hand side of the drawing. In an exaggerated illustration, a rupture sensing fiber 8 having an electrically insulating coating 10 extends through the first lateral surface 6 and a second lateral surface 12 at an opposite side of the component 2. The rupture sensing fiber 8 is a carbon fiber, which per se has an electrical conductivity. By providing the electrically insulating coating 10, the rupture sensing fiber 8 substantially has the function of an electrical cable that runs through the component 2. Hence, if the component 2 experiences a break or a rupture, which completely extends through the rupture sensing fiber 8, it is interrupted and thus cannot lead an electrical current from end to end. However, due to the rupture sensing fiber 8 being a carbon fiber, it comprises an exceptional tensile strength.

[0034] Also, a direct power source 14 is schematically illustrated and has a first pole 16 and a second pole 18, which are coupled with a first end 20 or a second end 22 of the rupture sensing fiber 8, respectively. Between the second pole 18 and the second end 22 of the rupture sensing fiber 8, an indication unit 24 in the form of a light bulb is provided in a series connection. If a switch 26, which is arranged between the first pole 16 and the first and 20 of the rupture sensing fiber 8 in a series connection is closed, the light bulb 24 lights. This can be interpreted as the rupture sensing fiber 8 being completely intact. The arrangement in FIG. 1 resembles a simple continuity circuit.

[0035] As shown in FIG. 2, the component 2 comprises a rupture 28, which exemplary extends through the rupture sensing fiber 8. Hence, the continuity circuit is interrupted and, consequently, the light bulb 24 does not light up. Consequently, this can be interpreted as the rupture sensing fiber 8 and the component 2 being broken.

[0036] For improving the monitoring capabilities, a plurality of rupture sensing fibers 8 can be used. For example, first rupture sensing fibers 30 may be arranged in the component 2 parallel and at a distance to each other. Second rupture sensing fibers 32 are arranged at an angle to the first rupture sensing fibers 30. The angle may exemplary be 90. Hence, a grid of rupture sensing fibers 30 and 32 is created for monitoring the mechanical integrity of the component 2 over a dens mesh.

[0037] In this illustration, a break 34 in an inner region of the component 2 is shown, which interrupts one of the first rupture sensing fibers 30 and one of the second rupture sensing fibers 32. All other rupture sensing fibers 30 and 32 remain intact. All rupture sensing fibers 30 and 32 are schematically part of four individual continuity circuits. Hence, in this example only two of four light bulbs 24 light up, which allows to at least roughly estimate the location of the break 34. Of course, this is also a very schematic illustration and the actual realization may be based on an electronic evaluation unit coupled with all rupture sensing fibers with a more rigid design, as shown in FIG. 4.

[0038] In FIG. 4 a component system 36 is shown, with the component 2 illustrated in a spatial view. Here, the rupture sensing fibers 30 and 32 are again shown in different orientations and alignments. While FIG. 4 explicitly only shows a single layer, it is clear that the component 2 may comprise a plurality of layers, wherein two or more layers may be equipped like the one shown in FIG. 4.

[0039] Again, first rupture sensing fibers 30 are arranged in the component 2 parallel and at a distance to each other. All first rupture sensing fibers 30 constitute a first group 38. Second rupture sensing fibers 32 extend along another direction, are arranged at a distance to each other and, similarly to the first rupture sensing fibers 32, are arranged parallel to each other. Thus, they constitute a second group 40 of rupture sensing fibers. The first rupture sensing fibers 30 and the second rupture sensing fibers 32 enclose an angle , which in this example is 90.

[0040] A first electrical connection device 42 is embedded into the component 2 and comprises a plurality of inputs coupled with one end of all rupture sensing fibers 30 and 32. At an outer edge 46 of the component 2 a number of outputs 48 are arranged, which allow to couple the rupture sensing fibers with an evaluation unit 49. For connecting the other ends of the rupture sensing fibers 30 and 32, a second electrical connection device 44 is present. Both connection devices 42 and 44 are coupled with the evaluation unit 49 through the outputs 48. The connection devices 42 and 44 and/or the outputs 48 may be adapted to provide a selective contacting of individual rupture sensing fibers 30 and 32 to conduct individual continuity tests.

[0041] As a side note, the connection devices 42 and 44 may be coupled with the evaluation unit 49 wirelessly. However, for this a voltage source and a continuity, resistance or current testing device is required in the vicinity of the connection devices 42 and 44 for providing a suitable signal for a wireless transfer to the evaluation unit 49.

[0042] FIG. 5 shows a component 50 having a plurality of layers 52, 54, 56, 58, 60 and 62, wherein each of the layers 52 to 62 may comprise fibers 4 embedded in a matrix material. As an example, the first layer 52 and the sixth layer 62 are each equipped with rupture sensing fibers 30 and 32, which may be arranged as shown in FIG. 4. However, in this example, the rupture sensing fibers 30 and 32 are enclosed between the first and second layer 52 and 54 as well as between the fifth and sixth layer 60 and 62.

[0043] As apparent, a break 64 occurs in the component 2, which interrupts some of the rupture sensing fibers 30 and 32. Due to the dens mesh of rupture sensing fibers 30 and 32, it can be detected that the break occurs somewhere in the first and second layer 52 and 54 as well as with a certain position along these layers.

[0044] As illustrated in FIG. 6 this may even further be improved to include still further individual arrangements of rupture sensing fibers 30 and 32 between the third and fourth layers 56 and 58.

[0045] FIG. 7 shows an exemplary process of integrating the rupture sensing fibers 30 and 32 into a component 2 during its manufacturing. Here, exemplarily a first layer 52 is shown, onto which a grid as depicted in FIG. 4 is attached. For this, the rupture sensing fibers 30 and 32 are arranged on a transfer foil 66, which is stored on a rotatably supported spool 68. This allows to use a tape placement head 70 arranged on a robotic arm 72 or any other suitable device for transferring the foil 66 onto the respective layer 52. After attaching the transfer foil 66 with the rupture sensing fibers 30 and 32, the transfer foil 66 may be removed from the respective layer 52 and the rupture sensing fibers 30 and 32. Afterwards, the additional second, third and all subsequent layers 54 to 62 can be arranged and the compound of all layers and rupture sensing fibers can be cured.

[0046] Finally, FIG. 8 shows an aircraft 74 having a component system 36 with at least one such component 2. As an example, the component 2 is a part of a fuselage. However, every other part, made of a composite, can be equipped with the rupture sensing fibers according to the invention.

[0047] In addition, it should be pointed out that comprising does not exclude other elements or steps, and a or an does not exclude a plural number. Furthermore, it should be pointed out that characteristics or steps which have been described with reference to one of the above exemplary embodiments may also be used in combination with other characteristics or steps of other exemplary embodiments described above. Reference characters in the claims are not to be interpreted as limitations.

[0048] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.

REFERENCE NUMERALS

[0049] 2 component [0050] 4 fiber [0051] 6 first lateral delimiting surface [0052] 8 rupture sensing fiber [0053] 10 electrically insulating coating [0054] 12 second lateral surface [0055] 14 direct power source [0056] 16 first pole [0057] 18 second pole [0058] 20 first end [0059] 22 second end [0060] 24 indication unit [0061] 26 switch [0062] 28 rupture [0063] 30 first rupture sensing fiber [0064] 32 second rupture sensing fiber [0065] 34 break [0066] 36 component system [0067] 38 first group [0068] 40 second group [0069] 42 first electrical connection device [0070] 44 second electrical connection device [0071] 46 outer edge [0072] 48 output [0073] 49 evaluation unit [0074] 50 component [0075] 52 layer [0076] 54 layer [0077] 56 layer [0078] 58 layer [0079] 60 layer [0080] 62 layer [0081] 64 break [0082] 66 transfer foil [0083] 68 spool [0084] 70 tape placement head [0085] 72 robotic arm [0086] 74 aircraft [0087] angle