Structural arrangement with a fiber reinforced polymer component and a cold gas sprayed electrically conductive layer

Abstract

A structural arrangement comprising a fiber reinforced polymer component, a cold gas spraying electrically conductive layer, and a polyether sulfone foil arranged on the fiber reinforced polymer component, at least in a region between the fiber reinforced polymer component and the cold gas sprayed electrically conductive layer.

Claims

1. A structural arrangement, comprising: a fiber reinforced polymer component having an outer surface with a first region and a second region; a cold gas sprayed electrically conductive layer; and a polyether sulfone foil that is arranged on the first region of the fiber reinforced polymer component between the fiber reinforced polymer component and the cold gas sprayed electrically conductive layer; and wherein neither the cold gas sprayed electrically conductive layer nor any polyether sulfone foil is arranged on the second region of the fiber reinforced polymer component.

2. The structural arrangement of claim 1, wherein the polyether sulfone foil is bonded onto the first region of the fiber reinforced polymer component.

3. The structural arrangement of claim 2, wherein the polyether sulfone foil is merged with epoxy resin of the fiber reinforced polymer component.

4. The structural arrangement of claim 1, wherein the polyether sulfone foil exhibits a thickness in a range of 50 μm to 100 μm.

5. The structural arrangement of claim 1, wherein the cold gas sprayed electrically conductive layer comprises copper, aluminium, silver, tin and/or alloy particles.

6. The structural arrangement of claim 1, wherein the polyether sulfone foil comprises at least one strip and/or patch made of polyether sulfone.

7. A rotary wing aircraft with a structural arrangement according to claim 1.

8. A structural arrangement, comprising: a fiber reinforced polymer component having an outer surface with a first region and a second region; a polyether sulfone foil on the first region of the fiber reinforced polymer component; and an electrically conductive layer on the polyether sulfone foil, the electrically conductive layer formed by cold gas spraying electrically conductive particles onto the polyether sulfone foil to create the electrically conductive layer; and wherein the polyether sulfone foil is arranged between the fiber reinforced polymer component and any cold gas sprayed electrically conductive layer and neither the polyether sulfone foil nor the electrically conductive layer is on the second region of the fiber reinforced polymer component.

9. The structural arrangement of claim 8, wherein the polyether sulfone foil is bonded onto the first region of the fiber reinforced polymer component.

10. The structural arrangement of claim 8, wherein the polyether sulfone foil is merged with epoxy resin of the fiber reinforced polymer component.

11. The structural arrangement of claim 8, wherein the polyether sulfone foil exhibits a thickness in a range of 50 μm to 100 μm.

12. The structural arrangement of claim 8, wherein the electrically conductive layer comprises copper, aluminum, silver, tin and/or alloy particles.

13. A structural arrangement comprising: a fiber reinforced polymer panel having an outer surface with a first region and a second region; an electrically conductive layer; and a polyether sulfone foil disposed on and integrally formed with the first region of the fiber reinforced polymer panel between the fiber reinforced polymer panel and the electrically conductive layer; and wherein the electrically conductive layer comprises two strips extending in different directions and electrically connected to each other by a junction; and neither the electrically conductive layer nor any polyether sulfone foil is disposed on the second region of the fiber reinforced polymer panel.

14. The structural arrangement of claim 13, wherein the polyether sulfone foil is bonded to the first region of the fiber reinforced polymer panel.

15. The structural arrangement of claim 13, wherein the polyether sulfone foil is merged with epoxy resin of the fiber reinforced polymer panel.

16. The structural arrangement of claim 13, wherein the polyether sulfone foil has a thickness of 50 μm to 100 μm.

17. The structural arrangement of claim 13, wherein the electrically conductive layer is a cold gas sprayed electrically conductive layer and the cold gas sprayed electrically conductive layer comprises copper, aluminium, silver, tin and/or alloy particles.

18. The structural arrangement of claim 13, wherein the electrically conductive layer is a cold gas sprayed electrically conductive layer and the cold gas sprayed electrically conductive layer comprises copper particles.

19. The structural arrangement of claim 13, wherein the polyether sulfone foil comprises at least one strip and/or patch made of polyether sulfone.

20. A rotary wing aircraft with a structural arrangement according to claim 13.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred embodiments of the invention are outlined by way of example in the following description with reference to the attached drawings. In these attached drawings, identical or identically functioning components and elements are labelled with identical reference signs and are, consequently, only described once in the following description.

(2) FIG. 1 shows a lateral view of a helicopter with a fuselage that comprises a structural arrangement according to the invention,

(3) FIG. 2 illustrates a method of manufacturing the structural arrangement of FIG. 1 according to one aspect,

(4) FIG. 3 shows a perspective view of an enlarged detail III of the structural arrangement of FIG. 2,

(5) FIG. 4 shows a perspective view of an enlarged detail IV of the structural arrangement of FIG. 2, and

(6) FIG. 5 illustrates a method of manufacturing the structural arrangement of FIG. 1 according to another aspect.

DETAILED DESCRIPTION OF THE INVENTION

(7) FIG. 1 shows an aircraft 1 that is exemplarily illustrated as a rotary wing aircraft and, more particularly, as a helicopter. Thus, for purposes of simplicity and clarity, the aircraft 1 is hereinafter referred to as the “helicopter” 1.

(8) Illustratively, the helicopter 1 comprises a fuselage 2 that is connected to a landing gear if and defines a cabin 2a and a rear fuselage 2b. The rear fuselage 2b is connected to a tail boom 3.

(9) According to one aspect, the fuselage 2 comprises at least one structural arrangement 6, or embodies the structural arrangement 6, which is preferably implemented using at least one fiber reinforced polymer component (7 in FIG. 2). The structural arrangement 6 is exemplarily and representatively described in detail below with respect to FIG. 2 to FIG. 5.

(10) Illustratively, the helicopter 1 further comprises at least one multi-blade main rotor 1a for providing lift and forward or backward thrust during operation. The at least one multi-blade main rotor 1a comprises a plurality of rotor blades 1b, 1c that are mounted at an associated rotor head 1d to a rotor shaft 1e, which rotates in operation of the helicopter 1 around an associated rotor axis.

(11) By way of example, the helicopter 1 further comprises at least one preferentially shrouded counter-torque device 4 configured to provide counter-torque during operation, i.e. to counter the torque created by rotation of the at least one multi-blade main rotor 1a for purposes of balancing the helicopter 1 in terms of yaw. The at least one counter-torque device 4 is illustratively provided at an aft section of the tail boom 3 and preferably comprises a tail rotor 4a. The aft section of the tail boom 3 preferably further comprises a vertical stabilizer 5. Illustratively, the tail boom 3 is also provided with a suitable horizontal stabilizer 3a.

(12) Preferably, the tail boom 3 is a composite tail boom, i.e. a tail boom that comprises composite material and that is preferably at least essentially manufactured from composite material, preferentially fiber reinforced polymer material. Illustratively, the composite tail boom 3 is preferably implemented as a slim beam element that comprises at least partly a tail boom cone 3b, which is preferably tubular. In other words, the composite tail boom 3 is preferentially a closed structure with a nearly circular cross section.

(13) FIG. 2 shows the structural arrangement 6 of FIG. 1, which is implemented according to one aspect. More specifically, FIG. 2 illustrates an exemplary method of manufacturing the structural arrangement 6 on the basis of a fiber reinforced polymer component 7.

(14) The at least one fiber reinforced polymer component 7 is preferably implemented as a panel or shell of the helicopter 1 of FIG. 1. More specifically, the at least one fiber reinforced polymer component 7 is preferentially made of non-conductive material 6a and illustratively implemented as a sandwich component. Preferably, the at least one fiber reinforced polymer component 7 is pre-produced by means of a standard procedure in a preliminary process.

(15) The at least one fiber reinforced polymer component 7 preferentially comprises carbon fiber reinforced polymers. However, the at least one fiber reinforced polymer component 7 may alternatively comprise also other kinds of reinforcement fibers, such as glass, aramid and so on. Even more generally, the present invention is not limited to such fiber reinforced polymer components, but likewise applies to any component that comprises non-conductive material, such as the non-conductive material 6a. Thus, in the context of the present invention the term “fiber reinforced polymer component” is construed for designating any component of non-conductive material, comprising components made of fiber reinforced polymers.

(16) According to one aspect, the method of manufacturing the structural arrangement 6 starts with providing the fiber reinforced polymer component 7. Then, one or more intermediate thermoplastic layers 8 are created on the fiber reinforced polymer component 7, at least in one or more regions where one or more electrically conductive layers 9 are to be formed. Preferably, the one or more intermediate thermoplastic layers 8 are created by fixing a polyether sulfone foil on the fiber reinforced polymer component 7.

(17) Illustratively, a polyether sulfone foil 8a is fixed on the fiber reinforced polymer component 7 in a region where an electrically conductive layer 9a is to be formed, and a polyether sulfone foil 8b is fixed on the fiber reinforced polymer component 7 in a region where an electrically conductive layer 9b is to be formed. Preferably, the polyether sulfone foils 8a, 8b are bonded onto the fiber reinforced polymer component 7. By way of example, the polyether sulfone foils 8a, 8b are provided in the form of strips.

(18) For simplicity and clarity of the drawings, each longitudinally arranged polyether sulfone foil strip is labelled with the reference sign “8a” and each transversally arranged polyether sulfone foil strip is labelled with the reference sign “8b”. Accordingly, in FIG. 2 two longitudinally arranged polyether sulfone foils 8a and only a single transversally arranged polyether sulfone foil 8b are exemplarily provided.

(19) However, it should be noted that the present invention is not intended to restrict the polyether sulfone foils 8a, 8b to strips. Instead, each one of the polyether sulfone foils 8a, 8b may exhibit a form and dimension that is application-specific. For instance, each one of the polyether sulfone foils 8a, 8b may have the form of a strip or alternatively be implemented as a patch or a large-area surface element, the strip, patch and large-scale surface element being respectively made of polyether sulfone.

(20) Furthermore, it should be noted that at least one and, preferably, each one of the polyether sulfone foils 8a, 8b preferably exhibits a thickness in a range of 50 μm to 100 μm. However, the present invention is not restricted to such a thickness range and other thicknesses are likewise possible. For instance, in an application-specific manner, a thickness of more than 100 μm can alternatively be selected.

(21) According to one aspect, a cold gas spraying process is performed in a subsequent method step for spraying electrically conductive particles 14 onto at least one and, preferably, each one of the polyether sulfone foils 8a, 8b. Thus, at least one and, preferably, each one of the electrically conductive layers 9a, 9b is created on the respective polyether sulfone foil 8a, 8b. Suitable electrically conductive particles 14 are e.g. copper, aluminium, silver, tin and/or alloy particles.

(22) For simplicity and clarity of the drawings, each longitudinally arranged electrically conductive layer is labelled with the reference sign “9a” and each transversally arranged electrically conductive layer is labelled with the reference sign “9b”. Accordingly, in FIG. 2 two longitudinally arranged electrically conductive layers 9a and only a single transversally arranged electrically conductive layer 9b are exemplarily provided.

(23) Preferably, spraying of the electrically conductive particles 14 is performed by means of a suitable spraying tool 13, preferentially in an automated process. However, it should be noted that respective spraying tools that can be used to implement the spraying tool 13 are, as such, not part of the present invention and, furthermore, well-known to the person skilled in the art. Therefore, a more detailed description of the spraying tool 13 is omitted for brevity and conciseness.

(24) Nevertheless, it should simply be noted that the present invention is not limited to an automated cold gas spraying process using the spraying tool 13 as described above. Instead, a manual spraying process using a suitable spraying tool is likewise contemplated.

(25) According to one aspect, a vacuum cleaning of the structural arrangement 6 is performed in a final method step after having performed the cold gas spraying process. However, it should be noted that the vacuum cleaning may alternatively or in addition also be performed during the cold gas spraying process. Thus, all electrically conductive particles that do not adhere to one of the polyether sulfone foils 8a, 8b can be evacuated.

(26) By way of example, FIG. 2 also shows a conductive layer bridge 11 and a conductive layer junction 12. The conductive layer bridge 11 is described in more detail below with reference to FIG. 3 and the conductive layers junction 12 is described in more detail below with reference to FIG. 4.

(27) FIG. 3 shows the structural arrangement 6 of FIG. 2 by way of example after manufacturing. Illustratively, the structural arrangement 6 comprises the at least one fiber reinforced polymer component 7, the cold gas sprayed electrically conductive layers 9a, 9b, and the polyether sulfone foils 8a, 8b that are arranged on the fiber reinforced polymer component 7 in the regions between the fiber reinforced polymer component 7 and the cold gas sprayed electrically conductive layers 9a, 9b.

(28) As described above with reference to FIG. 2, the polyether sulfone foils 8a, 8b, which are illustratively formed as strips and/or patches made of polyether sulfone, are preferably bonded onto the fiber reinforced polymer component 7 and preferentially exhibit a thickness in a range of 50 μm to 100 μm. Furthermore, as also described above with reference to FIG. 2, the cold gas sprayed electrically conductive layers 9a, 9b preferably comprise copper, aluminium, silver, tin and/or alloy particles.

(29) Illustratively, the cold gas sprayed electrically conductive layer 9a bridges the cold gas sprayed electrically conductive layer 9b, by way of example in the region of the conductive layer bridge 11 of FIG. 2. It should be noted that the cold gas sprayed electrically conductive layer 9a of FIG. 3 corresponds to the lower one of the two cold gas sprayed electrically conductive layers 9a of FIG. 2.

(30) According to one aspect, the conductive layer bridge 11 is equipped with an intermediate thermoplastic separator 10 that isolates the cold gas sprayed electrically conductive layer 9a from the cold gas sprayed electrically conductive layer 9b to avoid an undesired short circuit between both. The intermediate thermoplastic separator 10 is preferably bonded and/or welded to the polyether sulfone foil 8b in the region of the conductive layer bridge 11. Preferentially, the intermediate thermoplastic separator 10 comprises at least one polyether sulfone separator 10a.

(31) More specifically, the intermediate thermoplastic separator 10 resp. the at least one polyether sulfone separator 10a is preferably bonded and/or welded to the polyether sulfone foil 8b after having created the cold gas sprayed electrically conductive layer 9a as described above with reference to FIG. 2, and prior to creating the cold gas sprayed electrically conductive layer 9b as described above with reference to FIG. 2. The cold gas sprayed electrically conductive layer 9a can then be created as described above with reference to FIG. 2 such that a cold gas sprayed metal layer bridge 11a is created on the intermediate thermoplastic separator 10 resp. the at least one polyether sulfone separator 10a.

(32) FIG. 4 shows the structural arrangement 6 of FIG. 2 by way of example after manufacturing. Illustratively, the structural arrangement 6 comprises the at least one fiber reinforced polymer component 7, the cold gas sprayed electrically conductive layers 9a, 9b, and the polyether sulfone foils 8a, 8b that are arranged on the fiber reinforced polymer component 7 in the regions between the fiber reinforced polymer component 7 and the cold gas sprayed electrically conductive layers 9a, 9b.

(33) As described above with reference to FIG. 2, the polyether sulfone foils 8a, 8b, which are illustratively formed as strips and/or patches made of polyether sulfone, are preferably bonded onto the fiber reinforced polymer component 7 and preferentially exhibit a thickness in a range of 50 μm to 100 μm. Furthermore, as also described above with reference to FIG. 2, the cold gas sprayed electrically conductive layers 9a, 9b preferably comprise copper, aluminium, silver, tin and/or alloy particles.

(34) Illustratively, the cold gas sprayed electrically conductive layer 9a is connected to the cold gas sprayed electrically conductive layer 9b, by way of example at the conductive layers junction 12 of FIG. 2. It should be noted that the cold gas sprayed electrically conductive layer 9a of FIG. 4 corresponds to the upper one of the two cold gas sprayed electrically conductive layers 9a of FIG. 2.

(35) More specifically, according to one aspect a cold gas sprayed metal layer junction 12a electrically connects the cold gas sprayed electrically conductive layer 9a to the cold gas sprayed electrically conductive layer 9b at the conductive layers junction 12. Preferably, the polyether sulfone foils 8a, 8b are also connected at the conductive layers junction 12.

(36) FIG. 5 illustrates an alternative method of manufacturing the structural arrangement 6 of FIG. 1, which is slightly modified with respect to the method described above with reference to FIG. 2. More specifically, instead of using according to FIG. 2 the at least one fiber reinforced polymer component 7 that is preferably pre-produced by means of a standard procedure in a preliminary process, now a thermoset fiber reinforced polymer preform 7a is used.

(37) According to one aspect, a mold 15 is provided and the thermoset fiber reinforced polymer preform 7a, which is preferably impregnated with epoxy resin 16, is arranged in the mold 15. Then, a polyether sulfone foil, which is embodied and formed as described above with reference to FIG. 2, is positioned on top of, resp. above, the thermoset fiber reinforced polymer preform 7a in the mold 15. By way of example and for simplicity and clarity of the drawings, only the polyether sulfone foil 8a of FIG. 2 is positioned on top of, resp. above, the thermoset fiber reinforced polymer preform 7a.

(38) However, it should be noted that positioning of the polyether sulfone foil on top of, resp. above, the thermoset fiber reinforced polymer preform 7a in the mold 15 is merely described by way of example, and not for limiting the invention accordingly. Instead, the polyether sulfone foil may likewise be positioned on the bottom of, resp. below, the thermoset fiber reinforced polymer preform 7a in the mold 15, or respective polyether sulfone foils may be positioned above and below the thermoset fiber reinforced polymer preform 7a in the mold 15.

(39) According to one aspect, the polyether sulfone foil 8a is then cured together with the thermoset fiber reinforced polymer preform 7a for fixing the polyether sulfone foil 8a on the fiber reinforced polymer component 7. More specifically, the polyether sulfone foil 8a and the thermoset fiber reinforced polymer preform 7a are preferably cured together such that the polyether sulfone foil 8a merges with the epoxy resin 16 of the thermoset fiber reinforced polymer preform 7a.

(40) Thus, by curing the thermoset fiber reinforced polymer preform 7a, the fiber reinforced polymer component 7 of FIG. 2 is obtained. However, by curing the polyether sulfone foil 8a together with the thermoset fiber reinforced polymer preform 7a, the polyether sulfone foil 8a becomes an integrally formed part of the fiber reinforced polymer component 7 of FIG. 2, as it is merged with the epoxy resin 16 thereof. Thus, bonding of the polyether sulfone foil 8a to the fiber reinforced polymer component 7 of FIG. 2 as described above with reference to FIG. 2 can advantageously be omitted.

(41) It should be noted that modifications to the above described embodiments are within the common knowledge of the person skilled in the art and, thus, also considered as being part of the present invention. For instance, while the present invention is described above with reference to a structural arrangement for the helicopter 1 of FIG. 1, the inventive method can more generally be applied to any similar structural arrangement independent of a respective use thereof. In other words, the structural arrangement that is manufactured according to the present invention cannot only be used with helicopters, but instead with any aircraft and, furthermore, also with other vessels or even independent of a predetermined use with such a vessel or aircraft.

(42) Furthermore, it should be noted that the electrically conductive layers that are created according to the present invention on an associated fiber reinforced polymer component are advantageously usable as a suitable protection of the structural arrangement that is manufactured according to the present invention and, more particularly, of the associated respective fiber reinforced polymer component against LDEs and LIEs, as already described above. However, the present invention is not limited to such LDE and LIE protection. Instead, the electrically conductive layers can likewise be used for other purposes, such as e.g. electrical power supply and/or as data lines.

REFERENCE LIST

(43) 1 rotary wing aircraft 1a multi-blade main rotor 1b, 1c rotor blades 1d rotor head 1e rotor shaft 1f landing gear 2 fuselage 2a cabin 2b rear fuselage 3 tail boom 3a horizontal stabilizer 3b tail boom cone 4 counter-torque device 4a tail rotor 5 vertical stabilizer 6 structural arrangement 6a non-conductive material 7 fiber reinforced polymer component 7a thermoset fiber reinforced polymer preform 8 intermediate thermoplastic layers 8a longitudinal polyether sulfone foil 8b transversal polyether sulfone foil 9 electrically conductive layers 9a longitudinal cold gas sprayed metal layers 9b transversal cold gas sprayed metal layers 10 intermediate thermoplastic separator 10a polyether sulfone separator 11 conductive layer bridge 11a cold gas sprayed metal layer bridge 12 conductive layers junction 12a cold gas sprayed metal layer junction 13 spraying tool 14 electrically conductive particles 15 mold 16 epoxy resin