CN117485576A - Lightning impact protection method based on full composite material ducted tail rotor - Google Patents
Lightning impact protection method based on full composite material ducted tail rotor Download PDFInfo
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- CN117485576A CN117485576A CN202311736934.7A CN202311736934A CN117485576A CN 117485576 A CN117485576 A CN 117485576A CN 202311736934 A CN202311736934 A CN 202311736934A CN 117485576 A CN117485576 A CN 117485576A
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- culvert
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- lap joint
- lightning
- copper sheet
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- 239000002131 composite material Substances 0.000 title claims abstract description 53
- 238000000034 method Methods 0.000 title claims abstract description 37
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims abstract description 86
- 229910052802 copper Inorganic materials 0.000 claims abstract description 86
- 239000010949 copper Substances 0.000 claims abstract description 86
- 239000000853 adhesive Substances 0.000 claims abstract description 33
- 230000001070 adhesive effect Effects 0.000 claims abstract description 33
- 241000251468 Actinopterygii Species 0.000 claims abstract description 24
- 239000002313 adhesive film Substances 0.000 claims abstract description 18
- 210000001503 joint Anatomy 0.000 claims abstract description 18
- 238000005498 polishing Methods 0.000 claims description 22
- 229910052751 metal Inorganic materials 0.000 claims description 18
- 239000002184 metal Substances 0.000 claims description 18
- 239000004744 fabric Substances 0.000 claims description 12
- 229910052782 aluminium Inorganic materials 0.000 claims description 11
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 11
- 239000011521 glass Substances 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 9
- 239000011248 coating agent Substances 0.000 claims description 6
- 238000000576 coating method Methods 0.000 claims description 6
- 239000003292 glue Substances 0.000 claims description 6
- 238000004026 adhesive bonding Methods 0.000 claims description 5
- 239000000565 sealant Substances 0.000 claims description 5
- 238000005507 spraying Methods 0.000 claims description 5
- 238000007598 dipping method Methods 0.000 claims description 4
- 230000001680 brushing effect Effects 0.000 claims description 3
- 239000000835 fiber Substances 0.000 claims description 3
- 229920000728 polyester Polymers 0.000 claims description 3
- 238000009434 installation Methods 0.000 claims 1
- 238000013461 design Methods 0.000 description 32
- 208000025274 Lightning injury Diseases 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 4
- 238000005192 partition Methods 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- 241000623377 Terminalia elliptica Species 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
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- 238000006467 substitution reaction Methods 0.000 description 1
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64D—EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- B64D45/00—Aircraft indicators or protectors not otherwise provided for
- B64D45/02—Lightning protectors; Static dischargers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64F—GROUND OR AIRCRAFT-CARRIER-DECK INSTALLATIONS SPECIALLY ADAPTED FOR USE IN CONNECTION WITH AIRCRAFT; DESIGNING, MANUFACTURING, ASSEMBLING, CLEANING, MAINTAINING OR REPAIRING AIRCRAFT, NOT OTHERWISE PROVIDED FOR; HANDLING, TRANSPORTING, TESTING OR INSPECTING AIRCRAFT COMPONENTS, NOT OTHERWISE PROVIDED FOR
- B64F5/00—Designing, manufacturing, assembling, cleaning, maintaining or repairing aircraft, not otherwise provided for; Handling, transporting, testing or inspecting aircraft components, not otherwise provided for
- B64F5/10—Manufacturing or assembling aircraft, e.g. jigs therefor
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- Engineering & Computer Science (AREA)
- Aviation & Aerospace Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Transportation (AREA)
- Elimination Of Static Electricity (AREA)
Abstract
The invention discloses a lightning impact protection method based on a full composite material ducted tail rotor, which comprises the following steps: arranging a lightning protection composite film on the upper fairing of the vertical fin, the rear fairing of the culvert, the left skin of the culvert, the right skin of the culvert, the lower skin of the culvert, the front edge of the culvert and the fish mouth wall plate for surface protection; the upper fairing of the vertical fin and the rear fairing of the culvert are in lap joint with the left skin and the right skin of the culvert through bolts, and lap joint copper sheets are arranged at the lap joint positions for lightning protection; the front edge of the culvert and the fish mouth wall plate are assembled and connected through blind rivets, the left skin of the culvert, the right skin of the culvert and the lower skin of the culvert are glued with the front beam through a structural adhesive film, and then are riveted through blind rivets, and the skins, the front edge of the culvert and the fish mouth wall plate are in a butt joint mode; lightning protection is carried out at all riveted joints; the left skin of the culvert, the right skin of the culvert, the lower skin of the culvert and the inner ring of the culvert are connected with the inner rib of the culvert through the structural adhesive film in an adhesive joint manner, and lightning protection is carried out at all adhesive joints.
Description
Technical Field
The invention relates to a lightning protection design technology of composite material parts and components, in particular to a lightning impact protection method based on a full composite material ducted tail rotor.
Background
Aiming at the development needs of domestic civil aviation field, a novel four-ton double-altitude civil helicopter is developed; the machine has the advantages of strong power, large space, high safety performance, low use and maintenance cost and the like, and can meet the operation requirements of police, medical aid, emergency rescue, offshore petroleum service, altitude inspection and the like. The tail rotor structure for balancing the rotor reaction torque adopts a high-position duct type tail rotor layout, and all parts of the whole structure are made of resin matrix composite materials, so that the tail rotor structure has the excellent performances of light weight, good safety, high efficiency and the like.
According to the requirement of the "29.610 lightning and static protection" in the CCAR-29-R2 "airworthiness regulations of transport-type rotorcraft", the structure of rotorcraft must have protection measures to prevent catastrophic consequences caused by lightning—therefore, in order to ensure that the aircraft has the ability to safely return after suffering from lightning impact in daily use, it is necessary to demonstrate that an effective lightning protection design method is required.
The composite structural member has poor conductivity and far exceeds the metal material in the influence of lightning impact; therefore, the lightning protection design of the composite material component has become the most important measure for the lightning impulse resistance of the whole helicopter body structure.
The method for repairing the lightning protection capability of the helicopter composite material is disclosed in publication No. CN113928576A, and the lightning protection improvement design is carried out on a composite material component of an original old conventional tail rotor helicopter in a lightning partition.
Publication number CN106560399a, "method for transferring lightning current from skin fastener in composite nonmetallic structure," designed a method for effectively transferring lightning current through bolt fastener for nonmetallic skin connection area, which is an effective method for current transition between parts, but has no effective requirement for parts that are not connected through fastener, and at the same time, the protection design under lightning impact of parts themselves is not effectively demonstrated.
Publication number CN114180083A, "a method for conducting electricity between composite structural members realized by copper cups," designs a pneumatic appearance of a tail structure of a ducted helicopter, which comprises a vertical tail, a duct side wall, a tail rotor duct and a duct bottom, and belongs to the field of pneumatic appearance and the field of non-structural design.
Disclosure of Invention
The invention aims to provide a lightning impact protection method based on a full composite material ducted tail rotor, so that the model is ensured to meet the navigable management requirement, the helicopter is ensured to safely pass in thunderstorm weather, and an effective design thought is provided for the lightning stroke protection technology of the ducted tail rotor structure.
In order to realize the tasks, the invention adopts the following technical scheme:
a lightning strike protection method based on a full composite ducted tail rotor, comprising:
arranging a lightning protection composite film on the upper fairing of the vertical fin, the rear fairing of the culvert, the left skin of the culvert, the right skin of the culvert, the lower skin of the culvert, the front edge of the culvert and the fish mouth wall plate for surface protection;
the upper fairing of the vertical fin and the rear fairing of the culvert are in lap joint with the left skin and the right skin of the culvert through bolts, and lap joint copper sheets are arranged at the lap joint positions for lightning protection;
the front edge of the culvert and the fish mouth wall plate are assembled and connected through blind rivets, the left skin of the culvert, the right skin of the culvert and the lower skin of the culvert are glued with the front beam through a structural adhesive film, and then are riveted through blind rivets, and the skins, the front edge of the culvert and the fish mouth wall plate are in a butt joint mode; lightning protection is carried out at all riveted joints;
the left skin of the culvert, the right skin of the culvert, the lower skin of the culvert and the inner ring of the culvert are connected with the inner rib of the culvert through the structural adhesive film in an adhesive joint manner, and lightning protection is carried out at all adhesive joints.
Further, the lightning protection composite film is formed by solidifying an outer layer and an inner layer of polyester fiber surface felt and a middle metal copper mesh, wherein the density of the metal copper mesh is 260g/m 2 The thickness is 0.2mm, the long hole distance resistance of the metal copper net is less than or equal to 15 omega, and the short hole distance resistance of the metal copper net is less than or equal to 35 omega.
Further, the lap joint is provided with a lap copper sheet for lightning protection, wherein the lightning protection method for the left skin of the vertical fin upper fairing and the duct comprises the following steps:
(1) setting a lap joint copper sheet;
(2) selecting any bolt connection point of the vertical tail upper fairing and the left skin of the duct, and polishing the outer sides of the vertical tail upper fairing and the left skin of the duct at the position until the metal copper net is exposed;
(3) coating conductive adhesive on the naked leaked metal copper net;
(4) folding the lap joint copper sheet into a U shape, adhering the lap joint copper sheet to a polishing area by using an adhesive, wrapping the lap joint copper sheet at the end part of the upper fairing of the vertical fin, attaching one side of the lap joint copper sheet to the polishing area on the outer surface of the upper fairing of the vertical fin, and attaching one side of the lap joint copper sheet to the polishing area on the outer side of the left skin of the culvert;
(5) after the bonding of the lap joint copper sheets is completed, covering the exposed outer surface of the lap joint copper sheets by using a layer of dry glass cloth dipping adhesive, and spraying primer as it is to restore the appearance;
(6) and finally, connecting the upper fairing, the left duct skin and the lap joint copper sheets at the bolt connecting points by utilizing original bolts.
Further, the copper sheet material is H62M, and the thickness is 0.4mm; the model of the conductive adhesive is DAD-8-3, the model of the adhesive is EA9396, and the model of the dry glass cloth is EW210.
Further, the lightning protection is performed at all riveted joints, wherein for the riveted joint of the left skin of the culvert and the fish mouth wall plate, the protection method is as follows:
(1) the left skin of the duct is subjected to secondary cementing work with the front beam through a structural adhesive film;
(2) the fish mouth wall plate is installed and positioned, and is in butt joint with the left skin of the culvert, and the butt joint is 1mm;
(3) polishing the surfaces of the left skin and the fish mouth wall plate of the culvert until the metal copper net is exposed;
(4) brushing conductive adhesive on the metal copper mesh of the bare drain to increase conductivity;
(5) an overlap joint aluminum plate is arranged on the outer side of the left skin of the duct;
(6) riveting the lap joint aluminum plate, the fish mouth wall plate and the left skin of the duct through a self-plugging rivet so as to form a conductive path;
(7) after the riveting is finished, the periphery of the lap joint aluminum plate is sealed by using sealant.
Further, the model of the structural adhesive film is Reduc312.5, the lap joint aluminum plate material is 2024T3, and the thickness is 1.5mm; the model of the conductive adhesive is DAD-8-3, and the model of the sealant is HM105B2.
Further, the lightning protection is performed at all glue joints, wherein for the left in-duct skin and the lower in-duct skin, the protection method is as follows:
(1) setting a lap joint copper sheet;
(2) polishing the left skin of the culvert and the outer side of the lower skin of the culvert at any bonding position of the left skin of the culvert and the lower skin of the culvert until the metal copper mesh is exposed;
(3) coating conductive adhesive on the bare copper mesh;
(4) performing secondary gluing on the left skin of the culvert and the lower skin of the culvert by using an adhesive film, folding the lap joint copper sheets into a U shape, and adhering the lap joint copper sheets by using an adhesive, wherein the U-shaped lap joint copper sheets are wrapped at the edge of the left skin of the culvert, one side of the U-shaped lap joint copper sheets is jointed with a polishing area on the outer surface of the lower skin of the culvert, and the other side of the U-shaped lap joint copper sheets is jointed with a polishing area on the outer side of the left skin of the culvert;
(5) after bonding the lap joint copper sheets, riveting by using a self-plugging rivet;
(6) and then covering the outer surface of the naked leakage of the lap joint copper sheet by using a layer of dry glass cloth dipping adhesive, and spraying primer in the original state to restore the appearance.
Further, the material of the lap joint copper sheet is H62M, and the thickness is 0.4mm; the conductive adhesive is DAD-8-3, the adhesive film is Redux312.5, the adhesive is EA9396, and the dry glass cloth is EW210.
Compared with the prior art, the invention has the following technical characteristics:
1. the lightning protection composite film is comprehensively applied to the domestic ducted tail rotor helicopter for the first time.
2. The anti-lightning composite film J-399-3-141ED is a latest product, has low resistance and high lightning resistance, has good processing manufacturability, can be respectively solidified at medium temperature and high temperature, and has the functions of lightning resistance and surface quality improvement.
3. The lightning protection design is carried out on the whole structure of the large part of the full composite material culvert, and the lightning protection design is systematically demonstrated in the full composite material culvert type tail rotor structure for the first time in China.
4. The lightning impulse protection method adopted from the composite material part design stage to the structure assembly design stage is system, comprehensive and high in protection performance, fully considers all lightning damage possibilities caused by direct impulse and current sweep, can ensure that the residual strength of the bearing member after being subjected to lightning impulse meets the requirement, and does not influence the flight due to the damage degree of the non-bearing profile member after being subjected to lightning impulse.
5. The lightning impulse protection method designed by the invention is sufficient in demonstration aiming at the large composite material parts with weak conductivity, and can be used as a general design method in the subsequent domestic aviation field.
Drawings
FIG. 1 is a diagram of a lightning partition of a helicopter;
FIG. 2 is a schematic view of a ducted tail rotor;
FIG. 3 is a typical view of lightning protection for a composite part;
FIG. 4 is a schematic view of a lightning protection composite film;
FIG. 5 is a schematic view of a copper mesh used for the lightning protection composite film;
FIG. 6 is an example of a bolted assembled lightning protection conduction design;
FIG. 7 is an example of a rivet connection assembly lightning protection conduction design;
FIG. 8 is an example of a glue joint assembled lightning protection on design;
fig. 9 is a structural example of the lap joint copper sheet.
Detailed Description
In order to meet the requirements of model development and related lightning impact airworthiness clauses, an effective protection technology capable of guaranteeing flight safety under the direct action of lightning is provided for a composite structural member. Meanwhile, the large duct component comprises a lightning zone 1, a lightning zone 2 and a lightning zone 3, which are shown in the figure 1-very representative. Therefore, the lightning impulse protection method based on the ducted tail rotor of the full composite material can meet the lightning impulse protection requirement of the ducted tail rotor, and simultaneously provides an effective design method for the lightning protection field of the composite material for reference of the lightning design of the subsequent air craft. Meanwhile, the lightning stroke protection demonstration is carried out based on the full composite material ducted tail rotor, so that knowledge storage can be made for the lightning stroke protection technology in the aviation field of China.
The invention discloses a lightning impact protection method based on a design of a ducted tail rotor of a certain type of machine full composite material, and the technical scheme is discussed from three sides.
On the one hand, the lightning stroke area of the ducted tail rotor of the machine is shown in figure 1, the whole ducted tail rotor comprises 1 area, 2 areas and 3 areas, all lightning stroke areas are covered, and the definition of each lightning stroke area is shown in table 1.
Table 1 definition of lightning partition and analog current component
Meanwhile, the ducted tail rotor is designed and manufactured by adopting a full composite material, and the structural composition is shown in figure 2; the lightning stroke zone inner part comprises a duct inner ring 8, and a vertical fin upper fairing 1, a rear duct rear fairing 2, a left duct left skin 3, a right duct right skin 4, a lower duct lower skin 5, a front duct front edge 6, a front lower fishmouth wall plate 7 and a vertical fin 9 which are arranged at the upper part of the duct inner ring 8; the lightning strike area to which each part belongs is shown in Table 2.
TABLE 2 detailed listing of composite parts for different lightning regions of ducted tail rotor
And designing a lightning impact protection method according to comprehensive consideration of the positions of lightning strike areas and the sizes of current components of different parts.
On the one hand, lightning impact protection design is carried out in the part design stage, so that the residual strength of the main and secondary bearing composite material parts is more than or equal to 67% of limiting load under the direct impact action of lightning, and the non-bearing parts can basically ensure structural integrity, so that flight safety is ensured.
(1) Drop tail 9: a glass fiber composite structure; the lower end is located in the 1B area, the rest positions are located in the 2A area, the current component is larger, but the function of the drooping tail is to protect the duct tail rotor through breaking energy absorption when the tail touches the ground, and the drooping tail rotor is connected with the duct main body through bolts, so that the cost is low, the replacement is simple, and special lightning protection design is not performed based on the current component.
(2) Ducted inner ring 8: a carbon fiber honeycomb sandwich structure; the whole is positioned in a3 region, namely a region where lightning cannot directly strike, but in a subsequent current conduction and circulation region, the whole current component is smaller and is not directly impacted, so that special lightning protection design is not needed in the part stage.
(3) The vertical fin upper fairing 1, the duct rear fairing 2, the duct left skin 3, the duct right skin 4, the duct lower skin 5, the duct front edge 6 and the fish mouth wall plate 7: all are located 1 district and 2 district, receive lightning direct impact area, and the current component is big, and is destroyed greatly after receiving the lightning impulse, consequently the part stage need carry out effectual lightning protection design, adopts the brand-new composite film of lightning protection to carry out surface protection promptly, specifically as follows:
(1) the current impact resistance of the selected lightning protection composite film 14 specification was verified by manufacturing a typical composite test piece with a size of 500×500 and performing a "high current physical damage test" according to ARP5416, thereby selecting a suitable specification-J-399-3-141 ED (standard Q/HSYZ001, new product of black petrochemical institute).
(2) And (3) designing a composite material part: i.e. a layer of lightning protection composite film 14 is paved on the outer surface, the paving form is shown in figure 3, the composite film is positioned at the outermost side, and the copper mesh is allowed to overlap, and the overlapping range is 15-20mm.
(3) The lightning protection composite film is shown in fig. 4, and consists of an outer layer and an inner layer of polyester fiber surface felt 15 and a middle metal copper net 16.
Density of 260g/m 2 And a thickness of 0.2mm.
The long hole distance resistance of the copper net is less than or equal to 15, the short hole distance resistance is less than or equal to 35, the smaller the resistance value is, the stronger the protection capability is, and the performance of the copper net used by J-399-3-141ED belongs to one of the most advanced in China.
Can be cured at medium temperature of 120 ℃ or at high temperature of 180 ℃.
(4) And finally, selecting proper temperature according to the attribute of the prepreg cloth, and putting the prepreg cloth into a furnace for curing.
On the one hand, the lightning surge protection design is performed in the integral large component assembly connection, so that the current can be effectively conducted (with a low-impedance path) between structures under the lightning surge.
(1) And (3) bolt connection: the vertical tail upper fairing 1 and the duct rear fairing 2 are in lap joint with the duct left skin 3 and the duct right skin 4 through bolts.
The lightning protection design method comprises the following steps: taking the vertical tail upper fairing 1 and the duct left skin 3 as examples, the structural design schematic diagram is shown in fig. 6.
(1) Designing a lap joint copper sheet 13, see fig. 9; the copper sheet material is H62M (standard GB/T2059) and has the thickness of 0.4mm.
(2) And selecting any bolt connection point of the vertical fin upper fairing 1 and the left duct skin 3, and polishing the lightning protection composite film 14 on the outer sides of the vertical fin upper fairing 1 and the left duct skin 3 at the position until the metal copper net is exposed.
(3) And coating DAD-8-3 conductive adhesive on the bare copper mesh.
(4) And (3) bonding the lap joint copper sheet 13 to a polishing area by using an EA9396 adhesive, wherein one side of the U-shaped copper sheet is attached to the polishing area on the outer surface of the upper fairing 1 of the vertical fin, and the other side is attached to the polishing area on the outer side of the left skin 3 of the culvert.
(5) After the bonding of the lap joint copper sheet 13 is completed, the outer surface of the bare drain is covered by using a layer of EW210 dry glass cloth to dip EA9396 glue, and the primer S06-12 is sprayed in the original state to restore the appearance.
(6) Finally, the bolts 17 are reattached in place.
(2) And (3) riveting connection: the duct front edge 6 and the fish mouth wall plate 7 are assembled and connected through blind rivets. The left skin 3, the right skin 4 and the lower skin 5 are glued with the front beam 10 through the structural adhesive film and then riveted by using blind rivets. The skin is in butt joint with the duct leading edge 6 and the fish mouth wall plate 7.
The lightning protection design method comprises the following steps: taking the left skin 3 and the fishmouth wall plate 7 as examples, the schematic structural design is shown in fig. 7.
(1) The bypass left skin 3 completes the secondary cementing work with the front beam 10 through the structural adhesive film Reduc312.5.
(2) And (3) installing and positioning the fish mouth wall plate 7, butting the left skin 3 of the culvert, and butting the joint by 1mm.
(3) And polishing the surfaces of the left skin 3 and the fish mouth wall plate 7 of the culvert until the copper net is exposed.
(4) And (3) brushing DAD-8-3 conductive adhesive on the copper mesh of the bare drain to increase conductivity.
(5) An overlapping aluminum plate 12 was designed, with a material 2024T3 (standard ASNA 3012), and a thickness of 1.5mm.
(6) Riveting of the overlap aluminum plate 12 with the fish mouth wall plate 7 and the left duct skin 3 is performed by blind rivets 19, thereby forming a conductive path.
(7) After the riveting is completed, the periphery of the lap joint aluminum plate is sealed by using HM105B2 sealant.
(3) And (3) glue joint: the left skin 3, the right skin 4, the lower skin 5 and the inner ring 8 are connected with the inner rib 12 in a gluing way through the structural adhesive film, and the skin and the inner ring are in a lap joint mode.
The lightning protection design method comprises the following steps: taking the left skin 3 and the lower skin 5 as examples, the schematic structural design is shown in fig. 8.
(1) A lap copper sheet 13 is designed, see fig. 9 (without a central hole); the copper sheet material is H62M (standard GB/T2059) and has the thickness of 0.4mm.
(2) And (3) grinding the left skin 3 of the culvert and the outer side of the lower skin 5 of the culvert at any bonding position of the left skin 3 of the culvert and the lower skin 5 of the culvert until the copper mesh is exposed.
(3) And coating DAD-8-3 conductive adhesive on the bare copper mesh.
(4) In the secondary gluing process of the duct left skin 3 and the duct lower skin 5 by using the adhesive film Redux312.5, the EA9396 adhesive is used for gluing the lap joint copper sheet 13, one side of the U-shaped copper sheet is attached to the polishing area of the outer surface of the duct lower skin 5, and the other side is attached to the polishing area of the outer side of the duct left skin 3.
(5) After the bonding of the lap copper 13 is completed, riveting is performed using the blind rivet 19.
(6) And then, covering the outer surface of the bare drain by using a layer of EW210 dry glass cloth to dip EA9396 glue, and spraying primer S06-12 as is to recover the appearance.
All of the lightning protection conductive designs above are illustrated with arrows in figures 6, 7, 8 as current flow paths.
The above embodiments are only for illustrating the technical solution of the present application, and are not limiting thereof; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.
Claims (8)
1. A lightning strike protection method based on a full composite ducted tail rotor, comprising:
a lightning protection composite film is arranged on a vertical tail upper fairing (1), a culvert rear fairing (2), a culvert left skin (3), a culvert right skin (4), a culvert lower skin (5), a culvert front edge (6) and a fish mouth wallboard (7) for surface protection;
the vertical tail upper fairing (1) and the duct rear fairing (2) are in lap joint with the left duct skin (3) and the right duct skin (4) through bolts, and lap joint copper sheets are arranged at lap joint positions for lightning protection;
the culvert front edge (6) and the fish mouth wall plate (7) are assembled and connected through blind rivets, the left culvert skin (3), the right culvert skin (4) and the lower culvert skin (5) are glued with the front beam (10) through structural adhesive films, and then are riveted through blind rivets, wherein the skin is in butt joint with the culvert front edge (6) and the fish mouth wall plate (7); lightning protection is carried out at all riveted joints;
the left skin (3), the right skin (4), the lower skin (5) and the inner ring (8) are connected with the inner rib (12) through the structural adhesive film, and lightning protection is carried out at all the glued joints.
2. The lightning impulse protection method based on the full composite ducted tail rotor as claimed in claim 1, characterized in that the lightning impulse protection composite film is formed by solidifying an outer layer and an inner layer of polyester fiber surface felt (15) and a middle metallic copper net (16), wherein the density of the metallic copper net (16) is 260g/m 2 The thickness is 0.2mm, the long hole distance resistance of the metal copper net (16) is less than or equal to 15 omega, and the short hole distance resistance of the metal copper net (16) is less than or equal to 35 omega.
3. The lightning impulse protection method based on the full composite ducted tail rotor as claimed in claim 1, wherein a lap copper sheet is arranged at the lap joint for lightning protection, wherein the lightning protection method for the vertical tail upper fairing (1) and the ducted left skin (3) comprises the following steps:
(1) a lap joint copper sheet (13) is arranged;
(2) selecting any bolt connection point of the vertical tail upper fairing (1) and the left skin (3) of the culvert, and polishing the outer sides of the vertical tail upper fairing (1) and the left skin (3) of the culvert at the position until the metal copper mesh is exposed;
(3) coating conductive adhesive on the naked leaked metal copper net;
(4) folding the lap joint copper sheet (13) into a U shape, bonding the lap joint copper sheet (13) to a polishing area by using an adhesive, wrapping the end part of the vertical fin upper fairing (1), bonding one side of the lap joint copper sheet (13) to the polishing area of the outer surface of the vertical fin upper fairing (1), and bonding one side of the lap joint copper sheet to the polishing area of the outer side of the left skin (3) of the culvert;
(5) after the bonding of the lap joint copper sheet (13) is finished, covering the outer surface of the bare leak of the lap joint copper sheet (13) by using a layer of dry glass cloth dipping adhesive, and spraying primer as it is to restore the appearance;
(6) and finally, connecting the upper fairing (1), the left duct skin (3) and the lap joint copper sheets at the bolt connection points by utilizing original bolts (17).
4. The lightning impulse protection method based on the full composite ducted tail rotor of claim 3, wherein the copper sheet material is H62M, and the thickness is 0.4mm; the model of the conductive adhesive is DAD-8-3, the model of the adhesive is EA9396, and the model of the dry glass cloth is EW210.
5. The lightning impulse protection method based on a full composite ducted tail rotor according to claim 1, characterized in that the lightning protection is performed at all riveted joints, wherein for the riveted joint of the ducted left skin (3) and the fish mouth wall plate (7), the protection method is as follows:
(1) the left skin (3) of the duct completes secondary cementing work with the front beam (10) through a structural adhesive film;
(2) the installation and positioning of the fish mouth wall plate (7) are carried out, the fish mouth wall plate is in butt joint with the left skin (3) of the culvert, and the butt joint is 1mm;
(3) polishing the surfaces of the left skin (3) and the fish mouth wall plate (7) of the culvert until the metal copper net is exposed;
(4) brushing conductive adhesive on the metal copper mesh of the bare drain to increase conductivity;
(5) an overlap joint aluminum plate (12) is arranged at the outer side of the left skin (3) of the duct;
(6) riveting the lap joint aluminum plate (12) with the fish mouth wall plate (7) and the left skin (3) of the culvert is carried out through a blind rivet (19), so that a conductive path is formed;
(7) after the riveting is finished, the periphery of the lap joint aluminum plate is sealed by using sealant.
6. The lightning impulse protection method based on the full composite ducted tail rotor as claimed in claim 5, wherein the structural adhesive film is of the type of reduced 312.5, the lap aluminum plate (12) is of the material 2024T3, and the thickness is 1.5mm; the model of the conductive adhesive is DAD-8-3, and the model of the sealant is HM105B2.
7. The lightning impulse protection method based on a full composite ducted tail rotor according to claim 1, characterized in that the lightning protection is performed at all glue joints, wherein for the ducted left skin (3) and the ducted lower skin (5), the protection method is as follows:
(1) a lap joint copper sheet (13) is arranged;
(2) the left skin (3) of the culvert and the lower skin (5) of the culvert are subjected to random bonding positions, and the outer sides of the left skin (3) of the culvert and the lower skin (5) of the culvert in the positions are polished until the metal copper mesh is exposed;
(3) coating conductive adhesive on the bare copper mesh;
(4) the left skin (3) and the lower skin (5) of the culvert are subjected to secondary gluing by using an adhesive film, meanwhile, the lap joint copper sheet (13) is folded into a U shape, the lap joint copper sheet (13) is glued by using an adhesive, the U-shaped lap joint copper sheet is wrapped at the edge of the left skin (3) of the culvert, one side of the U-shaped lap joint copper sheet is attached to a polishing area on the outer surface of the lower skin (5) of the culvert, and the other side of the U-shaped lap joint copper sheet is attached to a polishing area on the outer side of the left skin (3) of the culvert;
(5) after the bonding of the lap joint copper sheet (13) is finished, a self-plugging rivet (19) penetrates through the lap joint copper sheet (13) to rivet the left skin (3) and the lower skin (5) of the duct;
(6) and then covering the outer surface of the naked leakage of the lap joint copper sheet (13) by using a layer of dry glass cloth dipping adhesive, and spraying primer in the original state to restore the appearance.
8. The lightning impulse protection method based on the full composite ducted tail rotor as claimed in claim 7, characterized in that the material of the lap copper sheet (13) is H62M, thickness 0.4mm;
the conductive adhesive is DAD-8-3, the adhesive film is Redux312.5, the adhesive is EA9396, and the dry glass cloth is EW210.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311736934.7A CN117485576A (en) | 2023-12-15 | 2023-12-15 | Lightning impact protection method based on full composite material ducted tail rotor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311736934.7A CN117485576A (en) | 2023-12-15 | 2023-12-15 | Lightning impact protection method based on full composite material ducted tail rotor |
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| Publication Number | Publication Date |
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| CN117485576A true CN117485576A (en) | 2024-02-02 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311736934.7A Pending CN117485576A (en) | 2023-12-15 | 2023-12-15 | Lightning impact protection method based on full composite material ducted tail rotor |
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| Country | Link |
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| CN (1) | CN117485576A (en) |
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- 2023-12-15 CN CN202311736934.7A patent/CN117485576A/en active Pending
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