Electrostatic protection design method for composite integral oil tank

Abstract

The invention belongs to the field of composite material integral oil tank electrostatic protection design, and particularly relates to a composite material integral oil tank electrostatic protection design method. Comprising the following steps: S1, carrying out electrostatic protection connection design on a metal wing rib and a composite wallboard; s2, performing electrostatic protection connection design on the composite spar and the composite wall plate at the wing rib connection corner box; and S3, carrying out grounding grid connection design on the oil tank. According to the electrostatic protection design method for the composite integral fuel tank, the electrostatic protection principle and typical design of the composite integral fuel tank are comprehensively and completely introduced from the aspects of structural design, coating selection, connection treatment and full-machine conductive path design aiming at the problems of electrostatic dissipation and fuel charge conduction caused by shaking of fuel in the composite fuel tank.

Description

Technical Field

[0001] This application belongs to the field of electrostatic protection design for composite integral fuel tanks, and specifically relates to a method for electrostatic protection design of composite integral fuel tanks. Background Technology

[0002] With the application of composite materials in the main load-bearing structure of aircraft—wing components—the composite material structure constituting the integral fuel tank of the wing is generally not a good electrical conductor, which is detrimental to the conduction of static charge within the integral fuel tank. The accumulation of static charge may generate high potentials that affect the fuel tank system, thereby endangering flight safety. The charge conduction characteristics within the composite fuel tank are related to the design of the coating system, electrical connection details, and fuel selection. While full-size composite integral fuel tank designs exist for aircraft such as the A350 and B787, publicly available information on related electrostatic protection design details and principles is extremely limited. Domestic full-size composite integral fuel tank designs are still in the research and development stage, and a complete design reference has not yet been established.

[0003] Existing technologies achieve co-curing of the conductive and load-bearing layers of the fuel tank skin structure through composite material laying processes, thus enabling conductivity of a single composite material skin structure. This method is relatively suitable for small and light aircraft, and it only addresses structural protection design, failing to solve the problems of electrostatic dissipation caused by fuel sloshing inside the composite fuel tank and the conduction of fuel charges.

[0004] Therefore, there is an urgent need for a technical solution to overcome or mitigate at least one of the aforementioned defects in the existing technology. Summary of the Invention

[0005] The purpose of this application is to provide a design method for electrostatic protection of composite integral oil tanks to solve at least one problem existing in the prior art.

[0006] The technical solution of this application is:

[0007] A method for electrostatic protection design of a composite integral oil tank, the oil tank comprising composite wall panels, composite wing beams, metal wing ribs, wing rib connecting corner boxes, and a leading or trailing edge metal structure, including:

[0008] Step S1: Design an electrostatic protection connection between the metal ribs and the composite wall panel;

[0009] Step S2: Design an electrostatic protection connection between the composite wing beam and the composite wall panel at the wing rib connecting corner box;

[0010] Step S3: Design the grounding grid connection on the fuel tank.

[0011] In at least one embodiment of this application, step S1, which involves designing an electrostatic protection connection between the metal ribs and the composite wall panel, includes:

[0012] Spray antistatic primer for composite parts onto one side of the inner surface of the oil tank of the composite wall panel;

[0013] Apply an antistatic primer to the metal ribs inside the fuel tank;

[0014] The fasteners connecting the composite wall panel and the metal ribs are sealed with sealant, and the edges of the metal ribs in contact with the composite wall panel are sealed with sealant.

[0015] Apply antistatic topcoat within L1mm of the edge of the area where the composite wall panel connects to the metal rib.

[0016] In at least one embodiment of this application, a sealant is applied to the edges of the metal ribs that are in contact with the composite wall panel.

[0017] In at least one embodiment of this application, L1 is 25.

[0018] In at least one embodiment of this application, step S2, which involves designing an electrostatic protection connection between the composite wing beam at the wing rib connecting corner box and the composite wall panel, includes:

[0019] Spray antistatic primer for composite parts onto one side of the inner surface of the oil tank of the composite wall panel;

[0020] Spray antistatic primer for composite parts onto the surface of the composite wing spar inside the fuel tank;

[0021] Apply an antistatic primer to the metal ribs inside the fuel tank;

[0022] Apply a weather-resistant primer to the metal structure surface at the leading or trailing edge of the fuel tank.

[0023] The fasteners connecting the composite wall panel and the metal ribs are sealed with sealant, and the edges of the metal ribs in contact with the composite wall panel are sealed with sealant.

[0024] The fasteners connecting the composite wing spar to the wing rib connecting box inside the fuel tank are sealed with sealant.

[0025] Apply antistatic topcoat within L2mm of the edge of the connection area between the composite wing beam and the composite wall panel at the wing rib connecting corner box.

[0026] In at least one embodiment of this application, a sealant is applied to the edges of the metal ribs that are in contact with the composite wall panel.

[0027] In at least one embodiment of this application, L2 is 25.

[0028] In at least one embodiment of this application, the leading or trailing edge metal structure is connected to the composite wing spars, wing ribs, and connecting corner boxes via fasteners.

[0029] In at least one embodiment of this application, step S3, which involves designing a grounding grid connection on the fuel tank, includes:

[0030] The metal components inside the fuel tank are connected to the metal ribs using fasteners.

[0031] The metal ribs are connected to the rib connection box using fasteners;

[0032] Connect the rib-connecting corner box to the leading or trailing edge metal structure using fasteners;

[0033] Connect the grounding grid to the metal wing beam at the root of the fuel tank section;

[0034] The grounding grid is arranged along the front or rear edge.

[0035] In at least one embodiment of this application, the leading or trailing edge metal structure is connected to the grounding grid by fasteners.

[0036] The invention has at least the following beneficial technical effects:

[0037] This application presents a design method for electrostatic discharge (ESD) protection of composite integral fuel tanks. Addressing the issues of ESD dissipation and fuel charge conduction caused by fuel sloshing inside composite fuel tanks, it comprehensively and completely introduces the ESD protection principles and typical designs of composite integral fuel tanks from aspects such as structural design, coating selection, connection treatment, and overall conductive path design. The related technology can provide a reference for the ESD protection design of composite integral fuel tank structures. It possesses sufficient novelty, inventiveness, and application value. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of a typical composite material integral fuel tank structure according to one embodiment of this application;

[0039] Figure 2 This is a schematic diagram of the connection design between the metal rib and the composite wall panel according to one embodiment of this application;

[0040] Figure 3 This is a schematic diagram of the design for the connection between the composite wing beam and the composite wall panel at the wing rib connecting corner box according to one embodiment of this application;

[0041] Figure 4 This is a schematic diagram of a grounding grid connection design according to one embodiment of this application. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0043] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this application.

[0044] The following is in conjunction with the appendix Figures 1 to 4 This application will be described in further detail.

[0045] This application provides a method for electrostatic protection design of composite integral oil tanks, including the following steps:

[0046] Step S1: Design an electrostatic protection connection between the metal ribs and the composite wall panel;

[0047] Step S2: Design an electrostatic protection connection between the composite wing beam and the composite wall panel at the wing rib connecting corner box;

[0048] Step S3: Design the grounding grid connection on the fuel tank.

[0049] Typical composite integral fuel tank structure, such as Figure 1 As shown. A typical fuel tank structure consists of composite upper / lower wall panels, composite front / rear wing beams, metal ribs, wing beam connecting corner boxes, and a front or rear edge metal structure. Typically, the composite wall panels and composite wing beams of the integral composite fuel tank are connected to the metal wall panels and metal wing beams at the root of the box section by fasteners. The grounding grid arranged at the front or rear edge of the fuel tank is connected to the front or rear edge metal structure and the metal wing beams.

[0050] In a preferred embodiment of this application, in step S1, the metal ribs and the composite wall panel are designed with electrostatic protection, such as... Figure 2 As shown, it includes:

[0051] Spray antistatic primer for composite parts onto one side of the inner surface of the oil tank of the composite wall panel;

[0052] Apply an antistatic primer to the metal ribs inside the fuel tank;

[0053] The fasteners connecting the composite wall panel and the metal ribs are sealed with sealant, and the edges of the metal ribs in contact with the composite wall panel are sealed with sealant.

[0054] Apply antistatic topcoat within L1mm of the edge of the area where the composite wall panel connects to the metal rib.

[0055] The sealant covers the edges of the metal ribs that contact the composite wall panel. An antistatic topcoat is sprayed within 25mm of the edge of the area where the composite wall panel connects to the metal ribs.

[0056] In a preferred embodiment of this application, in step S2, the composite wing beam at the corner box of the wing rib is designed with electrostatic protection for connection to the composite wall panel, such as... Figure 3 As shown, it includes:

[0057] Spray antistatic primer for composite parts onto one side of the inner surface of the oil tank of the composite wall panel;

[0058] Spray antistatic primer for composite parts onto the surface of the composite wing spar inside the fuel tank;

[0059] Apply an antistatic primer to the metal ribs inside the fuel tank;

[0060] Apply a weather-resistant primer to the metal structure surface at the leading or trailing edge of the fuel tank.

[0061] The fasteners connecting the composite wall panel and the metal ribs are sealed with sealant, and the edges of the metal ribs in contact with the composite wall panel are sealed with sealant.

[0062] The fasteners connecting the composite wing spar to the wing rib connecting box inside the fuel tank are sealed with sealant.

[0063] Apply antistatic topcoat within L2mm of the edge of the connection area between the composite wing beam and the composite wall panel at the wing rib connecting corner box.

[0064] The sealant covers the edges of the metal ribs in contact with the composite panel, and an antistatic topcoat is sprayed within 25mm of the edge of the connection area between the composite wing beam and the composite panel at the wing beam connecting corner box. The leading or trailing edge metal structure is connected to the composite wing beam and wing beam connecting corner box by fasteners.

[0065] In a preferred embodiment of this application, step S3 involves designing a grounding grid connection on the fuel tank, such as... Figure 4 As shown, it includes:

[0066] The metal components inside the fuel tank are connected to the metal ribs using fasteners.

[0067] The metal ribs are connected to the rib connection box using fasteners;

[0068] Connect the rib-connecting corner box to the leading or trailing edge metal structure using fasteners;

[0069] Connect the grounding grid to the metal wing beam at the root of the fuel tank section;

[0070] The grounding grid is arranged along the front or rear edge.

[0071] The metal components, such as fuel system parts, inside the fuel tank are connected to the metal ribs using fasteners. The leading or trailing edge metal structure is connected to the grounding grid using fasteners.

[0072] The electrostatic protection design method for composite integral oil tanks in this application, through... Figure 2 and Figure 3 The connection design and coating selection shown effectively prevent fuel charge accumulation inside the composite fuel tank; through Figure 3 and Figure 4 The connection design shown creates a complete electrostatic conductive path, which can effectively prevent isolated conductors from appearing inside the composite fuel tank and effectively conduct away fuel charge.

[0073] This application presents an electrostatic discharge (ESD) protection design method for composite integral fuel tanks. Based on the principles of internal electrostatic dissipation and fuel charge conduction within the composite integral fuel tank, it comprehensively and completely introduces the ESD protection principles and typical designs of composite integral fuel tanks from aspects such as structural design, coating selection, connection treatment, and overall conductive path design. This method can provide a reference for the ESD protection design of composite integral fuel tank structures, effectively reducing ESD protection design and development costs and shortening the development cycle.

[0074] This application presents a method for electrostatic discharge (ESD) protection design of composite integral fuel tanks. It implements the design of the entire internal coating system and the electrical connection pathways for the composite fuel tank structure, and explains the ESD protection design principle of composite fuel tanks. Several typical ESD protection designs and comprehensive electromechanical connection pathway designs are provided as references, which can be used to guide the ESD protection design of composite integral fuel tanks.

[0075] The electrostatic discharge protection design method for composite integral fuel tanks of this application has been applied to the electrostatic discharge protection design of a composite material integral fuel tank for an aircraft wing, and has passed electrostatic discharge test verification. The test shows that the electrostatic discharge protection design involved in this application has good and reliable protection effect.

[0076] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for electrostatic protection design of a composite integral fuel tank, the fuel tank comprising a composite wall panel, composite wing beams, metal wing ribs, wing rib connecting corner boxes, and a leading or trailing edge metal structure, characterized in that, include: Step S1: Design an electrostatic protection connection between the metal ribs and the composite wall panel; Step S2: Design an electrostatic protection connection between the composite wing beam and the composite wall panel at the wing rib connecting corner box; Step S3: Design the grounding grid connection on the fuel tank.

2. The electrostatic protection design method for composite integral oil tank according to claim 1, characterized in that, In step S1, the electrostatic protection connection design between the metal ribs and the composite wall panel is implemented, including: Spray antistatic primer for composite parts onto one side of the inner surface of the oil tank of the composite wall panel; Apply an antistatic primer to the metal ribs inside the fuel tank; The fasteners connecting the composite wall panel and the metal ribs are sealed with sealant, and the edges of the metal ribs in contact with the composite wall panel are sealed with sealant. Apply antistatic topcoat within L1mm of the edge of the area where the composite wall panel connects to the metal rib.

3. The electrostatic protection design method for composite integral oil tank according to claim 2, characterized in that, Sealant is applied to the edges of the metal ribs that come into contact with the composite wall panel.

4. The electrostatic protection design method for composite integral oil tank according to claim 3, characterized in that, L1 is 25.

5. The electrostatic protection design method for composite integral oil tank according to claim 4, characterized in that, In step S2, the composite wing beam at the corner box of the wing rib is designed to be electrostatically protected to the composite wall panel, including: Spray antistatic primer for composite parts onto one side of the inner surface of the oil tank of the composite wall panel; Spray antistatic primer for composite parts onto the surface of the composite wing spar inside the fuel tank; Apply an antistatic primer to the metal ribs inside the fuel tank; Apply a weather-resistant primer to the metal structure surface at the leading or trailing edge of the fuel tank. The fasteners connecting the composite wall panel and the metal ribs are sealed with sealant, and the edges of the metal ribs in contact with the composite wall panel are sealed with sealant. The fasteners connecting the composite wing spar to the wing rib connecting box inside the fuel tank are sealed with sealant. Apply antistatic topcoat within L2mm of the edge of the connection area between the composite wing beam and the composite wall panel at the wing rib connecting corner box.

6. The electrostatic protection design method for composite integral oil tank according to claim 5, characterized in that, Sealant is applied to the edges of the metal ribs that come into contact with the composite wall panel.

7. The electrostatic protection design method for composite integral oil tank according to claim 6, characterized in that, L2 is 25.

8. The electrostatic protection design method for composite integral oil tank according to claim 7, characterized in that, The leading or trailing edge metal structure is connected to the composite wing spars, wing ribs, and connecting corner boxes via fasteners.

9. The electrostatic protection design method for composite integral oil tank according to claim 8, characterized in that, In step S3, the grounding grid connection design on the fuel tank is carried out, including: The metal components inside the fuel tank are connected to the metal ribs using fasteners. The metal ribs are connected to the rib connection box using fasteners; Connect the rib-connecting corner box to the leading or trailing edge metal structure using fasteners; Connect the grounding grid to the metal wing beam at the root of the fuel tank section; The grounding grid is arranged along the front or rear edge.

10. The electrostatic protection design method for composite integral oil tank according to claim 9, characterized in that, Connect the leading or trailing edge metal structure to the grounding grid using fasteners.

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