Composite material skin and rib plate co-bonding forming method

Abstract

The invention relates to a co-bonding forming method for a composite material skin and a rib plate, a bonding area exists between the composite material skin and the rib plate, and a limited distance is expanded from the outline of the bonding area to form an easy-to-deform area; and the skin is a prepreg laminated material to be cured. The wallboard skin area between the solidified rib plates on the skin is filled with the gold sand, the defects that the rib plates are sunken, glue is accumulated at the edge strips and skin fibers are wrinkled in the co-glue joint forming process can be overcome, the mode that the vacuum bags are pasted on the rib plates is adopted, the problems of compression deformation of the edge strips of the stringer and position slippage of the rib plates can be avoided, and the production efficiency is improved. And meanwhile, the axis positioning difficulty of the stringer is reduced, the technological method is easy to operate, the forming quality of the co-glued wallboard is high, and the manufacturing cost is low.

Description

Technical Field

[0001] The invention relates to the technical field of composite material co-bonding manufacturing, in particular to a composite material skin and rib plate co-bonding molding method. Background Art

[0002] The integrated structure of composite materials is conducive to reducing the number of parts, improving the efficiency and reliability of the structure, and achieving structural weight reduction. The design form of the integrated wall panel consists of a flat / curved panel and a frame or ribs. The reinforced wall panel can effectively improve the bending resistance of the skin and is widely used in load-bearing structures such as aviation and ships. The molding process includes co-curing, co-bonding, secondary bonding, liquid molding, etc. Considering the manufacturing cost and manufacturing difficulty, the co-bonding molding process is widely used. The recent invention of the co-bonding molding method for reinforced wall panels is as follows:

[0003] 1) Process method for co-bonding and forming of I-shaped reinforced wall panels of composite materials for aircraft (authorization number CN111231364B): A process cover plate with the same thickness as the lower edge strip of the long stringer and a slot is used on the skin to position the long stringer, a gap of 0.5 mm is reserved between the long stringer edge strip and the process cover plate, a rubber core mold is filled at the web position of the I-shaped long stringer, and then a vacuum bag is made for co-bonding and curing. Due to the 0.5 mm gap between the long stringer edge strip and the process cover plate, there is a pressure difference at the gap position between the long stringer and the process cover plate during co-bonding and forming, and there are glue accumulation or fiber wrinkle defects on the surface of the wall panel skin after forming. Secondly, during the curing process, the resin in the skin prepreg and the film flows and fills into the gap. The demolding process after curing may cause the fiber splitting of the long stringer edge strip; in addition, since the rubber core mold is filled at the web position of the long stringer, the manufacturing cost is high, and the temperature uniformity of the co-bonded wall panel is affected, thereby affecting the forming quality of the co-bonded wall panel.

[0004] 2) A rib positioning device and method for composite wall panel structural parts (authorization number: CN113977983B): A composite material with a thermal expansion coefficient equivalent to that of the part is used to manufacture a positioning plate without demolding after the part skin is formed. The positioning plate mouth frame is a hollow structure, and the reference side reserves a margin of less than 0.5mm, and the margin side reserves a margin of 5-10mm. Rubber gaskets are used to fill the margin between the ribs and the positioning plate mouth frame, and the paste vacuum bag is cured and formed. The shortcomings of this invention are that the rubber gasket is filled at the margin, and it is not easy to fill the rubber gasket at a small gap. Secondly, there is a situation where the rubber gasket is not completely filled, and then the skin prepreg is not pressed firmly at this place, resulting in pores or fiber wrinkles on the skin.

[0005] 3) A positioning method for solving the problem of out-of-tolerance of the axis of the reinforced and co-glued wall panels of the composite material type (application number: CN202310992379.8): positioning holes are distributed in the chord direction of the long stringer, and pins are used to penetrate and position it on the metal tooling. Soft pressure pads supported by rubber and prepreg curing are used between the long stringers. The gap between the pressure pad and the long stringer is controlled to be 0.3-1.2mm, and a vacuum bag is pasted to glue and cure the long stringer and the skin. The disadvantage is that holes are made on the long stringer, which affects the force transmission effect of the long stringer, and there is a gap between the rubber pad and the long stringer. There is also the problem of inadequate pressure on the skin fibers, pores and fiber wrinkles.

[0006] In summary, the above-mentioned co-bonding molding method can be used to manufacture reinforced wall panels, but there are problems such as inadequate skin pressure between the long stringers and the cover plates, skin porosity and fiber wrinkles, which cannot meet high-quality manufacturing requirements. Summary of the invention

[0007] The purpose of the present invention is to propose a method for co-bonding and forming composite material reinforced wall panels, which can effectively improve the problems of poor pressurization between long stringer edge strips and cover plates, wrinkles of skin fibers, and compression deformation of long stringer edge strips without changing the design structure, so as to achieve low-cost and high-quality manufacturing of co-bonded reinforced wall panels, and can be widely used in the co-bonding manufacturing of wall panels with different forms of reinforced structures.

[0008] The technical solution of the present invention is:

[0009] Provided is a method for co-bonding a composite material skin and a rib plate, wherein a bonding area exists between the composite material skin and the rib plate, and a limited distance extending outward from the outline of the bonding area is an easily deformable area; the skin is a prepreg laminate material to be cured; the method comprises the following steps:

[0010] Step 1: Lay and position the skin on the co-bonding tooling;

[0011] Step 2, laying adhesive film on the bonding area of ​​the skin;

[0012] Step 3, placing the adhesive joint surface of the rib plate corresponding to the adhesive film;

[0013] Step 4: Lay the isolation film so that the isolation film covers the bonding area and the easily deformed area of ​​the rib plate;

[0014] Step 5: Set the barrier strip along the contour of the easily deformed area.

[0015] Step 6: laying fine sand in the annular area enclosed between the baffle and the rib plate, so that the height of the fine sand is not lower than the height of the pressure surface of the rib plate;

[0016] Step 7, placing a pressure equalizing plate on the pressure-bearing surface of the rib plate, and making a portion of the plate surface of the pressure equalizing plate cover the sand particles;

[0017] Step 8, vacuum bag the skin, rib plate and pressure equalizing plate as a whole, and evacuate and fix them;

[0018] Step 9: After vacuum fixing, pressurized heating and curing are performed to obtain a co-bonded structure of the skin and the stiffener.

[0019] Furthermore, the rib plate is a rigid component of the composite material after curing.

[0020] Furthermore, the skin is a prepreg laminate material to be cured.

[0021] Furthermore, the cross-section of the rib plate is I-shaped, T-shaped or L-shaped.

[0022] Furthermore, the particle size of the fine sand is 0.2-0.5 mm.

[0023] Furthermore, the laying height of the fine sand is 2-3 mm higher than the pressure surface of the rib plate.

[0024] Furthermore, the thickness of the pressure equalizing plate is 0.5 mm.

[0025] Furthermore, the isolation membrane is a non-porous isolation membrane.

[0026] Furthermore, the pressure equalizing plate is provided with air holes for discharging air in the fine sand, and the diameter of the air holes is not greater than 2.5 mm.

[0027] The advantages of the present invention are as follows: the present invention utilizes golden sand to fill the wall panel skin area between the solidified ribs on the skin, which can solve the defects of rib plate depression, glue accumulation at the edge strips and skin fiber wrinkles during the co-bonding molding process, and adopts the method of pasting vacuum bags on the rib plates to avoid the compression deformation of the long stringer edge strips and the slippage of the rib plate position, while reducing the difficulty of positioning the axis of the long stringer. The process method is simple to operate, the co-bonded wall panel molding quality is high, and the manufacturing cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the use of the present invention;

[0029] Among them: 1-rib plate; 2-vacuum extraction position; 3-adhesive film; 4-vacuum bag; 5-pressure equalizing plate; 6-breathable felt; 7-isolation film; 8-skin; 9-fine sand; 10-bar; 11-tooling. DETAILED DESCRIPTION

[0030] The disclosed examples will be more fully described with reference to the accompanying drawings, in which some (but not all) of the disclosed examples are shown. In fact, many different examples may be described and these examples should not be construed as limited to the examples set forth herein. Instead, these examples are described so that this disclosure will be thorough and complete and will fully convey the scope of the disclosure to those skilled in the art.

[0031] Provided is a method for co-bonding a composite material skin and a rib plate, wherein a bonding area exists between the composite material skin and the rib plate, and a limited distance extending outward from the outline of the bonding area is an easily deformable area; the skin is a prepreg laminate material to be cured; the method comprises the following steps:

[0032] Step 1: Lay and position the skin on the co-bonding tooling;

[0033] Step 2, laying adhesive film on the bonding area of ​​the skin;

[0034] Step 3, placing the adhesive joint surface of the rib plate corresponding to the adhesive film;

[0035] Step 4: Lay the isolation film so that the isolation film covers the bonding area and the easily deformed area of ​​the rib plate;

[0036] Step 5: Set the barrier strip along the contour of the easily deformed area.

[0037] Step 6: laying fine sand in the annular area enclosed between the baffle and the rib plate, so that the height of the fine sand is not lower than the height of the pressure surface of the rib plate;

[0038] Step 7, placing a pressure equalizing plate on the pressure-bearing surface of the rib plate, and making a portion of the plate surface of the pressure equalizing plate cover the sand particles;

[0039] Step 8, vacuum bag the skin, rib plate and pressure equalizing plate as a whole, and evacuate and fix them;

[0040] Step 9: After vacuum fixing, pressurized heating and curing are performed to obtain a co-bonded structure of the skin and the stiffener.

[0041] The rib plate is a rigid component of the composite material after curing.

[0042] The skin is a prepreg laminate material to be cured.

[0043] The cross section of the rib plate is I-shaped, T-shaped or L-shaped.

[0044] The particle size of the fine sand is 0.2-0.5 mm.

[0045] The laying height of the fine sand is 2-3 mm higher than the pressure surface of the rib plate.

[0046] The thickness of the pressure balancing plate is 0.5 mm.

[0047] The isolation membrane is a non-porous isolation membrane.

[0048] The pressure equalizing plate is provided with air holes for discharging air in the fine sand, and the diameter of the air holes is not greater than 2.5 mm.

[0049] The description of different advantageous arrangements has been presented for purposes of illustration and description, but the description is not intended to be exclusive or limited to examples of the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art. Additionally, different advantageous examples may describe different advantages over other advantageous examples. The selected example or examples are chosen and described in order to best illustrate the principles of the examples, the practical application, and to enable those of ordinary skill in the art to understand the disclosure with various examples with various modifications suitable for the particular use contemplated.

Claims

1. A method for co-bonding a composite material skin and a rib plate, wherein a bonding area exists between the composite material skin and the rib plate, and a limited distance extending outward from the outline of the bonding area is an easily deformable area; the skin is a prepreg laminate material to be cured; the method comprises the following steps: Step 1, laying and positioning the skin on the co-bonding tooling; Step 2, laying adhesive film on the bonding area of ​​the skin; Step 3, placing the adhesive joint surface of the rib plate corresponding to the adhesive film; Step 4: Lay the isolation film so that the isolation film covers the bonding area and the easily deformed area of ​​the rib plate; Step 5: Set the barrier strip along the contour of the easily deformed area. Step 6: laying fine sand in the annular area enclosed between the baffle and the rib plate, so that the height of the fine sand is not lower than the height of the pressure surface of the rib plate; Step 7, placing a pressure equalizing plate on the pressure-bearing surface of the rib plate, and making a portion of the plate surface of the pressure equalizing plate cover the sand particles; Step 8, vacuum bag the skin, rib plate and pressure equalizing plate as a whole, and evacuate and fix them; Step 9: After vacuum fixing, pressurized heating and curing are performed to obtain a co-bonded structure of the skin and the stiffener.

2. A composite material skin and rib co-bonding molding method as claimed in claim 1, characterized in that: The rib plate is a rigid component of the composite material after curing.

3. A composite material skin and rib co-bonding molding method as claimed in claim 1, characterized in that: The skin is a prepreg laminate material to be cured.

4. A composite material skin and rib co-bonding molding method as claimed in claim 1, characterized in that: The cross section of the rib plate is I-shaped, T-shaped or L-shaped.

5. A composite material skin and rib co-bonding molding method as claimed in claim 1, characterized in that: The particle size of the fine sand is 0.2-0.5 mm.

6. A composite material skin and rib co-bonding molding method as claimed in claim 1, characterized in that: The laying height of the fine sand is 2-3 mm higher than the pressure surface of the rib plate.

7. A composite material skin and rib co-bonding molding method as claimed in claim 1, characterized in that: The thickness of the pressure balancing plate is 0.5 mm.

8. A composite material skin and rib co-bonding molding method as claimed in claim 1, characterized in that: The isolation membrane is a non-porous isolation membrane.

9. A composite material skin and rib co-bonding molding method as claimed in claim 1, characterized in that: The pressure equalizing plate is provided with air holes for discharging air in the fine sand, and the diameter of the air holes is not greater than 2.5 mm.

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