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CN-117301579-B - Method for preventing deformation of stringer end skin and end gasket forming method

CN117301579BCN 117301579 BCN117301579 BCN 117301579BCN-117301579-B

Abstract

The invention discloses a method for preventing the deformation of a stringer end skin and a method for forming an end gasket, which belong to the technical field of composite material manufacturing processes, and comprise the following steps of placing a stringer in a forming groove on the upper surface of a forming and curing chemical industry; the method comprises the steps of placing a core mold, placing an end gasket in a gasket groove on the upper surface of a molding curing tool, enabling the gasket groove to be vertically communicated with a molding groove, ballasting and fixing the end gasket above the core mold, laying a skin on the upper surface of the molding curing tool, enabling the end part of the skin to be located on the end gasket, and curing. According to the invention, the end gaskets are used for carrying out vertical rigid support on the skin, so that the influence of uneven pressure on the skin can be reduced, the skin is prevented from deforming, the operation is simple, and the practicability is high.

Inventors

  • CHEN CHUN
  • LI YANG
  • LIU YANG
  • HUANG CHUNXU
  • WEI LUMING

Assignees

  • 中建材(上海)航空技术有限公司

Dates

Publication Date
20260505
Application Date
20230911

Claims (8)

  1. 1. A method of preventing deformation of a stringer termination skin, the method comprising the steps of: s10, placing the stringer (10) in a forming groove (21) on the upper surface of a forming and curing tool (20); S20, placing a mandrel (30); S30, placing an end gasket (40) in a gasket groove (22) on the upper surface of the forming and curing tool (20), wherein the gasket groove (22) is vertically communicated with the forming groove (21), and the end gasket (40) is ballasted and fixed above the core mold (30); S40, paving a skin (50) on the upper surface of the molding curing tool (20), wherein the end part of the skin (50) is positioned on the end gasket (40); s50, curing.
  2. 2. A method for preventing deformation of a stringer end skin according to claim 1, wherein the end gasket (40) includes a transverse plate body (41) and a longitudinal rib (42), the number of the longitudinal ribs (42) is an even number, the longitudinal ribs (42) are fixedly connected to the lower surface of the transverse plate body (41) vertically, and the cross section of the longitudinal ribs (42) is adapted to the shape of the cavity between the core mold (30) and the forming groove (21).
  3. 3. A method of preventing deformation of stringer termination skins according to claim 2, in which the transverse panel (41) comprises unidirectional carbon fibre prepreg layers and twill weave carbon fibre prepreg layers arranged alternately up and down.
  4. 4. A method of preventing deformation of stringer termination skin according to claim 2, wherein the transverse panel (41) has a thickness of 1.5mm to 2.5mm.
  5. 5. A method of preventing deformation of stringer termination skin according to claim 2, wherein the upper surface of the transverse panel (41) is provided with a barrier film.
  6. 6. A method of preventing deformation of stringer termination skin according to claim 2, wherein the transverse panel (41) is filled with a resin obtained by impregnating a prepreg with acetone.
  7. 7. A method of forming an end gasket for use in mounting on a form cure tooling and below a skin in a stringer cut-off region, the method comprising the steps of: s100, placing a core mold (30) in a forming groove (21) on the upper surface of a forming and curing tool (20), wherein a gasket groove (22) vertically communicated with the forming groove (21) is formed in the upper surface of the forming and curing tool (20), and two ends of the core mold (30) are located at two sides of the gasket groove (22) on the upper surface of the forming and curing tool (20) in a one-to-one correspondence manner; S200, filling a twisting strip (60) between the core mould (30) and the forming groove (21); s300, placing gasket materials into the gasket groove (22); S400, ballasting a cover plate above the gasket material; S500, curing.
  8. 8. The method of forming an end gasket for preventing deformation of a stringer end skin according to claim 7, wherein in S300, unidirectional carbon fiber prepregs and twill weave carbon fiber prepregs are placed in a staggered stack within the gasket groove (22).

Description

Method for preventing deformation of stringer end skin and end gasket forming method Technical Field The invention relates to the technical field of composite material manufacturing processes, in particular to a method for preventing a stringer end skin from deforming and a method for forming an end gasket. Background The rear fuselage wall plate of the wide-body civil aviation large aircraft is of a reinforced structure, and the stringers are cut off in advance at the edges of the skins, as shown in fig. 4, the rear fuselage process scheme adopts a co-curing female die forming mode, but the stringers are not arranged at the cut-off position, and after the skins are laid, the positions of the skins deform after curing is completed. In general, uneven distribution of pressure on the skin can cause deformation of the skin and affect the overall performance and life of the part, and therefore, methods for improving deformation of the skin have been a hot spot in research in the fields of mechanical engineering and manufacturing processes. In solving the skin deformation problem, many solutions have been proposed, such as changing the stress mode, adjusting the core mold structure, filling the twisted material, etc., which can uniformly distribute the pressure on the skin, thereby preventing the skin deformation phenomenon. However, when the core mold structure is adjusted or the filling amount of the twisted sliver is adjusted, the scheme is long in test period, high in implementation cost, high in operation difficulty and difficult to implement, so that the scheme is low in practicality and difficult to mass production. Therefore, how to improve the practicability of the method for preventing skin deformation is a technical problem to be solved by those skilled in the art. Disclosure of Invention Therefore, the invention aims to provide a method for preventing the deformation of the skin of the stringer end, so as to solve the technical problem of low practicality of the existing method for preventing the deformation of the skin. The technical scheme adopted by the invention is that the method for preventing the deformation of the skin of the stringer end head comprises the following steps: S10, placing the stringers in a molding groove on the upper surface of a molding curing process; S20, placing a mandrel; S30, placing the end gasket in a gasket groove on the upper surface of a forming and curing tool, wherein the gasket groove is vertically communicated with the forming groove, and the end gasket is ballasted and fixed above the core mold; s40, paving a skin on the upper surface of the molding curing tool, wherein the end part of the skin is positioned on the end gasket; s50, curing. Preferably, the end gasket comprises a transverse plate body and longitudinal ribs, the number of the longitudinal ribs is even, the longitudinal ribs are vertically and fixedly connected to the lower surface of the transverse plate body, and the cross section of the longitudinal ribs is matched with the shape of the cavity between the core die and the forming groove. Preferably, the transverse plate body comprises unidirectional carbon fiber prepreg layers and twill woven carbon fiber prepreg layers which are alternately arranged up and down. Preferably, the thickness of the transverse plate body is 1.5 mm-2.5 mm. Preferably, the upper surface of the transverse plate body is provided with a separation film. Preferably, the transverse plate body is filled with a resin obtained by soaking the prepreg with acetone. A second object of the present invention is to provide a method of forming an end gasket for preventing deformation of a stringer end skin, the method comprising the steps of: S100, placing a core die in a forming groove on the upper surface of a forming and curing tool, wherein two ends of the core die are located at two sides of a gasket groove on the upper surface of the forming and curing tool in a one-to-one correspondence manner; s200, filling a twisted sub-strip between the core mould and the forming groove; s300, placing a gasket material in the gasket groove; S400, ballasting a cover plate above the gasket material; S500, curing. Preferably, in S300, unidirectional carbon fiber prepreg and twill weave carbon fiber prepreg are placed in the gasket groove in a staggered stack. The invention has the beneficial effects that: According to the invention, the end gasket is fixedly arranged on the forming and curing tool below the skin in the stringer cut-off region, the skin can be vertically and rigidly supported through the end gasket, the influence of uneven pressure on the skin is effectively reduced, the skin can be prevented from deforming, the operation is simple, and the practicability is strong. Drawings FIG. 1 is a reference diagram of a usage state of a molding curing tool; FIG. 2 is a schematic structural view of a molding curing tooling; FIG. 3 is a schematic structural view of a tip washer; FIG. 4 is