CN104554701A - Suture technique enhanced foam sandwich hat stiffened wall panel structure and forming method thereof - Google Patents

Abstract

The invention relates to an improved suture technique enhanced foam sandwich hat stiffened wall panel structure and a forming method thereof, belonging to the technical field of fiber composite enhancement. The foam sandwich hat stiffened wall panel structure is characterized in that the suture technique is used for the foam sandwich hat stiffened wall panel and is used for improving the strength and stiffness of the hat stiffened wall panel. The method comprises the following steps: firstly, laying hat ribs and skin on a stiffened wall panel mould; secondly, perforating a foam core material along the thickness direction according to the pre-designed perforation pattern (the perforation directions of front and rear rows are symmetric along the vertical foam centerline) in a foam sandwich; thirdly, suturing upper and lower panels and the core material with a suture together; finally, combining and packaging the hat ribs, and solidifying. The strength, stiffness and stability of the composite hat stiffened wall panel structure are obviously improved. According to the bearing capacity required by the enhanced hat stiffened wall panel, the suture parameter meeting the requirement can be designed. The suture foam sandwich structure provided by the invention has the advantages of strong bearing capacity, simple manufacturing process, high structural efficiency and low manufacturing and maintenance cost.

Description

Stitching Technology Reinforced Foam Sandwich Hat Type Reinforced Wall Panel Structure and Its Forming Method

technical field

The invention belongs to the technical field of fiber composite material reinforcement, and in particular relates to a reinforced foam sandwich cap-type reinforced wall plate structure and a forming method thereof by using an improved stitching technology.

Background technique

Composite hat-shaped stiffened wall plate structure is widely used in aeronautical structures due to its good post-buckling load capacity, high specific stiffness, good structural stability, high efficiency of transferring circumferential load, and good weight reduction effect. First choice for tubular structural components such as fuselage sections for large passenger commercial aircraft.

However, a slender cavity structure will be formed between the hat-shaped rib and the skin, thereby reducing the stability of the hat-shaped stiffened panel. At present, some scholars fill the cavity of the hat-shaped stiffened panel with foam to improve the bending stiffness and structural efficiency of the structure. However, the bonding strength between the foam core material and the panel material itself is low, and the panel and the foam core material are easy to debond or delaminate, which seriously limits its application in the main load-bearing structure of the aircraft. The most typical failure mode of the foam sandwich structure is delamination and local damage due to the failure of the bonding between the face plate and the core material. Thus, the seaming technique is used for the structure of the foam sandwich hat type reinforced wall panel.

Suture technology refers to the technology of using suture thread to make two-dimensional fabrics form quasi-three-dimensional three-dimensional fabrics or to connect several separate pieces of fabrics into an overall structure. Because the sutures can prevent the initiation and expansion of debonding and delamination cracks, it not only improves the interlayer strength and damage tolerance of the foam sandwich structure, but also retains a high bending stiffness/mass ratio to achieve the reinforcement between the panel and the core material. connection, and suppresses the effect of layering.

Contents of the invention

The purpose of the present invention is to solve the problem that the foam-reinforced hat-shaped reinforced wall panel and the foam sandwich are easy to be debonded, and propose a hat-shaped reinforced wall panel that adopts an improved stitching technique to improve the strength, rigidity and stability of the hat-shaped reinforced wall panel. Type-reinforced panel structure and its forming method.

The technical solution adopted by the present invention to solve the problems of the technologies described above is:

A foam-reinforced hat-shaped reinforced wall panel structure using suture technology, including hat-shaped ribs and skins, hat-shaped ribs are fixed on the skin and a cavity is formed between the hat-shaped ribs and the skin, the hollow The cavity is filled with a foam core material, wherein: the hat-shaped reinforced wall panel structure passes through the hat-shaped rib, foam core material and skin at the same time through sutures, and the hat-shaped rib, foam core material and skin are sewed into a overall.

In order to optimize the above technical solutions, the specific measures taken also include:

The above-mentioned foam core material is provided with perforations along the thickness direction, and the perforation directions of the front and rear rows are symmetrical along the vertical foam center line, and the sutures pass through the perforations.

A method for forming a foam-reinforced hat-type reinforced wall panel structure utilizing a suture technique, comprising the following steps:

Step 1, laying hat-shaped ribs on the hat-shaped reinforcement mold respectively, and laying skin on the skin mold;

Step 2. Design suture parameters according to the load-bearing conditions of the foam-reinforced hat-shaped reinforced panel structure, and design the distribution of suture perforations on the foam core material according to the suture parameters;

Step 3, according to the distribution pattern of perforations in the foam core material, perforate the foam core material along the thickness direction;

Step 4. Position the perforated foam core material, capped ribs and skin combination, select the designed suture parameters and suture fibers, and sew the hat ribs, skin and foam core material with sutures through the sewing equipment. synthesize the whole

Step 5: Combining, positioning and encapsulating the stitched hat-shaped reinforced wall panel structure, and curing.

Before step one, there is also a step of applying a release agent on the surface of the mold.

The step of applying the release agent on the surface of the mold is as follows: dipping acetone with gauze to wipe the surfaces of the hat-shaped reinforced mold and the skin mold, and applying the release agent on the surfaces of the hat-shaped reinforced mold and the skin mold.

In the third step, the foam core material is perforated by mechanical processing.

Compared with the prior art, seams are introduced between the face plate and the core material of the hat-shaped reinforced wall plate structure, thereby enhancing the strength, rigidity and stability of the reinforced structure. According to the required load-bearing capacity of the reinforced hat-shaped stiffened wallboard, the stitching parameters that meet the requirements can be designed. The stitched foam sandwich structure of the present invention has a strong load-bearing capacity, simple manufacturing process, high structural efficiency, and low manufacturing and maintenance costs.

The structure of the suture foam sandwich reinforced composite material reinforced wallboard provided by the present invention has the following reinforcement principles:

The sutures in the foam sandwich cap-shaped reinforced wall panel structure alternately form an "X" shape, forming a three-dimensional truss structure, which improves the strength and rigidity of the structure

After the interface between the foam core and the hat-shaped rib and the skin is degummed, the suture begins to elongate elastically, forming a fiber bridge at the front end of the degumming, generating a closing force against degumming, until the suture is finally broken and pulled out. Since the stitching bears most of the load and reduces the stress concentration of the surrounding resin, the interlaminar strength between the hat stiffener and the skin is significantly improved.

Description of drawings

Fig. 1 is the structural representation of prior art;

Fig. 2 is a cross-sectional structure schematic diagram of the present invention;

FIG. 3 is a schematic cross-sectional view of the structure of the present invention along the rib direction.

Detailed ways

Embodiments of the present invention will be described in further detail below in conjunction with the accompanying drawings.

Fig. 1 shows the structural representation of the prior art, Fig. 2 shows the structural cross-sectional schematic diagram of the present invention, Fig. 3 shows the structural cross-sectional schematic diagram of the present invention along the direction of the rib, and the reference numerals therein are: cap Rib 1, skin 2, foam core 3, suture 4.

As shown in Figures 1 to 3, the suture technology of the present invention strengthens the structure of the foam sandwich hat-shaped reinforced wall panel, including a hat-shaped rib 1 and a skin 2, and the hat-shaped rib 1 is fixed on the skin 2 and caps A cavity is formed between the rib 1 and the skin 2, and the cavity is filled with a foam core material 3, wherein: the hat-shaped reinforced wall panel structure passes through the hat-shaped rib 1 and the foam core through the suture 4 at the same time The material 3 and the skin 2 sew the hat rib 1, the foam core material 3 and the skin 2 into a whole.

In the embodiment, the foam core material 3 is provided with perforations along the thickness direction, the sutures 4 pass through the perforations, and the perforation directions of the front and rear rows are symmetrical along the vertical foam centerline.

The forming method of the foam reinforced hat type reinforced wall plate structure in the present embodiment comprises the following steps:

Use gauze dipped in acetone to wipe the surface of the hat-shaped reinforced mold and the skin mold, and apply a release agent on the surface of the hat-shaped reinforced mold and the skin mold.

Then pave hat-shaped ribs 1 on the hat-shaped reinforced mold respectively, and pave skin 2 on the skin mold;

According to the load-bearing conditions of the foam-reinforced cap-shaped reinforced wallboard structure, the parameters of the sutures are designed, and the distribution of the perforations of the sutures is designed on the foam core material 3 according to the parameters of the sutures;

Next, according to the distribution pattern of perforations in the foam core material 3, the foam core material 3 is perforated along the thickness direction by adopting a mechanical processing method;

Then the perforated foam core material 3, the cap-shaped rib 1 and the skin 2 are combined and positioned, the suture parameters and the suture fiber are selected, and the cap-shaped rib 1, the skin 2 and the skin 2 are assembled with the suture 4 by the suture equipment. The foam core material 3 is stitched into a whole;

Finally, the stitched hat-shaped reinforced wall panel structure is combined, positioned and packaged, and cured.

The structure of the hat-shaped reinforced panel after forming is shown in Figure 2.

The above are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions under the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims (6)

1. Stitching technology strengthens the foam sandwich hat-shaped reinforced wallboard structure, including hat-shaped ribs (1) and skin (2), and described hat-shaped ribs (1) are fixed on the skin (2) and A cavity is formed between the hat-shaped rib (1) and the skin (2), and the cavity is filled with a foam core material (3). (4) Sew the cap rib (1), foam core (3) and skin (2) through the cap rib (1), foam core (3) and skin (2) at the same time . 2. The suture technology-enhanced foam sandwich cap-shaped reinforced wallboard structure according to claim 1, characterized in that: the foam core (3) is provided with perforations along the thickness direction, and the two rows of perforations The direction is symmetrical along the vertical foam centerline, and the suture (4) passes through the perforation. 3. The forming method of the suture technology reinforced foam sandwich cap type reinforced wallboard structure as claimed in any one of claims 1-2, characterized in that: comprising the following steps: Step 1, laying hat-shaped ribs (1) on the hat-shaped reinforcement mold respectively, and laying skin (2) on the skin mold; Step 2, according to the structural bearing conditions of the foam-reinforced hat-shaped reinforced wall plate, design suture parameters, and design the distribution of suture perforations on the foam core material (3) according to the suture parameters; Step 3, according to the distribution pattern of perforations in the foam core material (3), perforate the foam core material (3) along the thickness direction; Step 4: Combine and position the perforated foam core material (3), capped ribs (1) and skin (2), select the designed suture parameters and suture fibers, and use sutures (4) to seal the Hat-shaped ribs (1), skin (2) and foam core material (3) are sewn into a whole; Step 5: Combining, positioning and encapsulating the stitched hat-shaped reinforced wall panel structure, and curing. 4. The molding method of the suture technology reinforced foam sandwich cap-type reinforced wallboard structure according to claim 3, characterized in that: before step 1, there is also a step of applying a release agent on the surface of the mold. 5. According to the forming method of the suture technology reinforced foam sandwich hat type reinforced wallboard structure shown in claim 4, it is characterized in that: the step of applying a release agent on the surface of the mold is: dipping it with gauze Acetone was used to wipe the surfaces of the hat-shaped reinforced mold and the skin mold, and a mold release agent was applied on the surfaces of the hat-shaped reinforced mold and the skin mold. 6. according to the forming method of the described seaming technology shown in claim 5 enhanced foam sandwich cap type reinforced wall plate structure, it is characterized in that: in step 3, the foam core material (3) is perforated by adopting mechanical processing method .