A method and device for acquiring pressure transmission of a T-stringer mold

Abstract

The application discloses a T-shaped stringer mold pressure transmission acquisition method and device. The method comprises a tank pressure P, a downward pressure P1, an oblique pressure P2, a leftward pressure P3, a T-shaped stringer web plate pressure P4 received from a moving mold transmission, a moving mold height H, a moving mold width W, a T-shaped stringer web plate laying height h, a moving mold sliding friction, a friction coefficient mu, a moving mold oblique angle theta and a moving mold support force. The method finds a T-shaped stringer mold pressure transmission calculation method by combining theory with practice.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aircraft composite material manufacturing, and particularly relates to a T-shaped stringer mold pressure transmission acquisition method and device. BACKGROUND

[0002] The composite T-shaped stringer is generally used in the aircraft wing wall plate, the composite T-shaped stringer is long in size and large in quantity, and the length of the T-shaped stringer reaches 30 meters. The composite T-shaped stringer mold is made of yin steel, is very expensive, and a medium-sized aircraft often spends billions of RMB to manufacture the composite T-shaped stringer mold. Therefore, the stability of the design performance of the T-shaped stringer mold is very important.

[0003] The forming of the T-shaped stringer part generally adopts the structure that the movable mold and the fixed mold are placed on the flat plate frame, the carbon fibers are pasted on the movable mold and the fixed mold respectively, the movable mold and the fixed mold are then clamped, and the vacuum bag is made on the flat plate frame after the clamping. The pressure of the T-shaped stringer web surface is transmitted through the movement of the movable mold to the fixed mold. The current situation is that the transmission principle is not clear, the T-shaped stringer mold is designed only according to the past experience, and the pressure transmission is too small or too large, which causes the expensive composite T-shaped stringer and the mold to be scrapped.

[0004] An urgent need exists for a T-shaped stringer mold pressure transmission calculation method to accurately calculate the sizes of the movable mold and the fixed mold, so that the movable mold transmits the correct pressure to the T-shaped stringer web surface. SUMMARY

[0005] The application provides a T-shaped stringer mold pressure transmission acquisition method and device, which accurately calculates the sizes of the movable mold and the fixed mold, so that the movable mold transmits the correct pressure to the T-shaped stringer web surface.

[0006] The application provides a T-shaped stringer mold pressure transmission acquisition method, which comprises the following steps.

[0007] Obtain the tank pressure P, the movable mold height H, the movable mold width W, the T-shaped stringer web pasting height h, and the movable mold sliding friction coefficient μ, and the relationship between all the above parameters.

[0008] The formula P4=(P*H-P*W*μ) / h is used to obtain the pressure P4 transmitted by the movable mold to the T-shaped stringer web.

[0009] Optionally, the T-shaped stringer web pasting height h=(H-μW) / 1.3.

[0010] Optionally, the T-shaped stringer mold comprises a bottom plate, a movable mold and a fixed mold.

[0011] The bottom plate and the fixed mold are welded together, and the movable mold is slidably arranged on the bottom plate.

[0012] Optionally, the movable mold is rectangular.

[0013] Optionally, the moving die is a rectangle with bevel edges.

[0014] Optionally, μ is the friction coefficient, and the maximum value is 0.2.

[0015] The second aspect of the present application provides a T-stringer die pressure transmission acquisition device for performing the method according to any one of the first aspect.

[0016] The third aspect of the present application provides a computer program for performing the method according to any one of the first aspect.

[0017] The present application provides a T-stringer die pressure transmission acquisition method and device, which finds a simple formula by combining theory with practice, not only provides a theoretical basis for T-stringer die design, but also can accurately transmit pressure by controlling the length of the web surface for the manufactured die. T-stringers are widely used in the aviation industry, and the die made of invar steel accounts for a large proportion of the cost. The present application can improve the efficiency of the die structure, improve the product qualification rate, and greatly reduce the production cost. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a T-stringer die structure schematic diagram;

[0019] Figure 2 is a T-stringer die under tank pressure schematic diagram;

[0020] Figure 3 is a T-stringer die key size schematic diagram;

[0021] BRIEF DESCRIPTION OF DRAWINGS

[0022] 1-bottom plate;

[0023] 2-fixed die;

[0024] 3-moving die;

[0025] 4-T-stringer;

[0026] 5-vacuum cavity;

[0027] 6-vacuum bag area;

[0028] P-heat tank pressure;

[0029] H-moving die height;

[0030] W-moving die width;

[0031] h-stringer web height. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application.

[0033] Referring to the drawings Figures 1-3 , the present application mainly controls the mold pressure transmission by controlling the width, height of the T-shaped stringer mold and the laying size of the product web surface, so as to control the curing thickness of the T-shaped stringer web surface and the non-damage qualification.

[0034] The T-shaped stringer mold mainly comprises a bottom plate 1, a fixed mold 2 and a movable mold 3, the bottom plate 1 and the fixed mold 2 are welded as a whole, and the movable mold 3 can slide on the bottom plate 1.

[0035] The use process of the mold is as follows: first, the fixed mold 2 and the movable mold 3 are pulled apart, and the carbon fiber laying is carried out respectively, after the laying is completed, the movable mold 3 is moved, so that the fixed mold and the movable mold are combined, after the combination, the sealing strip is pasted in the vacuum bag area 6 of the bottom plate 1 to make a vacuum bag, the vacuum bag wraps the fixed mold 2, the movable mold 3 and the T-shaped stringer 4, after the vacuum bag is made, it is sent into a hot press tank, and the mold in the hot press tank is subjected to a pressure P, as shown in Figure 2 .

[0036] The pressure P acts on the upper part and the side part of the movable mold, since the fixed mold 2 and the bottom plate 1 are welded and fixed, the fixed mold does not transmit the pressure to the stringer web, only the movable mold 3 transmits the pressure to the stringer web. The present application aims to calculate the pressure transmission of the movable mold 3.

[0037] The present application provides a T-shaped stringer mold pressure transmission calculation method, comprising the following steps:

[0038] Step one: the movable mold 3 is subjected to the gravity, the downward pressure P1, the oblique pressure P2, the leftward pressure P3, the bottom friction and the support force of the T-shaped stringer web surface. (P1, P2, P3 have the same value, and are all the tank pressure P).

[0039] Step two: the oblique pressure is P2*m*L (L is the length of the movable mold, and m and θ are shown in Figure 2 ), the downward component force is P2*m*L*cosθ, and the leftward component force is P2*m*L*sinθ, so it can be known that the force transmission of the movable mold with the oblique side with the angle θ is the same as that of the rectangular movable mold.

[0040] Step three: the curing tank pressure of the carbon fiber T-shaped stringer is generally 0.5-0.8 MPa, and the weight of one-meter length movable mold is about 100 Kg, so the friction force generated by the weight of the movable mold is ignored.

[0041] Step four: Figure 3 h is the laying height of the T-shaped stringer web, the final purpose of the present application is that the pressure P4 of the T-shaped stringer web received by the movable mold is greater than or equal to the tank pressure P, and μ is the maximum friction coefficient, which is 0.2.

[0042] P4=(P*H*L-P*W*L*μ) / h*L

[0043] P4 = (P*H - P*W*μ) / h

[0044] The web face pressure P4 and the tank pressure P are the same, and the relationship between the wide W and the high H of the dynamic die is obtained:

[0045] h = H - μW

[0046] h includes the long web face and the laying allowance, so when H and W are fixed, the laying allowance can be changed to control the pressure on the web face.

[0047] Step five: through the combination of a large number of successful cases and theoretical calculation analysis, when P4 = 1.3P, the quality of the long web reaches the best and the most stable, at this time:

[0048] 1.3h = H - μW

[0049] The present application finds a simple formula by combining theory with practice, which not only provides a theoretical basis for T long web die design, but also can accurately transmit pressure by controlling the web face laying length for the die that has been manufactured. T long web is widely used in the aviation industry, and the die of the steel material occupies a large proportion of the cost. The present application can improve the efficiency of the die structure, improve the product qualification rate, and greatly reduce the production cost.

[0050] The above is only part of the specific embodiments of the present application, but the protection scope of the present application is not limited to this. Any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A T-string die pressure transmission acquisition method characterized by, Comprise: Obtain the tank pressure P, the movable die height H, the movable die width W, the T long stringer web laying height h, the movable die sliding friction coefficient μ, the relationship between all the above parameters; Use the formula P4=(P*H-P*W*μ) / h to obtain the pressure P4 that the T long stringer web receives from the movable die; P4=1.3P, 1.3h=H-μW, h includes the long stringer web surface and the laying allowance, when H and W are fixed, the pressure received by the web surface is controlled by changing the laying allowance.

2. The method of claim 1, wherein, The T-shaped long stringer mold comprises a bottom plate, a movable die and a fixed die. The bottom plate and the fixed die are welded together, and the movable die is slidably arranged on the bottom plate.

3. The method of claim 2, wherein the T-string die pressure transfer acquisition method is characterized by, The movable die is rectangular.

4. The method of claim 3, wherein, The movable die is a rectangle with bevels.

5. The method of claim 1, wherein, μ is the maximum friction coefficient of 0.

2.

6. A T-string die pressure transfer acquisition device characterized by comprising: For executing the method as claimed in any one of claims 1-5.

7. A computer-readable storage medium, characterized in that, Comprise: Memory and processor; The memory is configured to save executable instructions; The processor is configured to implement the method as claimed in any one of claims 1-5 when executing the executable instructions saved by the memory.

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