Composite long stringer fillet transition zone structure and composite reinforced wall panel

Abstract

The present invention discloses a composite material long stringer rounded corner transition zone structure and a composite material reinforced wall panel, which belong to the field of aviation manufacturing. The long stringer rounded corner transition zone structure includes a skin outer layer, which is located on one side of the long stringer rounded corner transition zone structure; a skin middle layer, which is located on the upper part of the skin outer layer; a long stringer layer, which is located on the upper part of the skin middle layer, and is arranged in a U-shape or T-shape; a long stringer interlayer, which is inserted between the long stringer layers, includes multiple layers of interlayers of different lengths, and the interlayers are terminated at different lengths so that the long stringer layers always transition according to a smooth function curve in the rounded corner transition zone; a twist strip filling area, which is composed of the long stringer layers on both sides in the rounded corner transition zone. The structure involved in the present application can effectively solve the problems of low interlayer quality existing in the rounded corner transition zone of general long stringers. The proposed structure is suitable for a variety of U-shaped / T-shaped long stringer interlayer quantities, and improves the layer quality of the composite material U-shaped / T-shaped long stringer structure.

Description

Technical Field

[0001] The invention belongs to the field of aviation manufacturing, and in particular relates to a composite material long stringer fillet transition zone structure and a composite material reinforced wall panel. Background Art

[0002] At present, the composite material reinforced wall panel structure in China is mainly based on the two configurations of T-shaped long stringer reinforced wall panel and Ω-shaped long stringer reinforced wall panel. There are not many application examples for the U-shaped reinforced wall panel configuration. At present, the U-shaped reinforced wall panel configuration is used on some large passenger aircraft rudders and other parts in the aviation field. The U-shaped long stringer reinforced wall panel structure configuration mainly includes two parts: skin wall panel and U-shaped long stringer. The bottom layer of the U-shaped long stringer and the basic layer of the skin are solidified to form the skin structure of the reinforced wall panel. The edge strip area of ​​the two U-shaped long stringers is solidified to form the wall panel ribs on the reinforced wall panel. Twist strips are added to the local area where the long stringers are connected to fill the gap. Its configuration is as follows Figure 1 As shown in the figure, the structure includes 1-skin layer, 2-long stringer layer, 3-long stringer edge strip insertion layer, 4-twist strip filling area, and 5-rounded transition area.

[0003] In order to improve the rigidity of the U-shaped long stringer, it is inevitable to add a series of inserts in the middle of the web of the long stringer, as shown in the U-shaped wall panel diagram. The number of inserts is usually 4 to 8. Similar to the insert zone structure and forming scheme of the T-shaped long stringer, the existing U-shaped long stringer rounded insert transition zone structure mainly includes the following three types, such as Figure 2 to Figure 4 The structure in the figure includes 1-skin layer, 2-long stringer layer, 3-skin middle layer, 4-twisted strip filling area, 5-long stringer web layer, and 6-center of the circle where the long stringer is laid into a rounded corner.

[0004] The main methods used in the prior art include:

[0005] Method 1: The "U"-shaped long stringer insert extends into the inside of the fillet area until the skin layer, and the insert always remains perpendicular to the skin layer. This insert area structure divides the long stringer fillet area into two independent parts, requiring two twist strips. The advantage is that the size of the twist strip in the fillet area is reduced and divided into two independent twist strips, which is beneficial to improve the mechanical properties of the fillet area; the disadvantage is that the distance between the insert and the skin layer is not easy to control (such as the skin layer loss area), and the insert in the fillet area is prone to wrinkles (especially when the number of inserts is small and the stiffness is poor). The two twist strips for each fillet also increase the process complexity to a certain extent.

[0006] Method 1: Intercalation method. The R zone intercalation is prone to deformation during the molding process, resulting in poor quality of the R zone. Figure 5 The figure shows a cross-sectional view after the first intercalation method is used for molding.

[0007] Method 2: The "U"-shaped long stringer insert does not extend into the rounded corner area, but ends at the beginning of the long stringer rounded corner area, and a twist strip is filled in the rounded corner area. This insert transition zone structure leaves a large space in the long stringer R area. The advantage is that the long stringer insert is not easy to wrinkle. The disadvantage is that a large space is left in the rounded corner area, and a large twist strip needs to be added in the rounded corner area, which affects the mechanical properties of the U-shaped long stringer structure.

[0008] Method 2: Intercalation method. In this intercalation method, the R zone is larger. During the molding process, the R zone is more easily deformed, and the quality of the R zone after molding is poor.

[0009] Method three: The "U"-shaped long stringer insert extends into the fillet area until it reaches the skin layer. After entering the fillet area, the insert fits with the fillets of the left and right long stringers (no longer perpendicular to the skin layer), and extends toward the skin layer along the radius of the fillet. One twist strip is filled in the fillet area. The advantage of this insert area structure is that the size of the twist strip in the fillet area is controlled, and wrinkles are not likely to occur when the insert fits with the fillet area, which is beneficial to improving the mechanical properties of the fillet area, and only one twist strip is needed for each fillet area, reducing the difficulty of the process. The disadvantage is that it is difficult to control the length of the insert (for example, the skin layer loss area), and improper design of the insert length or failure of the process accuracy to meet the design requirements will affect the quality of the fillet area.

[0010] Method three: intercalation method. The intercalation layer in the R zone is easily deformed during the molding process, resulting in poor quality of the R zone. Summary of the invention

[0011] In order to overcome the above problems, the present application provides a composite material long stringer rounded corner transition zone structure and a composite material reinforced wall panel, involving a method of inserting layers of composite material U-shaped long stringers with rounded corners, and a method for calculating the insertion length. The structure involved in the present application can effectively solve the problems of low insertion quality in the rounded corner transition zone of general long stringers. The proposed structure is suitable for a variety of U-shaped / T-shaped long stringer insertion numbers, thereby improving the layup quality of the composite material U-shaped / T-shaped long stringer structure.

[0012] According to a first aspect of the present invention, there is provided a composite material long stringer fillet transition zone structure, comprising:

[0013] The outer layer of the skin is located on the side of the structure of the rounded corner transition area of ​​the long stringer;

[0014] The middle layer of the skin is located on the upper part of the outer layer of the skin;

[0015] Multi-layer long stringer plies are located on the upper part of the middle plies of the skin and are arranged in a U-shape or T-shape;

[0016] Long stringer inserts are inserted between multiple long stringer plies, including multiple layers of inserts with different lengths. By setting the inserts to terminate at different lengths, the multiple long stringer plies always transition according to a smooth function curve in the rounded corner transition zone;

[0017] The twist bar filling area is composed of multiple layers of long stringers laid on both sides in the rounded transition area.

[0018] Furthermore, the multi-layer long stringer ply comprises:

[0019] The long stringer ply on the inner side of the insert is located on the upper part of the middle ply of the skin, arranged in a U-shape or T-shape, and distributed according to a certain function curve in the fillet transition area;

[0020] The outer side long stringer ply of the intercalation layer is located on the upper part of the inner side long stringer ply of the intercalation layer, is arranged in a U-shape or a T-shape, and forms a 1 / 4 arc in the rounded corner transition zone.

[0021] Furthermore, the long stringer interlayer comprises multiple layers of interlayers of different lengths and uniform thickness that are assembled together.

[0022] Furthermore, in the direction from the outer long girder ply of the intercalation layer to the inner long girder ply of the intercalation layer, the plurality of intercalation layers of different lengths and uniform thickness assembled together include N intercalation layers of different lengths and uniform thickness, namely the first long girder intercalation layer, the second long girder intercalation layer...the i-th long girder intercalation layer...the N-th long girder intercalation layer, and at the end point of the i-th long girder intercalation layer length, the distance h(θ) between the outer long girder ply of the intercalation layer and the inner long girder ply of the intercalation layer is in the range of: h(θ)=0.70×(N+1-i)t~0.95×(N+1-i)t, wherein t is the thickness of the intercalation layer, and N is a positive integer and its value range is 1≤N≤10.

[0023] Furthermore, the long stringer intercalation layer includes a plurality of intercalation layer groups, each intercalation layer group includes a plurality of intercalation layers of different lengths and uniform thicknesses, and the plurality of intercalation layer groups and the plurality of long stringer intercalation layers are spaced from the outside to the inside of the plurality of long stringer intercalation layers.

[0024] Furthermore, from the outside to the inside of the multi-layer long stringer ply, each insertion group includes N layers of insertions of different lengths and uniform thickness, namely the first long stringer insertion layer, the second long stringer insertion layer...the i-th long stringer insertion layer...the N-th long stringer insertion layer, and at the end point of the i-th long stringer insertion layer, the distance h(θ) between the outer long stringer ply of the insertion layer and the inner long stringer ply of the insertion layer ranges from: h(θ)=0.70×(N+1-i)t to 0.95×(N+1-i)t, where t is the thickness of the insertion layer, and N is a positive integer and its value range is 1≤N≤10.

[0025] Furthermore, the stringer inserts include a plurality of inserts of different lengths and uniform thicknesses, and in a direction from the outside to the inside of the multi-layer stringer ply, the plurality of inserts are spaced apart from the multi-layer stringer ply.

[0026] Furthermore, from the outside to the inside of the multi-layer long stringer ply, the multiple intercalation layers of different lengths and uniform thickness include N intercalation layers of different lengths and uniform thickness, namely the first long stringer intercalation layer, the second long stringer intercalation layer...the i-th long stringer intercalation layer...the N-th long stringer intercalation layer, and at the end point of the i-th long stringer intercalation layer length, the distance h(θ) between the outer long stringer ply of the intercalation layer and the inner long stringer ply of the intercalation layer is in the range of: h(θ)=0.70×(N+1-i)t~0.95×(N+1-i)t, wherein t is the intercalation layer thickness, and N is a positive integer and its value range is 1≤N≤10.

[0027] Here, “inner side of the multi-layer stringer ply” means the side of the multi-layer stringer ply close to the twist rod filling area, and “outer side of the multi-layer stringer ply” means the side of the multi-layer stringer ply away from the twist rod filling area.

[0028] Furthermore, the thickness of the long stringers on the outer side of the insertion layer is 1 to 10 layers.

[0029] Furthermore, the thickness of the intercalated inner layer long stringer ply is 1 to 10 layers.

[0030] Furthermore, the combined layup of the interlayer inner long stringer layup and the interlayer outer long stringer layup is symmetrical to the outer side layup of the skin.

[0031] Furthermore, the thickness of the middle layer of the skin is 1 to 20 layers.

[0032] According to a second aspect of the present invention, there is provided a composite material stiffened wall panel, wherein the composite material stiffened wall panel comprises the long stringer rounded corner transition zone structure as described in any one of the aforementioned aspects.

[0033] Beneficial effects of the present invention:

[0034] 1. The composite material U-shaped long stringer web insert is laid in the middle of the long stringer web layer, which effectively ensures the molding quality of the rounded corner transition area of ​​the U-shaped long stringer with insert, and prevents the problems of insert wrinkles, pore defects, etc.

[0035] 2. This solution divides the web insert into multiple parts, and the center line of the symmetrical long stringer web is laid in the middle of each web layer, which effectively solves the problem of low molding quality of the fillet area of ​​the U-shaped long stringer of the composite material.

[0036] 3. This scheme gives a method for calculating the length of the web insert of the long truss, which provides a simple and convenient calculation method for the design of the insert length of this configuration. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0038] Figure 1 An example of a U-shaped reinforced wall panel configuration in the prior art is shown.

[0039] Figure 2-4 An example of a U-shaped long stringer rounded corner intercalation transition zone structure commonly used in the prior art is shown.

[0040] Figure 5 The cross section of the R region of the long stringer after being formed by an interlayer method in the prior art is shown.

[0041] Figure 6 A composite material U-shaped long stringer fillet intercalation transition zone structure 1 according to an embodiment of the present invention is shown.

[0042] Figure 7 A composite material U-shaped long stringer rounded corner intercalation transition zone structure 2 according to another embodiment of the present invention is shown.

[0043] Figure 8 A schematic diagram of a rounded corner ply curve for a long stringer according to an embodiment of the present invention is shown.

[0044] Fig. 9 The coordinate system transformation of the rounded corner ply curve of the long stringer according to an embodiment of the present invention is shown.

[0045] Fig.10 A schematic diagram of a rounded corner ply curve for a long stringer according to an embodiment of the present invention is shown.

[0046] Fig.11 A graph showing a conversion diagram of a long stringer ply curve according to an embodiment of the present invention is shown.

[0047] Fig.12 Another intercalation method 1 according to an embodiment of the present invention is shown.

[0048] Fig.13 Another intercalation method 2 according to an embodiment of the present invention is shown.

[0049] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0050] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0051] The terms "first", "second", etc. in the specification and claims of the present disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein, for example.

[0052] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus that includes a series of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, method, product, or apparatus.

[0053] Multiple includes two or more.

[0054] It should be understood that the term "and / or" used in this disclosure is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone.

[0055] Example 1

[0056] For example, when the number of web plies of the long stringer is 12 and the web inserts are 4 and 8, the inserts are divided into two symmetrical parts inserted in the middle of the web plies. Figure 6 , Figure 7 shown.

[0057] The composite material U-shaped long stringer rounded corner intercalation transition zone structure mainly includes 1-skin outer layer, 3-skin middle layer, 2-intercalation outer long stringer layer, 6-intercalation inner long stringer layer, 5-long stringer intercalation layer, and 4-twisted strip filling zone. The intercalation outer long stringer layer (2) has 1 to 10 layers, the intercalation inner long stringer layer (6) has 1 to 10 layers, and the combined layer composed of 2 and 6 is symmetrical with the skin outer layer (1). The skin middle layer (3) is located between the skin outer layer (1) and the intercalation inner long stringer layer (6), and has a thickness of 1 to 20 layers. The long stringer intercalation layer (5) is located between the outer long stringer layer (2) and the inner long stringer layer (6), and has a thickness of 1 to 20 layers. The intercalation outer long stringer layer (2) forms a U shape, and forms a 1 / 4 arc with point (7) as the center in the rounded corner transition zone. The inner long stringer ply (6) of the insert layer forms a U shape and is distributed in the rounded corner transition zone according to a certain function curve. The ply of the long stringer insert layer (5) in the rounded corner transition zone is terminated at a certain length, so as to ensure that the inner long stringer insert layer (6) transitions smoothly according to the function curve. The inner long stringer ply (6) of the insert layer on both sides forms a twist bar filling area (4) in the rounded corner transition zone, and the twist bar is filled in (4).

[0058] like Figure 6 As shown in the figure, since the long stringer insert is in the middle of the web insert, it is necessary to theoretically calculate the length of the long stringer insert to provide a design benchmark for the actual process, so as to ensure that the insert is completely filled in the U-shaped long stringer fillet area, thereby ensuring the quality of the long stringer fillet area after forming.

[0059] The two-dimensional shape of the long stringer ply in the fillet area that is not affected by the insertion layer is a quarter circle; after adding the insertion layer, the long stringer ply in the fillet area satisfies a given mathematical curve distribution, such as a cubic spline curve distribution. Taking the insertion of 4 layers in the web of the long stringer as an example, the theoretical calculation method of the insertion length of the long stringer is as follows:

[0060] Assume that the long stringer ply is a curve s(x) on the long stringer cross section. Figure 8 As shown, taking the bottom end of the fillet of the second layer of the long stringer ply as the origin, a local coordinate system is established along x and y in the figure, where the x-axis is perpendicular to the web direction and the y-axis is parallel to the web direction. The lower edge curve of the second layer of the long stringer ply is s1(x), and the upper edge curve of the third layer is s2(x).

[0061] The equations s1(x) and s2(x) can be solved by the cubic spline difference method. The distance between the curves s1(x) and s2(x) is approximately equal to the difference in distance from the two curves to the origin o at the same deflection angle. For the sake of simplicity, Figure 7 The median coordinate system is transformed into the polar coordinate system, such as Fig. 9 As shown, s1(θ) = s1(x), s2(θ) = s2(x), h(θ) is the distance between the two curves, and satisfies:

[0062] 4.h(θ)=s2(θ)-s1(θ)

[0063] As the spacing between s1(θ) and s2(θ) becomes smaller and smaller, theoretically, the cut-off position of intercalation layer 1 is s1(θ)=t (t is the thickness of intercalation layer), and the cut-off position of intercalation layer 2 is s2(θ)=2t. Considering the actual manufacturing situation, to ensure that there is no gap between the intercalation layer and the long stringer ply, the cut-off position of intercalation layer 1 is taken as h(θ)=0.70×2t~0.95×2t, and the cut-off position of intercalation layer 2 is taken as h(θ)=0.70t~0.95t.

[0064] Example 2

[0065] Take a U-shaped long stringer with 4 layers of long stringer ply and 4 layers of interlayer with a ply thickness of 2 mm as an example. A coordinate system is established in the U-shaped long stringer fillet interlayer area as follows: Fig.10 shown.

[0066] Depend on Fig.10 It can be seen that the upper boundary curve of the intercalation region is s2(x), the lower boundary is s1(x), and the lower boundary is a 1 / 4 arc with the origin as the center and a radius of 3mm. s1(x) = s1(θ), s2(x) = s2(θ), and the spacing of the intercalation region at an angle of θ is recorded as h(θ).

[0067] make:

[0068] M i =s″(x i )(i=0,1,...,n) (1)

[0069] Since s(x) is in the subinterval [x i-1 ,xi] is an algebraic polynomial of degree not higher than 3, so s′(x) is a linear function in this interval, and we have:

[0070]

[0071] where h i =x i -x i-1 Integrating equation (2) twice, we get:

[0072]

[0073] Using the difference condition

[0074]

[0075] Determine the integral constants c1 and c2, and then substitute them into equation (3) and rearrange them to obtain:

[0076]

[0077] As long as you can put M i(i=1,2,...,n) is obtained, and the expression of the required cubic spline difference function s(x) on each subinterval is determined by formula (4). i , we need to use s′(x) at each internal node x i (i=1,2,...,n-1) continuous conditions. From formula (4), we get:

[0078]

[0079] From formula (5), we can know that:

[0080]

[0081]

[0082] Since s′(x) is i Continuous, so there should be:

[0083] s′(x i - )=s′(x i + )(i=1,2,...,n-1)

[0084] This results in n-1 equations (called three-moment equations)

[0085] γ i M i-1 +2M i +α i M i+1 =β i (i=1,2,...,n-1) (6)

[0086] in:

[0087] γ i =1-α i

[0088]

[0089] Formula (6) is about the position number M0, M1, ..., M n To uniquely determine the n+1 unknowns in the linear equation system, two more equations must be added.

[0090] For the U-shaped long stringer web ply cross-section curve, the curve s(x) satisfies the following conditions in the fillet transition area:

[0091] s′(x0)=y′0,s′(x n ) = y′ n

[0092] From formula (5), we can get the following two equations:

[0093]

[0094]

[0095] After sorting, these two equations can be written as follows:

[0096] α0=1,

[0097] γ n =1,

[0098] The above formulas give the following information about M0,M1,...,M n The linear equations are in the form of:

[0099]

[0100] because Figure 1 When y=0, the tangent derivative of the curve is infinite. To make the calculation more convenient, we can establish Fig.11 The equivalent coordinate system shown in the figure is as follows: the curves s1(x) and s2(x) are obtained by the above calculation formula.

[0101] The known information of s1(x) and s2(x) is as follows:

[0102] Table 1 s1(x) curve information

[0103] x -2.1213 2.1213 s1(x) 2.1213 2.1213 s1′(x) 1 -1

[0104] Table 2 s2(x) curve information

[0105] x -2.4042 2.1213 s2(x) 2.40412 2.1213 s2′(x) 1 -1

[0106] Using formula (4) and formula (7), we can get the equations of s1(x) and s2(x):

[0107]

[0108] s2(x)=-0.0292(2.1213-x) 3 -0.0199(x+2.1213) 3 +1.0638(2.1213-x)+0.5331(x+2.1213),(-2.1213≤x≤2.1213) (9)

[0109] Suppose the distance between a point on the curve s1(x) and the origin at an angle θ is h1(θ), and the distance between a point on the curve s2(x) and the origin at an angle θ is h2(θ), then the curve spacing can be expressed as h(θ)=h2(θ)-h1(θ).

[0110] Let x1 and y1 be points on the curve s1(θ), and x2 and y2 be points on the curve s2(θ), then:

[0111] x1=h1 cos(θ), y1=h1 sin(θ) (10)

[0112] x2=h2 cos(θ), y2=h2 sin(θ) (11)

[0113] Since s1(x) = s1(θ), s2(x) = s2(θ), substituting (10) and (11) into (8) and (9) yields:

[0114] h1=3

[0115] h2 sin(θ)=-0.0292(2.1213-h2 cos(θ)) 3 -0.0199(h2 cos(θ)+2.1213) 3 +1.0638(2.1213-h2 cos(θ))+0.5331(h2 cos(θ)+2.1213),(-2.1213≤h2 cos(θ)≤2.1213)

[0116] h(θ)=h2(θ)-h1(θ)

[0117] The cutoff position of intercalation layer 1 is set between h(θ)=0.70×2t~0.95×2t and h(θ)=2.8mm~3.8mm, and the cutoff position of intercalation layer 2 is set between h(θ)=0.70t~0.95t and h(θ)=1.4mm~1.9mm.

[0118] According to the configuration of this patent, U-shaped long stringer configurations with different insert numbers and positions can be designed. Here are several other different insert forms such as Fig.12 , Fig.13 shown.

[0119] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A composite material long stringer rounded corner transition zone structure, characterized in that: include: The outer layer of the skin is located on the side of the structure of the rounded corner transition area of ​​the long stringer; The middle layer of the skin is located on the upper part of the outer layer of the skin; Multi-layer long stringer plies are located on the upper part of the middle plies of the skin and are arranged in a U-shape or T-shape; Long stringer inserts are inserted between multiple long stringer plies, including multiple long stringer inserts of different lengths. By arranging the long stringer inserts to terminate at different lengths, the multiple long stringer plies are always transitioned according to a smooth function curve in the rounded corner transition zone; The twist bar filling area is composed of multiple layers of long stringers on both sides in the rounded transition area. Wherein, the multi-layer long stringer ply comprises: The long stringer ply on the inner side of the insert is located on the upper part of the middle ply of the skin, arranged in a U-shape or T-shape, and distributed according to a certain function curve in the fillet transition area; The long stringer ply on the outer side of the insert layer is located on the upper part of the long stringer ply on the inner side of the insert layer, arranged in a U-shape or T-shape, and forms a 1 / 4 arc in the fillet transition area; Wherein, the long stringer insert layer comprises a plurality of long stringer insert layers of different lengths and uniform thickness assembled together; Wherein, from the direction of the long stringer layer outside the insertion layer to the long stringer layer inside the insertion layer, the multi-layer long stringer insertion layers with different lengths and uniform thicknesses assembled together include N layers of long stringer insertion layers with different lengths and uniform thicknesses, namely, the first long stringer insertion layer, the second long stringer insertion layer, ... the Long stringer interlayer...Nth long stringer interlayer, the The distance between the outer and inner long stringer layers at the end point of the long stringer layer insertion The value range is: ,in, is the thickness of the long stringer insert, N is a positive integer and its value range is .

2. The composite long stringer rounded corner transition zone structure according to claim 1, characterized in that: The combined layup of the long stringer ply on the inner side of the insert and the long stringer ply on the outer side of the insert is symmetrical with the outer side ply of the skin.

3. A composite material long stringer rounded corner transition zone structure, characterized in that: include: The outer layer of the skin is located on the side of the structure of the rounded corner transition area of ​​the long stringer; The middle layer of the skin is located on the upper part of the outer layer of the skin; Multi-layer long stringer plies are located on the upper part of the middle plies of the skin and are arranged in a U-shape or T-shape; Long stringer inserts are inserted between multiple long stringer plies, including multiple long stringer inserts of different lengths. By arranging the long stringer inserts to terminate at different lengths, the multiple long stringer plies are always transitioned according to a smooth function curve in the rounded corner transition zone; The twist bar filling area is composed of multiple layers of long stringers on both sides in the rounded transition area. Wherein, the multi-layer long stringer ply comprises: The long stringer ply on the inner side of the insert is located on the upper part of the middle ply of the skin, arranged in a U-shape or T-shape, and distributed according to a certain function curve in the fillet transition area; The long stringer ply on the outer side of the insert layer is located on the upper part of the long stringer ply on the inner side of the insert layer, arranged in a U-shape or T-shape, and forms a 1 / 4 arc in the fillet transition area; The long stringer inserts include a plurality of long stringer insert groups, each long stringer insert group includes a plurality of long stringer inserts of different lengths and uniform thicknesses, and the plurality of long stringer insert groups are spaced apart from the plurality of long stringer layers from the outside to the inside of the plurality of long stringer layers; Among them, from the outside to the inside of the multi-layer long stringer ply, each long stringer insert group includes N layers of long stringer inserts of different lengths and uniform thicknesses, namely the first long stringer insert, the second long stringer insert, ... Long stringer interlayer...Nth long stringer interlayer, the The distance between the outer and inner long stringer layers at the end point of the long stringer layer insertion The value range is: ,in, is the thickness of the long stringer insert, N is a positive integer and its value range is .

4. The composite long stringer rounded corner transition zone structure according to claim 3, characterized in that: The combined layup of the long stringer ply on the inner side of the insert and the long stringer ply on the outer side of the insert is symmetrical with the outer side ply of the skin.

5. A composite material long stringer rounded corner transition zone structure, characterized in that: include: The outer layer of the skin is located on the side of the structure of the rounded corner transition area of ​​the long stringer; The middle layer of the skin is located on the upper part of the outer layer of the skin; Multi-layer long stringer plies are located on the upper part of the middle plies of the skin and are arranged in a U-shape or T-shape; Long stringer inserts are inserted between multiple long stringer plies, including multiple long stringer inserts of different lengths. By arranging the long stringer inserts to terminate at different lengths, the multiple long stringer plies are always transitioned according to a smooth function curve in the rounded corner transition zone; The twist bar filling area is composed of multiple layers of long stringers on both sides in the rounded transition area. Wherein, the multi-layer long stringer ply comprises: The long stringer ply on the inner side of the insert is located on the upper part of the middle ply of the skin, arranged in a U-shape or T-shape, and distributed according to a certain function curve in the fillet transition area; The long stringer ply on the outer side of the insert layer is located on the upper part of the long stringer ply on the inner side of the insert layer, arranged in a U-shape or T-shape, and forms a 1 / 4 arc in the fillet transition area; Wherein, the long stringer inserts include a plurality of long stringer inserts of different lengths and uniform thicknesses, and from the outside to the inside of the multi-layer long stringer ply, the plurality of long stringer inserts are spaced apart from the multi-layer long stringer ply; Wherein, from the outside to the inside of the multi-layer long stringer ply, the plurality of long stringer inserts of different lengths and uniform thickness include N layers of long stringer inserts of different lengths and uniform thickness, namely, the first long stringer insert, the second long stringer insert, ... the Long stringer interlayer...Nth long stringer interlayer, the The distance between the outer and inner long stringer layers at the end point of the long stringer layer insertion The value range is: ,in, is the thickness of the long stringer insert, N is a positive integer and its value range is .

6. The composite long stringer rounded corner transition zone structure according to claim 5, characterized in that: The combined layup of the long stringer ply on the inner side of the insert and the long stringer ply on the outer side of the insert is symmetrical with the outer side ply of the skin.

7. A composite material reinforced wall panel, wherein: The composite stiffened wall panel comprises a long stringer rounded transition zone structure according to any one of claims 1 to 6.

Images