Composite material double-lug joint structure and layering design method thereof

Abstract

The invention discloses a composite material double-lug connector structure and a laying layer design method thereof. The composite material double-lug connector structure comprises a metal double-lug lining area, a double-lug lining inner wrapping area, a first main body rod inner layer area, an arc-shaped gasket area, a second main body rod inner layer area, a third main body rod inner layer area, a variable-thickness patch inner layer area, a variable-thickness patch outer layer area and an outermost layer wrapping area. Compared with a method for connecting the double-lug structure by using common parts, the composite material is used for replacing metal parts for splicing, so that the number of parts in the whole structure can be reduced, the installation difficulty and the installation instability are reduced, the structure weight can be reduced, and the application value of the double-lug structure is higher; in the engineering application of typical double-lug structures (such as airplane fuselage reinforcing frames and wing girders), the working stability of the structures can be effectively improved, so that vibration is reduced, noise is lowered, and the service life is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of composite material joint structures, in particular to a composite material double-ear joint structure and a layer design method thereof. Background Art

[0002] Double-ear structure is a common structural component in engineering, such as aircraft fuselage reinforcement frame, wing beam, etc. Its failure mode is mainly bending deformation when subjected to out-of-plane load, affecting the in-plane load distribution and the bearing capacity of the ear. The single ear with spherical bearing is generally connected with double ears by bolts. In order to prevent the wear of bolts and ears, bushings are installed in the inner holes of the double ears. The bushing and the ear are assembled in an interference fit, and the bushing has a boss. Generally, after the bushing is pressed in, the boss end face of the bushing is supplemented to ensure that a small gap is left to ensure the smooth installation and fixation of the single ear. This connection structure mainly relies on the bolt tightening torque to generate additional lateral loads on the double ears to fix the single ear. Due to the gap between the single ear and the end face of the bushing, there is an additional bending moment in the double ears, and the fatigue life is affected.

[0003] At present, by controlling the assembly tolerance between the single ear and the double ears and ensuring a small gap fit, the stress concentration of the double ears can be reduced, but the existence of lateral bending moment cannot be avoided. At the same time, the small gap fit also causes inconvenience to the disassembly and assembly between the ear pieces. Therefore, in order to improve the connection strength between the double ear structure and other structures, it is necessary to design an integral structure containing the double ears to avoid stress concentration and lateral bending moment caused by too many parts, thereby causing structural damage. Consider using a composite material layup design method to connect the double ear structure with other structures. The composite material layup design method can connect the double ear structure with other structures by fiber cloth layup, and then solidify and mold. This is an integral molding method that reduces the number of parts, reduces the overall weight of the structure, reduces the difficulty of installation, and improves practicality. The one-piece molding greatly improves the strength and impact resistance of the overall structure to a certain extent.

[0004] The invention patent with application number CN117901446A and titled "A method for preparing three-dimensional joints using a two-dimensional layering method of composite materials" provides a method for preparing three-dimensional joints using a two-dimensional layering method. This method uses a group design module and a mold to perform cutting and paving and finally solidify the formed parts. Although the patent uses a two-dimensional layering method to prepare a three-dimensional preform, which reduces the weight of the structure and has better apparent quality, its structural parts have a bearing capacity equivalent to that of metal structural parts, and does not give full play to the high specific strength and high specific modulus characteristics of composite materials, and cannot improve the strength and impact resistance of the structure, which limits its engineering application value.

[0005] To this end, we proposed a composite double-ear joint structure and its layup design method to solve the above problems. Summary of the invention

[0006] The object of the present invention is to provide a composite material double-ear joint structure and a layup design method thereof, so as to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A composite double-ear joint structure and a layup design method thereof, comprising a metal double-ear bushing area, a double-ear bushing inner wrapping area, a main rod inner layer area 1, an arc-shaped gasket area, a main rod inner layer area 2, a main rod inner layer area 3, a variable thickness patch inner layer area, a variable thickness patch outer layer area, and an outermost wrapping area; wherein,

[0009] The inner wrapping area of ​​the double ear bushing is divided into a first cut piece of the inner wrapping area of ​​the double ear bushing, a second cut piece of the inner wrapping area of ​​the double ear bushing and a third cut piece of the inner wrapping area of ​​the double ear bushing;

[0010] The second inner layer area of ​​the main body rod is divided into a first cut piece of the second inner layer area of ​​the main body rod, a second cut piece of the second inner layer area of ​​the main body rod, and a third cut piece of the second inner layer area of ​​the main body rod;

[0011] The variable thickness patch outer layer area is divided into variable thickness patch outer layer area cut piece 1 and variable thickness patch outer layer area cut piece 2;

[0012] The outermost wrapping area is divided into outermost wrapping area patch area 1 cutting piece 1, outermost wrapping area patch area 2 cutting piece 2, outermost wrapping area variable thickness area cutting piece 3, outermost wrapping area overall paving area cutting piece 4 and outer wrapping area cutting piece 5;

[0013] The inner wrapping area of ​​the double-ear bushing, the first inner layer area of ​​the main rod, the arc-shaped gasket area, the second inner layer area of ​​the main rod, the third inner layer area of ​​the main rod, the inner layer area of ​​the variable thickness patch, the outer layer area of ​​the variable thickness patch and the outermost wrapping area are integrally formed by laying layers;

[0014] Another object of the present invention is to provide a ply design method for a composite double-ear joint structure:

[0015] The steps include:

[0016] S1, observe the characteristics of the metal double-ear bushing area and measure the size of the metal double-ear bushing. It is found that the metal double-ear bushing area has three characteristics: raised texture, symmetrical texture, and one side of the bushing is missing half. The design starts from these three characteristics;

[0017] S2, design the inner wrapping layer area of ​​the double ear bushing. The inner wrapping layer area of ​​the double ear bushing needs to fit the texture on both sides of the double ear bushing and have a certain thickness to cover the texture and reach the same height as the missing part. Three types of cut pieces are designed for layering according to the characteristics of the texture;

[0018] S3, design the first area of ​​the inner layer of the main rod. The shape of the first area of ​​the inner layer of the main rod is designed according to the size of the rocker core mold. The shape of the upper half of the first area of ​​the inner layer of the main rod is consistent with the arc of the metal double-ear bushing area 1, and there is no overall thickness change. The overall design is a cut piece. When the cut piece is laid, the upper part has a curved arc that fits the shape of the core mold. Several layers are laid in sequence according to the designed thickness, and the laying angle is [0 / 45 / 90 / -45 / 0];

[0019] S4, design the arc-shaped gasket area to fit the arc of the lower half of the metal double-ear bushing area, the protruding width is flush with the height of the metal double-ear bushing area, and there is a closed arc designed according to the size of the hollow of the rocker arm, which fits the size of the upper part of the inner layer of the main rod. The arc-shaped gasket area has no thickness change as a whole. The overall design is a cut piece. When the cut piece is laid, the upper half needs to be bent to fit the height of the missing part of the metal double-ear bushing area. Several layers are laid in sequence according to the thickness. The laying angle is [0 / 90 / 0]. The shape and position are fixed during laying, and there is no cutting transfer between adjacent layers.

[0020] S5, design the second inner layer area of ​​the main rod, the inner part fits the curvature design of the first inner layer area of ​​the main rod, the upper part fits the curve of the arc-shaped gasket area, the width is designed along the thickest position of the first inner layer area of ​​the main rod, the second inner layer area of ​​the main rod has thickness variation, which can be divided into a constant thickness area and a variable thickness area, and three types of cut pieces are designed for layering;

[0021] S6, design the inner three zones of the main pole. The inner three zones of the main pole are the outer wrapping of the main pole to enhance the thickness and strength. The inner part fits the curvature design of the inner two zones of the main pole, and the upper part fits the curve of the arc-shaped gasket zone. Since the shapes of the inner three zones of the main pole are roughly the same and there is no overall thickness change, the same type of cut pieces are designed for paving during layering. Several layers are laid in sequence according to the thickness, and the laying angle is [0 / 45 / 90 / -45 / 0];

[0022] S7, design the inner layer area of ​​the variable thickness patch. The inner layer area of ​​the variable thickness patch is a variable thickness area. It is designed along the arc of the arc gasket area and the inner layer area of ​​the main rod. The width is the width of the inner layer area of ​​the main rod. The starting point of the variable thickness is the edge of the metal double ear bushing area. Since the thickness of the inner layer area of ​​the variable thickness patch varies greatly and the shape is relatively regular, the cutting piece is designed and laid in several layers in sequence according to the thickness. The laying angle is [0 / 45 / -45 / 0 / 90 / -45 / 45 / 90]. After laying eight layers, the laying angle is cycled once. Since the position of the cutting piece is fixed and this area is the patch area, there is no change in the position of the cutting edge of the adjacent layers.

[0023] S8, design the outer area of ​​the variable thickness patch. The outer area of ​​the variable thickness patch is expanded outward along the outer contour of the inner area of ​​the variable thickness patch. The side height is tangent to the arc-shaped gasket area. The starting point of the variable thickness area coincides with the edge of the metal double-ear bushing area. The curvature design of the lower part is designed according to the width of the arc-shaped gasket area. The outer area of ​​the variable thickness patch is mainly divided into the inner layer fitting area and the outer layer wrapping area. Two types of cut pieces are designed;

[0024] S9, the design and laying of the main rod position are completed, the design and laying of the metal double-ear bushing area are also completed, and the outermost wrapping area is designed. The outermost wrapping area is an area that wraps the metal double-ear bushing area and the main rod as a whole. The side is tangent to the metal double-ear bushing area, the height is flush with the arc-shaped gasket area, and the width is the same as the width of the metal double-ear bushing area. The design of the outermost wrapping area is relatively complicated. It not only needs to connect and wrap the main rod and the metal double-ear bushing area, but also is a variable thickness area, which smoothly connects the main rod and the metal double-ear bushing area. A total of 4 areas are designed and 5 types of cut pieces are laid;

[0025] S10, after the connection position between the rocker arm and the fuselage is designed by the above-mentioned design ideas and the number of layers of each area is obtained, the layers of each area are unfolded by using the unfolding software, and the layout software is used to layout according to the number of pieces, and the pieces are cut. After the cut pieces are obtained, the core mold is connected by the positioning bracket, and the patches are laid layer by layer according to the positioning position and a certain order, and the order is as follows: the inner wrapping area of ​​the double ear bushing, the inner layer area 1 of the main rod, the arc-shaped gasket area, the inner layer area 2 of the main rod, the inner layer area of ​​the main rod, the inner layer area of ​​the variable thickness patch, the outer layer area of ​​the variable thickness patch, and the outermost wrapping area;

[0026] Preferably, the step S2 specifically includes:

[0027] S2-1, the first cut piece of the inner wrapping area of ​​the double-ear bushing is rectangular, and the thickness difference between the raised pattern and the bushing surface is compensated. The layers are laid in sequence according to the thickness, and the laying angle is [0 / 90 / 0];

[0028] S2-2, the second piece of the inner wrapping area of ​​the double-ear bushing is in the shape of "N". Its main purpose is to make up the thickness difference between the raised patterns. The layers are laid in sequence according to the thickness, and the laying angle is [0 / 45 / 90 / -45 / 0];

[0029] S2-3, the third cut piece of the inner wrapping area of ​​the double-ear bushing is a rectangle. The entire curved surface of the double-ear bushing is layered in sequence according to the thickness. The layering angle is [0 / 90 / 0]. In order to avoid stress concentration caused by cuts at the same position or attachment position leading to premature failure of the material, the distance between the cuts of adjacent layers is guaranteed to be greater than 50mm when designing the cuts.

[0030] Preferably, the step S5 is specifically as follows:

[0031] S5-1, the first part of the inner layer of the main rod is the plying of the area with constant thickness. The plying is carried out in sequence according to the thickness. The designed plying angle is [0 / 45 / -45 / 0 / 90 / -45 / 45 / 90]. After eight layers are laid, the plying angle is cycled once. The distance between the cut edges of adjacent layers is 40mm to prevent stress concentration.

[0032] S5-2, the second piece of the second zone of the inner layer of the main rod is used for laying the thickness change zone. The thickness change zone has a large change, and the layers are laid in sequence according to the thickness. The length of the pieces is reduced layer by layer to achieve the effect of variable thickness. The laying of the variable thickness area is completed. The laying angle is [0 / 45 / -45 / 0 / 90 / -45 / 45 / 90]. After laying eight layers, the laying angle is cycled once, and the cutting distance between adjacent layers is 40mm.

[0033] S5-3, the third piece of the second zone of the inner layer of the main rod is laid as a whole on the outermost layer after the laying of the two areas is completed. The layers are laid in sequence according to the thickness. The laying angle is [0 / 90] and the distance between the cuts of adjacent layers is 100mm.

[0034] Preferably, the step S8 specifically includes:

[0035] S8-1, the inner layer bonding area is mainly bonded with the inner layer area 7 of the variable thickness patch for local strong increase, and the outer layer area of ​​the variable thickness patch is designed to be laid in sequence according to the thickness. The laying angle is [0 / 45 / 90 / -45 / 0 / 45 / 90]. Since the position of the cutting piece is fixed and this area is the patch area, there is no change in the cutting position of the adjacent layers;

[0036] S8-2, design the variable thickness patch outer layer area piece 2 in the outer wrapping area. The variable thickness patch outer layer area piece 2 is mainly used to wrap up the variable thickness patch areas on both sides to complete the overall connection. The layers are laid in sequence according to the thickness. The laying angle is [0 / 90] and the distance between the cutting edges of adjacent layers is 100mm.

[0037] Preferably, the step S9 specifically includes:

[0038] S9-1, design the outermost wrapping area patch area-cut piece-to strengthen the area between the metal double ear bushing area, and lay the layers in sequence according to the thickness. The laying angle is [0 / 45 / 90 / -45]. Since the position of the cut piece is fixed and this area is the patch area, there is no change in the position of the cut edge of the adjacent layers;

[0039] S9-2, design the outermost wrapping area patch area second piece 2 for further reinforcement between the metal double ear bushing area, and lay the layers in sequence according to the thickness, with the laying angle of [0 / 45 / 90 / -45 / 0], and one cycle of five layers. Since the position of the piece is fixed and this area is the patch area, there is no change in the position of the cut edge of the adjacent layers;

[0040] S9-3, design the third piece of variable thickness area in the outermost wrapping area, lay them out in sequence according to the thickness, reduce the pieces layer by layer, and then lay them out in sequence according to the height. The laying angle is [0 / 45 / -45 / 0 / 90 / -45 / 45 / 90]. After laying eight layers, the laying angle is cycled once. Since the area is fixed, there is no change in the position of the cutouts in adjacent layers.

[0041] S9-4, the overall ply area connects the metal double ear bushing area with the main rod position, and the outermost wrapping area is designed to have four pieces of overall ply area. The ply is laid in sequence according to the thickness, and the ply angle is [0 / 45 / 90 / -45 / 0], with five layers in one cycle, and the distance between the cuts of adjacent layers is greater than 40mm;

[0042] S9-5, the outer wrapping area is to wrap the two areas as a whole, design the outer wrapping area piece five 95, and lay the layers according to the thickness.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1. Compared with the method of connecting the double-ear structure with ordinary parts, the present invention uses composite materials instead of metal parts for assembly, which can reduce the number of parts in the overall structure, reduce the difficulty and instability of installation, and reduce the weight of the structure, making it more valuable for application. In the engineering application of typical double-ear structures (such as aircraft fuselage reinforcement frames and wing beams), it can effectively improve the stability of the structure, thereby reducing vibration, reducing noise and increasing service life.

[0045] 2. The method of using composite materials for integrated design and then solidifying and forming in the present invention reduces the weight of the overall structure, optimizes the complexity of the design, reduces the design difficulty, gives full play to the characteristics of high specific strength and high specific modulus of composite materials, improves the strength of the overall structural parts, prolongs the service life in actual engineering applications, and has a wider application background.

[0046] 3. Compared with other methods of using two-dimensional pieces to construct three-dimensional structures, there is no strong improvement, and the bearing capacity is equivalent to that of metal structures. The present invention performs large-area paving after local paving, which has a certain degree of enhancement in strength, improves the designability of three-dimensional structure construction using two-dimensional pieces, and can design some structures with more complex structures, thereby improving the practical value of the structure and having good engineering application prospects.

[0047] The structural parts in the present invention are also enhanced to a certain extent in appearance design due to the final overall curing. During the paving process, a variety of laying angles and different cutting edge offset distances are designed according to the characteristics of each cut piece, and local and overall paving optimization is performed to avoid stress concentration and impact loss, thereby causing local damage or overall structural failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the structure of the present invention;

[0049] Figure 2 It is a schematic diagram of the structure of the present invention without the outermost wrapping area;

[0050] Figure 3 It is a schematic diagram of the structure of the present invention without the outermost wrapping area and the outer area of ​​the variable thickness patch;

[0051] Figure 4 It is a longitudinal schematic diagram of the structure of the present invention;

[0052] Figure 5 It is a schematic diagram of the inner wrapping area of ​​the double-ear bushing of the present invention;

[0053] Figure 6 It is a schematic diagram of the inner wrapping area of ​​the double-ear bushing of the present invention;

[0054] Figure 7 It is a schematic diagram of the second zone of the inner layer of the main body rod of the present invention;

[0055] Figure 8 is a schematic diagram of the inner layer area of ​​the variable thickness patch of the present invention;

[0056] Fig. 9 Schematic diagram of the outermost wrapping area of ​​the present invention;

[0057] Fig.10 Schematic diagram of the outermost wrapping area of ​​the present invention;

[0058] Fig.11 It is a flow chart of the present invention;

[0059] Fig.12 is a flow chart of step S2 of the present invention;

[0060] Fig.13 is a flow chart of step S5 of the present invention;

[0061] Fig.14 is a flow chart of step S8 of the present invention;

[0062] Fig.15 It is the flow chart of step S9 of the present invention.

[0063] In the figure: 1. Metal double-ear bushing area; 2. Double-ear bushing inner wrapping area; 21. Double-ear bushing inner wrapping area cut piece 1; 22. Double-ear bushing inner wrapping area cut piece 2; 23. Double-ear bushing inner wrapping area cut piece 3; 3. Main rod inner layer area 1; 4. Arc gasket area; 5. Main rod inner layer area 2; 51. Main rod inner layer area 2 cut piece 1; 52. Main rod inner layer area 2 cut piece 2; 53. Main rod inner layer area 2 cut piece 3; 6. Main rod inner Layer three area; 7. Inner area of ​​variable thickness patch; 8. Outer area of ​​variable thickness patch; 81. Piece one of variable thickness patch outer area; 82. Piece two of variable thickness patch outer area; 9. Outermost wrapping area; 91. Piece one of patch area one of outermost wrapping area; 92. Piece two of patch area two of outermost wrapping area; 93. Piece three of variable thickness area of ​​outermost wrapping area; 94. Piece four of overall ply area of ​​outermost wrapping area; 95. Piece five of outer wrapping area. DETAILED DESCRIPTION

[0064] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0065] Example: See attached Figure 1-4 A composite double-ear joint structure and its layup design method are designed and laid up in nine areas: a metal double-ear bushing area 1, a double-ear bushing inner wrapping area 2, a main rod inner layer area 1 3, an arc-shaped gasket area 4, a main rod inner layer area 2 5, a main rod inner layer area 3 6, a variable thickness patch inner layer area 7, a variable thickness patch outer layer area 8, and an outermost wrapping area 9; wherein, refer to the attached Figure 5-6 The inner wrapping area 2 of the double ear sleeve is divided into a double ear sleeve inner wrapping area cut piece 1 21, a double ear sleeve inner wrapping area cut piece 22 and a double ear sleeve inner wrapping area cut piece 3 23; see attached Figure 7 The second inner layer area 5 of the main body rod is divided into a first inner layer area 51 of the main body rod, a second inner layer area 52 of the main body rod and a third inner layer area 53 of the main body rod; see the attached Figure 8 The variable thickness patch outer layer area 8 is divided into a variable thickness patch outer layer area cutting piece 1 81 and a variable thickness patch outer layer area cutting piece 2 82; see attached Figure 9-10The outermost wrapping area 9 is divided into the outermost wrapping area patch area one piece 91, the outermost wrapping area patch area two piece 92, the outermost wrapping area variable thickness area piece 3 93, the outermost wrapping area overall plying area piece 4 94 and the outer layer wrapping area piece 5 95; the metal double-ear bushing area 1 does not require plying; the double-ear bushing inner wrapping area 2, the main rod inner layer area 1 3, the arc-shaped gasket area 4, the main rod inner layer area 2 5, the main rod inner layer area 3 6, the variable thickness patch inner layer area 7, the variable thickness patch outer layer area 8 and the outermost wrapping area 9 are integrally formed by plying.

[0066] According to the description of this structure, set the following fabric parameters:

[0067] 1) The ply fiber cloth is 0.2 mm thick.

[0068] As attached Figure 1-11 As shown, according to the description of the prefabricated fabric and its parameter setting according to the above structure (the geometric size and microscopic parameters of the structure need to be set according to the requirements of the engineering project), the laying method includes the following steps:

[0069] S1, see Appendix Figure 1-4 , observe the characteristics of the metal double-ear bushing area 1, and measure the size of the metal double-ear bushing. It is found that the metal double-ear bushing area 1 has three characteristics: raised texture, symmetrical texture, and one side of the bushing is missing half. The design starts from these three characteristics;

[0070] S2, see Appendix Figure 5 and 12 , design the inner wrapping layer area 2 of the double ear bushing, the inner wrapping layer area 2 of the double ear bushing needs to fit the texture on both sides of the double ear bushing and have a certain thickness, so as to cover the texture and achieve the same height as the missing part. According to the characteristics of the texture, three types of cut pieces are designed for layering, including:

[0071] S2-1, the cut piece 21 in the inner wrapping area of ​​the double-ear bushing is rectangular, and the thickness difference between the raised pattern and the bushing curved surface is compensated, the thickness is 0.52mm, 3 layers are laid on each bushing, a total of 6 layers are laid, and the laying angle is [0 / 90 / 0];

[0072] S2-2, the second cut piece 22 in the inner wrapping area of ​​the double-ear bushing is in the shape of a "non" character, and its main purpose is to make up the thickness difference between the raised patterns. The thickness is 1.04mm, and the bushings are laid with 5 layers each, for a total of 10 layers, and the laying angle is [0 / 45 / 90 / -45 / 0];

[0073] S2-3, see Appendix Figure 6, the cut piece 3 23 of the inner wrapping area of ​​the double-ear bushing is rectangular, and the entire curved surface of the double-ear bushing is laid with a thickness of 0.54mm, 3 layers are laid on each bushing, a total of 6 layers are laid, and the laying angle is [0 / 90 / 0]. In order to avoid stress concentration caused by the cutouts at the same position or the attachment position, which leads to premature failure of the material, the distance between the cutout positions of adjacent layers is guaranteed to be greater than 50mm when designing the cutouts;

[0074] S3, see Appendix Figure 1-4 , design the inner layer area 3 of the main rod, design the shape of the inner layer area 3 of the main rod according to the size of the rocker core mold, the shape of the upper half of the inner layer area 3 of the main rod is consistent with the arc of the metal double-ear bushing area 1, and there is no overall thickness change. The overall design is a cut piece. When the cut piece is laid, the upper part has a curved arc that fits the shape of the core mold. The thickness is 0.9mm. A total of 5 layers are laid, the laying angle is [0 / 45 / 90 / -45 / 0], and the distance between the cutting positions of adjacent layers is 40mm;

[0075] S4, see Appendix Figure 1-3 , the arc-shaped gasket area 4 is designed to fit the arc of the lower half of the metal double-ear bushing area 1. The protruding width is flush with the height of the metal double-ear bushing area 1. There is a closed arc designed according to the size of the hollow of the rocker arm, which fits the size of the upper part of the inner layer area 3 of the main rod. The arc-shaped gasket area 4 has no overall thickness change. The overall design is a cut piece. When the cut piece is laid, the upper half needs to be bent to fit the height of the missing part of the metal double-ear bushing area 1. The thickness is 0.6mm and a total of 3 layers are laid. The laying angle is [0 / 90 / 0]. The shape and position are fixed during laying, and there is no cutting transfer between adjacent layers;

[0076] S5, see Appendix Figure 7 and 13 , design the second inner layer area 5 of the main rod, the inner part fits the curvature design of the first inner layer area 3 of the main rod, the upper part fits the curve of the arc-shaped gasket area 4, and the width is designed along the thickest position of the first inner layer area 3 of the main rod. The second inner layer area 5 of the main rod has thickness variation, which can be divided into a constant thickness area and a variable thickness area. Three types of cut pieces are designed for layering, including:

[0077] S5-1, the second zone cut piece 51 of the inner layer of the main rod is used for the ply laying in the constant thickness zone, with a thickness of 17.09 mm, and a total of 85 layers are laid. Due to the large number of layers, the designed ply laying angle is [0 / 45 / -45 / 0 / 90 / -45 / 45 / 90]. After laying eight layers, the ply laying angle is cycled once, and the distance between the cut edges of adjacent layers is 40 mm to prevent stress concentration;

[0078] S5-2, the second cut piece 52 in the second zone of the inner layer of the main rod is used for laying in the thickness variation zone. The thickness variation in the thickness variation zone is relatively large, with a length of 72.25 mm and a thickness of 17.09 mm. A total of 85 layers are laid. The length of the cut piece is reduced by 0.85 mm layer by layer, thereby achieving the effect of variable thickness. The laying of the variable thickness area is completed. The laying angle is [0 / 45 / -45 / 0 / 90 / -45 / 45 / 90]. After laying eight layers, the laying angle is cycled once, and the cutting distance between adjacent layers is 40 mm.

[0079] S5-3, the third cut piece 53 of the second zone of the inner layer of the main rod is laid as a whole on the outermost layer after the laying of the two areas is completed. The thickness is 0.4mm, and two layers are laid in total. It is not only for the overall aesthetics but also to improve the impact resistance to a certain extent. The laying angle is [0 / 90], and the distance between the cut edges of adjacent layers is 100mm;

[0080] S6, see Appendix Figure 1-4 , the design of the main rod inner layer three zone 6, the main rod inner layer three zone 6 is the outer layer wrapping of the main rod, to enhance the thickness and strength, the inner part fits the arc design of the main rod inner layer two zone 5, and the upper part fits the curve of the arc gasket zone 4. Since the shape of the main rod inner layer three zone 6 is roughly the same and there is no overall thickness change, the same type of cut pieces are designed for laying, the thickness of the cut pieces is 5.4mm, a total of 27 layers are laid, the laying angle is [0 / 45 / 90 / -45 / 0], and the distance between the cut edges of adjacent layers is 40mm;

[0081] S7, see Appendix Figure 3 , design the variable thickness patch inner layer area 7, the variable thickness patch inner layer area 7 is a variable thickness area, designed along the arc of the arc gasket area 4 and the main rod inner layer three area 6, the width is the width of the main rod inner layer three area 6, the variable thickness starting point is the edge of the metal double ear bushing area 1, due to the variable thickness patch inner layer area 7 thickness variation is large, and the shape is relatively regular, the design of cutting piece, thickness of 19.62mm, a total of 98 layers, a total of 196 layers on both sides, the area has thickness changes, height changes of 66.48mm, each layer is reduced by 0.67 height for cutting, the laying angle is [0 / 45 / -45 / 0 / 90 / -45 / 45 / 90], after laying eight layers, the laying angle is cycled once, because the cutting piece position is fixed and this area is the patch area, there is no change in the cutting position of the adjacent layers;

[0082] S8, see Appendix Figure 2 , 814, design the variable thickness patch outer layer area 8, the variable thickness patch outer layer area 8 is expanded outward along the outer contour of the variable thickness patch inner layer area 7, the side height is tangent to the arc-shaped gasket area 4, the starting point of the variable thickness area coincides with the edge of the metal double ear bushing area 1, the curvature design of the lower part is designed according to the width of the arc-shaped gasket area 4, the variable thickness patch outer layer area 8 is mainly divided into an inner layer fitting area and an outer layer wrapping area, and two types of cut pieces are designed, specifically including:

[0083] S8-1, the inner layer bonding area is mainly bonded with the inner layer area 7 of the variable thickness patch for local strong increase. The outer layer area of ​​the variable thickness patch is designed to have a cutting piece 81 with a thickness of 1.45mm. Seven layers are laid on each side, for a total of 14 layers. The laying angle is [0 / 45 / 90 / -45 / 0 / 45 / 90]. Since the cutting piece position is fixed and this area is the patch area, there is no change in the cutting position of the adjacent layers.

[0084] S8-2, design a variable thickness patch outer layer area cut piece 82 in the outer layer wrapping area. The variable thickness patch outer layer area cut piece 82 is mainly used to wrap the variable thickness patch areas on both sides to complete the overall connection and play a reinforcing role. The thickness is 0.41mm, and two layers are laid. The laying angle is [0 / 90], and the distance between the cut edges of adjacent layers is 100mm.

[0085] S9, see Appendix Fig. 9 and 15 At this time, the design and laying of the main rod position are completed, and the design and laying of the metal double-ear bushing area 1 are also completed. It is necessary to design a layer of the layer to connect the two parts without damaging the strength. Design the outermost wrapping area 9. The outermost wrapping area 9 is an area that wraps the metal double-ear bushing area 1 and the main rod as a whole. The side is tangent to the metal double-ear bushing area 1, the height is flush with the arc-shaped gasket area 4, and the width is the same as the width of the metal double-ear bushing area 1. The design of the outermost wrapping area 9 is relatively complicated. It not only needs to connect and wrap the main rod and the metal double-ear bushing area 1, but also is a variable thickness area to smoothly connect the main rod and the metal double-ear bushing area 1. A total of 4 areas are designed, and 5 types of cut pieces are laid, including:

[0086] S9-1, design the outermost wrapping area patch area one piece ...

[0087] S9-2, design the outermost wrapping area patch area 2 cut piece 2 92 for further reinforcement between the metal double ear liner area 1, with a thickness of 2.84mm, 14 layers on each side, a total of 28 layers, the layer angle is [0 / 45 / 90 / -45 / 0], five layers in one cycle, because the cut piece position is fixed and this area is the patch area, there is no change in the cut position of the adjacent layers;

[0088] S9-3, design the outermost wrapping area variable thickness area piece three 93, thickness 8.51mm, 43 layers on each side, totaling 86 layers, the pieces are reduced layer by layer, the height is 74.7mm, and the height of each layer of pieces is reduced by 1.74mm. The laying angle is [0 / 45 / -45 / 0 / 90 / -45 / 45 / 90]. After laying eight layers, the laying angle is cycled once. Since the area is fixed, there is no change in the position of the cut edge of the adjacent layers;

[0089] S9-4, the overall ply area is to connect the metal double ear bushing area 1 with the main rod position, and the design of the outermost wrapping area overall ply area cut piece four 94, thickness 5.75mm, a total of 29 layers, the ply angle is [0 / 45 / 90 / -45 / 0], five layers in one cycle, and the distance between the cut positions of adjacent layers is greater than 40mm;

[0090] S9-5, see Appendix Fig.10 The outer wrapping area wraps the two areas as a whole. The outer wrapping area is designed to be cut into pieces of 95, with a thickness of 0.2mm and 1 layer, which not only improves the overall appearance but also enhances the overall strength.

[0091] S10, see Appendix Fig.11 , after the connection position between the rocker arm and the fuselage is designed through the above design ideas, the number of layers of each area is obtained. The layers of the above areas are unfolded using the unfolding software, and the layout software is used to layout according to the number of pieces, and the pieces are cut. After the pieces are obtained, the core mold is connected through the positioning bracket, and the patches are laid layer by layer according to the positioning position and a certain order. The order is as follows: double ear bushing inner wrapping area 2, main rod inner layer area 1 3, arc gasket area 4, main rod inner layer area 2 5, main rod inner layer area 3 6, variable thickness patch inner layer area 7, variable thickness patch outer layer area 8, outermost wrapping area 9.

[0092] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0093] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A composite material double-ear joint structure, characterized in that: It comprises a metal double-ear bushing area (1), a double-ear bushing inner wrapping area (2), a main body rod inner layer area 1 (3), an arc-shaped gasket area (4), a main body rod inner layer area 2 (5), a main body rod inner layer area 3 (6), a variable thickness patch inner layer area (7), a variable thickness patch outer layer area (8), and an outermost wrapping area (9); wherein, The double-ear bushing inner wrapping area (2) is divided into a double-ear bushing inner wrapping area cut piece 1 (21), a double-ear bushing inner wrapping area cut piece 2 (22) and a double-ear bushing inner wrapping area cut piece 3 (23); The second inner layer area of ​​the main body rod (5) is divided into a first cut piece (51) of the second inner layer area of ​​the main body rod, a second cut piece (52) of the second inner layer area of ​​the main body rod and a third cut piece (53) of the second inner layer area of ​​the main body rod; The variable thickness patch outer layer area (8) is divided into a variable thickness patch outer layer area cutting piece 1 (81) and a variable thickness patch outer layer area cutting piece 2 (82); The outermost wrapping area (9) is divided into outermost wrapping area patch area one cutting piece one (91), outermost wrapping area patch area two cutting piece two (92), outermost wrapping area variable thickness area cutting piece three (93), outermost wrapping area overall paving area cutting piece four (94) and outer wrapping area cutting piece five (95); The inner wrapping area (2) of the double-ear bushing, the first inner layer area (3) of the main rod, the arc-shaped gasket area (4), the second inner layer area (5) of the main rod, the third inner layer area (6) of the main rod, the inner layer area (7) of the variable thickness patch, the outer layer area (8) of the variable thickness patch and the outermost wrapping area (9) are integrally formed by a layer-laying method.

2. A method for laying layers of a composite double-ear joint structure according to claim 1, characterized in that: The steps include: S1, observe the characteristics of the metal double-ear bushing area (1), and measure the size of the metal double-ear bushing. It is found that the metal double-ear bushing area (1) has three characteristics: raised texture, symmetrical texture, and one side of the bushing is missing half. The design starts from these three characteristics; S2, designing the inner wrapping layer area (2) of the double-ear bushing, the inner wrapping layer area (2) of the double-ear bushing needs to fit the texture on both sides of the double-ear bushing and have a certain thickness, so as to cover the texture and achieve the same thickness as the missing part, and designing three types of cut pieces for layering according to the characteristics of the texture; S3, design the first inner layer area (3) of the main rod, design the shape of the first inner layer area (3) of the main rod according to the size of the rocker arm core mold, the shape of the upper half of the first inner layer area (3) of the main rod is consistent with the arc of the metal double ear bushing area (1), and there is no thickness change as a whole, and a cut piece is designed as a whole. When the cut piece is laid, the upper part has a curved arc that fits the shape of the core mold, and several layers are laid in sequence according to the designed thickness, and the laying angle is [0 / 45 / 90 / -45 / 0]; S4, designing an arc-shaped gasket area (4) to fit the arc of the lower half of the metal double-ear bushing area (1), with the protruding width flush with the height of the metal double-ear bushing area (1), and a closed arc designed according to the size of the hollow of the rocker arm, fitting the size of the upper part of the inner layer area (3) of the main rod, and the arc-shaped gasket area (4) has no thickness change as a whole. The overall design is a cut piece. When the cut piece is laid, the upper half needs to be bent to fit the height of the missing part of the metal double-ear bushing area 1, and several layers are laid in sequence according to the thickness. The laying angle is [0 / 90 / 0]. The shape and position are fixed during laying, and there is no cutting edge transfer between adjacent layers; S5, design the second inner layer area (5) of the main rod, the inner part is in line with the curvature design of the first inner layer area (3) of the main rod, the upper part is in line with the curve of the arc-shaped gasket area (4), the width is designed along the thickest position of the first inner layer area (3) of the main rod, the second inner layer area (5) of the main rod has thickness variation, and can be divided into a constant thickness area and a variable thickness area, and three types of cut pieces are designed for layering; S6, design the inner three zones (6) of the main body rod. The inner three zones (6) of the main body rod are used to wrap the outer layer of the main body rod to enhance thickness and strength. The inner part fits the curvature design of the inner two zones (5) of the main body rod, and the upper part fits the curve of the arc-shaped gasket zone (4). Since the shapes of the inner three zones (6) of the main body rod are roughly the same and there is no overall thickness change, the same type of cut pieces are designed for laying. Several layers are laid in sequence according to the thickness, and the laying angle is [0 / 45 / 90 / -45 / 0]; S7, design the variable thickness patch inner layer area (7). The variable thickness patch inner layer area (7) is a variable thickness area, which is designed along the arc of the arc-shaped gasket area (4) and the inner layer area 3 of the main rod (6). The width is the width of the inner layer area 3 of the main rod (6). The starting point of the variable thickness is the edge of the metal double-ear bushing area (1). Since the thickness of the variable thickness patch inner layer area (7) varies greatly and the shape is relatively regular, the cutting piece is designed and laid in several layers in sequence according to the thickness. The laying angle is [0 / 45 / -45 / 0 / 90 / -45 / 45 / 90]. After laying eight layers, the laying angle is cycled once. Since the cutting piece position is fixed and this area is the patch area, there is no change in the cutting position of the adjacent layers. S8, designing the outer layer area (8) of the variable thickness patch, the outer layer area (8) of the variable thickness patch is expanded outward along the outer contour of the inner layer area (7) of the variable thickness patch, the side height is tangent to the arc-shaped gasket area (4), the starting point of the variable thickness area coincides with the edge of the metal double ear bushing area (1), the curvature design of the lower part is designed according to the width of the arc-shaped gasket area (4), the outer layer area (8) of the variable thickness patch is mainly divided into an inner layer fitting area and an outer layer wrapping area, and two types of cut pieces are designed; S9, the design and laying of the main rod position are completed, the design and laying of the metal double-ear bushing area (1) are also completed, and the outermost wrapping area (9) is designed. The outermost wrapping area (9) is an area that wraps the metal double-ear bushing area (1) and the main rod as a whole. The side surface is tangent to the metal double-ear bushing area (1), the height is flush with the arc-shaped gasket area (4), and the width is the same as the width of the metal double-ear bushing area (1). The design of the outermost wrapping area (9) is relatively complex. It not only needs to connect and wrap the main rod and the metal double-ear bushing area (1), but also is a variable thickness area that smoothly connects the main rod and the metal double-ear bushing area (1). A total of 4 areas are designed and 5 types of cut pieces are laid; S10, after the connection position between the rocker arm and the fuselage is designed by the above-mentioned design ideas and the number of layers of each area is obtained, the layers of each area are unfolded by using the unfolding software, and the layout software is used to layout according to the number of pieces, and the pieces are cut. After the cut pieces are obtained, the core mold is connected by a positioning bracket, and the patches are laid layer by layer according to the positioning position and a certain order. The order is as follows: the inner wrapping area of ​​the double-ear bushing (2), the inner layer area 1 of the main rod (3), the arc-shaped gasket area (4), the inner layer area 2 of the main rod (5), the inner layer area 3 of the main rod (6), the inner layer area of ​​the variable thickness patch (7), the outer layer area of ​​the variable thickness patch (8), and the outermost wrapping area (9).

3. The laying method of the composite double-ear joint structure according to claim 2, characterized in that: The step S2 specifically includes: S2-1, the cut piece 1 (21) in the inner wrapping area of ​​the double-ear bushing is rectangular, and the thickness difference between the raised pattern and the bushing curved surface is compensated, and the layers are laid in sequence according to the thickness, and the laying angle is [0 / 90 / 0]; S2-2, the second cut piece (22) in the inner wrapping area of ​​the double-ear bushing is in the shape of a "non" character, and its main purpose is to make up the thickness difference between the raised patterns. The layers are laid in sequence according to the thickness, and the laying angle is [0 / 45 / 90 / -45 / 0]; S2-3, the third cut piece (23) in the inner wrapping area of ​​the double-ear bushing is a rectangle, and the entire curved surface of the double-ear bushing is layered in sequence according to the thickness, and the layering angle is [0 / 90 / 0]. In order to avoid stress concentration caused by the cuts at the same position or the attachment position leading to premature failure of the material, the cut position distance between adjacent layers is guaranteed to be greater than 50mm when designing the cuts.

4. The laying method of the composite double-ear joint structure according to claim 2, characterized in that: The step S5 is specifically as follows: S5-1, the first cut piece (51) of the second zone of the inner layer of the main rod is used for plying in the constant thickness zone. The plying is performed in sequence according to the thickness. The designed plying angle is [0 / 45 / -45 / 0 / 90 / -45 / 45 / 90]. After eight layers are laid, the plying angle is cycled once. The distance between the cut edges of adjacent layers is 40 mm to prevent stress concentration. S5-2, the second area of ​​the inner layer of the main rod is cut (52) for laying the thickness change area. The thickness change area has a large change, and the layers are laid in sequence according to the thickness. The length of the cut piece is reduced layer by layer, so as to achieve the effect of variable thickness. The laying of the variable thickness area is completed. The laying angle is [0 / 45 / -45 / 0 / 90 / -45 / 45 / 90]. After laying eight layers, the laying angle is cycled once, and the cutting distance between adjacent layers is 40mm. S5-3, the third cut piece (53) of the second zone of the inner layer of the main rod is laid as a whole on the outermost layer after the laying of the two zones is completed. The layers are laid in sequence according to the thickness. The laying angle is [0 / 90] and the cutting distance between adjacent layers is 100mm.

5. The laying method of the composite double-ear joint structure according to claim 2, characterized in that: The step S8 specifically includes: S8-1, the inner layer bonding area is mainly bonded with the inner layer area (7) of the variable thickness patch to locally increase the strength, and the outer layer area of ​​the variable thickness patch is designed to be laid in sequence according to the thickness, and the laying angle is [0 / 45 / 90 / -45 / 0 / 45 / 90]. Since the position of the cutting piece is fixed and the area is the patch area, there is no change in the cutting position of the adjacent layers; S8-2, design the variable thickness patch outer layer area cutting piece 2 (82) in the outer layer wrapping area. The variable thickness patch outer layer area cutting piece 2 (82) is mainly used to wrap the variable thickness patch areas on both sides to complete the overall connection. The layers are laid in sequence according to the thickness. The laying angle is [0 / 90] and the cutting distance between adjacent layers is 100mm.

6. The laying method of the composite double-ear joint structure according to claim 2, characterized in that: The step S9 specifically includes: S9-1, design the outermost wrapping area patch area one piece one (91) to strengthen the area between the metal double ear bushing area (1), and lay the layers in sequence according to the thickness, and the laying angle is [0 / 45 / 90 / -45]. Since the position of the piece is fixed and the area is the patch area, there is no change in the position of the cut edge of the adjacent layers; S9-2, design the outermost wrapping area patch area second piece 2 (92) to further strengthen the metal double ear liner area (1), and lay them in sequence according to the thickness, the laying angle is [0 / 45 / 90 / -45 / 0], and the five layers are in one cycle. Since the position of the piece is fixed and the area is the patch area, there is no change in the position of the cut edge of the adjacent layers; S9-3, design the outermost wrapping area variable thickness area piece three (93), lay them in sequence according to thickness, reduce the pieces layer by layer, and then lay them in sequence according to height. The laying angle is [0 / 45 / -45 / 0 / 90 / -45 / 45 / 90]. After laying eight layers, the laying angle is cycled once. Since the area is fixed, there is no change in the position of the cut edge of the adjacent layers. S9-4, the overall ply area is to connect the metal double ear bushing area (1) with the main rod position, design the outermost wrapping area overall ply area cut piece four (94), and lay them in sequence according to the thickness, the ply angle is [0 / 45 / 90 / -45 / 0], five layers in one cycle, and the distance between the cut positions of adjacent layers is greater than 40mm; S9-5, the outer wrapping area is to wrap the two areas as a whole, design the outer wrapping area cut piece five (95), and lay it according to the thickness.

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