A spoke plate, a layup method, and a layup optimization method

Abstract

This invention provides a spoke plate, a layup method, and a layup optimization method, belonging to the field of spoke plate layup technology. The spoke plate is a rotating structure with a central axial hole. The rotating cross-section of the spoke plate includes: Block I to Block V, where Block I is the innermost region of the spoke plate, with a constant thickness along the first radial direction; and Block II, connected to Block I, with a constant thickness along the first radial direction. The spoke plate of this invention divides the rotating cross-section into multiple blocks. By laying up each block in a fixed sequence, a superior spoke plate structure is obtained. This invention overcomes the limitations of traditional layup methods by dividing the spoke plate structure into thickness zones, determining the layup method for the carbon fiber spoke plate, and achieving flexibility and intelligence in carbon fiber spoke plate layup optimization by combining CAE analysis with genetic algorithms, resulting in a theoretically optimal layup structure in terms of mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of spoke layup technology, and specifically relates to a spoke, a layup method, and a layup optimization method. Background Technology

[0002] In addition to their excellent mechanical properties, continuous fiber reinforced composites also offer a high degree of flexibility in structural design. Unlike common metal structures, continuous fiber reinforced composite structural components often require stacking layers of prepreg to obtain the corresponding prefabricated shape and size. The entire structure involves a great deal of structural information, including thickness variations, number of layup layers, layup angles, and layup sequence.

[0003] To further reduce the weight of the transmission system and improve its power-to-weight ratio, carbon fiber gear spokes, as a lightweight alternative to metal gear spokes, can significantly reduce the overall weight of the structure while meeting the required structural performance. However, achieving optimal mechanical properties for carbon fiber spokes remains a major challenge. Besides traditional structural design and optimization, specific layup designs and optimizations based on the structure's load characteristics can also significantly improve the mechanical properties of carbon fiber spoke structures. However, the complexity of the structure brings design challenges related to the number of layups and layup angles, meaning that current carbon fiber spoke layup design optimization still relies on traditional empirical methods. How to efficiently determine the optimal layup sequence for carbon fiber gear spokes to achieve better structural performance is a problem that needs to be solved.

[0004] Currently, there are relatively few examples of optimized layup designs for carbon fiber gear spokes, both domestically and internationally. Anderson et al., in their work on lightweight carbon fiber design for gears in advanced transmission systems, listed several different layup sequences and compared the structural performance corresponding to different layup designs. They first constructed, for instance... Figure 1 The CAE model of carbon fiber gear spoke layup shown accurately expresses the layup information of the spoke structure by constructing each layup unit. When optimizing the layup sequence, they compared the analysis results corresponding to common layups of [0°,+45°,-45°,90°], [0°,+60°,-60°,90°], and [0°,+60°,-60°,+60°,-60°,90°].

[0005] The carbon fiber gear spoke layup design method proposed by Anderson et al. effectively reflects the significant impact of layup design on the mechanical properties of spoke structures, and they provided corresponding layup design guidelines based on empirical methods. However, they did not solve the problem of finding the optimal layup sequence.

[0006] Therefore, the current design and optimization of carbon fiber gear spokes are still in their early stages, which means that the potential of the structure cannot be fully explored and the spokes layup process tends to be conservative. Therefore, it is urgent to develop a layup method and optimization method to improve the entire carbon fiber gear spokes layup process. Summary of the Invention

[0007] To address at least one of the problems in the background art, the present invention proposes a spoke plate, a layup method, and a layup optimization method.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A spoke plate, wherein the spoke plate is a rotating structure with a centrally located shaft hole, and the rotating cross section of the spoke plate includes:

[0010] Block I is the innermost region of the spokes, with a constant thickness along the first radial direction of the spokes;

[0011] Block II, connected to Block I, has a constant thickness along the first radial direction of the spokes;

[0012] Block III is a reinforcing rib used to connect Block I and Block II, and the thickness of Block III gradually decreases along the first radial direction;

[0013] Block IV is connected to the end of Block II that is furthest from Block I, and the thickness of Block IV gradually decreases along the first radial direction;

[0014] Block V is connected to the end of Block IV that is away from Block IV, and the thickness of Block V gradually decreases along the first radial direction.

[0015] Preferably, the first radial direction is the direction from the innermost side of the spoke to the outermost side of the spoke.

[0016] Preferably, the material of the spokes includes carbon fiber.

[0017] A layup method for spokes, used for laying up the aforementioned spokes, includes the following steps:

[0018] Perform alternating layups until regions with gradually decreasing thickness in blocks IV and V are formed;

[0019] Perform alternating layups until the region with gradually decreasing thickness in block III is formed.

[0020] Preferably, alternating layups are performed to form regions with gradually decreasing thickness in blocks IV and V, including the following steps:

[0021] A first layup is obtained by continuously plying blocks I, II, IV and V along the first radial direction;

[0022] Alternatively, a second ply can be obtained by continuously plying blocks II, IV, and V along the first radial direction;

[0023] A third ply is obtained by continuously plying blocks I and II along the first radial direction;

[0024] The first and third plies are stacked alternately, or the second and third plies are stacked alternately.

[0025] Preferably, alternating layups are performed until a region with gradually decreasing thickness in block III is formed, including the following steps:

[0026] The fourth ply is obtained by continuously plying blocks I and II along the first radial direction until the outermost part of block II.

[0027] Continue laying layers continuously along the first radial direction for blocks I and II until the midpoint of block II, to obtain the fifth layer;

[0028] The sixth ply is obtained by continuously plying blocks I and II along the first radial direction until the thickness of block II begins to change.

[0029] Alternately stack the fourth, fifth, and sixth plies.

[0030] A method for optimizing the ply of a spoke is used for an initial ply, wherein the initial ply is any one of a first ply, a second ply, a third ply, a fourth ply, a fifth ply, and a sixth ply.

[0031] Preferably, the layup optimization method includes the following steps:

[0032] Generate multiple sets of initial ply angle variables;

[0033] The generated angle variables are substituted into the finite element model of the spokes for CAE analysis to obtain the target values ​​corresponding to each initial ply.

[0034] The angle variable and its corresponding target value are used as the initial input parameters of the genetic algorithm to obtain the next generation ply angle solution;

[0035] Determine whether the current ply angle solution and the corresponding target value have reached the optimization termination condition. If the solution converges or the optimization reaches the maximum number of iterations, output the final converged solution.

[0036] Preferably, the angle variable takes the value of 0°, 30° or 60°.

[0037] The beneficial effects of this invention are:

[0038] 1. The spokes of the present invention divide the cross section of rotation into multiple blocks, and by laying each block in a fixed order, a better spoke structure is obtained;

[0039] 2. The spokes of the present invention break away from the limitations of traditional layup methods. By dividing the spoke structure into thickness zones, the layup method of carbon fiber spokes is determined. Furthermore, by combining CAE analysis with genetic algorithms, the flexibility and intelligence of carbon fiber spoke layup optimization are achieved, resulting in a layup structure with theoretically optimal mechanical properties.

[0040] 3. This invention breaks free from the limitations imposed by traditional experience with carbon fiber spokes, provides a specific method for carbon fiber spoke layup, and enables the optimization of carbon fiber spoke layup to obtain the optimal solution theoretically, while also achieving intelligent optimization process.

[0041] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 A diagram of the existing spoke structure is shown;

[0044] Figure 2 A top view of a spoke of the present invention is shown;

[0045] Figure 3 This is a structural schematic diagram showing that blocks I and II of the present invention are of equal height;

[0046] Figure 4 A schematic diagram of the structure of the present invention, showing that blocks I and II have unequal heights, is shown;

[0047] Figure 5 It's out Figure 4 Ply layout diagram of the center plate;

[0048] Figure 6 A structural diagram of ply 2a of ply 1 of the present invention is shown;

[0049] Figure 7 The structural diagrams of ply 2b and ply 3 of the present invention are shown;

[0050] Figure 8 A structural diagram of the layup 4 of the present invention is shown;

[0051] Figure 9 A structural diagram of the layup 5 of the present invention is shown;

[0052] Figure 10 A structural diagram of the layup 6 of the present invention is shown;

[0053] Figure 11 The CAE finite element analysis model diagram of the spoke plate of the present invention is shown;

[0054] Figure 12 A flowchart of the layup optimization method for the spokes of the present invention is shown. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] A type of spoke, such as Figure 2 The structure shown is a rotating body with a central axial hole in the spokes. It is made by stacking carbon fiber prepregs layer by layer along the thickness direction. In order to determine how the structure was obtained through the layup design, the entire structure was divided into different sections according to the change of the cross-sectional thickness of the spokes.

[0057] like Figure 3 and Figure 4 As shown, the zones can be distinguished according to the gyroscopic cross section of the spokes, where: Zone I is the innermost region of the spokes, with a constant thickness along the first radial direction; Zone II is connected to Zone I, with a constant thickness along the first radial direction; Zone III is a reinforcing rib used to connect Zone I and Zone II, and the thickness of Zone III gradually decreases along the first radial direction; Zone IV is connected to the end of Zone II away from Zone I, and the thickness of Zone IV gradually decreases along the first radial direction; Zone V is connected to the end of Zone IV away from Zone IV, and the thickness of Zone V gradually decreases along the first radial direction.

[0058] It should be noted that the first radial direction is the direction from the innermost side of the spoke to the outermost side of the spoke. Among them, blocks I and II are multi-layered ply structures with constant thickness, while blocks III, IV and V are variable ply structures with continuously varying thickness.

[0059] It needs to be further explained that, in Figure 3 The left sides of both block I and block II are of equal thickness. Figure 4In this case, the thickness of block II is greater than that of block I, which affects the layup of the spokes. The layup method for the spokes is explained below for these two situations:

[0060] by Figure 3 Taking a spoke as an example, a layup method for spokes includes the following steps:

[0061] S1: Perform alternating lay-up until regions with gradually decreasing thickness in blocks IV and V are formed;

[0062] S101: Continuously lay up blocks I, II, IV and V along the first radial direction to obtain the first layup;

[0063] S102: Continuously lay up blocks I and II along the first radial direction to obtain the third layup;

[0064] S103: The first and third plies are stacked alternately.

[0065] S2: Perform alternating lay-up until the region with gradually decreasing thickness in block III is formed.

[0066] S201: Continuously lay up blocks I and II along the first radial direction until the outermost part of block II is reached to obtain the fourth layup;

[0067] S202: Continuously lay up blocks I and II along the first radial direction until the midpoint of block II, to obtain the fifth layup;

[0068] S203: Continuously lay up blocks I and II along the first radial direction until the thickness of block II begins to change, thus obtaining the sixth layup;

[0069] S204: Alternately stack the fourth, fifth, and sixth plies.

[0070] by Figure 4 For example, when laying the spokes, they can be divided into multiple areas, specifically as follows: Figure 5 As shown, the spokes are divided into (1) a bottom layer ply design area; (2) a middle main ply design area; and (3) an upper reinforcing rib ply design area. According to Figure 4 Thickness partitioning and Figure 5 The layup zoning has the following carbon fiber spoke layup design from bottom to top, as detailed below:

[0071] B1: Two types of plies are designed for the bottom layer area: ply 1, which runs through blocks II, IV, and V, and ply 2a, which only covers block II. Because these two plies have different lengths, ply 2a only extends to the rightmost end of block II. Therefore, when the two plies are laid alternately, a change in ply thickness will occur in area IV. Schematic diagrams of ply 1 and ply 2a are shown below. Figure 6 As shown, where r1 is Figure 2 The distance r2 from the center of the circle to the leftmost side of block II is Figure 2 The distance from the center of the circle to the rightmost side of block V, r3 is Figure 2 The distance from the center of the circle to the leftmost side of block IV.

[0072] B2: For the central main ply design area, two ply types are also designed: one is a continuous ply 3 that runs through blocks I, II, IV, and V; the other is a ply 2b that only covers blocks II and III. Schematic diagrams of ply 3 and ply 2b are shown below. Figure 7 As shown, the meanings of r2 and r3 are the same as... Figure 6 Same, r4 represents Figure 2 The distance from the center of the circle to the leftmost side of block I. Similarly, the alternating laying of ply 3 and ply 2b will create a change in thickness in region IV. The alternating laying of ply 1, 2a, 2b, 3, and 4 in the bottom ply design area and the middle main ply design area together form the continuous thickness change in block IV.

[0073] B3: For the upper reinforcing rib layup design area, due to the long transition area of ​​the reinforcing rib thickness, three different rib sizes were designed, such as... Figure 8 As shown. Layer 4 runs through the entire blocks I and II; as... Figure 9 As shown, layer 5 is laid to the middle part of block II; as Figure 10 As shown, ply 7 is laid only at the point where the thickness of block II begins to change. The alternating laying of plies 4, 5, and 6 creates a continuous thickness variation throughout the entire reinforcing rib structure area.

[0074] It should be noted that, Figure 4 The spokes and Figure 3 The difference in the layup methods of the spokes lies only in Figure 4 In the process, blocks II, IV, and V need to be continuously padded along the first radial direction to obtain the second ply (corresponding to B1). The steps for B2 are the same as those in S101-S103. Therefore, the correspondence between the first to sixth plies and plies 1 to 6 is as follows: the first ply corresponds to ply 1, the second ply corresponds to plies 2a and 2b (that is, in the bottom ply design area, the second ply is ply 2a, and in the middle main ply design area, the second ply is ply 2b), the third ply corresponds to ply 3, the fourth ply corresponds to ply 4, the fifth ply corresponds to ply 5, and the sixth ply corresponds to ply 6.

[0075] like Figure 11As shown, a CAE finite element analysis model of a 1 / 8-inch carbon fiber spoke was constructed based on the layup method of the carbon fiber spokes. The number of layers corresponding to layups 1 through 6 are 17, 8, 65, 53, 14, 13, and 18, respectively. The thickness of a single prepreg layer is approximately 0.21 mm, and the layup angle variables can be selected as 0°, 30°, and 60°. By modeling each layup layer, the layup characteristics of the structure are accurately reflected, and the variability of the layup angle is realized.

[0076] Based on the established finite element model of the carbon fiber spokes and the defined spoke ply design information, the ply optimization process can be further determined. Each ply angle is a design variable. The entire carbon fiber spoke has 188 ply layers, therefore the entire ply optimization involves 188 variables, with each ply angle potentially taking one of 0°, 30°, or 60°. The entire optimization method is as follows:

[0077] A method for optimizing the ply of a spoke, used for an initial ply, wherein the initial ply is any one of a first ply, a second ply, a third ply, a fourth ply, a fifth ply, and a sixth ply, comprising the following steps:

[0078] A1: Generates multiple sets of initial ply angle variables; the variable values ​​correspond to... Figure 11 The ply angles are selected sequentially from bottom to top. Some design principles can be introduced at this point.

[0079] A2: Substitute the generated angle variables into the finite element model of the spokes and perform CAE analysis to obtain the target value corresponding to each initial layup.

[0080] A3: The angle variable and the corresponding target value are used as the initial input parameters of the genetic algorithm and the initial evolution input parameters. Crossover, mutation and selection operations are performed to obtain the next generation of ply angle solutions.

[0081] A4: Determine whether the current ply angle solution and the corresponding objective value have reached the optimization termination condition. If the solution converges or the optimization reaches the maximum number of iterations, output the final converged solution.

[0082] It should be noted that the process of steps A1-A4 is as follows: Figure 12 As shown, where Figure 12 The optimization termination condition in the conditional block diagram is to determine whether the solution has converged or whether the optimization has reached the maximum number of iterations.

[0083] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A web, characterized in that, The spoke is a rotary body structure with an axial hole in the center, and the rotary cross section of the spoke includes: Block I, which is the innermost region of the spoke, has a constant first radial thickness along the spoke; the first radial direction is from the innermost side of the spoke to the outermost side of the spoke; the material of the spoke includes carbon fiber; Block II, which is connected to Block I along the first radial direction of the spoke, has a constant first radial thickness along the spoke; Block III, which is a reinforcing rib for connecting Block I and Block II, gradually decreases in first radial thickness; Block III is connected to Block I along the first radial direction of the spoke and is located above Block II; Block IV, which is connected to the end of Block II away from Block I, gradually decreases in first radial thickness; Block V, which is connected to the end of Block IV away from Block II, gradually decreases in first radial thickness.

2. A method of laying up a web, characterized in that A method for layering the spoke of claim 1.

3. A method of laying up a web according to claim 2, wherein, The method comprises the following steps: performing alternating layering until the region with gradually decreasing thickness in Block IV and Block V is formed; performing alternating layering until the region with gradually decreasing thickness in Block III is formed.

4. A method of laying up a web according to claim 3, wherein The method for forming the region with gradually decreasing thickness in Block IV and Block V comprises the following steps: continuously layering Block I, Block II, Block IV, and Block V along the first radial direction to obtain a first layer; alternatively, continuously layering Block II, Block IV, and Block V along the first radial direction to obtain a second layer; continuously layering Block I and Block II along the first radial direction to obtain a third layer; alternately stacking the first layer and the third layer, or alternately stacking the second layer and the third layer.

5. A method of laying up a web according to claim 4, wherein, The method for performing alternating layering until the region with gradually decreasing thickness in Block III is formed comprises the following steps: continuously layering Block I and Block II along the first radial direction until the outermost side of Block II to obtain a fourth layer; continuously layering Block I and Block II along the first radial direction until the midpoint of Block II to obtain a fifth layer; continuously layering Block I and Block II along the first radial direction until the position where the thickness of Block II starts to change to obtain a sixth layer; alternately stacking the fourth layer, the fifth layer, and the sixth layer.

6. A method of optimizing a ply of a web, characterized by, A method for initial layering, wherein the initial layering is any one of the first layer, the second layer, the third layer, the fourth layer, the fifth layer, and the sixth layer described in claim 5.

7. The method of claim 6, wherein, The method comprises the following steps: generating a plurality of sets of angle variables for the initial layering; inputting the generated angle variables into a finite element model of the spoke to perform CAE analysis, thereby obtaining a target value corresponding to each initial layering; using the angle variables and the corresponding target values as initial input parameters of a genetic algorithm to obtain a next-generation layering angle solution; determining whether the current obtained layering angle solution and the corresponding target value meet the termination condition of optimization, and if the solution converges or the optimization reaches the maximum number of iterations, outputting the final converged solution.

8. The method of claim 7, wherein, The angle variable has a value of 0°, 30°, or 60°.

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