Integrated optimization method for two-stage placement path planning of complex surface composites

Abstract

The present invention discloses an integrated optimization method for two-stage laying path planning of complex curved composite materials, which belongs to the technical field of automatic laying and forming of composite materials. The method is specifically as follows: 1) establishing an initial laying design model; 2) based on the determined laying material, performing a laying suitability analysis on the initial laying design model; 3) dividing the laying surface structure of the laying design model suitable for laying into regions, and determining the laying process parameters of each path planning region; 4) in each path planning region, using a multi-constraint initial laying path generation method to generate an initial laying path; 5) using a multi-constraint optimized path densification method to generate an offset laying path; 6) completing the laying path planning of all path planning regions in each laying layer. The present invention solves the problem of mutual constraints of laying process constraints in the automatic laying process by optimizing the generation method of the initial path and the offset path, and provides a more accurate and efficient automatic laying path planning method.

Description

Technical Field

[0001] The present invention belongs to the technical field of automatic placement and molding of composite materials, and in particular relates to an integrated optimization method for two-stage placement path planning of complex curved surface composite materials. Background Art

[0002] Composite materials, due to their excellent mechanical properties, lightweight characteristics, and high strength-to-weight ratio, have become a key material for modern high-performance structural components. However, the composite molding process is complex. Precisely controlling the fiber placement path and ensuring the quality and efficiency of placement are key to achieving high-performance composite manufacturing, especially when manufacturing large or complex structural components.

[0003] Automatic Fiber Placement (AFP), a key technology in composites manufacturing, is widely used in the production of high-performance composites. This technology uses automated actuators to place prepreg fibers onto a mold surface or prepreg layer in a precise trajectory and pattern, achieving precise composite molding. Compared to traditional manual placement methods, AFP offers higher placement accuracy, repeatability, and production efficiency, making it particularly suitable for the manufacture of large-scale, highly complex composite structures.

[0004] In the process of automatic fiber placement, the path planning algorithm plays a vital role. The reasonable planning of the placement path not only affects the laying quality, but is also directly related to the production efficiency, material utilization and mechanical properties of the final product. The selection of the placement path in the automatic fiber placement process must comprehensively consider multiple factors, such as the placement angle deviation, the gap between prepreg tapes, the minimum turning radius of the prepreg bundle, the performance of the placement equipment, etc. At present, in the automatic fiber placement technology, the path planning algorithm faces the following challenges: (1) The problem of uniformity of process constraints: Due to the actual stress conditions, complex curved surface components may have regional personalized requirements. Unified process constraints (such as placement angle deviation, prepreg tape gap, minimum turning radius of prepreg bundles, gap / overlap ratio) are often difficult to meet the production requirements of the entire complex curved surface component. (2) Limitations of single constraint control: For complex curved surface components, the initial placement path generated by the single constraint method cannot meet other process constraints. For example, the initial placement path generated based on the fixed angle method (considering only the placement angle deviation constraint) does not meet the constraint of the minimum turning radius of the prepreg tow, which may cause placement defects such as wrinkles; the initial placement path generated based on the geodesic method (considering only the minimum turning radius constraint of the prepreg tow) does not meet the constraint of the placement angle deviation. (3) Defects of the densification path generation algorithm: Densification path generation mainly refers to generating other offset paths based on the initial placement path. The equidistant densification method can avoid introducing gap / overlap defects, but on complex components, it may cause conflicts with other process constraints; the non-equidistant densification method can avoid conflicts with other process constraints, but it will cause more gap / overlap defects between adjacent placement paths. In addition, the overlapping interruptions between placement paths make it difficult to fully utilize the excellent mechanical properties of the complete prepreg tow.

[0005] In summary, how to develop a placement path planning algorithm that adapts to the needs of different complex components under multiple process constraints, reduce defects such as gaps / overlaps and wrinkles introduced by placement path planning, and improve production efficiency and material utilization has become a hot issue in the research of automatic wire placement technology. Summary of the Invention

[0006] The purpose of the present invention is to solve the deficiencies in the prior art and provide an integrated optimization method for two-stage placement path planning of complex curved composite materials.

[0007] The specific technical solutions adopted in the present invention are as follows:

[0008] The present invention provides an integrated optimization method for two-stage placement path planning of complex curved composite materials, the specific steps of which are as follows:

[0009] S1: Establish an initial layup design model for complex curved composite components;

[0010] S2: Based on the determined laying material, performing a laying suitability analysis on the initial laying design model in step S1 to obtain a laying design model suitable for laying;

[0011] S3: Dividing the placement surface structure of the ply design model suitable for placement into regions to obtain a plurality of path planning regions, and determining placement process parameters for each path planning region;

[0012] S4: In each path planning area, based on the ply angle and ply angle deviation in the ply design parameters and the minimum turning radius of the prepreg tow in the placement process parameters, a multi-constraint initial placement path generation method is used to generate an initial placement path for each path planning area;

[0013] S5: Using the initial placement path determined in step S4 as a reference, generate an offset placement path through a multi-constraint optimization path densification method; using the initial placement path or the offset placement path as a reference, generate other offset placement paths through a multi-constraint optimization path densification method until the placement path covers each path planning area; thus, completing the placement path planning for the path planning area;

[0014] S6: Repeat steps S4 and S5 to complete the placement path planning for all path planning areas in each layer;

[0015] S7: Plan all prepreg tow placement paths based on the planned placement paths using the equidistant offset technique.

[0016] Preferably, the initial layup design model in step S1 includes a placement surface structure of the composite component and layup design parameters; the method for establishing the initial layup design model is as follows:

[0017] S11: Determine the performance requirements that the composite components need to meet based on design requirements, including the strength, stiffness, and weight of the composite components; determine the placement surface structure of the composite components based on the performance requirements;

[0018] S12: Establishing a placement surface structure for the composite component in 3D software; dividing the placement surface structure according to different layup angles based on the working load and stress boundary conditions of the composite component to obtain several path planning areas;

[0019] S13: Determining a ply design scheme for each path planning area based on the principles of symmetry and balance according to the ply design parameters determined for each path planning area, thereby obtaining a preliminary model; the ply design parameters include ply angle, stacking sequence, number of plies, ply angle deviation, and maximum belt gap width;

[0020] S14: Use finite element analysis software to perform stress analysis on the preliminary model. Based on the stress analysis results, repeatedly adjust the layup design plan until an initial layup design model of the complex curved composite component that meets the design requirements is obtained.

[0021] Preferably, the laying suitability analysis in step S2 is specifically as follows:

[0022] S21: Obtaining Gaussian curvature distribution of the laid surface structure of the initial layup design model;

[0023] S22: Based on the determined placement material, compare the minimum width of the prepreg tow of the placement material with the placement width corresponding to the Gaussian curvature of each path planning area of the placement curved surface structure; if the minimum width of the prepreg tow is smaller than the placement width corresponding to the Gaussian curvature of each path planning area of the placement curved surface structure, then the placement condition is met;

[0024] S23: If the placement conditions are not met, the placement surface structure of the composite component is re-optimized and steps S21 and S22 are repeated until a layup design model suitable for placement is obtained.

[0025] Furthermore, the placement process parameters include the width of the prepreg tow, the number of prepreg tows in a single path, and the minimum turning radius of the prepreg tows; step S3 is specifically as follows:

[0026] S31: obtaining a directional curvature distribution of a laying surface structure of a ply design model suitable for laying;

[0027] S32: Determine the width of the prepreg tows laid in each path planning area, the number of prepreg tows in a single path, and the minimum turning radius of the prepreg tows based on the directional curvature distribution.

[0028] Preferably, the initial paving path generation method in step S4 is specifically as follows:

[0029] S41: selecting a starting path point of the path planning area, and generating a second path point using a fixed angle method according to the ply angle and path generation step length in the ply design parameters; wherein the path generation step length is determined according to the directional curvature distribution of the ply surface structure;

[0030] S42: The next path point is generated using a quadratic programming method with the constraints that the geodesic curvature radius of the current path point is not less than the minimum turning radius of the prepreg tow of the placement material and that the next path point is located on the placement surface structure, and the optimization goal is to minimize the ply angle deviation at the current path point.

[0031] S43: Repeat step S42 until the boundary of the path planning area is reached to obtain an initial path point set of the path planning area; and fit a curve based on the initial path point set to obtain an initial paving path of the path planning area.

[0032] Furthermore, the offset placement path generation method in step S5 is specifically as follows:

[0033] S51: Discretizing the initial placement path to obtain a plurality of discrete path points; multiplying the prepreg tow width of the path planning area by the number of prepreg tows in a single path to calculate a path offset reference distance;

[0034] S52: Based on the discrete path points, with the constraints that the geodesic curvature radius of the current offset path point is not less than the minimum turning radius of the prepreg tow of the placement material, the actual path offset distance of the next offset path point is not less than the path offset reference distance and not more than the sum of the path offset reference distance and the maximum belt gap width, and the next offset path point is located on the placement surface structure, and with the optimization goal of minimizing the ply angle deviation at the current offset path point, solve the next offset path point;

[0035] S53: Repeat step S52 until the offset path point solution for each discrete path point is completed; determine whether the last offset path point reaches the path planning area boundary; if the last offset path point is not on the path planning area boundary, use boundary processing optimization to generate the next offset path point until the last offset path point is on the path planning area boundary; fit the curve based on all offset path points to obtain the offset placement path;

[0036] S54: Using the initial paving path or the offset paving path as a reference path, repeat steps S52 and S53 until the path planning area achieves the full paving target.

[0037] Preferably, step S7 is as follows:

[0038] The actual placement width corresponding to each placement path is calculated according to the placement process parameters of each path planning area; the equidistant offset method is used to generate the prepreg tow placement paths for all path planning areas based on the actual placement width of each placement path.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) Setting process parameters by region to adapt to complex curved surface requirements: This invention innovatively proposes a method for determining placement process parameters by region. For complex curved surface components with different curvature regions, numerical simulation analysis is used to differentiate key parameters such as the width of a single prepreg tow and the number of prepreg tows in a single path. This method effectively solves the technical bottleneck of the traditional unified parameter placement process, which is difficult to adapt to the characteristics of various parts of complex curved surfaces. It significantly improves the placement accuracy and quality uniformity of complex curved surface components, and meets the stringent requirements for component performance under complex working conditions.

[0041] 2) Innovative Initial Path Method to Ensure Mechanical Performance and Placement Quality: The initial path generation method proposed in this paper fully considers the dual constraints of layup angle deviation and measured curvature radius. During the path planning process, optimization theory and intelligent methods are used to ensure that the generated placement path not only meets the component's mechanical performance indicators, load distribution, and structural strength requirements, but also avoids defects such as placement wrinkles caused by the measured curvature radius of the placement path being less than the minimum turning radius of the prepreg tow, thus ensuring high component manufacturing quality from the source.

[0042] 3) Multi-constraint optimization of the densification path to reduce defects and improve placement quality: This paper proposes a multi-constraint optimization densification path generation method. Minimizing ply angle deviation is the core optimization objective, and constraints include surface equations, geodesic curvature radius, and belt gaps. Through nonlinear programming and iterative optimization strategies, this method effectively overcomes the excessive ply angle deviation and gap / overlap defects associated with traditional equidistant densification methods, significantly improving the overall quality and stability of components and meeting the urgent demand for high-precision, high-performance components in high-end manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Flow chart of the optimization method provided by the present invention;

[0044] Figure 2 This is a diagram of the initial placement path generation process in this embodiment;

[0045] Figure 3 This is a diagram of the offset placement path generation process in this embodiment. DETAILED DESCRIPTION

[0046] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention may be combined accordingly, provided that there is no conflict between them.

[0047] As a preferred embodiment of the present invention, this embodiment provides a two-stage laying path planning integrated optimization method for complex curved composite materials, the process is as follows: Figure 1 The specific steps of this optimization method are as follows:

[0048] 1. Establish an initial layup design model for complex curved composite components.

[0049] The initial layup design model includes the composite component's placement surface structure and layup design parameters. The initial layup design model is established as follows:

[0050] (1) Determine the performance requirements that the composite component needs to meet based on the design requirements, including the strength, stiffness, and weight of the composite component. Determine the placement surface structure of the composite component based on the performance requirements.

[0051] (2) Establish the placement surface structure of the composite component in 3D software, such as CAD software. Based on the working load and stress boundary conditions of the composite component, divide the placement surface structure into regions according to different laying angles to obtain several path planning regions.

[0052] (3) Determine the ply design parameters for each path planning area, including ply angle, stacking sequence, number of plies, ply angle deviation, and maximum belt gap width. Based on the determined ply design parameters, the ply design scheme for each path planning area is determined based on the principles of symmetry and balance to obtain a preliminary model.

[0053] The principle of symmetry is adhered to to ensure that the layup is symmetrical on both sides of the axis of symmetry. This symmetrical design avoids tension-shear and tension-bending coupling effects, thus preventing warping of the resulting composite material. The principle of balance is adhered to to ensure a balanced number of plies in different directions, thus ensuring consistent mechanical properties in multiple directions. Those skilled in the art will be able to determine the layup design for each path planning area based on actual needs.

[0054] (4) Use finite element analysis software to perform stress analysis on the preliminary model. Based on the stress analysis results, if the preliminary model does not meet the design requirements, repeat step (3) and adjust the layup design scheme through repeated iterations to finally obtain the initial layup design model of the complex curved composite component that meets the design requirements.

[0055] 2. Analysis of laying suitability

[0056] (1) Use CATIA secondary development tools to obtain the Gaussian curvature distribution of the laying surface structure of the initial layup design model obtained in step 1.

[0057] (2) The grade of the laying material selected in this embodiment is EH104 (1 / 4 inch, 6.35 mm). Based on the determined laying material, it is determined whether the laying material is suitable for laying on the curved surface structure. Specifically, it is determined whether the minimum width of the prepreg tow of the laying material is equal to the laying width corresponding to the Gaussian curvature of the path planning area of the laying curved surface structure. If the minimum width of the prepreg tow is less than the laying width corresponding to the Gaussian curvature of each path planning area of the laying curved surface structure, then the laying condition is met.

[0058] (3) If the laying conditions are not met, it is necessary to re-optimize the laying surface structure of the composite component and then repeat the above steps (1) and (2) until a suitable laying design model is obtained.

[0059] 3. Determine the laying process parameters for each path planning area

[0060] The placement surface structure of the ply design model suitable for placement is meshed according to different ply angles to obtain several path planning areas. In this embodiment, the placement surface structure is divided into two path planning areas, namely S1 and S2. The placement process parameters of each path planning area are determined, including the prepreg tow width, the number of prepreg tows per path, and the minimum turning radius of the prepreg tows. The placement process parameters are determined as follows:

[0061] (1) CATIA secondary development tools are used to obtain the directional curvature distribution of the laying surface structure of the ply design model suitable for laying. The directional curvature reflects the degree of curvature of the surface in a certain direction. The larger the value, the greater the curvature of the surface in that direction.

[0062] (2) Determine the width of the prepreg tow to be laid in each path planning area based on the distribution of directional curvature. In areas with large directional curvature, the width of the prepreg tow should be appropriately reduced to adapt to the curvature of the surface; in areas with small directional curvature, wider prepreg tows can be used to improve laying efficiency. Select an appropriate prepreg tow width to ensure that wrinkles or fiber buckling will not occur during laying. The width of the prepreg tow is usually between 3.2-12.7mm, and the specific width should be determined based on the distribution of directional curvature and the requirements of the laying process.

[0063] Based on the area of the placement area and the width of the prepreg tows, the number of single-pass prepreg tows required for each path planning area is calculated. Areas with greater directional curvature may require more tows to cover the same area to ensure placement quality.

[0064] The minimum turning radius of the prepreg tows to be laid in each path planning area is determined based on the distribution of directional curvature. The minimum turning radius of the prepreg tows should be larger than the minimum bending radius corresponding to the directional curvature of the surface in that area to avoid wrinkles or fiber buckling during placement.

[0065] 4. Generation of initial laying path

[0066] In each path planning area, based on the ply angle and ply angle deviation in the ply design parameters and the minimum turning radius of the prepreg tow in the placement process parameters, a multi-constraint initial placement path generation method is used to generate the initial placement path for each path planning area, such as Figure 2 The specific method is as follows:

[0067] (1) Select the starting point of the path planning area S1 , according to the ply angle and path generation step in the ply design parameters, the first path point is generated using the fixed angle method ; The path generation step size is determined according to the directional curvature distribution of the laid surface structure.

[0068] (2) Based on the current path point The geodesic curvature radius is not less than the minimum turning radius of the prepreg tow of the laying material and the next path point is located on the laying surface structure as the constraint conditions. The optimization goal is to minimize the ply angle deviation, and the next path point is generated using the quadratic programming method. , n≥2.

[0069] For example, to generate the third path point , you need to use the second waypoint The first constraint condition is that the geodesic curvature radius is not less than the minimum turning radius of the prepreg tow of the placement material. The second constraint condition is located on the laying surface structure. The first and second constraints are satisfied at the same time, and the second path point The optimization goal is to minimize the ply angle deviation, and the quadratic programming method is used to generate the third path point. .

[0070] (3) Repeat the above step (2) until the boundary of the path planning area S1 is reached, and the initial path point set of the path planning area is obtained. ; Based on the fitting curve of the initial path point set, the initial laying path P0 of the path planning area S1 is obtained.

[0071] 5. Generation of offset placement path

[0072] The initial placement path P0 determined in step 4 is used as a benchmark, and the offset placement path is generated by the multi-constraint optimization path densification method, as shown in Figure 3 The specific method is as follows:

[0073] (1) Discretize the initial placement path P0 to obtain several discrete path points. Those skilled in the art can select an appropriate degree of discreteness according to actual needs to discretize the initial placement path P0. The path offset reference distance is calculated by multiplying the prepreg tow width W of the path planning area and the number of prepreg tows N in a single path. The width W of the prepreg tow is generally 3.2 mm, 6.35 mm or 12.7 mm, and the number N of prepreg tows in a single path is generally 2, 4, 8, 16, 32, etc. In this embodiment, the number of prepreg tows in a single path in the path planning areas S1 and S2 is 4 and 8 respectively, and the width of the prepreg tow is 3.2 mm and 6.35 mm respectively.

[0074] (2) Based on the discrete path points, the current bias path point The geodesic curvature radius of the placement material is not less than the minimum turning radius of the prepreg tow, the next offset path point The actual path offset distance is not less than the path offset reference distance and not greater than the sum of the path offset reference distance and the maximum belt gap width, the next offset path point The constraint condition is that the current offset path point is located on a complex surface. The optimization goal is to minimize the ply angle deviation and solve the next offset path point. , i≥3.

[0075] For example, to generate the third offset path point , you need to use the second offset path point The first constraint condition is that the geodesic curvature radius is not less than the minimum turning radius of the prepreg tow of the placement material, and the third offset path point is The actual path offset distance is not less than the path offset reference distance And not higher than the path offset reference distance The sum of the maximum band gap width is the second constraint, and the third bias path point The third constraint condition is located on the laying surface structure. The first, second and third constraints are met at the same time, and the second offset path point is used. The optimization goal is to minimize the ply angle deviation, and the quadratic programming method is used to generate the third offset path point. .

[0076] It should be noted that the calculation of the first offset path point and the second offset path point When the first path point and the second waypoint As a benchmark, the calculated path offset benchmark distance Offset to obtain the first offset path point and the second offset path point .

[0077] (3) Repeat step (2) above, using each discrete path point as a benchmark to solve for the corresponding offset path point. Determine whether the last offset path point reaches the boundary of the path planning area S1.

[0078] If the last offset path point is not on the boundary of the path planning area, the next offset path point is generated using boundary processing optimization. The fixed angle method or quadratic programming method in step 4 can be used to continue generating the remaining path points of the offset path.

[0079] For example, using the last offset path point generated above as the starting point, the fixed angle method is used to continue generating the remaining path points of the offset path based on the ply angle and path generation step size in the ply design parameters. Alternatively, the quadratic programming method is used to continue generating path points, with the constraints that the geodesic curvature radius of the offset path point to be generated is not less than the minimum turning radius of the prepreg tow of the placement material, and that the offset path point to be generated is located on the placement surface structure, and the optimization goal is to minimize the ply angle deviation at the offset path point to be generated.

[0080] Until the last path point is located on the boundary of the path planning area; based on the fitting curve of all offset path points, the offset placement path P1 is obtained.

[0081] (4) Use the initial placement path P0 or offset placement path P1 generated above as the reference path and repeat steps (2) and (3) above until the path planning area completes the full coverage target and the placement path planning of the path planning area S1 is completed.

[0082] 6. Refer to steps 4 and 5 to complete the laying path planning of another path planning area S2.

[0083] 7. Complete the prepreg tow placement path planning

[0084] Based on the placement process parameters of path planning area S1 and path planning area S2, the actual placement width corresponding to each placement path is calculated. Using the equal distance offset method, based on the actual placement width of each placement path, the prepreg tow placement path for all path planning areas is generated.

[0085] 8. Generate CNC machining instruction set

[0086] (1) Discretize all prepreg tow placement paths according to the set step size to obtain a placement path information set, which specifically includes the three-dimensional coordinates, normal vectors, and tangent vector information of the path points. This information is used to determine the precise operation of the placement equipment.

[0087] (2) Based on the prepreg tow path information, the prepreg tow cutting information is added to the placement path information set. The cutting information includes the starting point, end point and specific cutting operation instructions of the prepreg tow, ensuring the correct placement and cutting of the prepreg tow during the placement process.

[0088] (3) Combining the parameters of the placement equipment and the placement path information set, compile a numerical control (CNC) machining instruction set.

[0089] The embodiment described above is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Persons skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent substitution or equivalent transformation falls within the scope of protection of the present invention.

Claims

1. A two-stage placement path planning integrated optimization method for complex curved composite materials, characterized by: The specific steps are as follows: S1: Establish an initial layup design model for complex curved composite components; S2: Based on the determined laying material, performing a laying suitability analysis on the initial laying design model in step S1 to obtain a laying design model suitable for laying; S3: Dividing the placement surface structure of the ply design model suitable for placement into regions to obtain a plurality of path planning regions, and determining placement process parameters for each path planning region; S4: In each path planning area, based on the ply angle and ply angle deviation in the ply design parameters and the minimum turning radius of the prepreg tow in the placement process parameters, a multi-constraint initial placement path generation method is used to generate an initial placement path for each path planning area; S5: Using the initial placement path determined in step S4 as a reference, an offset placement path is generated through a multi-constraint optimization path densification method; Using the initial placement path or offset placement path as a benchmark, other offset placement paths are generated through a multi-constraint optimization path densification method until the placement path covers each path planning area. Complete the laying path planning for the path planning area; S6: Repeat steps S4 and S5 to complete the placement path planning for all path planning areas in each layer; S7: Plan all prepreg tow placement paths based on the planned placement paths using the equidistant offset technique. The method for generating the initial laying path in step S4 is specifically as follows: S41: selecting a starting path point of the path planning area, and generating a second path point using a fixed angle method according to the ply angle and path generation step length in the ply design parameters; The path generation step length is determined according to the directional curvature distribution of the laid surface structure; S42: The next path point is generated using a quadratic programming method with the constraints that the geodesic curvature radius of the current path point is not less than the minimum turning radius of the prepreg tow of the placement material and that the next path point is located on the placement surface structure, and the optimization goal is to minimize the ply angle deviation at the current path point. S43: Repeat step S42 until the boundary of the path planning area is reached, and obtain an initial path point set of the path planning area; and fit a curve based on the initial path point set to obtain an initial paving path of the path planning area; The offset placement path generation method in step S5 is specifically as follows: S51: Discretizing the initial placement path to obtain a plurality of discrete path points; multiplying the prepreg tow width of the path planning area by the number of prepreg tows in a single path to calculate a path offset reference distance; S52: Based on the discrete path points, with the constraints that the geodesic curvature radius of the current offset path point is not less than the minimum turning radius of the prepreg tow of the placement material, the actual path offset distance of the next offset path point is not less than the path offset reference distance and not more than the sum of the path offset reference distance and the maximum belt gap width, and the next offset path point is located on the placement surface structure, and with the optimization goal of minimizing the ply angle deviation at the current offset path point, solve the next offset path point; S53: Repeat step S52 until the offset path point solution for each discrete path point is completed; determine whether the last offset path point reaches the path planning area boundary; if the last offset path point is not on the path planning area boundary, use boundary processing optimization to generate the next offset path point until the last offset path point is on the path planning area boundary; fit the curve based on all offset path points to obtain the offset placement path; S54: Using the initial paving path or the offset paving path as a reference path, repeat steps S52 and S53 until the path planning area achieves the full paving target.

2. The integrated optimization method for two-stage placement path planning of complex curved composite materials according to claim 1 is characterized in that: The initial layup design model in step S1 includes the placement surface structure of the composite component and layup design parameters. The method for establishing the initial layup design model is as follows: S11: Determine the performance requirements that the composite components need to meet based on design requirements, including the strength, stiffness, and weight of the composite components; determine the placement surface structure of the composite components based on the performance requirements; S12: Establishing a placement surface structure for the composite component in 3D software; dividing the placement surface structure according to different layup angles based on the working load and stress boundary conditions of the composite component to obtain several path planning areas; S13: Determining a ply design scheme for each path planning area based on the principles of symmetry and balance according to the ply design parameters determined for each path planning area, thereby obtaining a preliminary model; the ply design parameters include ply angle, stacking sequence, number of plies, ply angle deviation, and maximum belt gap width; S14: Use finite element analysis software to perform stress analysis on the preliminary model. Based on the stress analysis results, repeatedly adjust the layup design plan until an initial layup design model of the complex curved composite component that meets the design requirements is obtained.

3. The integrated optimization method for two-stage placement path planning of complex curved composite materials according to claim 1 is characterized in that: The laying suitability analysis in step S2 is specifically as follows: S21: Obtaining Gaussian curvature distribution of the laid surface structure of the initial layup design model; S22: Based on the determined placement material, compare the minimum width of the prepreg tow of the placement material with the placement width corresponding to the Gaussian curvature of each path planning area of the placement curved surface structure; if the minimum width of the prepreg tow is smaller than the placement width corresponding to the Gaussian curvature of each path planning area of the placement curved surface structure, then the placement condition is met; S23: If the placement conditions are not met, the placement surface structure of the composite component is re-optimized and steps S21 and S22 are repeated until a layup design model suitable for placement is obtained.

4. The integrated optimization method for two-stage placement path planning of complex curved composite materials according to claim 3 is characterized in that: The placement process parameters include the width of the prepreg tow, the number of prepreg tows in a single path, and the minimum turning radius of the prepreg tows; step S3 is specifically as follows: S31: obtaining a directional curvature distribution of a laying surface structure of a ply design model suitable for laying; S32: Determine the width of the prepreg tows laid in each path planning area, the number of prepreg tows in a single path, and the minimum turning radius of the prepreg tows based on the directional curvature distribution.

5. The integrated optimization method for two-stage placement path planning of complex curved composite materials according to claim 1, characterized in that: Step S7 is specifically as follows: The actual placement width corresponding to each placement path is calculated according to the placement process parameters of each path planning area; the equidistant offset method is used to generate the prepreg tow placement paths for all path planning areas based on the actual placement width of each placement path.

Images