Annular fiber placement track design method for complex-shape revolving body

Abstract

The invention belongs to the technical field of general structure design, and particularly relates to an annular fiber placement track design method for a complex-shape rotary body. Selecting one point from any position on the surface of the revolution body as a fiber placement starting point; making an initial annular track reference line by passing through a fiber placement starting point; setting an angular deviation limit range of the fiber placement track and the reference line, and determining the fiber placement direction of the fiber placement starting point according to the limit range; gradually generating short straight line segments in a discrete mode and forming a first segment variable curvature track; the turning angle of the adjacent straight line segments is limited in a given range, and the turning radius of the variable curvature track of the segment must be continuous; the variable curvature track of the first segment is generated until the variable curvature tracks of the first n segments jointly form an annular fiber placement track bypassing a complete circle; wherein the generated track bypassing one circle must meet the spiral line limiting condition, and the spiral line is generated by repeating the track bypassing one circle in parallel; and repeating the above process in the rest areas without the fiber placement track design to complete the annular fiber placement track design. According to the method, the turning radius distribution condition of the annular track is calculated and optimized in a segmented variable curvature mode, the annular spiral line is gradually generated, and finally the high-quality annular fiber placement track is obtained.

Description

Technical Field

[0001] This invention belongs to the field of general structural design technology, and specifically relates to a method for designing the circumferential filament laying trajectory of a complex rotating body. Background Technology

[0002] Automated fiber placement, as an advanced automated composite material component manufacturing technology, far surpasses manual fiber placement in terms of placement quality, efficiency, part consistency, and suitability for complex surfaces. This technology is currently primarily used in the aerospace field to manufacture large integral composite structures such as fuselage sections and panels for military and civilian aircraft. The three key elements—material, fiber placement trajectory, and process—are closely interrelated and jointly determine the part's process and mechanical properties. A major challenge in fiber placement trajectory design is that the human brain struggles to visualize the fiber placement effect on non-developable surfaces. Without physically displaying each trajectory, effective evaluation is impossible. Although there are numerous papers and examples on trajectory generation algorithms in China, practical engineering experience shows that most trajectory generation algorithms are only suitable for simple or specific shapes. Relying entirely on fiber placement software to generate good trajectories is unrealistic, and may not even guarantee the successful generation of complete fiber placement trajectories, especially for the complex shapes of modern aircraft air intakes. Summary of the Invention

[0003] The purpose of this invention is to provide a highly versatile and high-quality circumferential filament placement trajectory design method to address the difficulty of generating complex rotating bodies using conventional filament placement software. This method employs a segmented variable curvature approach to calculate and optimize the turning radius distribution of the circumferential trajectory, and progressively generates the circumferential helix, ultimately obtaining a high-quality circumferential filament placement trajectory.

[0004] The technical solution of this invention: a method for designing circumferential filament placement trajectories for complex-shaped rotating bodies, comprising the following steps:

[0005] Step S1: Select a point at any position on the surface of the rotating body as the starting point for wire laying;

[0006] Step S2: Draw an initial circumferential trajectory reference line through the starting point of the yarn layup;

[0007] Step S3: Set the angular deviation limit range between the filament placement trajectory and the reference line, and determine the filament placement direction of the filament placement starting point based on the limit range;

[0008] Step S4: Short straight line segments are generated step by step in a discrete manner to form the first segmented variable curvature trajectory. The number and length of the straight line segments are user-defined or program defaults. The turning angle of adjacent straight line segments is limited to a given range and is user-defined or program defaults. The turning radius of this segmented variable curvature trajectory must be continuous.

[0009] Step S5: Generate the first step in the manner described in step S4. The segmented curvature trajectory until , The process is user-defined or program-controlled until the first n segmented variable curvature trajectories together form a circumferential filament-laying trajectory that completes one revolution. The generated trajectory for one revolution must meet the helical constraint condition, and the helical trajectory is generated by repeating the parallel trajectory for one revolution.

[0010] Step S6: In the remaining areas where the filament placement trajectory has not been designed, perform circumferential filament placement trajectory design according to steps S1-S5.

[0011] Furthermore, in step S1, for complex rotating bodies, the starting point of the fiber placement trajectory is best selected in a non-edge corner area, because the starting point of fiber placement is necessarily the position where the fiber is cut, while edges and corners generally have good stiffness and therefore bear a large load. It is best to ensure the continuity of the fiber, otherwise it will affect the mechanical properties.

[0012] Furthermore, in step S2, the trajectory reference line is determined by the user based on the direction of force on the rotating body, the arrangement direction of the frame beam, and the degree of visual coordination.

[0013] Furthermore, in step S3, the wire laying direction can be controlled manually or through the program's default parameters.

[0014] Furthermore, in steps S3 and S4, the angular deviation between the initial circumferential trajectory reference line and the initial circumferential trajectory is controlled, and short straight line segments are generated step by step in a discrete manner to form the first segmented variable curvature trajectory; wherein, the turning radius of the first segmented variable curvature trajectory is uniformly distributed and continuously changes, and the size of the turning radius is not less than the minimum limit.

[0015] Generate the second segmented variable curvature trajectory, wherein the turning radius of the second segmented variable curvature trajectory is uniformly distributed and continuously varies, and the size of its turning radius is not less than the minimum limit; at the intersection of the first segmented variable curvature trajectory and the second segmented variable curvature trajectory, the tangent is guaranteed to be continuous, and the turning radius of adjacent segmented trajectories at the intersection point can be discontinuous.

[0016] Furthermore, the turning radius is controlled by adjusting the angle of adjacent straight segments to meet the minimum turning radius limit and make the angular deviation between the trajectory and the theoretical reference line controllable.

[0017] Furthermore, within each segmented trajectory, the angle changes of adjacent straight line segments are continuous, and the turning radius of each segmented trajectory changes continuously.

[0018] Furthermore, in step S5, the spiral constraint conditions refer to: the tangents at the beginning and end of the trajectory are parallel; the line connecting the beginning and end is perpendicular to the trajectory; and the pitch is an integer multiple of the width of the filament bundle.

[0019] Furthermore, in step S5, during the process of generating the spiral, the circumferential wire laying trajectory is repeated to form a complete parallel loop, until after a certain parallel loop, the turning radius value at any point on the parallel trajectory exceeds the limit. The resulting spiral trajectory satisfies both the angle deviation and the turning radius within the limit range, and has the longest detour distance, thus ensuring both mechanical properties and laying process performance.

[0020] Furthermore, a complete spiral trajectory is formed by multiple equidistant parallel loops of the filament-laying path, ensuring that the minimum turning radius limit is met at the spiral trajectory.

[0021] The beneficial effects of this invention are as follows: The circumferential filament laying trajectory design method for complex-shaped rotating bodies proposed in this invention is a circumferential filament laying track method that takes into account both process performance and mechanical performance. The trajectory generation method proposed in this invention eliminates the need for conventional meshing operations on the curved surface. By discretizing the trajectory into a certain number of finite-length straight line segments and controlling the turning angle of adjacent straight line segments, the turning radius of the circumferential filament laying trajectory can be effectively controlled to ensure that it does not exceed the limit, thus guaranteeing process performance. Furthermore, the adjustment process of discrete trajectories is easier than that of non-discrete trajectories, greatly simplifying calculations and fully considering the convenience and practicality requirements of engineering applications. By controlling the distribution of the turning radius of the trajectory, the angular deviation between the actual filament laying trajectory and the ideal circumferential trajectory can be ensured to meet design requirements. Theoretically, the laying length of the helix can also be maximized by controlling the distribution of the turning radius. Therefore, using this method to design the circumferential filament laying trajectory for complex-shaped rotating bodies can reduce filament cutting, improve laying efficiency, and reduce mechanical performance loss, thus possessing high engineering practical value. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the trajectory wire laying of the present invention;

[0023] Figure 2 This is a schematic diagram of a complex rotating body structure that can be implemented according to the present invention;

[0024] Figure 3 This is a schematic diagram illustrating the angular deviation between the initial circumferential trajectory reference line and the initial circumferential trajectory controlled by the present invention.

[0025] Figure 4 This invention generates a schematic diagram of the second segmented variable curvature trajectory;

[0026] Figure 5 This is a schematic diagram of the circumferential filament laying trajectory for a complete revolution in this invention.

[0027] Figure 6 This is a schematic diagram illustrating the generation of the complex rotating spiral trajectory of the present invention. Detailed Implementation

[0028] 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, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] In the specific implementation of this invention, a circumferential wire laying method that takes into account both process performance and mechanical performance is proposed, including the following steps:

[0030] Step S1: Select the starting point for fiber placement. Generally, the starting point can be any position on the surface. For complex...

[0031] For hybrid rotating bodies, the starting point of the fiber placement trajectory should ideally be selected in a non-edge or corner area, because the starting point of fiber placement is necessarily the location where the fiber is cut, while edges and corners generally have good stiffness and therefore high load-bearing capacity. It is best to ensure the continuity of the fiber, otherwise it will affect the mechanical properties.

[0032] Step S2: Draw an initial circumferential trajectory reference line from the starting point of the wire laying. This reference line is determined by the user based on the force direction of the rotating body, the arrangement direction of the frame beam, and the degree of visual coordination.

[0033] Step S3: Set the angular deviation limit range between the fiber placement trajectory and the reference line, and determine the fiber placement direction of the starting point based on this limit range. The fiber placement direction can be controlled manually or through the program's default parameters.

[0034] Step S4: Short straight line segments are generated step by step in a discrete manner to form the first segmented variable curvature trajectory. The number and length of the straight line segments are user-defined or program defaults. The turning angle of adjacent straight line segments is limited to a given range and is user-defined or program defaults. The turning radius of this segmented variable curvature trajectory must be continuous.

[0035] Step S5: Generate the first step in the manner described in step S4. The segmented curvature trajectory until , The process is user-defined or program-controlled until the first n segmented variable curvature trajectories combine to form a complete circumferential filament placement trajectory. The generated trajectory must satisfy helical constraints: the tangent at the start of filament placement is parallel to the tangent at the end; the line connecting these two points on the curved surface is perpendicular to the filament placement trajectory; and the pitch is an integer multiple of the filament width. This helical trajectory can be generated by repeatedly creating parallel circumferential trajectories. See the appendix for helical constraints and parallel generation. Figure 1 .

[0036] In the specific implementation of this invention, the process of generating a spiral trajectory can be implemented through program code. One pseudocode form for generating a spiral trajectory is as follows:

[0037]

[0038] While

[0039] Create %Note: Generates the first [number] according to the turning radius constraint. A trajectory

[0040]

[0041] End

[0042] %Note: will The individual trajectories are integrated into a complete week's worth of silk-laying trajectory.

[0043]

[0044] While

[0045] Parallel %Note: The wire placement trajectory Repeated equidistant parallel

[0046] Check radius of PC % (Note: Check the turning radius of parallel lines)

[0047] If RPC satisfied

[0048] %Note: If the turning radius requirement is met, further generation will proceed.

[0049] Else if RPC is not satisfied

[0050] Break %Note: Generation will terminate if the turning radius requirement is not met.

[0051] End

[0052] End

[0053] End

[0054] Step S6: In the remaining areas where the filament placement trajectory has not been designed, perform circumferential filament placement trajectory design according to steps S1-S5.

[0055] Example 1, with appendix Figure 2Taking the manufacturing of complex rotating structures as an example, the implementation process of using the circumferential wire placement trajectory design method includes the following steps:

[0056] Step S1: For the attached Figure 2 The circumferential filament placement trajectory of the rotating body shown is designed by first selecting the filament placement starting point in the non-corner area;

[0057] Step S2: Draw an initial circumferential trajectory reference line through the starting point of the filament laying. Here, the intersection of the partition plane and the solid of revolution is selected as the circumferential trajectory reference line. See Appendix. Figure 3 , 4 To demonstrate the advantages of the method of the present invention, a geodesic line passing through the initial filament laying point is also constructed as a performance comparison object.

[0058] Steps S3-S4: Control the angular deviation between the initial circumferential trajectory reference line and the initial circumferential trajectory, and gradually generate short straight line segments using a discrete method to form the first segmented variable curvature trajectory, see appendix. Figure 3 Among them, the turning radius of the first segmented variable curvature trajectory is uniformly distributed and continuously varies, and the size of the turning radius is not less than the minimum limit;

[0059] The second piecewise variable curvature trajectory was generated, see appendix. Figure 4 In the second segmented variable curvature trajectory, the turning radius is uniformly distributed and continuously varies, with each turning radius not less than the minimum limit. At the intersection of the first and second segmented variable curvature trajectories, the tangent is guaranteed to be continuous, but the turning radius value may be discontinuous. (See attached...) Figure 4 It can also be seen that the geodesic trajectory has deviated significantly from the circumferential reference line, while the method of the present invention can effectively control the trajectory angle deviation.

[0060] Step S5: A total of 3 segmented variable curvature trajectories are used to form a complete circumferential filament-laying trajectory, satisfying the helical constraint conditions. See Appendix. Figure 5 ;

[0061] Repeat the parallel circumferential wire-laying trajectory for a complete cycle to form a spiral trajectory, until after a certain parallelization, the turning radius at any point on the parallel trajectory exceeds the limit. See the attached spiral trajectory diagram. Figure 6 This spiral trajectory simultaneously satisfies the requirements that the trajectory angle deviation and turning radius are within a limited range, and also achieves the longest possible detour distance, thus ensuring both mechanical performance and laying process performance.

[0062] Step S6: In the remaining areas where trajectory design has not yet been performed, generate circumferential wire laying trajectories according to S1-S5.

[0063] The circumferential filament placement trajectory design method described above can effectively control the turning radius of the circumferential filament placement trajectory to not exceed the limit, thereby ensuring process performance; by controlling the distribution of the turning radius of the trajectory, it ensures that the angle deviation between the actual filament placement trajectory and the ideal circumferential trajectory meets the requirements; it maximizes the laying length of the spiral, reduces filament cutting, improves laying efficiency, reduces mechanical property loss, and has high engineering practical value.

[0064] The above description is merely a specific embodiment of the present invention, providing a detailed description of the invention. Parts not covered herein are conventional techniques. However, the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for designing the circumferential filament placement trajectory of a complex-shaped rotating body, characterized in that, Includes the following steps: Step S1: Select a point at any location on the surface of the rotating body as the starting point for wire laying; Step S2: Draw an initial circumferential trajectory reference line through the starting point of the yarn layup; Step S3: Set the angular deviation limit range between the filament placement trajectory and the reference line, and determine the filament placement direction of the filament placement starting point based on the limit range; Step S4: Short straight line segments are generated step by step in a discrete manner to form the first segmented variable curvature trajectory. The number and length of the straight line segments are user-defined or program defaults. The turning angle of adjacent straight line segments is limited to a given range and is user-defined or program defaults. The turning radius of this segmented variable curvature trajectory must be continuous. Step S5: Generate the first step in the manner described in step S4. The segmented curvature trajectory until , The process is user-defined or program-controlled until the first n segmented variable curvature trajectories together form a circumferential filament-laying trajectory that completes one revolution. The generated trajectory for one revolution must meet the helical constraint condition, and the helical trajectory is generated by repeating the parallel trajectory for one revolution. Step S6: In the remaining areas where the filament placement trajectory has not been designed, perform circumferential filament placement trajectory design according to steps S1-S5.

2. The method for designing the circumferential filament placement trajectory of a complex-shaped rotating body as described in claim 1, characterized in that, In step S1, for complex rotating bodies, the starting point of the wire laying trajectory is selected in the non-edge corner area.

3. The method for designing the circumferential filament placement trajectory of a complex-shaped rotating body as described in claim 1, characterized in that, In step S2, the trajectory reference line is determined by the user based on the direction of force on the rotating body, the arrangement direction of the frame beam, and the degree of visual coordination.

4. The method for designing the circumferential filament placement trajectory of a complex-shaped rotating body as described in claim 1, characterized in that, In step S3, the wire laying direction is controlled manually or by the program's default parameters.

5. A method for designing the circumferential filament placement trajectory of a complex-shaped rotating body as described in claim 1 or 4, characterized in that, In steps S3 and S4, the angular deviation between the initial circumferential trajectory reference line and the initial circumferential trajectory is controlled, and short straight line segments are generated step by step in a discrete manner to form the first segmented variable curvature trajectory; wherein, the turning radius of the first segmented variable curvature trajectory is uniformly distributed and continuously varies, and the size of the turning radius is not less than the minimum limit. Generate the second segmented variable curvature trajectory, wherein the turning radius of the second segmented variable curvature trajectory is uniformly distributed and continuously varies, and the size of its turning radius is not less than the minimum limit; at the intersection of the first segmented variable curvature trajectory and the second segmented variable curvature trajectory, the tangent is guaranteed to be continuous, and the turning radius of adjacent segmented trajectories at the intersection point can be discontinuous.

6. The method for designing the circumferential filament placement trajectory of a complex-shaped rotating body as described in claim 5, characterized in that, The turning radius is controlled by adjusting the angle of adjacent straight segments to meet the minimum turning radius limit and to keep the angular deviation between the trajectory and the theoretical reference line controllable.

7. The method for designing the circumferential filament placement trajectory of a complex-shaped rotating body as described in claim 5, characterized in that, In each segmented trajectory, the angle changes of adjacent straight line segments are continuous, and the turning radius of each segmented trajectory changes continuously.

8. The method for designing the circumferential filament placement trajectory of a complex-shaped rotating body as described in claim 1, characterized in that, In step S5, the spiral constraint conditions are: the tangents at the beginning and end of the trajectory are parallel; the line connecting the beginning and end is perpendicular to the trajectory; and the pitch is an integer multiple of the width of the filament bundle.

9. The method for designing the circumferential filament placement trajectory of a complex-shaped rotating body as described in claim 1, characterized in that, In step S5, during the process of generating the spiral, the circumferential wire laying trajectory is repeated to form a complete parallel loop, until after a certain parallel loop, the turning radius value at any point on the parallel trajectory exceeds the limit. The resulting spiral trajectory satisfies both the angle deviation and the turning radius within the limit range, and has the longest detour distance, thus ensuring both mechanical properties and laying process performance.

10. The method for designing the circumferential filament placement trajectory of a complex-shaped rotating body as described in claim 9, characterized in that, A complete spiral trajectory is formed by multiple parallel, equidistant loops of the filament, ensuring that the minimum turning radius requirement is met at the spiral trajectory.

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