Method and apparatus for collaborative optimization of continuous fiber 3D printing path

Abstract

This application discloses a method and apparatus for collaborative optimization of continuous fiber 3D printing paths, relating to the field of 3D printing technology. It solves the problems of high computational load and sharp corners in the paths of existing technologies. The method includes setting the end nodes of the rods as design variables and determining the initial position values ​​of the end nodes; determining the relationship between the coordinates of the end nodes and the angles between adjacent rods and the total rod length, using analytical functions to control the angles and the total rod length; establishing the horizontal set function of the rod chain structure; determining the optimization objective of the minimum overall flexibility of the rod chain structure; optimizing the rod chain structure according to gradient optimization algorithms and constraints, and determining the optimization results; thus achieving an optimized design of the rod chain layout while avoiding sharp corners in the path with relatively low computational load.

Description

Technical Field

[0001] This application relates to the field of 3D printing technology, and in particular to a method and apparatus for collaborative optimization of continuous fiber 3D printing paths. Background Technology

[0002] Currently, 3D printing technology utilizes the discrete-stacking approach, fundamentally avoiding the difficulties in forming and processing inherent in traditional building material manufacturing. This not only effectively improves manufacturing efficiency and material utilization, reducing production costs, but also enables rapid and precise manufacturing of complex structures. Fiber-reinforced composite materials, as a type of asymmetrical material, offer advantages over metals, including high specific strength, high specific modulus, high designability, and multifunctional integration. Through structural design methods such as topology optimization, lightweighting can be achieved while maintaining performance.

[0003] The published design method can perform anisotropic topology optimization on the structure under simple working conditions, followed by path planning on the resulting geometry. However, it suffers from the following problems: 1. Topology optimization and continuous fiber path planning are performed separately, lacking complete coupling, which limits the optimization potential to some extent. 3. Although traditional methods use anisotropic topology optimization, and path planning based on this improves structural performance, the structure obtained from anisotropic topology optimization can only serve as a reference for fiber path planning and is not identical to the actual structure containing continuous fibers. 5. Paths generated by traditional methods often result in "dead ends" beyond the structural boundaries, requiring manual cutting and wasting fibers, and requiring roughening of the assembly surface. In conclusion, it is necessary to develop a method that fully coordinates topology optimization and continuous printing paths to truly simulate the mechanical behavior of continuous fibers in the matrix, satisfy various boundary conditions during printing, and analytically control engineering constraints. Summary of the Invention

[0004] This application provides a continuous fiber 3D printing path collaborative optimization method and apparatus, which solves the problems of large computational load and sharp corners in the path in the prior art. It achieves optimized design of the rod chain layout by avoiding sharp corners in the path with a smaller computational load.

[0005] In a first aspect, embodiments of the present invention provide a method for collaborative optimization of continuous fiber 3D printing paths, the method comprising:

[0006] Set the pole end node as a design variable and determine the initial position value of the end node;

[0007] Determine the relationship between the coordinates of the end node, the angle between the adjacent rods, and the rod length;

[0008] Establish the horizontal set function for the link-chain structure;

[0009] Determine the constraints for the minimum overall flexibility of the link-chain structure;

[0010] The link-chain structure is optimized based on the gradient optimization algorithm and the constraints, and the optimization result is determined.

[0011] In conjunction with the first aspect, in one possible implementation, determining the relationship between the end node coordinates and the angle between adjacent rods and the rod length includes:

[0012] Determine the total length of the rod-chain structure;

[0013] Establish the included angle constraint model function and the distance model function between the rod chain structure and the design domain boundary.

[0014] In conjunction with the first aspect, in one possible implementation, the horizontal set function for establishing the link-chain structure includes:

[0015]

[0016]

[0017]

[0018] Where, x e ,y e d represents the coordinate position of a point within the design domain; e,i Represents a point (x) within the design domain. e ,y e ) to rod l i The distance between them; Φ represents the horizontal set function of a single rod.

[0019] x e In conjunction with the first aspect, in one possible implementation, the constraints include: constraining the total length of the rod-chain structure and the angles between rods with the objective of minimizing the overall flexibility of the rod-chain structure.

[0020] In conjunction with the first aspect, in one possible implementation, the constraint condition further includes: constraining the distance between the link structure and the boundary of the design domain.

[0021] Secondly, embodiments of the present invention provide a continuous fiber 3D printing path collaborative optimization device, the device comprising:

[0022] An initial value setting unit is used to set the pole end node as a design variable and determine the initial position value of the end node;

[0023] The variable relationship determination unit is used to determine the relationship between the coordinates of the end node and the angle between adjacent poles and the total pole length, and uses analytical functions to control the angle and the total pole length.

[0024] Function creation unit, used to create the horizontal set function of the link chain structure;

[0025] A constraint determination unit is used to determine the optimization objective of the minimum overall flexibility of the link chain structure;

[0026] An optimization unit is used to optimize the link-chain structure according to a gradient optimization algorithm and the constraints, and to determine the optimization result.

[0027] In conjunction with the second aspect, in one possible implementation, the variable relationship determination unit is used to determine the total length of the link chain structure; establish an angle constraint model function; and establish a distance model function between the link chain structure and the design domain boundary.

[0028] In conjunction with the second aspect, in one possible implementation, the function establishment unit is based on...

[0029]

[0030]

[0031]

[0032] Where, x e ,y e d represents the coordinate position of a point within the design domain; e,i Represents a point (x) within the design domain. e ,y e ) to rod l i The distance between them; Φ represents the horizontal set function of a single rod.

[0033] x e In conjunction with the second aspect, in one possible implementation, the constraint determination unit includes: constraining the total length of the rod-chain structure and the angles between rods with the objective of minimizing the overall flexibility of the rod-chain structure.

[0034] In conjunction with the second aspect, in one possible implementation, the constraint determination unit further includes constraining the distance between the link structure and the design domain boundary.

[0035] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0036] This invention employs a continuous fiber 3D printing path collaborative optimization method and apparatus. The method includes: setting end nodes as design variables and determining initial values ​​for their positions; determining the relationship between end node coordinates, the angles between adjacent nodes, and the total length of the nodes, using analytical functions to control these angles and the total length; establishing a horizontal set function for the link chain structure; determining the optimization objective of minimum overall flexibility for the link chain structure; optimizing the link chain structure based on gradient optimization algorithms and constraints, and determining the optimization result. This method first defines node coordinates as design variables, uses horizontal set functions to establish a geometric model of sequentially connected link chains, and establishes a total fiber path length constraint to save fiber material. To avoid sharp fiber corners, an angle constraint between adjacent nodes is established, and topology optimization is performed with the goal of minimizing structural flexibility, resulting in a streamlined layout optimization design. This effectively solves the problems of high computational load and sharp corners in the path in existing technologies, achieving optimized link chain layout design while minimizing computational load. Attached Figure Description

[0037] 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 of the present invention 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.

[0038] Figure 1 A flowchart illustrating the steps of the continuous fiber 3D printing path collaborative optimization method provided in this application embodiment;

[0039] Figure 2 This is a flowchart of the positional relationship determination steps in the continuous fiber 3D printing path collaborative optimization method provided in the embodiments of this application;

[0040] Figure 3 A schematic diagram showing the geometric model dimensions and actual working conditions of the cantilever beam provided in the embodiments of this application;

[0041] Figure 4 A schematic diagram illustrating the determination of variable relationships for a cantilever beam provided in the application embodiment;

[0042] Figure 5 A schematic diagram of a rod-chain structure conforming to the shape characteristic of the design domain, provided in an embodiment of this application;

[0043] Figure 6 This is a schematic diagram of the optimized model of a continuous fiber composite material under unconstrained angles, provided in an embodiment of this application.

[0044] Figure 7A schematic diagram of the optimized model of feature-driven continuous fiber composite material under constraint angle provided in an embodiment of this application;

[0045] Figure 8 This is a schematic diagram of a continuous fiber 3D printing path collaborative optimization device provided in an embodiment of this application. Detailed Implementation

[0046] 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, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0047] In existing methods, the first step involves using the pseudo-density and anisotropy of each element as design variables, and employing the anisotropic SIMP method to obtain an optimized topology. The anisotropic properties of each element are then obtained through the energy method. The second step involves generating fiber paths on the topology-optimized structural profile using methods such as offset, equal spacing, and streamlines. Existing design methods can perform anisotropic topology optimization on structures under simple working conditions, followed by path planning on the resulting geometry. However, the following problems exist: 1. Structural topology optimization and continuous fiber path planning are performed separately, without complete coupling, which limits the structural optimization potential to some extent. 2. Traditional methods are only applicable to simple cases. When boundary conditions or design spaces are complex, and there are many stress concentration areas, the fiber paths will produce sharp corners. 3. Although traditional methods use anisotropic topology optimization, and path planning on this basis improves structural performance, the structure obtained through anisotropic topology optimization can only serve as a reference for fiber path planning and is not the same as the actual structure containing continuous fibers. 4. Traditional methods require additional steps to generate continuous paths. 5. Traditional methods often generate "dead ends" that extend beyond structural boundaries, requiring manual cutting and wasting fibers, and resulting in rough assembly surfaces after grinding. 6. Traditional methods require extracting the orientation field and using complex algorithms to plan fiber paths, often introducing significant computational overhead. In conclusion, it is necessary to develop a method that fully coordinates topology optimization with continuous printing paths, truly simulating the mechanical behavior of continuous fibers in the matrix, satisfying various boundary conditions in printing, and analytically controlling engineering constraints.

[0048] To address the aforementioned problems, this invention provides a method for collaborative optimization of continuous fiber 3D printing paths, comprising the following steps S101 to S105.

[0049] S101, set the pole end node as a design variable and determine the initial position value of the end node.

[0050] S102, determine the relationship between the coordinates of the end node and the angle between adjacent poles and the total pole length, and use analytical functions to control the angle and the total pole length.

[0051] S103, establish the horizontal set function of the rod-chain structure.

[0052] S104, determine the optimization objective for the minimum overall flexibility of the link-chain structure.

[0053] S105, optimize the link chain structure according to the gradient optimization algorithm and constraints, and determine the optimization result.

[0054] In the method provided in this application, the component node coordinates are defined as design variables, and a set model of sequentially connected rod chain structure is established using the level set function. In order to save the amount of fiber material, the total length constraint of the fiber path is established. In order to avoid the existence of sharp fiber corners, the adjacent angle constraint is established. Topology optimization is performed with the goal of minimizing structural flexibility, and the optimized design result of the rod chain structure layout is obtained.

[0055] In step S102, the relationship between the end node coordinates and the angle between adjacent rods and the rod length is determined, including the following two steps S201 to S202.

[0056] S201, Determine the total length of the link chain structure. Define the location of the link end nodes as a design variable, and give the initial values ​​for the node locations.

[0057] S202, establish the included angle constraint model function and the distance model function between the rod chain structure and the design domain boundary.

[0058] In step S202, firstly, the relationship between the node coordinates and the angles between adjacent rods and the rod lengths is established:

[0059] B i =(x i -x i+1 (x) i+2 -x i+1 )+(y i -y i+1 )(y i+2 -y i+1 )

[0060]

[0061]

[0062]

[0063]

[0064] Where, x i ,y i B represents the x and y coordinates of the i-th node; i It means (x) i -x i+1 ,y i -y i+1 ) and (x i+2 -x i+1 ,y i+2 -y i+1 The vector product of ); l i β represents the length of the i-th rod; i L represents the angle formed by the i-th rod and the (i+1)-th rod; total N represents the total length of the link-chain structure. node Indicates the number of nodes.

[0065] Secondly, by replacing the maximum value function with a smoothing function, a KS model function for the angle constraint function is established:

[0066]

[0067] Among them, A total Model parameters representing the angles of the link-chain structure; p KS The KS model specifies the parameters for the angle constraint function; cosβ i N represents the cosine of the angle formed by the i-th rod and the (i+1)-th rod; angle Indicates the number of angles formed by the link; f max This represents the maximum cosine value of the included angle formed by the link-chain structure.

[0068] Simultaneously, establish a KS model function for the distance between the linkage structure and the design domain boundary:

[0069]

[0070] Where, δ total A model index representing the distance from a point inside the rod to the boundary; ξ i,n This indicates that the i-th rod m is divided into equal parts, and the current position is at the n-th node; δ(ξ) i,n ) represents the distance from a point inside the rod to the boundary; p KS This indicates the distance specified in the KS model.

[0071] In step S103, the horizontal set function of the link chain structure is established, including:

[0072]

[0073]

[0074]

[0075] Where, x e ,y e d represents the coordinate position of a point within the design domain; e,i Represents a point (x) within the design domain. e ,y e ) to rod l i The distance between them; G ei express and The mixed product; Φ represents the level set function of a single rod.

[0076] The constraints in step S104 include: aiming to minimize the overall flexibility of the link-chain structure, constraining the total length of the link-chain structure and the angles between links. The link-chain structure layout optimization aims to minimize overall flexibility while simultaneously constraining parameters such as angles, total length, and volume fraction, specifically satisfying the following formula requirements:

[0077] Find ξ = (x1, x2, ..., x Nnode ,y1,y2,...,y Nnode )

[0078] Minimise C = F T U(5)

[0079]

[0080] Where C represents the structural flexibility; H(Φ(ξ)) represents the Heaviside function; E0 represents the elastic modulus of the solid material; u e k e Let U, K, and F represent the nodal displacement vector and element stiffness matrix of the e-th element, respectively; U, K, and F represent the nodal displacement vector, overall stiffness matrix, and nodal load vector of the entire structure, respectively.

[0081] The constraints in S104 also include: constraining the distance between the link chain structure and the boundary of the design domain.

[0082] In a specific embodiment provided in this application, the position of the rod endpoint is defined as a design variable, and initial values ​​for the node positions are given. The cantilever beam model is as follows: Figure 3 The dimensions shown are 120*75, and a concentrated load is applied at the center of the right side. For example... Figure 4 As shown, the initial structural shape consists of 34 sequentially connected moving rods, and the initial node coordinates can be obtained simultaneously. Formulas (2), (3), and (4) are used to establish the relationship between the angle between the left side of the node and the adjacent rod, and the rod length, as follows: Figure 5As shown. Constraints are applied according to formula (5). Sensitivity analysis is performed on the compliance, total length, and angle constraint functions of the link chain structure. The above problems are optimized according to the gradient optimization algorithm, and the results are obtained iteratively. The topology optimization results without angle constraints are shown below. Figure 4 As shown, the optimization results for peeling under angle constraints are as follows: Figure 6 As shown, from Figure 6 and Figure 7 The comparison reveals that the feature-driven topology method, which largely maintains the component order, and the continuous 3D printing path co-optimization method treat it as a sequentially connected chain structure to ensure continuity during processing. Under angular constraints, it effectively avoids sharp corners in the fiber path, thus preventing fiber breakage caused by abrupt turns in practical applications. Under the distance constraint between the chain structure and the design domain boundary, it effectively prevents the fiber path from exceeding the structural boundary. Furthermore, this method directly couples topology optimization with path planning during the processing of continuous fiber composite materials, effectively improving the optimization potential.

[0083] This invention provides a continuous fiber 3D printing path collaborative optimization device 800, such as... Figure 8 The device shown includes:

[0084] The initial value setting unit 801 is used to set the pole end node as a design variable and determine the initial position value of the end node;

[0085] The variable relationship determination unit 802 is used to determine the relationship between the coordinates of the end nodes and the angles between adjacent rods and the rod lengths; determine the total length of the rod chain structure; establish the angle constraint model function; and establish the distance model function between the rod chain structure and the boundary of the design domain.

[0086] Function creation unit 803 is used to create the horizontal set function of the link chain structure; the function creation unit is based on...

[0087]

[0088]

[0089]

[0090] Where, x e ,y e d represents the coordinate position of a point within the design domain; e,i Represents a point (x) within the design domain. e ,y e ) to rod l i The distance between them; Φ represents the horizontal set function of a single rod, and the horizontal set function is established.

[0091] Constraint determination unit 804 is used to determine the constraints for the minimum overall flexibility of the link-chain structure. With the goal of minimizing the overall flexibility of the link-chain structure, constraints are imposed on the total length of the link-chain structure and the angles between links. Constraints also include the distance between the link-chain structure and the design domain boundary.

[0092] The optimization unit 805 is used to optimize the link chain structure according to the gradient optimization algorithm and the constraints, and to determine the optimization result.

[0093] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A continuous fiber 3D printing path coordination optimization method, characterized in that, The method comprises the following steps: setting a rod end node as a design variable and determining an initial value of a position of the end node; determining a relationship between the end node coordinates and an angle between adjacent rods and a total rod length, and using an analytical function to control the angle and the total rod length; establishing a level set function of the rod chain structure; determining an optimization target of minimum total flexibility of the rod chain structure; optimizing the rod chain structure according to a gradient optimization algorithm and a constraint condition to determine an optimization result; the step of establishing the level set function of the rod chain structure comprises the following steps: wherein, , denotes the coordinate position of a point within the design domain; denotes the distance between a point (x, y) within the design domain and the rod , ; denotes the distance between a point (x, y) within the design domain and the rod denotes the level set function of a single rod; the constraint condition comprises: the total length of the rod chain structure and the angle between the rods are constrained to minimize the total flexibility of the rod chain structure, the rod chain structure layout optimization is targeted at minimizing the total flexibility, and the angle, the total length, and a volume fraction parameter of the rod chain structure are constrained, and the following formula is satisfied: in, Indicates the flexibility of the structure; This represents the Heaviside function; Represents the elastic modulus of a solid material; , They represent the first The nodal displacement vectors and element stiffness matrices of each element; U, K, and F are the nodal displacement vectors, overall stiffness matrix, and nodal load vectors of the entire structure, respectively.

2. The method of claim 1, wherein, the step of determining the relationship between the end node coordinates and the angle between adjacent rods and the rod length comprises the following steps: determining the total length of the rod chain structure; establishing an angle constraint model function and a distance model function between the rod chain structure and a design domain boundary.

3. The method of claim 1, wherein, the constraint condition comprises: the total length of the rod chain structure and the angle between the rods are constrained to minimize the total flexibility of the rod chain structure.

4. The method of claim 1, wherein, the constraint condition further comprises: the distance between the rod chain structure and the design domain boundary is constrained.

5. A continuous fiber 3D printing path collaborative optimization device, characterized in that, The method comprises the following steps: an initial value setting unit is configured to set a rod end node as a design variable and determine an initial value of a position of the end node; a variable relationship determining unit is configured to determine a relationship between the end node coordinates and an angle between adjacent rods and a total rod length, and use an analytical function to control the angle and the total rod length; a function establishing unit is configured to establish a level set function of the rod chain structure; a constraint condition determining unit is configured to determine an optimization target of minimum total flexibility of the rod chain structure; an optimization unit is configured to optimize the rod chain structure according to a gradient optimization algorithm and a constraint condition to determine an optimization result. the step of establishing the level set function of the rod chain structure comprises the following steps: wherein, , represents the coordinate position of a point within the design domain; represents the distance between a point (x, y) within the design domain and the rod , ; represents the distance between a point (x, y) within the design domain and the rod represents the level set function of a single rod; the constraint condition comprises: the total length of the rod chain structure and the angle between the rods are constrained to minimize the total flexibility of the rod chain structure, the rod chain structure layout optimization is targeted at minimizing the total flexibility, and the angle, the total length, and a volume fraction parameter of the rod chain structure are constrained, and the following formula is satisfied: wherein, denotes the flexibility of the structure; denotes the Heaviside function; denotes the elastic modulus of the solid material; , denote the node displacement vector and the element stiffness matrix of the first element, respectively; U, K and F are the node displacement vector, the global stiffness matrix and the node load vector of the structure as a whole, respectively.

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