Composite material fiber direction simulation modeling method and system

Abstract

The invention relates to the technical field of fiber direction simulation, in particular to a composite material fiber direction simulation modeling method and system. The method comprises the following steps: collecting a fiber laying track, and correcting a bending radius and a unit tangential direction of a path point to obtain a fiber laying correction track; constructing a first direction distribution diagram according to the tangential direction of each path point in the fiber laying correction track; analyzing the coverage range of each path in the first direction distribution diagram on the curved surface of the component, identifying a curved surface overlapping intersection area, and calculating the included angle adjustment amount of the direction vector; dividing the first direction distribution diagram into finite volume units so as to obtain a second direction distribution diagram; and executing fiber direction simulation verification according to the second direction distribution diagram in combination with a preset material anisotropy attribute so as to obtain a fiber direction simulation result. According to the method, the spatial accuracy of fiber direction modeling and the consistency of simulation prediction can be improved.

Description

Technical Field

[0001] This invention relates to the field of fiber orientation simulation technology, and in particular to a method and system for simulating and modeling the fiber orientation of composite materials. Background Technology

[0002] Composite materials, due to their lightweight, high strength, and corrosion resistance, have been widely used in aerospace, automotive, rail transportation, and high-end manufacturing industries. The fiber orientation within a composite material directly determines the mechanical properties of its structural components under different load conditions.

[0003] In existing technologies, fiber orientation modeling of composite materials typically relies on idealized layup descriptions in CAD or CAE systems, establishing finite element models by simplifying them to two-dimensional layup angles or region-averaged direction vectors. However, such methods struggle to cover the three-dimensional spatial fiber displacement caused by interlayer slippage or local thickening in multilayer overlapping areas, thus lacking an accurate characterization of the three-dimensional fiber orientation under the actual molding path. Summary of the Invention

[0004] Therefore, the present invention needs to provide a method and system for simulating and modeling the fiber orientation of composite materials to solve at least one of the above-mentioned technical problems.

[0005] To achieve the above objectives, a simulation modeling method for fiber orientation of composite materials includes the following steps: Step S1: Collect the fiber placement trajectory through the process control interface connected to the automatic fiber placement equipment; based on the fitting error of the fiber placement trajectory on the component surface, correct the bending radius and unit tangent direction of the path points to obtain the fiber placement correction trajectory; Step S2: Map the tangent direction of each path point in the fiber placement correction trajectory to the tangent base of the preset CAD model surface of the molding component to construct the first direction distribution map; Step S3: Analyze the coverage of each path on the component surface in the first direction distribution map, identify the overlapping and intersecting areas of the surfaces; calculate the fiber disturbance offset amplitude in the normal direction of each layer in the overlapping and intersecting areas of the surfaces, and calculate the angle adjustment of the direction vector based on the fiber disturbance offset amplitude and the path intersection angle of the overlapping and intersecting areas of the surfaces. Step S4: Divide the first directional distribution map into finite volume units, and use the angle adjustment of the directional vectors to characterize the spatial distribution trend of the fiber principal directional vector and the fiber secondary directional vector in the corresponding finite volume units to obtain the second directional distribution map; Step S5: Take the fiber principal direction vector of the second direction distribution map as the principal axis direction, the fiber secondary direction vector as the transverse reference direction orthogonal to the principal axis, and perform fiber direction simulation verification in combination with the preset material anisotropy properties to obtain the fiber direction simulation results.

[0006] This invention acquires the actual fiber placement trajectory through an interface with an automated fiber placement device and corrects path errors using the CAD surface of the component, establishing a correspondence between the actual placement direction and the surface. A first directional distribution map is then constructed on the component surface, and disturbances caused by interlayer crossings in overlapping areas are identified, calculating the adjustment amount of the path angle. Based on this adjustment, the directional data is mapped to continuously divided finite volume units, and the primary and secondary directions are extracted using the statistical characteristics of the directional vectors, forming a second directional distribution map of the fiber spatial distribution. The second direction is then mapped to the anisotropic properties of the material, and simulation analysis is performed, comparing the results with the expected performance. If the deviation exceeds a threshold, the angle adjustment amount is iteratively adjusted using a disturbance sensitivity coefficient to optimize simulation accuracy. Ultimately, this achieves an integrated feedback closed loop for modeling the spatial distribution of the actual fiber direction in composite material components and simulating performance. This effectively solves the problem in existing technologies where two-dimensional idealized layup modeling cannot accurately reflect three-dimensional fiber displacement issues such as interlayer overlap slippage and local thickening. By constructing an angle adjustment and disturbance feedback mechanism, closed-loop optimization of fiber orientation modeling and material anisotropic performance simulation is achieved, which significantly improves the spatial accuracy of fiber orientation modeling and the consistency of simulation prediction in composite material components, and is suitable for high-precision engineering structure design and performance evaluation.

[0007] Optionally, this application provides a composite material fiber orientation simulation modeling system for executing the composite material fiber orientation simulation modeling method described above. The composite material fiber orientation simulation modeling system includes: The trajectory acquisition module is used to acquire the fiber placement trajectory through the process control interface connected to the automatic fiber placement equipment; based on the fitting error of the fiber placement trajectory on the curved surface of the component, the bending radius and unit tangent direction of the path points are corrected to obtain the fiber placement correction trajectory; The tangent direction mapping module is used to map the tangent direction of each path point in the fiber laying correction trajectory to the tangent base of the preset molding component CAD model surface to construct a first direction distribution map; The angle adjustment calculation module is used to analyze the coverage of each path on the component surface in the first direction distribution map, identify the overlapping and intersecting areas of the surface; calculate the fiber disturbance offset amplitude in the normal direction of each layer in the overlapping and intersecting areas of the surface, and calculate the angle adjustment of the direction vector based on the fiber disturbance offset amplitude and the path intersection angle of the overlapping and intersecting areas of the surface. The primary and secondary direction division module is used to divide the first direction distribution map into finite volume units. The spatial distribution trend of the fiber primary direction vector and the fiber secondary direction vector is characterized by the adjustment of the angle between the direction vectors in the corresponding finite volume units, so as to obtain the second direction distribution map. The simulation module is used to take the fiber principal direction vector of the second direction distribution map as the principal axis direction and the fiber secondary direction vector as the transverse reference direction orthogonal to the principal axis, and perform fiber direction simulation verification in combination with the preset material anisotropy properties, so as to obtain the fiber direction simulation results.

[0008] The composite material fiber orientation simulation modeling system of the present invention can implement any of the composite material fiber orientation simulation modeling methods of the present invention. It is used to combine the operation and signal transmission medium between various modules to complete the composite material fiber orientation simulation modeling method. The internal modules of the system cooperate with each other, thereby improving the spatial accuracy of fiber orientation modeling in composite material components and the consistency of simulation prediction. Attached Figure Description

[0009] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the steps in the composite material fiber orientation simulation modeling method of the present invention; Figure 2 This is a schematic diagram of the first directional distribution map in an embodiment of the present invention; The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0010] The technical method of the present invention will now be clearly and completely described 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 inventive effort are within the scope of protection of the present invention.

[0011] Furthermore, the accompanying drawings are merely illustrative of the invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor methods and / or microcontroller methods.

[0012] It should be understood that although the terms "first," "second," etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are used merely to distinguish one unit from another. For example, without departing from the scope of the exemplary embodiments, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0013] To achieve the above objectives, please refer to Figures 1 to 2 This invention provides a simulation modeling method for the fiber orientation of composite materials, the method comprising the following steps: Step S1: Collect the fiber placement trajectory through the process control interface connected to the automatic fiber placement equipment; based on the fitting error of the fiber placement trajectory on the component surface, correct the bending radius and unit tangent direction of the path points to obtain the fiber placement correction trajectory; In one embodiment of the present invention, fiber placement trajectory data during the molding process of composite material components is acquired in real time through a process control interface connected to an automated fiber placement device. This data is recorded in the form of a path point sequence, with each point containing three-dimensional coordinates (X, Y, Z), placement speed, and tangential direction vector. The acquired path point coordinates are projected onto the CAD model of the molded component, and the corresponding position of the path point in the component's surface coordinate system is obtained using a local surface parametric method (such as NURBS or Bezier surface UV coordinates). The surface normal vector at this position is calculated and vector difference is performed with the tangent vector of the path point to extract the offset components of the tangential and normal directions. Error thresholds for tangential and normal offsets are set (e.g., 0.2 mm and 0.1 rad), and continuous segments of path points with errors exceeding the thresholds are identified as path segments to be corrected. Curvature continuity analysis is performed on the path segment to be corrected and its adjacent path points, and curve fitting is performed using cubic B-splines to maintain the continuity of the first derivative of adjacent segments, ensuring a smooth transition of the fiber placement trajectory and avoiding abrupt changes. Based on the positional variation relationship of continuous points in the fitted path segment, the tangent direction vector is calculated using the central difference method, and the new direction vector of the path point is obtained by normalization, thus forming the fiber laying correction trajectory.

[0014] Step S2: Map the tangent direction of each path point in the fiber placement correction trajectory to the tangent base of the preset CAD model surface of the molding component to construct the first direction distribution map; In one embodiment of the present invention, coordinate difference is performed on adjacent path points in the fiber placement correction trajectory, using... Calculate the unit tangent vector for each path point. The first step in the fiber placement correction trajectory Spatial coordinate vectors of path points. For the first The unit tangent direction vector at each path point represents the instantaneous direction of fiber placement. , respectively path points The coordinates of two adjacent path points are used to calculate the central difference. For each path point, its U and V parameter positions are extracted from the CAD model, and the orthogonal tangent basis (i.e., the tangent vectors in the U and V directions) of the local surface are obtained using CAD kernel functions, denoted as... . The tangent vector of each path point Project to Calculate the directional projection of the local base in the surface coordinate system. This refers to the fiber placement direction on the component surface. These are the weighting coefficients for projecting the tangential directions of path points onto the U / V direction basis of the surface. By performing position matching and interpolation fitting (such as Gaussian weighted interpolation) on the direction projections of all path points, a first direction distribution map covering the entire component surface is generated. This distribution map can be represented as a direction vector field on the component surface mesh.

[0015] Step S3: Analyze the coverage of each path on the component surface in the first direction distribution map, identify the overlapping and intersecting areas of the surfaces; calculate the fiber disturbance offset amplitude in the normal direction of each layer in the overlapping and intersecting areas of the surfaces, and calculate the angle adjustment of the direction vector based on the fiber disturbance offset amplitude and the path intersection angle of the overlapping and intersecting areas of the surfaces. In this embodiment, the tangent vectors of all path points are extracted from the first direction distribution map. The bandwidth values ​​in each extension direction on both sides (e.g., ±3mm), construct a rectangular projection strip corresponding to each path point (center at the path point coordinates, direction is...). Width is (The length is determined by the point spacing). Perform spatial intersection operations (such as AABB box detection) on the rectangular projections of all path points to identify areas where paths intersect or overlap, forming path intersection candidate areas. Based on the laying order, identify path pairs with a "first-laid-last-laid" relationship within the intersection areas. Calculate their center-to-center spacing in the normal direction of the component surface. And calculate the angle between the two path direction vectors. If satisfied (e.g., 0.8mm) and If the angle is 20°, then the candidate intersection area is considered an effective surface overlap intersection region. Extract the set of path points in these regions, calculate their center height in the normal direction, and calculate the relative height difference layer by layer according to the laying order. Combined with the path curvature sign, determine whether the upper-layer path is shifted upwards or downwards, thus obtaining the fiber perturbation offset amplitude. Calculate the angle of the path direction Based on the normalized value of the disturbance offset Combined with the disturbance sensitivity coefficient The direction adjustment amount is obtained. .in This represents the fiber disturbance offset amplitude.

[0016] Step S4: Divide the first directional distribution map into finite volume units, and use the angle adjustment of the directional vectors to characterize the spatial distribution trend of the fiber principal directional vector and the fiber secondary directional vector in the corresponding finite volume units to obtain the second directional distribution map; In this embodiment, the number of path points in each local region is calculated using a sliding window based on the path point density distribution on the component surface. A density threshold is set (e.g., ≥5 path points per square centimeter), and regions meeting this condition are extracted as effective path distribution regions. Within the effective region, the maximum vertical spacing of path points in the normal direction (e.g., maximum layer spacing of 2mm) is counted and set as the vertical partitioning spacing of the volume element. Iso-slices are performed along the normal direction of the component surface to obtain a three-dimensional finite volume element mesh. Each path point (including its direction vector) is mapped to its corresponding volume element based on its three-dimensional coordinates, forming a path point set and direction vector set within the element. For each volume element, the direction vector of its path point set is taken. Based on the obtained angle adjustment, each direction vector is corrected: Perform covariance matrix analysis on the corrected direction vector set and construct the matrix. Find its eigenvalues ​​and eigenvectors, where After the angle is adjusted, the first The direction vectors of the path points; It is the average value of the set of direction vectors; This illustrates a vector transpose operation. The eigenvector corresponding to the largest eigenvalue is taken as the principal fiber direction of that unit. The eigenvector corresponding to the second largest eigenvalue is used as the second direction. Thus, a second directional distribution map is obtained.

[0017] Step S5: Take the fiber principal direction vector of the second direction distribution map as the principal axis direction, the fiber secondary direction vector as the transverse reference direction orthogonal to the principal axis, and perform fiber direction simulation verification in combination with the preset material anisotropy properties to obtain the fiber direction simulation results.

[0018] In this embodiment, a local coordinate system is established for each volume element, so as to... Main axis direction As the lateral reference direction, A fiber spatial orientation coordinate system is established along the thickness direction. The orientation of this local coordinate system is then mapped to anisotropic properties in the material database, such as the tensile modulus along the principal axes. lateral modulus shear modulus First, a third-dimensional orientation map, or "material property orientation map," is constructed. This map is then integrated with the three-dimensional finite element model of the component, incorporating ply properties, mesh generation, and boundary conditions. Structural simulation is performed in finite element software (such as ABAQUS or ANSYS) to obtain the stress-strain response and anisotropic behavior. The directional responses of each element in the simulation results (such as the elastic modulus along the principal axes) are compared with the target values ​​in the material library, and the differences are calculated. ; The anisotropic response (such as principal direction modulus) extracted from the simulation results. The target attribute value is provided in the materials database. If the maximum difference value... (e.g., 2%), then based on the difference gradient feedback perturbation sensitivity coefficient Update the included angle adjustment amount, repeat steps S4 and S5 until the error converges, and finally output the fiber orientation distribution map that has passed the simulation verification.

[0019] Optionally, step S1 includes: Step S11: Collect the fiber placement trajectory through the process control interface connected to the automatic fiber placement equipment; In this embodiment of the invention, during the automatic carbon fiber placement process, a data channel is established with the fiber placement machine control unit (e.g., a FANUC controller or a Siemens PLC) of the automatic fiber placement equipment to collect trajectory data of the fiber bundle placement process in real time. The collected data includes, but is not limited to: the three-dimensional coordinates of the trajectory path points in the workpiece coordinate system, the placement speed, the tool head attitude angle information (e.g., the rotation angle around the workpiece tangent), channel number, and timestamp. This trajectory data is recorded at a sampling period of 10ms and packaged into a trajectory sequence file for subsequent geometric deviation analysis and path reconstruction processing.

[0020] Step S12: Project the path points of the fiber laying trajectory onto the component surface coordinate system in the preset CAD model of the molded component, and calculate the position error of the path points in the tangential and normal directions of the surface based on the deviation between the local normal vector of the component surface and the tangent vector of the path points. In this embodiment of the invention, a CAD model of the formed component is invoked, and the parametric coordinate system of each surface fragment in the model is extracted, including the surface tangential vector pair and the normal vector. For each acquired path point, based on its nearest neighbor distance relationship, it is projected onto the CAD surface to obtain the projection point on the surface, and the local surface tangential and normal vectors are read at this point. Furthermore, by comparing the angular deviation between the tangent direction of the path point and the surface normal, the deviation distance of the path point in the surface normal direction is estimated as the normal error; simultaneously, the projection length of the path point on the surface tangential base is compared with the ideal laying path to obtain the tangential error.

[0021] In another embodiment, error calculation is performed using a sliding window mode with each 5mm path distance as a group, which ensures the stable extraction of the continuous distribution trend of errors.

[0022] It is important to note that the CAD model of a molded component refers to a 3D modeling file describing the shape of the target composite material component. It is typically stored in industry-standard formats such as .STEP, .IGES, .SLDPRT, or .STL and generated by computer-aided design (CAD) software, such as SolidWorks, UG NX, CATIA, or Creo. This model contains not only the geometric contour surface information of the component but also parametric patch definitions for spatial fitting and path projection processing. In practice, a local coordinate system for the molded component's surface is constructed based on this CAD model, and the local tangent vectors (U and V directions) and normal vectors (N direction) of the surface are extracted for trajectory projection and fiber layup path error calculation. If the CAD model contains assembly reference surfaces, connection boundaries, or molding die partitioning information, this information can also be used for automatic division of the layup area and classification of path segments.

[0023] In other embodiments, the ideal layup path refers to a theoretical sequence of fiber placement trajectories designed by process engineers in a CAD / CAM environment based on component surface characteristics, fiber orientation requirements, and molding process constraints. It is typically defined as a point sequence or toolpath format and includes spatial coordinates, orientation vectors, layup order, and speed information.

[0024] Step S13: Identify the path segment to be corrected in the fiber laying trajectory based on the positional error of the path point in the tangential and normal directions of the curved surface; In this embodiment of the invention, based on a preset process error tolerance threshold (e.g., 0.5 mm for normal error and 1.0 mm for tangential error), error judgment is performed on each path point. If the error value of consecutive path points within a path segment exceeds the threshold, the path segment is determined to be an abnormal path segment. During the identification process, a dynamic path segment sliding window identification method is used to extract segments from the path point sequence that have more than N consecutive points (e.g., N=5) with errors exceeding the limit, and their start and end indices are marked. If multiple discontinuous abnormal segments exist within a path segment, adjacent abnormal point segments are further merged, and their overall length, path offset trend, and upstream and downstream path continuity are jointly evaluated, ultimately outputting a set of path segments to be corrected.

[0025] It is important to note that if multiple intermittent anomalies exist within a path segment, further fusion of adjacent anomaly segments refers to the process of merging adjacent anomaly segments during actual trajectory error identification. This occurs when multiple segments with short intervals (e.g., less than a set time window T=0.5s or path distance D=15mm) exceed the error limit (i.e., error points exhibit a "jumping distribution"). These adjacent but discontinuous anomaly segments are merged. This fusion process may include, but is not limited to: if the time interval between two anomaly segments is less than a set time window threshold, or the distance between their spatial path points is less than a set threshold (e.g., 10~20mm), they are considered a single anomaly segment; if adjacent anomaly segments have the same error direction (e.g., both are downward offset), they are determined to be of the same type of anomaly, and segment fusion is performed; by fitting the error change trend curve of the anomaly segment boundary, it is determined whether there may be undetected error points ("missed detection segments") between the two segments to prevent misclassification.

[0026] In another embodiment, the joint evaluation of its overall length, path offset trend, and upstream and downstream path continuity refers to the comprehensive analysis of the following three aspects when identifying multiple abnormal path segments and determining whether they need to be merged or processed separately: 1) Overall length evaluation: If the length of a single abnormal segment is lower than the minimum control threshold (e.g., 20mm), but it appears continuously in a certain area and the total length exceeds the set upper limit (e.g., 80mm), then it is treated as a continuous abnormal segment that needs to be corrected; this avoids misjudging small error segments as negligible, thus missing potential curvature deformation areas. 2) Path offset trend analysis: The error vector sequence of each abnormal path is judged for directional consistency (e.g., multiple errors shift downwards, indicating a consistent trend); if continuous abnormal segments show offset in the same direction (e.g., an increase in negative normal offset), these abnormal points are considered to originate from the same working condition or a failure of path planning logic. 3) Upstream and downstream path continuity detection: Check the tangent direction and curvature changes of the normal path segments on both sides of the abnormal segment; if there is an obvious angle change or curvature discontinuity between the abnormal segment and the normal segments before and after it (such as the tangent direction angle is greater than 10° or the curvature change rate is greater than 0.05 / mm), it is recommended to fit it separately; otherwise, it can be included in the unified path segment for integrated reconstruction.

[0027] Step S14: Based on the curvature continuity between the path segment to be corrected and the adjacent path segments, perform a smooth fitting of the curved boundary of the path segment to be corrected to obtain the fitted path segment; In this embodiment of the invention, the first and last points of each path segment to be corrected are extracted, and 3 to 5 path points from the adjacent normal path segments are selected as fitting boundary control points. To ensure the continuity and physical feasibility of the fitted path, a fitting algorithm based on cubic B-splines is used to construct a smooth curve, and the curvature change trend is constrained to ensure that the tangent direction and curvature value of the fitted path at the connection boundary are consistent with or similar to those of the adjacent path segments. During the fitting process, a fitting residual control threshold is set (e.g., the maximum fitting residual does not exceed 0.2 mm), and the control point weights are automatically adjusted to ensure that the fitted path segment is continuous, smooth, and without abrupt changes in space. After the fitting is completed, the fitted path segment is used as the updated path to replace the original error segment and is integrated into the original trajectory sequence.

[0028] Step S15: Based on the differential direction vector relationship between path points in the fitted path segment, calculate the instantaneous tangent direction of the path point as the new tangent direction of the path segment to obtain the fiber laying correction trajectory.

[0029] In this embodiment of the invention, forward differencing is performed on the coordinates of each pair of adjacent path points in the fitted path segment to calculate their differential displacement vector. This vector is then normalized to serve as the instantaneous tangent direction of the path point. This tangent direction is used for subsequent fiber orientation calculations, layup head attitude control, and molding quality simulation. To improve the stability of the orientation vector, the system further performs a sliding weighted average after the differential orientation calculation, performing vector weighted smoothing on the orientation vectors of 3 to 5 consecutive path points to avoid sudden changes in local attitude due to minor disturbances. The final updated path segment includes: updated three-dimensional spatial coordinates, a new tangent direction vector, curvature information, and local orientation gradient values, constituting a fiber layup correction trajectory segment, which is then spliced ​​with the preceding and following path segments to form a complete trajectory sequence.

[0030] Figure 2 This is a schematic diagram of the first directional distribution map in an embodiment of this application. For example... Figure 2 As shown in the figure, the spatial region is divided based on a grid. Multiple directional arrows are drawn inside each grid cell. The red arrows indicate the local tangent direction of the path points in that region (i.e., the fiber laying direction), while the blue dots indicate the path points of the correction trajectory.

[0031] The first directional distribution map reflects the fiber layup trajectory distribution of the composite component during the actual molding process. It can be seen that there are local concentrated changes or intersections of fiber directions in multiple grid areas, especially in areas with high arrow density or convergent directions. This indicates that the path points in these areas have abrupt changes or spatial superposition of layup directions, which may correspond to interlayer overlap, curvature abrupt changes, or path disturbances in the actual component.

[0032] In addition, such as Figure 2 As shown in the first directional distribution diagram, some red arrows have clear outlines and well-defined directions, while others appear blurry and have divergent directions. This is mainly because the local spatial curvature and normal perturbation of the component surfaces at different path points vary.

[0033] Specifically, areas with clearer arrows typically correspond to regions with lower curvature and smoother, more continuous fiber layup paths on the component surface. In these areas, the projection of path points onto the surface tangent is stable, and the direction vectors are consistent, forming a relatively regular directional distribution. Conversely, areas with blurred or divergent arrows are often located in high-curvature regions of the component surface or between adjacent layers where the surface normal changes rapidly. In these regions, the local tangent direction of the path points is significantly affected by surface normal disturbances, path reversals, or local overlap, resulting in significant shifts in the projection direction. This causes multiple direction vectors to interfere with each other within a single element, exhibiting blurred or divergent unstable characteristics. Therefore, changes in arrow clarity essentially reflect the influence of the component surface morphology on the consistency of fiber layup direction and are also an important basis for judging path disturbances, normal shifts, and abnormal layup areas.

[0034] Optionally, step S2 includes: Step S21: Extract the tangential vector of each path point from the spatial position of the continuous path points in the differential fiber placement correction trajectory. In this embodiment, the spatial positions of adjacent path points in the differential fiber placement correction trajectory are differentially analyzed to extract their relative displacement relationships, thereby constructing a local tangential vector sequence for each path point. The path points within each trajectory have a clear arrangement order, and the instantaneous motion direction of the trajectory can be obtained through segment-by-segment differential processing. This tangential vector represents the main extension direction of the fiber bundle on the component surface during actual placement.

[0035] In particular, for trajectory segments with uneven path intervals, a local weighted difference method can be used to improve the stability of direction estimation.

[0036] Step S22: Calculate the local orthogonal tangent base at any given path point on the surface of the component in the CAD model of the formed component; In this embodiment, for each path point, its projection point is located in the CAD model of the formed component, and a local coordinate system is defined based on the surface of the component where the projection point is located. This coordinate system consists of two principal tangential directions (corresponding to the u and v directions) that vary along the surface direction, and the normal direction, forming a set of orthogonal bases.

[0037] Step S23: Project the tangent vector of each path point onto the local orthogonal tangent basis to obtain the direction vector of each path point on the component surface; In another embodiment of the invention, the obtained tangential vector is projected onto the constructed local orthogonal tangent basis to obtain the tangent projection vector of the path point in the component surface coordinate system, thus obtaining the direction vector of each path point on the component surface. This direction vector reflects the actual laying direction of the path point relative to the geometric shape of the component surface. For regions with large curvature changes, it indicates that there may be a significant angle difference between the spatial tangential vector of the path point and its surface tangential projection. In this case, the projection vector is used to correct the response of the path direction to the surface normal disturbance.

[0038] Step S24: According to the coordinate positions of the path points on the component surface coordinate system, interpolate and stitch together the direction vectors of each path point on the component surface to obtain the first direction distribution map.

[0039] In this embodiment, based on the coordinate positions of the path points on the component surface, the direction projection vector of each path point is embedded into a set of preset mesh structures. Weighted interpolation and graphical stitching are then performed on the direction data in each unit according to the component surface parameter space (such as the component surface defining a local coordinate system). The set of direction vectors within each mesh unit is used to draw arrow markers, representing the main fiber placement trend within that area, ultimately forming a structure like... Figure 2 The first directional distribution diagram is shown. Red arrows indicate the distribution characteristics of the direction vectors of each path point within the grid cell, while blue dots mark the critical path points of the corrected trajectory. Some arrows in the diagram show a clear and uniform orientation, typically corresponding to smooth surface areas and stable placement regions; while others are blurry and divergent, often appearing in spatial regions with rapid curvature changes or severe normal perturbations. These phenomena reflect the coupling relationship between local placement consistency and surface perturbations, providing crucial information for subsequent identification of abnormal placement areas and the execution of direction field reconstruction.

[0040] In some embodiments, weighted interpolation and graphical stitching specifically include: dividing the surface of the CAD model of the formed component into a regular two-dimensional grid structure in its local parametric coordinate system (such as the (u,v) parameter space). The size of the grid cell can be adaptively adjusted according to the path point density and the local curvature of the component (e.g., using a finer grid in high curvature regions). For each path point with a known direction vector, the system determines its grid cell based on its (u,v) coordinates in the component surface coordinate system and maps the direction vector of the path point into that grid cell. For each grid cell, the system extracts the direction vectors of all associated path points within that cell and calculates the representative direction of that region. To improve the smoothness and local consistency of the direction estimation, a weighted interpolation method is used to calculate the mean of the direction vector. The weights can be determined based on the distance between the path point and the grid center; the closer the distance, the higher the weight. Gaussian kernel functions or inverse distance weighting (IDW) models are commonly used for weighting. For certain mesh cells where no path points fall (such as edges or sparse regions), neighborhood diffusion or surface interpolation is used to introduce directional information from adjacent valid meshes to achieve local continuity and avoid breakage in the directional pattern. After directional interpolation, the representative directional vector of each mesh cell is drawn as an arrow on the component surface diagram. The arrow starts at the center of the mesh, and its direction and length represent the average direction and laying tendency intensity of the fibers in that region, respectively.

[0041] Optionally, identifying the overlapping and intersecting regions of the surfaces in step S3 includes: Based on the first directional distribution map, extract the tangential direction vector of each path point in the component surface in the tangential direction, and construct a rectangular projection band along the component surface in the tangential direction by extending half of the tangential direction vector on both sides according to the preset directional bandwidth value, so as to determine the coverage range of each path direction. In this embodiment, for each path point in the fiber laying correction trajectory, its direction vector in the tangential direction of the component surface is extracted from the first direction distribution map and used as the main extension direction reference for that path point. Then, according to a preset direction bandwidth value (e.g., in millimeters, such as a direction bandwidth of 2.0 mm), a rectangular projection zone is constructed along the tangential direction by extending half the bandwidth value on both sides of the direction vector, forming the influence area of ​​the path in the component surface coordinate system. This rectangular projection zone is constructed point by point with the path point as the center, and then spliced ​​and merged along the path point sequence to finally form a continuous strip-shaped area covering the entire path.

[0042] Solve for the spatial overlap region of the rectangular projection zone to identify areas on the component surface where two or more fiber paths overlap or intersect, and obtain path intersection candidate areas; In this embodiment, based on the obtained rectangular projection strips of each path, spatial overlap region detection is performed in the component surface coordinate system. Specifically, the boundary overlap calculation is performed on the projection strips of any two paths in sequence. If the two paths have a significant tendency to intersect or cross in the surface space (e.g., the overlap length exceeds a set threshold or there is an angle), the spatial location can be marked as a path intersection candidate region. The intersection candidate region generally manifests as the convergence or cross-linking of multiple path projection regions in local space, which may correspond to the mutual stacking, twisting, or abnormal trajectory behavior of the paving paths in actual working conditions.

[0043] It is important to note that if the overlap length exceeds a set threshold, this threshold is determined comprehensively based on the design dimensions of the composite component, the precision of the fiber placement process, and structural safety requirements. Generally, a reasonable threshold range is between 2mm and 10mm, which can be flexibly adjusted according to the following factors: high-precision automatic fiber placement equipment allows for a smaller threshold setting (e.g., 2-5mm) to capture minor path overlap risks; for larger or thicker components, the threshold can be appropriately relaxed (e.g., 5-10mm) to avoid oversensitivity leading to frequent misjudgments.

[0044] Based on the laying order of the paths in the fiber laying correction trajectory, extract the path pairs with upper and lower layer relationships in the path intersection candidate area, and calculate the interlayer spacing and intersection angle in the normal direction of the component surface for each path pair. In this embodiment, after identifying candidate intersection regions, the path pairs with clear upper and lower layer relationships are further extracted by combining the temporal order or hierarchical identifier of each path in the actual laying sequence. For example, if path A is laid earlier than path B and they overlap in a certain area, then path B can be considered to be above path A. By identifying and pairing all path combinations that meet this condition, a set of path pairs with potential inter-layer interference is obtained for subsequent spatial structure evaluation. For each extracted upper and lower layer path pair, the inter-layer spacing in the normal direction of the component surface and the intersection angle between the tangential direction vectors of the two paths are calculated.

[0045] The path intersection candidate area that simultaneously meets the preset interlayer spacing threshold and intersection angle threshold is taken as the surface overlap intersection area.

[0046] In this embodiment, if the interlayer spacing of a path pair in the intersection area is less than a preset spacing threshold (e.g., 0.5 mm) and the intersection angle is greater than the intersection angle threshold (e.g., 30 degrees), then the area is considered to have potential physical overlap or spatial interpenetration risks and can be marked as a curved surface overlap intersection area. The identification result of this intersection area can be used for subsequent process correction steps such as path reconstruction, fiber layup optimization, or layup sequence adjustment to ensure the spatial integrity and structural stability between layers during the molding process.

[0047] Optionally, step S3, calculating the fiber perturbation offset magnitude in the normal direction for each layer in the overlapping intersection region of the surfaces, includes: Extract the rectangular projection zone corresponding to each path in the overlapping and intersecting area of ​​the curved surface, and calculate the center position of each path in the local curved surface normal direction based on the normal coordinates of the path points of the rectangular projection zone on the curved surface of the formed component in the CAD model of the component. In this embodiment of the invention, for the identified overlapping and intersecting areas of curved surfaces, the corresponding rectangular projection bands are first extracted sequentially for each fiber path involved in the area. These projection bands are constructed based on the tangential direction vectors of the path points and a preset bandwidth value, covering the main extension direction of the path on the curved surface and its influence range. The path points in the rectangular projection bands are then mapped to their normals in the corresponding surface parameter coordinate system of the component's 3D CAD model, obtaining the projection value of each path point in the surface normal direction (i.e., the unit normal vector direction). The average normal coordinate of all points in each rectangular projection band is used as the center normal position of the path within the overlapping area, i.e., the center elevation reference of the path within the area.

[0048] In one implementation of this invention, if the rectangular projection zone of path A in a certain overlapping area contains 68 path points, the surface normal height values ​​corresponding to the 68 points are averaged to calculate the center normal height of path A in the area as 12.38 mm; similarly, the center normal height of path B is calculated to be 13.02 mm.

[0049] Arrange the center positions according to the laying order, and use the lower layer center position in the laying order as a reference benchmark to calculate the relative height difference of the corresponding upper layer path in the normal direction layer by layer to obtain the initial inter-layer distance. In this embodiment of the invention, the paths are sorted according to the fiber layup time sequence or layer coding to clarify the path relationship between upper and lower layers. Then, using the center normal height of the lower layer path as a reference, the difference between the normal center positions of the paths above it is calculated to obtain the initial interlayer distance between path pairs. This interlayer distance represents the theoretical ply spacing of the path in the normal direction under undisturbed conditions and is a fundamental parameter for subsequently determining the impact of disturbances.

[0050] In one implementation of this invention, the laying sequence number of path A is #12, and the laying sequence number of path B is #17, indicating that path A is laid before path B. The normal center height of path A is 12.38 mm, and that of path B is 13.02 mm. Therefore, the initial interlayer distance of this path pair is 0.64 mm.

[0051] The normal offset trend of each path is determined based on the path curvature and laying sequence in the fiber laying correction trajectory; In this embodiment of the invention, based on the fiber layup correction trajectory of each path, the curvature change in the overlapping and intersecting areas is extracted. Combined with the local geometry of the component surface where the path is located (such as surface concavity / convexity changes, local corners, etc.) and the layup direction, a fitting algorithm is used to calculate the normal offset trend vector of the path. A larger path curvature, or its location within a region of drastic local curvature change, usually indicates that a certain degree of offset or bending may have occurred during the layup process, forming a normal disturbance. This trend vector is expressed in millimeters; a positive value indicates an upward deviation from the normal direction, and a negative value indicates a downward deviation.

[0052] In one implementation of this invention, path B exhibits a concave trajectory within the overlapping region, with an average curvature of 0.021. Based on the local surface concavity trend, the normal disturbance trend is calculated to be +0.22mm; path A is in a relatively straight area, and the disturbance trend is only +0.04mm.

[0053] The fiber perturbation offset magnitude in the normal direction of each path is obtained by superimposing the normal offset trend with the initial interlayer distance between the path pairs.

[0054] In this embodiment of the invention, the obtained initial interlayer distance and the obtained normal perturbation trend are numerically superimposed to obtain the fiber perturbation offset amplitude in the normal direction between actual paths. This amplitude can be used to determine whether a physical interference judgment condition is triggered, such as being less than a certain spacing threshold (e.g., 0.5 mm) and the perturbation angle being greater than a set limit angle (e.g., 30°).

[0055] In one implementation of this invention, the initial interlayer spacing between paths A and B is 0.64 mm, and the normal perturbation trend of path B is +0.22 mm. Therefore, its final perturbation offset is 0.64 mm - 0.22 mm = 0.42 mm. Since this perturbation offset is less than 0.5 mm, and given that the intersection angle is greater than 30 degrees, this path pair is determined to have a potential physical contact or intersection risk area, and can be included in the surface overlap intersection area identification results.

[0056] Optionally, the calculation of the angle adjustment of the direction vector in step S3 includes: Extract path pairs with an upper and lower layer relationship in the overlapping and intersecting regions of the curved surface, calculate the angle between the paving direction vectors of the path pairs, and obtain the initial angle value; In this embodiment of the invention, path pairs with established upper and lower layer relationships are extracted from the overlapping and intersecting areas of curved surfaces. Each path can be represented as a spatial curve segment composed of continuous path points during the laying process. The tangential direction vector at the corresponding position in the path segment is selected and defined as the laying direction vector of the path. For each pair of upper and lower layer paths, their corresponding tangential vectors within the overlapping area are selected, and the initial angle between their laying direction vectors is calculated according to the three-dimensional vector angle formula. This angle is used to measure the relative laying direction difference between the upper and lower paths during the laying process and is one of the important parameters for judging the risk of path interference and offset.

[0057] In one implementation of this invention, path A is a lower-level path and path B is an upper-level path, with their laying direction vectors in the overlapping area being: vector VA = (0.92, 0.12, 0.36) and vector VB = (0.88, 0.14, 0.45), respectively; the vector angle calculation formula is used. The calculated included angle is approximately 11.4°, which is the included angle of the path relative to the initial laying direction in this area.

[0058] The normalized fiber perturbation offset amplitude is combined with a preset perturbation sensitivity coefficient to construct a correction factor. This correction factor is then multiplied by the initial included angle value to calculate the included angle adjustment amount of the direction vector.

[0059] In this embodiment of the invention, the fiber disturbance offset amplitude calculated in the normal direction for each pair of paths is normalized using a preset standard disturbance range (e.g., 0 to 1 mm). This normalization normalizes the offset amplitude to a value between [0, 1]. The normalization result, combined with a preset disturbance sensitivity coefficient K (range 0.5 to 2.0) for different materials and laying scenarios, constitutes an amplification or suppression factor for angle correction. This correction factor is used to dynamically adjust the sensitivity of the angle determination between paths.

[0060] In one implementation of this invention, the disturbance offset amplitude of the path pair is 0.42 mm, which is obtained after normalization. If the current material type is high-modulus carbon fiber, which is sensitive to directional perturbations, and the preset perturbation sensitivity coefficient is K=1.5, then the correction factor can be calculated as follows: .

[0061] In this embodiment of the invention, the calculated initial included angle value is multiplied by the calculated disturbance correction factor to obtain the final included angle adjustment amount. This adjustment is used to correct the original included angle determination value and can be further used to adjust the laying path strategy or determine the level of potential interference risk.

[0062] In one implementation of this invention, the initial included angle value is... With a correction factor of 0.63, the calculated adjustment amount for the included angle is: The angle adjustment amount indicates that, after considering the disturbance offset effect, the original... The impact of path direction differences on the risk of laying interference is equivalent to approximately The actual laying deflection angle. If this value exceeds the interference warning threshold set by the system (e.g., If the path pair is deemed to have a high risk of directional interference, further path optimization or interlayer compression adjustment is required.

[0063] Optionally, dividing the first directional distribution map into finite volume elements in step S4 includes: Based on the spatial position of each path point in the first direction distribution map on the component surface of the CAD model of the formed component, the continuous area with a path point density greater than the preset laying density threshold is extracted to obtain the effective path distribution area. In this embodiment of the invention, by analyzing the mapping coordinates of each path point in the first directional distribution map in the component CAD model, and based on their projection relationship on the component surface, the number of path points within a unit area is counted, thereby constructing a path point density distribution map. A preset laying density threshold can be set according to the component material type, path control precision, and process requirements, for example, 30 path points per square centimeter. A sliding window (e.g., 2mm × 2mm) is used to scan the entire component surface area, identifying areas where the path point density continuously exceeds the threshold, and extracting them as valid path distribution areas using a connectivity clustering algorithm (e.g., a 4-neighborhood-based aggregation rule).

[0064] In one implementation of this invention, the component surface region is a complex hyperboloid, and the first direction distribution map records 15,380 path points. A 2mm × 2mm sliding window is used to traverse the CAD surface, extracting multiple continuous regions with path densities exceeding 40 points / cm². After region aggregation and boundary culling, three effective path distribution regions are finally identified, with the largest region size being 56mm × 88mm and the smallest being 18mm × 27mm, for subsequent spatial partitioning and volume modeling.

[0065] The maximum vertical spacing between each path point in the effective path distribution area on the component surface and in the thickness direction of its adjacent layer is used as the partitioning spacing. Combined with the component surface coordinate system, the component surface is divided at equal intervals in the normal direction of the component surface according to the partitioning spacing to obtain the initial finite volume element. In this embodiment of the invention, the projected distances of all path points in the effective path distribution area on the normal direction of the component surface are further extracted, and the maximum vertical spacing is calculated as the partition spacing d. To ensure the accuracy of structural modeling and disturbance calculation, this partition spacing can be set to the maximum spacing value rounded up to a set accuracy level (e.g., 0.1 mm). Subsequently, using the component surface as the reference plane and combining its normal direction (derived from the CAD surface derivative), several layers of parallel surfaces are constructed at equal intervals from the surface upwards and downwards at partition spacing d, and then expanded tangentially along the boundary contour of the effective path distribution area to construct a spatial frame, ultimately forming an initial finite volume element set covering the effective path area.

[0066] In one implementation of this invention, a certain effective path distribution area contains 12 layers, including upper and lower path layers. Statistical analysis shows that the maximum path point normal distance is 2.35 mm. With a rounding interval of 0.5 mm, five sets of inter-layer slices are constructed outward from the curved surface in the normal direction within this area, forming a 6-layer spatial segmentation region. Each inter-layer section maintains parallel normal to the component surface, forming a closed mesh through the boundary of the transverse path region, thereby constructing an initial finite volume element, generating a total of 312 finite element volumes.

[0067] Based on the spatial relationship of each path point, the spatial coordinates of each path point in the first direction distribution map and its corresponding laying direction vector are mapped to the initial finite volume element to obtain the finite volume element.

[0068] In this embodiment of the invention, spatial inclusion is determined by comparing the coordinates of path points in three-dimensional space (generated in real-time by three-dimensional path control or obtained through CAD surface mapping) with the spatial boundaries of initial finite volume units. A bounding box is constructed to quickly determine whether a path point is inside a certain volume unit; if so, the path point is assigned to that unit. Furthermore, the laying direction vector (tangent vector) carried by the path point is synchronously mapped to the volume unit to form a directional field distribution within a unit volume. After multiple path points are assigned to the same volume unit, structural parameters such as their average laying direction and directional difference (e.g., angular variance) can be statistically analyzed for subsequent interference judgment, disturbance propagation modeling, and laying optimization analysis.

[0069] Optionally, step S4, which characterizes the spatial distribution relationship between the fiber principal direction and the fiber secondary direction, includes: By adjusting the angle between the direction vectors, the direction vectors of all path points within a finite volume element are adjusted to obtain the set of adjusted direction vectors. In this embodiment of the invention, for each constructed finite volume unit, the adjustment amount is based on the included angle between the path pairs obtained in the preceding steps ( This involves adjusting the angle of the original laying direction vector for each path point in the unit. Specifically, if the angle between a path point and its adjacent path points exceeds an adjustment threshold, the direction vector of that path point is adjusted accordingly. The direction is adjusted by linear interpolation or slight rotation to make it more consistent with the local main direction.

[0070] In a specific implementation, let the original direction vector of the path point be... The directional adjustment amount of the finite volume element it belongs to is The corresponding target adjustment direction is a unit vector. (The nearest principal direction vector or the local average direction can be taken), then the new vector after adjusting the direction vector. It can be represented as: ;in Indicates the direction of rotation A rotation matrix for small-angle rotations. In this embodiment, if a cell contains 6 path points, after calculation, If the value range is 5.2° to 11.8°, then the direction vector of each path point is fine-tuned according to this adjustment amount to obtain the set of adjusted direction vectors.

[0071] In some embodiments, when performing a direction vector adjustment operation, based on the path number of the path point, the corresponding angle adjustment amount and disturbance sensitivity coefficient are first extracted, and a direction offset judgment quantity for fine-tuning is constructed. The physical meaning of this judgment quantity is: to what extent the direction vector of the path point should deviate from the original direction in order to approach its lower-level path direction and reduce the angle abrupt change between layers. If the angle adjustment amount is positive, it means that the current path direction should be offset towards its lower-level direction; if the angle adjustment amount is negative, it means that the current path direction has been over-deflected relative to the lower-level direction and should be partially reversed. This deflection processing is performed in a small-angle rotation mode in a three-dimensional coordinate system, and its adjustment range is limited by a preset fine-tuning tolerance threshold, not exceeding 10% of the angle of the original direction vector.

[0072] For example, in a high-density path region, if a significant tilting or offset trend is detected between the upper-layer path and the lower-layer path, and the angle adjustment is positive, the direction vector of the upper-layer path point is rotated slightly clockwise or counterclockwise to gradually approach the direction of the lower-layer path; if the adjustment is negative, the direction is reversed. This fine-tuning effectively reduces the dispersion of path point directions within a finite volume element. If the angle adjustment is close to zero, it indicates that the directional difference of the path pair in the normal direction is negligible and no adjustment is needed.

[0073] Calculate the covariance matrix of the adjusted direction vector set, and decompose the eigenvalues ​​and corresponding eigenvectors of the covariance matrix. Take the eigenvector corresponding to the largest eigenvalue as the fiber principal direction vector, and take the eigenvector corresponding to the second largest eigenvalue as the fiber secondary direction vector. In this embodiment of the invention, spatial statistical analysis is performed on the adjusted set of path point direction vectors in each finite volume unit to identify the main fiber laying direction and secondary disturbance trends within that region. Based on the obtained adjusted set of direction vectors, a covariance matrix of the direction vector distribution in three-dimensional space is constructed. This covariance matrix reflects the joint change trend of the path point direction vectors along different coordinate axes, and its value represents the strength of the correlation between different directional components. Specifically, by statistically analyzing the overall changes of each component in the path point direction vectors, the clustering and dispersion of these vectors along each direction in three-dimensional coordinate space can be comprehensively determined.

[0074] In one implementation of this invention, for a finite volume unit, the direction vectors of all path points within it are extracted. Using a unified local coordinate system as a reference, the spatial distribution characteristics of the direction vectors of each path point are calculated one by one, thereby constructing the direction vector covariance matrix within the unit. This matrix constitutes the basic structure describing the overall direction distribution characteristics within the unit. Subsequently, feature analysis is performed on the covariance matrix to identify the main characteristic directions representing the trend of direction change. In this process, the covariance matrix is ​​decomposed into several eigenvectors and their corresponding eigenvalues. The eigenvector corresponding to the largest eigenvalue represents the direction in which the direction change of path points is most concentrated, and is defined as the fiber principal direction vector within the finite volume unit. The eigenvector corresponding to the second largest eigenvalue represents the aggregation trend in path disturbances or non-dominant directions, and is defined as the fiber secondary direction vector.

[0075] For example, within a certain fiber laying area, the path point direction exhibits significant consistency along the component's length direction, resulting in the largest variation in the extracted covariance matrix along this direction; the corresponding eigenvector is then identified as the primary direction vector. Conversely, the path offset is smaller along the component's normal or width directions, but still exhibits certain distributional characteristics. The direction vector associated with its second-largest eigenvalue is then identified as the secondary direction vector. The primary and secondary direction vectors are orthogonal.

[0076] By integrating the fiber direction vectors of the primary and secondary directions, a second direction distribution map is obtained.

[0077] In this embodiment of the invention, based on the principal and secondary direction vectors extracted from all finite volume elements, they are remapped back to the component surface coordinate system according to their path spatial positions. A second direction distribution map is constructed by combining the center point coordinates of each element with its corresponding fiber principal and secondary directions. This second direction distribution map not only includes the primary fiber laying direction of each spatial region but also captures local directional disturbance trends and laying consistency information, serving as a crucial foundation for subsequent path planning optimization, forming stress prediction, and interlayer disturbance analysis.

[0078] In some embodiments, the second directional distribution map can be visualized as: a vector field map on the component surface (with long arrows for the main direction and short arrows for the secondary direction); or an ellipse or directional cone can be drawn with the principal axis direction of the directional tensor of each unit for 3D printing path disturbance identification.

[0079] The second directional distribution map finally formed in this embodiment contains 624 vector pairs, covering about 95% of the effective laying area on the component surface, and reflects significant differences in fiber orientation concentration in different areas, providing important input basis for subsequent laying correction, orientation disturbance modeling and stress control analysis.

[0080] Optionally, step S5 includes: Step S51: Using the fiber principal direction vector corresponding to each finite volume unit in the second directional distribution diagram as the principal axis direction, and the fiber secondary direction vector orthogonal to the principal axis direction as the lateral reference direction, construct the local coordinate system of each finite volume unit; In this embodiment of the invention, to accurately characterize the spatial orientation of fibers in various regions of the component surface, a local coordinate system is constructed based on the principal and secondary direction vectors of each finite volume element in the second direction distribution diagram. Specifically, all finite volume elements in the second direction distribution diagram are traversed first, and the principal and secondary direction vectors of the fibers corresponding to each element are extracted. The principal direction vector of the fibers is used as the principal axis direction of the local coordinate system to characterize the main force direction of the material in that region; at the same time, the secondary direction vector of the fibers, which is orthogonal to the principal axis direction, is set as the local lateral reference direction to help establish a reference system for the performance direction of anisotropic materials.

[0081] In a typical application scenario, if the main direction of a certain element extends along the longitudinal laying direction of the component, it will be marked as the X-axis direction of that element; if the secondary direction is relatively uniformly distributed in the width direction of the component, it will be set as the Y-axis direction, and the normal direction will correspond to the Z-axis. Finally, an independent local three-dimensional coordinate system is generated for each finite volume element, providing a directional reference for subsequent material property mapping and simulation analysis.

[0082] Step S52: Map the principal axis direction and transverse reference direction in the local coordinate system of each finite volume element to the preset mechanical and transverse properties of the material anisotropy, and construct a third anisotropic distribution map. In embodiments of the present invention, based on a constructed local coordinate system, the direction vector of each finite volume element is mapped to the direction of mechanical performance parameters corresponding to the anisotropic properties of the material. Specifically, the principal fiber direction corresponding to the principal axis direction in the local coordinate system is mapped to the preset longitudinal performance parameter direction (such as elastic modulus, tensile strength, etc.) in the material database; the transverse reference direction is mapped to the transverse performance parameter direction. In this way, a one-to-one correspondence between "direction → mechanical property" is established in each element, forming an anisotropic performance mapping driven by fiber direction. This mapping relationship is integrated into a third-party anisotropic distribution map, which not only contains information about the fiber direction but also clarifies the spatial distribution of anisotropic material properties in different regions of the component, used to support subsequent simulation and response analysis of mechanical behavior.

[0083] Step S53: Input the third anisotropic distribution diagram into the preset finite element model to perform composite material mechanical simulation and obtain the anisotropic response results; In this embodiment of the invention, a third-party directional distribution map is imported as input data into a preset finite element simulation model to perform anisotropic response simulation of the composite material component. The simulation model defines corresponding element types, mesh structures, and boundary conditions. Based on the principal and secondary directions of each element provided in the third-party directional distribution map, the anisotropic properties of the material are automatically loaded onto the corresponding mesh elements, achieving mechanical modeling that couples directional material properties with the structure. Subsequently, loads, boundary conditions, or thermal field conditions consistent with actual working conditions are applied, and the solution calculation process is executed. The simulation output results include indicators such as stress distribution, displacement response, interlaminar shear, and local deformation of the component under different loads, reflecting the true stress state of the composite material under direction-dependent conditions.

[0084] Step S54: Compare the attribute difference values ​​of the material anisotropic properties and the anisotropic response results to obtain the fiber orientation simulation results; if the attribute difference value of the fiber orientation simulation results is greater than the preset difference value threshold, then adjust the perturbation sensitivity coefficient according to the attribute difference value gradient to update the angle adjustment of the orientation vector, and then iteratively execute steps S4 to S5 until the attribute difference value is less than the preset difference value threshold; if the attribute difference value of the fiber orientation simulation results is less than the difference value threshold, then the second orientation distribution map is the actual fiber orientation distribution map of the composite material component.

[0085] In embodiments of the present invention, the simulation results are analyzed, and the anisotropic response results obtained in the simulation are compared with the anisotropic mechanical properties preset in the material design stage on a unit-by-unit basis to calculate the property difference value between the two. If the mechanical index of a certain unit's simulation response in the principal direction or transverse direction deviates from the preset material property by more than the difference value threshold (e.g., the elastic modulus error exceeds 5%), it is determined that there is a risk of fiber orientation error or insufficient correction of orientation disturbance in that region. Based on the gradient information of the difference value in spatial distribution, the value of the disturbance sensitivity coefficient is adjusted in reverse, thereby affecting the calculation result of the subsequent angle adjustment amount. The adjusted sensitivity coefficient is used to update the angle adjustment amount of the path point orientation vector, and then steps S4 to S5 are re-executed, including orientation vector adjustment, covariance analysis, local coordinate system construction, and simulation analysis, forming an iterative closed loop. After the difference value is less than the preset threshold, it is considered that the current second orientation distribution map has fully met the material anisotropic performance distribution requirements and can be used as the final fiber orientation distribution result of the composite material component for subsequent process path planning and manufacturing execution.

[0086] In another embodiment of the invention, the attribute difference values ​​of all finite volume elements in the current round of simulation results are first statistically analyzed. The difference value is defined as the absolute or relative deviation between the simulation output of the element's directional performance and the expected design value. For example, the error in the elastic modulus of the principal direction, the error in the transverse tensile strength, etc. Subsequently, based on the component surface coordinate system, the attribute difference values ​​are spatially discretized, and a gradient operator (such as central difference) is used to calculate the local rate of change of the difference values ​​in the principal and transverse directions, forming a difference gradient field. This gradient value reflects the degree of drastic change in material response in space. For regions where the difference gradient exceeds a set threshold (e.g., gradient exceeds 10% / mm), it is considered that the region is highly sensitive to directional disturbances, and the current disturbance correction is insufficient or the directional adjustment is inadequate. If the element's difference value is too large (exceeding the preset deviation threshold) and the gradient value is large, the disturbance sensitivity coefficient is appropriately increased to enhance the amplification effect of the angle adjustment in the next round; if the difference value is too small but the gradient change is significant, it is considered that the local directional disturbance is too strong, and the disturbance sensitivity coefficient is appropriately reduced to avoid excessive adjustment causing path discontinuity. If both the difference and the gradient are within the threshold range, the perturbation sensitivity coefficient is kept constant or finely adjusted. For example, if the initial perturbation sensitivity coefficient is 0.6, it is adjusted to 0.75 in the high-sensitivity region and to 0.45 in the low-sensitivity region.

[0087] In some embodiments, the adjustment range of a single iteration is limited to within ±0.1, that is, the new value of the perturbation sensitivity coefficient during each adjustment does not change by more than 0.1 compared to the previous value; the overall perturbation sensitivity coefficient after adjustment is limited to the range of 0.3 to 0.9, so as to avoid the perturbation sensitivity coefficient being too small, which would lead to ineffective adjustment, or too large, which would lead to excessive path perturbation.

[0088] Optionally, this application provides a composite material fiber orientation simulation modeling system for executing the composite material fiber orientation simulation modeling method described above. The composite material fiber orientation simulation modeling system includes: The trajectory acquisition module is used to acquire the fiber placement trajectory through the process control interface connected to the automatic fiber placement equipment; based on the fitting error of the fiber placement trajectory on the curved surface of the component, the bending radius and unit tangent direction of the path points are corrected to obtain the fiber placement correction trajectory; The tangent direction mapping module is used to map the tangent direction of each path point in the fiber laying correction trajectory to the tangent base of the preset molding component CAD model surface to construct a first direction distribution map; The angle adjustment calculation module is used to analyze the coverage of each path on the component surface in the first direction distribution map, identify the overlapping and intersecting areas of the surface; calculate the fiber disturbance offset amplitude in the normal direction of each layer in the overlapping and intersecting areas of the surface, and calculate the angle adjustment of the direction vector based on the fiber disturbance offset amplitude and the path intersection angle of the overlapping and intersecting areas of the surface. The primary and secondary direction division module is used to divide the first direction distribution map into finite volume units. The spatial distribution trend of the fiber primary direction vector and the fiber secondary direction vector is characterized by the adjustment of the angle between the direction vectors in the corresponding finite volume units, so as to obtain the second direction distribution map. The simulation module is used to take the fiber principal direction vector of the second direction distribution map as the principal axis direction and the fiber secondary direction vector as the transverse reference direction orthogonal to the principal axis, and perform fiber direction simulation verification in combination with the preset material anisotropy properties, so as to obtain the fiber direction simulation results.

[0089] Therefore, the embodiments should be considered as exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the application are intended to be included within the invention.

[0090] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A simulation modeling method for fiber orientation of composite materials, characterized in that, Applied to automated fiber placement equipment, it includes the following steps: Step S1: Collect the fiber placement trajectory through the process control interface connected to the automatic fiber placement equipment; based on the fitting error of the fiber placement trajectory on the component surface, correct the bending radius and unit tangent direction of the path points to obtain the fiber placement correction trajectory; Step S2: Map the tangent direction of each path point in the fiber placement correction trajectory to the tangent base of the preset CAD model surface of the molding component to construct the first direction distribution map; Step S3: Analyze the coverage of each path on the component surface in the first direction distribution map, identify the overlapping and intersecting areas of the surfaces; calculate the fiber disturbance offset amplitude in the normal direction of each layer in the overlapping and intersecting areas of the surfaces, and calculate the angle adjustment of the direction vector based on the fiber disturbance offset amplitude and the path intersection angle of the overlapping and intersecting areas of the surfaces. Step S4: Divide the first directional distribution map into finite volume units, and use the angle adjustment of the directional vectors to characterize the spatial distribution trend of the fiber principal directional vector and the fiber secondary directional vector in the corresponding finite volume units to obtain the second directional distribution map; Step S5: Take the fiber principal direction vector of the second direction distribution map as the principal axis direction, the fiber secondary direction vector as the transverse reference direction orthogonal to the principal axis, and perform fiber direction simulation verification in combination with the preset material anisotropy properties to obtain the fiber direction simulation results.

2. The composite material fiber orientation simulation modeling method according to claim 1, characterized in that, Step S1 includes: Step S11: Collect the fiber placement trajectory through the process control interface connected to the automatic fiber placement equipment; Step S12: Project the path points of the fiber laying trajectory onto the component surface coordinate system in the preset CAD model of the molded component, and calculate the position error of the path points in the tangential and normal directions of the surface based on the deviation between the local normal vector of the component surface and the tangent vector of the path points. Step S13: Identify the path segment to be corrected in the fiber laying trajectory based on the positional error of the path point in the tangential and normal directions of the curved surface; Step S14: Based on the curvature continuity between the path segment to be corrected and the adjacent path segments, perform a smooth fitting of the curved boundary of the path segment to be corrected to obtain the fitted path segment; Step S15: Based on the differential direction vector relationship between path points in the fitted path segment, calculate the instantaneous tangent direction of the path point as the new tangent direction of the path segment to obtain the fiber laying correction trajectory.

3. The composite material fiber orientation simulation modeling method according to claim 1, characterized in that, Step S2 includes: Step S21: Extract the tangential vector of each path point from the spatial position of the continuous path points in the differential fiber placement correction trajectory. Step S22: Calculate the local orthogonal tangent base at any given path point on the surface of the component in the CAD model of the formed component; Step S23: Project the tangent vector of each path point onto the local orthogonal tangent basis to obtain the direction vector of each path point on the component surface; Step S24: According to the coordinate positions of the path points on the component surface coordinate system, interpolate and stitch together the direction vectors of each path point on the component surface to obtain the first direction distribution map.

4. The composite material fiber orientation simulation modeling method according to claim 1, characterized in that, Step S3, which identifies overlapping and intersecting areas of curved surfaces, includes: Based on the first directional distribution map, extract the tangential direction vector of each path point in the component surface in the tangential direction, and construct a rectangular projection band along the component surface in the tangential direction by extending half of the tangential direction vector on both sides according to the preset directional bandwidth value, so as to determine the coverage range of each path direction. Solve for the spatial overlap region of the rectangular projection zone to identify areas on the component surface where two or more fiber paths overlap or intersect, and obtain path intersection candidate areas; Based on the laying order of the paths in the fiber laying correction trajectory, extract the path pairs with upper and lower layer relationships in the path intersection candidate area, and calculate the interlayer spacing and intersection angle in the normal direction of the component surface for each path pair. The path intersection candidate area that simultaneously meets the preset interlayer spacing threshold and intersection angle threshold is taken as the surface overlap intersection area.

5. The composite material fiber orientation simulation modeling method according to claim 1, characterized in that, Step S3, which calculates the fiber perturbation offset amplitude in the normal direction for each layer in the overlapping intersection region of the curved surfaces, includes: Extract the rectangular projection zone corresponding to each path in the overlapping and intersecting area of ​​the curved surface, and calculate the center position of each path in the local curved surface normal direction based on the normal coordinates of the path points of the rectangular projection zone on the curved surface of the formed component in the CAD model of the component. Arrange the center positions according to the laying order, and use the lower layer center position in the laying order as a reference benchmark to calculate the relative height difference of the corresponding upper layer path in the normal direction layer by layer to obtain the initial inter-layer distance. The normal offset trend of each path is determined based on the path curvature and laying sequence in the fiber laying correction trajectory; The fiber perturbation offset magnitude in the normal direction of each path is obtained by superimposing the normal offset trend with the initial interlayer distance between the path pairs.

6. The composite material fiber orientation simulation modeling method according to claim 1, characterized in that, Step S3 involves calculating the angle adjustment of the direction vector, including: Extract path pairs with an upper and lower layer relationship in the overlapping and intersecting regions of the curved surface, calculate the angle between the paving direction vectors of the path pairs, and obtain the initial angle value; The normalized fiber perturbation offset amplitude is combined with a preset perturbation sensitivity coefficient to construct a correction factor. This correction factor is then multiplied by the initial included angle value to calculate the included angle adjustment amount of the direction vector.

7. The composite material fiber orientation simulation modeling method according to claim 1, characterized in that, Step S4, which divides the first directional distribution map into finite volume elements, includes: Based on the spatial position of each path point in the first direction distribution map on the component surface of the CAD model of the formed component, the continuous area with a path point density greater than the preset laying density threshold is extracted to obtain the effective path distribution area. The maximum vertical spacing between each path point in the effective path distribution area on the component surface and in the thickness direction of its adjacent layer is used as the partitioning spacing. Combined with the component surface coordinate system, the component surface is divided at equal intervals in the normal direction of the component surface according to the partitioning spacing to obtain the initial finite volume element. Based on the spatial relationship of each path point, the spatial coordinates of each path point in the first direction distribution map and its corresponding laying direction vector are mapped to the initial finite volume element to obtain the finite volume element.

8. The composite material fiber orientation simulation modeling method according to claim 1, characterized in that, Step S4, which characterizes the spatial distribution relationship between the principal and secondary fiber directions, includes: By adjusting the angle between the direction vectors, the direction vectors of all path points within a finite volume element are adjusted to obtain the set of adjusted direction vectors. Calculate the covariance matrix of the adjusted direction vector set, and decompose the eigenvalues ​​and corresponding eigenvectors of the covariance matrix. Take the eigenvector corresponding to the largest eigenvalue as the fiber principal direction vector, and take the eigenvector corresponding to the second largest eigenvalue as the fiber secondary direction vector. By integrating the fiber direction vectors of the primary and secondary directions, a second direction distribution map is obtained.

9. The composite material fiber orientation simulation modeling method according to claim 1, characterized in that, Step S5 includes: Step S51: Using the fiber principal direction vector corresponding to each finite volume unit in the second directional distribution diagram as the principal axis direction, and the fiber secondary direction vector orthogonal to the principal axis direction as the lateral reference direction, construct the local coordinate system of each finite volume unit; Step S52: Map the principal axis direction and transverse reference direction in the local coordinate system of each finite volume element to the preset mechanical and transverse properties of the material anisotropy, and construct a third anisotropic distribution map. Step S53: Input the third anisotropic distribution diagram into the preset finite element model to perform composite material mechanical simulation and obtain the anisotropic response results; Step S54: Compare the attribute difference values ​​of the material anisotropic properties and the anisotropic response results to obtain the fiber orientation simulation results; if the attribute difference value of the fiber orientation simulation results is greater than the preset difference value threshold, then adjust the perturbation sensitivity coefficient according to the attribute difference value gradient to update the angle adjustment of the orientation vector, and then iteratively execute steps S4 to S5 until the attribute difference value is less than the preset difference value threshold; if the attribute difference value of the fiber orientation simulation results is less than the difference value threshold, then the second orientation distribution map is the actual fiber orientation distribution map of the composite material component.

10. A simulation modeling system for fiber orientation of composite materials, characterized in that, For executing the composite material fiber orientation simulation modeling method as described in claim 1, the composite material fiber orientation simulation modeling system includes: The trajectory acquisition module is used to acquire the fiber placement trajectory through the process control interface connected to the automatic fiber placement equipment; based on the fitting error of the fiber placement trajectory on the curved surface of the component, the bending radius and unit tangent direction of the path points are corrected to obtain the fiber placement correction trajectory; The tangent direction mapping module is used to map the tangent direction of each path point in the fiber laying correction trajectory to the tangent base of the preset molding component CAD model surface to construct a first direction distribution map; The angle adjustment calculation module is used to analyze the coverage of each path on the component surface in the first direction distribution map, identify the overlapping and intersecting areas of the surface; calculate the fiber disturbance offset amplitude in the normal direction of each layer in the overlapping and intersecting areas of the surface, and calculate the angle adjustment of the direction vector based on the fiber disturbance offset amplitude and the path intersection angle of the overlapping and intersecting areas of the surface. The primary and secondary direction division module is used to divide the first direction distribution map into finite volume units. The spatial distribution trend of the fiber primary direction vector and the fiber secondary direction vector is characterized by the adjustment of the angle between the direction vectors in the corresponding finite volume units, so as to obtain the second direction distribution map. The simulation module is used to take the fiber principal direction vector of the second direction distribution map as the principal axis direction and the fiber secondary direction vector as the transverse reference direction orthogonal to the principal axis, and perform fiber direction simulation verification in combination with the preset material anisotropy properties, so as to obtain the fiber direction simulation results.

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