Modeling method of cae model of composite lattice sandwich propeller blade

Abstract

This invention relates to a CAE modeling method for composite material lattice sandwich propeller blades, belonging to the fields of marine propulsion technology and advanced composite material structure design. The method comprises the following steps: Step 1: Constructing a 3D geometric model of the lattice unit cell; Step 2: Reconstructing the blade solid model based on the geometric shape point data of the target propeller, establishing the design's spatial boundaries and baseline shape; Step 3: Generating first and second equidistant curved surfaces from the outside to the inside of the blade solid model, and dividing the blade solid model into a composite material panel domain, a ply base domain, and a lattice sandwich domain; Step 4: Performing Boolean intersection operations on the remaining lattice cell array located within the lattice sandwich domain to obtain a lattice sandwich structure that precisely fits the boundary of the lattice sandwich domain; Step 5: Performing Boolean addition operations on the composite material panel domain, ply base domain, and lattice sandwich structure to combine them into a complete composite material lattice sandwich propeller blade CAE model. This invention is used for CAE modeling of composite material lattice sandwich propeller blades.

Description

Technical Field

[0001] This invention belongs to the field of ship propulsion technology and advanced composite material structure design, specifically involving a CAE modeling method for composite material lattice sandwich propeller blades. Background Technology

[0002] As a core component of a ship's propulsion system, the performance of a ship's propeller directly affects its efficiency, noise, vibration, and safety. These factors also represent the direction of modern propeller improvement. To improve efficiency and reduce vibration and noise, using composite materials to manufacture propellers is an effective solution. Furthermore, a lattice structure can be added to this structure, and propeller blades can be prepared using a composite material lattice sandwich structure E.

[0003] Composite materials possess numerous advantages, including high specific strength, high specific stiffness, good damping performance, and excellent designability, and have been widely applied in aerospace, shipbuilding, and many other fields. The composite lattice sandwich structure E is a novel lightweight porous structure consisting of two side panels and a central lattice core. The side panels are thin and have high stiffness, while the core layer is thick and lightweight. Combining the advantages of both composite materials and porous materials, the composite lattice sandwich structure E not only achieves lightweighting but, more importantly, exhibits superior performance in impact resistance and vibration reduction / noise reduction. Therefore, it has broad application prospects in the shipbuilding industry. Currently, the lattice sandwich structure E is transitioning from key technology verification to engineering application. Thanks to the development of 3D printing additive manufacturing technology, complex lattice structures are being implemented.

[0004] However, when applying the lattice sandwich structure E to a propeller blade, a curved surface component with complex spatial torsional deformation, conventional modeling methods face challenges such as difficulty in adapting the lattice to the curved surface boundary and poor model manufacturability. Currently, there is a lack of an efficient modeling method that can effectively process the boundaries and generate a clean CAE model (Computer-Aided Engineering Model) with clear boundaries, conformal to the curved surface, and meeting the requirements of additive manufacturing processes, based on rapid filling using a regular lattice array. This invention is proposed to solve the above problems. Propeller blades have complex curved surface shapes, making the application of lattice structures to propeller blades challenging. Therefore, it is essential to propose a CAE modeling method for composite material lattice sandwich propellers. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a CAE modeling method for composite material lattice sandwich propeller blades, thereby solving the problems of conformal adaptation between the lattice structure and the complex curved surface of the blade, interface connection reliability, and model manufacturability.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A CAE modeling method for composite material lattice sandwich propeller blades, the method comprising the following steps:

[0008] Step 1: Construction of the three-dimensional geometric model of the lattice unit cell; Based on the mechanical performance requirements of the target propeller blade and the additive manufacturing process capability, select, optimize and construct a three-dimensional geometric model of the lattice unit cell with a specific topological configuration as the basic unit for manufacturing.

[0009] Step 2: Generation of the propeller solid model; Obtain the geometric value point data of the target propeller, and reconstruct a propeller solid model with an accurate shape based on the data, establishing the spatial boundary and reference shape of the design.

[0010] Step 3: Division of multi-layer structural domains; Based on the total thickness of the composite material layup design, a first equidistant surface is generated on the inner side of the blade solid model; then, based on the minimum feature size allowed by the additive manufacturing process, a second equidistant surface is generated on the basis of the first equidistant surface. The blade solid model is divided into three structural domains using the first and second equidistant surfaces: the composite material panel domain C located on the outer side, the layup base domain D located in the middle, and the lattice sandwich domain B located on the inner side;

[0011] Step 4: Spatial filling and topological trimming of the lattice structure; the lattice cells described in Step 1 are arrayed in three-dimensional space to form a lattice cell array, and the envelope of the lattice cell array completely covers the lattice sandwich domain B described in Step 3; then, the parts of the lattice cell array that do not intersect with the lattice sandwich domain B are deleted; finally, Boolean intersection is performed on the remaining lattice cell array located inside the lattice sandwich domain B to obtain a lattice sandwich structure E that precisely fits the boundary of the lattice sandwich domain B;

[0012] Step 5: Assembly and integration of the overall model; perform Boolean addition operations on the outer composite material panel domain C, the middle ply base domain D obtained in Step 3, and the lattice sandwich structure E obtained in Step 4 to combine them into a complete composite material lattice sandwich propeller blade CAE model.

[0013] Furthermore, in step one, the construction process of the three-dimensional geometric model of the lattice unit cell is as follows:

[0014] (1) Select the unit cell configuration based on the mechanical performance requirements of the target propeller blade;

[0015] (2) The selected unit cell configuration is given a parameterized geometric definition, including the unit cell length L, the rod form and cross-sectional area S, and the relative density ρ;

[0016] (3) Based on the defined geometric parameters, an initial unit cell geometric model is generated in the 3D modeling software; then, the geometric parameters are optimized according to the mechanical performance optimization target and the minimum precision limit and constraint of the additive manufacturing process.

[0017] Furthermore, the specific implementation process of step two is as follows:

[0018] (1) The composite lattice sandwich propeller blades will deform under actual working load. In order to meet the hydrodynamic performance requirements, the blades must be pre-deformed. Finite element calculation of the blade model is carried out according to the actual working load.

[0019] {[K l ]+[K o ]+[K g ]-[K r ]}{u}={F ext}+{F r}+{F h}

[0020] Among them, [K l ],[K o ],[K g ],[K r ] are the linear stiffness matrix, initial displacement stiffness matrix, geometric stiffness matrix, and rotational stiffness matrix, respectively; {u} is the nodal displacement vector in local coordinates; {F ext},{F r},{F h These are external load, fluid load, and centrifugal load, respectively.

[0021] (2) Derive the displacement field from the finite element calculation results and reconstruct the finite element model of the blade with pre-deformation;

[0022] (3) Based on the shape points of the finite element model of the pre-deformed blade, establish a solid geometric model of the blade with an accurate shape.

[0023] Furthermore, in step three, the generation processes of the first and second equidistant surfaces are as follows:

[0024] (1) Design the composite material plywood on the outer surface and calculate the total thickness t_1 of the composite material plywood;

[0025] (2) Based on the total thickness t_1 of the composite material layup design, the surface of the blade solid model is offset inward by a distance t_1 to generate the first equidistant surface;

[0026] (3) Based on the first equidistant surface, offset inward to the minimum feature size t_2 allowed by the additive manufacturing process to generate the second equidistant surface.

[0027] Furthermore, in step four, the calculation process of the Boolean intersection operation is as follows:

[0028] (1) Select the remaining lattice cell array A located inside the lattice sandwich domain B and the lattice sandwich domain B as the input geometric objects for the Boolean intersection operation;

[0029] (2) In the 3D modeling software environment, perform the A∩B Boolean intersection operation, that is, retain all geometric parts of the operand A that are located inside the operand B, and automatically delete the geometric parts of the operand A that extend outside the operand B.

[0030] (3) Through the Boolean intersection operation, a lattice sandwich structure E that is precisely geometrically fitted to the boundary of the lattice sandwich domain B is obtained. The outline of the structure is strictly limited by the boundary definition of the lattice sandwich domain B.

[0031] Furthermore, in step five, the calculation process of the Boolean addition operation is as follows:

[0032] (1) Select the composite material panel domain C, the ply base domain D obtained in step three, and the lattice sandwich structure E obtained in step four as the input geometric objects for Boolean addition operation.

[0033] (2) In the 3D modeling software environment, perform the C∪D∪E Boolean addition operation, which merges the three originally independent geometric objects into a single geometric body with a unified and closed boundary representation;

[0034] (3) Through the Boolean addition operation, the contact interface between the lattice sandwich structure E, the composite material panel domain C, and the layup base domain D is eliminated, generating a geometrically seamless and complete composite material lattice sandwich propeller blade CAE model.

[0035] The advantages of this invention over the prior art are:

[0036] 1. Solved the conformal adaptation problem: Through the topology trimming method of "spatial array + Boolean intersection operation", the regular lattice unit can accurately and adaptively fill the internal space of the irregular blade, ensuring the integrity of the structure and the accuracy of the design.

[0037] 2. Optimized interface connection: By introducing the "layout base domain D", a transition layer with a specific thickness is formed between the lattice structure and the composite material panel. This layer not only provides reliable connection anchor points for the lattice rods and optimizes the force transmission path, but also ensures that the connection interface meets the manufacturing process requirements, improves the strength and durability of the overall structure, and is compatible with the composite material layup preparation process.

[0038] 3. Ensures manufacturability: The layup thickness and minimum process dimensions are considered from the beginning of model generation, avoiding the creation of unmanufacturable micro-features from the source. The generated model can be directly used for additive manufacturing, realizing the integration of design and manufacturing.

[0039] 4. This invention is applicable to the construction of computer-aided engineering models for composite material lattice sandwich propeller blades with complex curved surface shapes. Attached Figure Description

[0040] Figure 1 This is a diagram of the body-centered cubic lattice unit cell configuration established in Example 1;

[0041] Figure 2 This is a model diagram of the 4381 model propeller established in Example 1;

[0042] Figure 3 This is a schematic diagram of the first and second equidistant surfaces established in Example 1; Figure 4 This is a schematic diagram of the blade division in Example 1;

[0043] Figure 5 This is a schematic diagram of the lattice unit cell array and the lattice sandwich layer in Example 1;

[0044] Figure 6 This is a schematic diagram of the lattice sandwich core after the intersection is determined in Example 1;

[0045] Figure 7 This is a model diagram of the 4381 composite material lattice sandwich propeller established in Example 1;

[0046] Figure 8 This is a partial schematic diagram of the root of the 4381 composite material lattice sandwich blade established in Example 1;

[0047] Figure 9 This is a schematic diagram of the 4381 paddle matrix sandwich core obtained by printing in Example 1;

[0048] Figure 10 This is a schematic diagram of the blade root of the 4381 propeller matrix sandwich core obtained by printing in Example 1. Detailed Implementation

[0049] Specific implementation method one: as follows Figure 1 , Figures 3-6 As shown in the figure, this embodiment describes a CAE modeling method for composite material lattice sandwich propeller blades, the method including the following steps:

[0050] Step 1: Construction of the three-dimensional geometric model of the lattice unit cell; Based on the mechanical performance requirements of the target propeller blade and the additive manufacturing process capability, select, optimize and construct a three-dimensional geometric model of the lattice unit cell with a specific topological configuration as the basic unit for manufacturing.

[0051] Step 2: Generation of the propeller solid model; Obtain the geometric value point data of the target propeller, and reconstruct a propeller solid model with an accurate shape based on the data, establishing the spatial boundary and reference shape of the design.

[0052] Step 3: Division of multi-layer structural domains; Based on the total thickness of the composite material layup design, a first equidistant surface is generated on the inner side of the blade solid model; then, based on the minimum feature size allowed by the additive manufacturing process, a second equidistant surface is generated on the basis of the first equidistant surface, such as... Figure 3 As shown; the blade solid model is divided into three structural domains using the first and second equidistant surfaces: the outer composite panel domain C (composite layer), the middle ply base domain D (ply base layer), and the inner lattice sandwich domain B (lattice sandwich layer), as shown. Figure 4 As shown.

[0053] This step precisely defines different functional material regions using two parameters: "layout thickness" and "process dimensions." In particular, it creates a "layout base domain D" between the lattice structure and the panel. This layout base domain D not only provides an anchoring foundation for the lattice but also ensures the manufacturing precision and strength at the connection between the panel and the lattice. At the same time, it provides a basic layup platform for the preparation of composite material layups.

[0054] The outer composite material panel region C is the area enclosed between the inner surface of the blade and the first equidistant curved surface.

[0055] The intermediate ply base region D: is the area enclosed between the first equidistant surface and the second equidistant surface;

[0056] The inner lattice sandwich region B is the area enclosed by the second equidistant curved surface.

[0057] Step 4: Spatial Filling and Topological Trimming of the Lattice Structure; Array the lattice unit cells described in Step 1 in three-dimensional space to form a lattice cell array, ensuring that the envelope of the lattice cell array completely covers the lattice sandwich region B described in Step 3, such as... Figure 5 As shown; then, the portions of the lattice cell array that do not intersect with the lattice sandwich region B are deleted; finally, a Boolean intersection operation is performed on the remaining lattice cell array located inside the lattice sandwich region B to obtain the lattice sandwich structure E that precisely fits the boundary of the lattice sandwich region B, as shown. Figure 6 As shown.

[0058] In this step, the lattice unit cells described in step one are arrayed in the three-dimensional space of the lattice core domain B to form a lattice cell array. This step achieves adaptive filling of the irregular blade space from a regular lattice. By using the method of "first array coverage, then Boolean intersection", the conformal problem between the lattice and the complex curved surface is solved, ensuring that the lattice core fills the entire design space with neat boundaries and forms a clear connection interface with the ply base domain D.

[0059] Step 5: Assembly and Integration of the Overall Model; Perform Boolean addition operations on the outer composite material panel domain C and the middle ply base domain D obtained in Step 3, and the lattice sandwich structure E obtained in Step 4, to combine them into a complete composite material lattice sandwich propeller blade CAE model, as shown below. Figure 7 , Figure 8 As shown, this forms an integrated digital model that can be used for simulation analysis, optimization, and direct driving of 3D printing.

[0060] Furthermore, in step one, the three-dimensional geometric model of the constructed lattice unit cell is as follows:

[0061] (1) Select the unit cell configuration (such as body-centered cubic (BC), face-centered cubic (FC), or Kagome configuration as the basic unit cell topology) according to the mechanical performance requirements of the target propeller blade;

[0062] (2) The selected unit cell configuration is given a parameterized geometric definition, including the unit cell length L, the rod form and cross-sectional area S, and the relative density ρ;

[0063] (3) Based on the defined geometric parameters, an initial unit cell geometric model is generated in the 3D modeling software; then, the geometric parameters are optimized according to the mechanical performance optimization objectives (i.e., based on mechanical performance optimization objectives such as stiffness, strength, and modal fundamental frequency) and combined with the minimum precision limit and constraints of the additive manufacturing process.

[0064] For example, if the modal fundamental frequency is used as the mechanical performance optimization target, an initial unit cell geometric model is generated in 3D modeling software based on the defined geometric parameters. Then, using the modal fundamental frequency as the mechanical performance optimization target, specific frequency points are avoided, and the geometric parameters are optimized in combination with the minimum precision limit and constraints of the additive manufacturing process.

[0065] Furthermore, the specific implementation process of step two is as follows:

[0066] (1) The composite lattice sandwich propeller blades will deform under actual working load. In order to meet the hydrodynamic performance requirements, the blades must be pre-deformed. Finite element calculation of the blade model is carried out according to the actual working load.

[0067] {[K l ]+[Ko ]+[K g ]-[K r ]}{u}={F ext}+{F r}+{F h}

[0068] Among them, [K l ],[K o ],[K g ],[K r ] are the linear stiffness matrix, initial displacement stiffness matrix, geometric stiffness matrix, and rotational stiffness matrix, respectively; {u} is the nodal displacement vector in local coordinates; {F ext},{F r},{F h These are external load, fluid load, and centrifugal load, respectively.

[0069] (2) Derive the displacement field from the finite element calculation results and reconstruct the finite element model of the blade with pre-deformation;

[0070] (3) Based on the shape points of the finite element model of the pre-deformed blade, establish a solid geometric model of the blade with an accurate shape.

[0071] Furthermore, in step three, the generation processes of the first and second equidistant surfaces are as follows:

[0072] (1) Design the composite material plywood on the outer surface and calculate the total thickness t_1 of the composite material plywood;

[0073] (2) Based on the total thickness t_1 of the composite material layup design, the surface of the blade solid model is offset inward by a distance t_1 to generate the first equidistant surface;

[0074] (3) Based on the first equidistant surface, offset inward to the minimum feature size t_2 allowed by the additive manufacturing process to generate the second equidistant surface.

[0075] The minimum permissible feature size for additive manufacturing processes varies. For metal additive manufacturing such as SLM, the minimum feature size can reach 0.5mm-1mm; for plastic or resin SLA / DLP technology, the minimum feature size can reach 0.2mm-0.5mm; and for SLS technology, the minimum feature size is typically around 0.5mm-1mm. The actual minimum feature size depends on the specific process adopted.

[0076] Furthermore, in step four, the calculation process of the Boolean intersection operation is as follows:

[0077] (1) Select the remaining lattice cell array A located inside the lattice sandwich domain B and the lattice sandwich domain B as the input geometric objects for the Boolean intersection operation;

[0078] (2) In the 3D modeling software environment, perform the A∩B Boolean intersection operation, that is, retain all geometric parts of the operand A that are located inside the operand B, and automatically delete the geometric parts of the operand A that extend outside the operand B.

[0079] (3) Through the Boolean intersection operation, a lattice sandwich structure E that is precisely geometrically fitted to the boundary of the lattice sandwich domain B is obtained. The outline of the structure is strictly limited by the boundary definition of the lattice sandwich domain B.

[0080] Furthermore, in step five, the calculation process of the Boolean addition operation is as follows:

[0081] (1) Select the composite material panel domain C, the ply base domain D obtained in step three, and the lattice sandwich structure E obtained in step four as the input geometric objects for Boolean addition operation.

[0082] (2) In the 3D modeling software environment, perform the C∪D∪E Boolean addition operation, which merges the three originally independent geometric objects into a single geometric body with a unified and closed boundary representation;

[0083] (3) Through the Boolean addition operation, the contact interface between the lattice sandwich structure E, the composite material panel domain C, and the layup base domain D is eliminated, generating a geometrically seamless and complete CAE model of the composite material lattice sandwich propeller blade. This integrated digital model can be used for subsequent finite element mesh generation, mechanical property simulation analysis, and can also serve as a 3D printing file for driving additive manufacturing equipment.

[0084] Example 1:

[0085] This embodiment uses the 4381 model propeller as the object to construct its CAE model of composite material lattice sandwich blades.

[0086] Step 1: Select a body-centered cubic (BC) lattice unit cell configuration, which possesses excellent specific strength and energy absorption characteristics. Based on the propeller's performance requirements, establish optimization objectives. In this embodiment, it is necessary to avoid specific natural frequencies. Considering the minimum printing accuracy requirements, the side length of the BC unit cell members is determined to be 4 mm, and the cross-section of the members is circular with a diameter of 1 mm. In 3D modeling software, construct a BC unit cell model with a side length of 4 mm, as follows... Figure 1 As shown.

[0087] Step 2: Import the shape point data file of the 4381 model propeller. Through spline curve fitting and surface lofting operations, reconstruct a precise 3D solid model of the propeller blade, such as... Figure 2 As shown.

[0088] Step 3: In this embodiment, the total thickness of the composite material panel is designed to be 1mm, and the thickness of the layup base layer is designed to be 1.5mm. Accordingly, firstly, the inner surface of the solid model of the blade is offset inward by 1mm to generate a first equidistant curved surface (corresponding to the inner boundary of the outer composite material panel domain C); then, considering the minimum printable angle and support capability of the 3D printing equipment for the suspended structure, the first equidistant curved surface is offset inward by another 1.5mm to generate a second equidistant curved surface. Using these two curved surfaces as cutting tools, the solid model of the blade is divided into three structural domains: the outer composite material panel domain C (outermost layer thickness 1mm), the middle layup base domain D (middle layer thickness 1.5mm), and the inner lattice sandwich domain B (internal remaining space).

[0089] Step 4: Array the BC unit cells from Step 1 in the X, Y, and Z directions, ensuring the array range completely covers the lattice sandwich region B defined in Step 3. Then, delete all unit cells completely outside the lattice sandwich region B. Finally, perform a Boolean intersection operation between the remaining unit cell array and the solid lattice sandwich region B to obtain the internal lattice sandwich structure E whose boundary perfectly conforms to the blade surface.

[0090] Step 5: Perform Boolean addition operations on the composite material panel domain C, the layup base domain D, and the lattice sandwich structure E generated in Step 4 to finally form a complete solid model.

[0091] Results Verification: Finite element analysis of the CAE model established using the method in this embodiment shows that, under the same weight, its specific stiffness and specific strength are significantly optimized compared to traditional solid blades. More importantly, after the model was directly imported into a selective laser melting 3D printing device, it successfully manufactured a complete layup base layer and the internal lattice sandwich structure E, as shown in the figure. Figure 9 , Figure 10 As shown, the effectiveness of the method described in this invention in addressing model manufacturability is demonstrated.

Claims

1. A composite lattice sandwich propeller blade CAE model modeling method, characterized in that: The method includes the following steps: Step 1: Construction of the three-dimensional geometric model of the lattice unit cell; Based on the mechanical performance requirements of the target propeller blade and the additive manufacturing process capability, select, optimize and construct a three-dimensional geometric model of the lattice unit cell with topological configuration as the basic unit for manufacturing. Step 2: Generation of the propeller solid model; Obtain the geometric value point data of the target propeller, and reconstruct a propeller solid model with an accurate shape based on the data, establishing the spatial boundary and reference shape of the design. Step 3: Division of Multi-Layer Structural Domains; Based on the total thickness of the composite material layup design, a first equidistant surface is generated on the inner side of the blade solid model; then, based on the minimum feature size allowed by the additive manufacturing process, a second equidistant surface is generated on the first equidistant surface. The first and second equidistant surfaces are used to divide the blade solid model into three structural domains: the outer composite material panel domain C, the middle layup base domain D, and the inner lattice sandwich domain B; the generation processes of the first and second equidistant surfaces are as follows: (1) Design the composite material plywood on the outer surface and calculate the total thickness t_1 of the composite material plywood; (2) Based on the total thickness t_1 of the composite material layup design, the surface of the blade solid model is offset inward by a distance t_1 to generate the first equidistant surface; (3) Based on the first equidistant surface, offset inward by the minimum feature size t_2 allowed by the additive manufacturing process to generate the second equidistant surface; Step 4: Spatial filling and topological trimming of the lattice structure; the lattice cells described in Step 1 are arrayed in three-dimensional space to form a lattice cell array, and the envelope of the lattice cell array completely covers the lattice sandwich domain B described in Step 3; then, the parts of the lattice cell array that do not intersect with the lattice sandwich domain B are deleted; finally, Boolean intersection is performed on the remaining lattice cell array located inside the lattice sandwich domain B to obtain a lattice sandwich structure E that precisely fits the boundary of the lattice sandwich domain B; Step 5: Assembly and integration of the overall model; perform Boolean addition operations on the outer composite material panel domain C, the middle ply base domain D obtained in Step 3, and the lattice sandwich structure E obtained in Step 4 to combine them into a complete composite material lattice sandwich propeller blade CAE model.

2. The composite lattice sandwich propeller blade CAE modeling method according to claim 1, characterized in that: In step one, the construction process of the three-dimensional geometric model of the lattice unit cell is as follows: (1) Select the unit cell configuration based on the mechanical performance requirements of the target propeller blade; (2) The selected unit cell configuration is given a parameterized geometric definition, including the unit cell length L, the rod form and cross-sectional area S, and the relative density ρ; (3) Based on the defined geometric parameters, an initial unit cell geometric model is generated in the 3D modeling software; then, the geometric parameters are optimized according to the mechanical performance optimization target and the minimum precision limit and constraint of the additive manufacturing process.

3. The composite lattice sandwich propeller blade CAE modeling method according to claim 1, characterized in that: The specific implementation process of step two is as follows: (1) The composite material lattice sandwich propeller blades will deform under actual working load. In order to meet the hydrodynamic performance requirements, the blades must be pre-deformed. Finite element analysis of the blade model was performed based on the actual operating load. {[ ]+[ ]+[ ]-[ ]}{ }={ }+{ }+{ } Wherein, ], ], ], ] are linear stiffness matrix, initial displacement stiffness matrix, geometric stiffness matrix, rotational stiffness matrix respectively, } is the node displacement vector in local coordinates, ], ], ] are external load, fluid load, centrifugal load respectively; (2) Derive the displacement field from the finite element calculation results and reconstruct the finite element model of the blade with pre-deformation; (3) Based on the shape points of the finite element model of the pre-deformed blade, establish a solid geometric model of the blade with an accurate shape.

4. The composite lattice sandwich propeller blade CAE modeling method according to claim 1, characterized in that: In step four, the calculation process of the Boolean intersection operation is as follows: (1) Select the remaining lattice cell array A located inside the lattice sandwich domain B and the lattice sandwich domain B as the input geometric objects for the Boolean intersection operation; (2) In the 3D modeling software environment, perform the A∩B Boolean intersection operation, that is, retain all geometric parts of the operand A that are located inside the operand B, and automatically delete the geometric parts of the operand A that extend outside the operand B. (3) Through the Boolean intersection operation, a lattice sandwich structure E that is precisely geometrically fitted to the boundary of the lattice sandwich domain B is obtained. The outline of the structure is strictly limited by the boundary definition of the lattice sandwich domain B.

5. The composite lattice sandwich propeller blade CAE modeling method according to claim 1, characterized in that: In step five, the Boolean addition operation is performed as follows: (1) Select the composite material panel domain C, the ply base domain D obtained in step three, and the lattice sandwich structure E obtained in step four as the input geometric objects for Boolean addition operation. (2) In the 3D modeling software environment, perform the C∪D∪E Boolean addition operation, which merges the three originally independent geometric objects into a single geometric body with a unified and closed boundary representation; (3) Through the Boolean addition operation, the contact interface between the lattice sandwich structure E, the composite material panel domain C, and the layup base domain D is eliminated, generating a geometrically seamless and complete composite material lattice sandwich propeller blade CAE model.

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