Mold design method and mold for rapid forming of small-sized composite material rotary body

Abstract

The application relates to the fields of rotary body machining die design and die technology, and discloses a die design method and a die for rapid forming of small composite rotary bodies, the design method comprising defining structural parameters of the die, including fixed parameters and variable parameters; modeling based on the structural parameters, and performing mechanical and thermal collaborative finite element analysis; taking the variable parameters as optimization variables, combining the data obtained through the finite element analysis, and determining optimal variable parameters of the die for rapid forming of small composite rotary bodies. The die is a coaxially nested tile valve structure, comprising a center core column, an inner valve and an outer valve from inside to outside. The application realizes miniaturization and light weight of the die while taking into account mechanical transmission performance and thermal response efficiency, can quickly find an optimal die parameter combination through an efficient parameter optimization strategy, and improves forming efficiency and product quality.

Description

Technical Field

[0001] This application relates to the field of rotary body machining mold design and mold technology, specifically a mold design method and mold for rapid prototyping of small composite rotary bodies. Background Technology

[0002] Composite material rotating parts, due to their superior properties such as high specific strength, high specific modulus, and good corrosion resistance, have been widely used in fields such as lightweight ammunition, aerospace structural components such as engine nacelles, and high-end sports equipment (such as high-performance bicycle frames). Currently, the main molding methods for composite material rotating parts include filament winding, compression molding, and autoclave molding. Among these, while autoclave molding can produce high-quality products, it suffers from problems such as high equipment investment, high energy consumption, long production cycles, and high costs. Especially for small composite material rotating parts, autoclave molding is less economical. Compression molding, as an external molding process, has advantages such as low equipment investment, high production efficiency, and low energy consumption, making it an ideal choice for molding small composite material rotating parts.

[0003] Furthermore, composite components often require interlayer reinforcement particles (such as silicon carbide, alumina, or other ceramic or metal particles) to achieve specific functional properties, such as improved wear resistance, enhanced thermal conductivity, and improved electromagnetic shielding, based on the practical need for functional and structural integration. This interlayer reinforcement particle filling structure places higher demands on the uniformity of pressure transmission during the molding process. Uneven pressure application can lead to defects such as porosity, delamination, and fiber breakage within the composite material, and increased interlayer misalignment can severely impact the product's mechanical properties. Therefore, achieving uniform pressure transmission is crucial for ensuring the integrity and functional integration of the composite material's interlayer reinforcement structure.

[0004] However, existing compression molding dies face the following technical bottlenecks when dealing with multi-segment rotating composite material components:

[0005] First, the mold structure design is relatively fixed, making it difficult to flexibly adjust according to different product shapes. As a result, a set of molds can usually only correspond to one specific product specification, which has poor versatility and increases the mold development cost.

[0006] Secondly, uneven pressure transmission during the molding process can easily lead to uneven stress distribution on the outer surface of the product, affecting the mechanical properties and surface quality of the product, making it difficult to achieve the quality level of autoclave molding.

[0007] Third, while pursuing the effect of pressure transmission, the requirements for miniaturization and lightweighting of molds are often ignored. The molds are large in size, which is not conducive to the layout and operation of the production site.

[0008] Fourth, it lacks in-situ heating capabilities, making it impossible to achieve rapid molding of composite materials. Furthermore, since the mold structure parameters simultaneously affect pressure transmission and heat conduction, simply optimizing mechanical properties often results in low thermal efficiency or excessive temperature differences, making it difficult to achieve simultaneous optimization of mechanical and thermal properties.

[0009] Therefore, developing a mold design method and mold for rapid prototyping of small composite material rotary bodies that can be flexibly adjusted according to the product shape, with uniform pressure transmission, small size, and rapid heating, in order to achieve high-quality molding outside the can, reduce production costs, and shorten the production cycle, has become an urgent technical problem to be solved. Summary of the Invention

[0010] The purpose of this application is to provide a mold design method and mold for rapid prototyping of small composite rotating bodies, so as to solve the technical problems of difficulty in achieving high-quality molding outside the can, high production cost and long production cycle in the prior art.

[0011] To achieve the above objectives, this application provides a mold design method for rapid prototyping of small composite material rotary bodies. This method, in response to the demand for rapid prototyping of small composite material rotary bodies, designs and optimizes the corresponding mold. The design method includes:

[0012] Obtain the design parameters for the small composite material rotating body to be processed;

[0013] Based on the design parameters, the structured parameters of the mold are defined, which include fixed parameters and variable parameters;

[0014] Based on the structured parameters, the mold is modeled, and the modeling results are subjected to finite element analysis to obtain the analysis results.

[0015] Based on the analysis results, the variable parameters were optimized to obtain the optimal variable parameters. The optimization process was constrained by the external surface stress of the small composite material rotating body to be processed, the mold volume, and the processing index parameters.

[0016] Based on fixed parameters and optimal variable parameters, molds are fabricated for rapid prototyping of small composite rotating bodies.

[0017] Preferably, the finite element analysis of the modeling results includes:

[0018] The modeling results are processed as follows: component disassembly, assembly, translation instance, attribute and section assignment, analysis step creation, contact settings, application of mechanical loads and heat source boundary conditions, and mesh generation.

[0019] Submit a finite element analysis task to obtain the mechanical response parameters of the small composite material rotating body to be processed, and record the corresponding mold volume data; among which, the mechanical response parameters include the stress distribution data of the outer surface of the small composite material rotating body to be processed and the overall stress level data;

[0020] Submit a thermal finite element analysis task to obtain the thermal response parameters of the small composite material rotating body to be processed, and record the corresponding mold volume data; among them, the thermal response parameters correspond to the processing index parameters, including the time to reach the curing temperature, the temperature uniformity index during the heating process, and the energy utilization efficiency.

[0021] Preferably, the optimization process is constrained by the external surface stress of the small composite material rotating body to be processed, the mold volume, and the processing parameters, including:

[0022] A Bayesian optimization model is constructed with multiple optimization objectives, including more uniform stress distribution on the outer surface of the small composite material rotating body to be processed, higher overall stress level on the outer surface of the small composite material rotating body to be processed, smaller mold volume, shorter time to reach the standard, better temperature uniformity, and higher energy utilization efficiency.

[0023] Using variable parameters as optimization variables and the analysis results as training samples, a Gaussian surrogate model is established.

[0024] The optimal variable parameters are determined by iteratively optimizing the Gaussian surrogate model using the Bayesian optimization algorithm.

[0025] To achieve the above objectives, this application also provides a mold based on the mold design method for rapid prototyping of small composite material rotary bodies as described above. The mold is a coaxially nested tile-like structure, comprising a central core, an inner valve, and an outer valve from the inside out. Specifically, the coaxial nesting means that the central core, inner valve, and outer valve are coaxially arranged and all coincide with the axis of the small composite material rotary body to be processed. A cavity is formed between the central core and the inner valve to place the composite material raw material corresponding to the small composite material rotary body to be processed. The central core integrates a heating device for heating during the rapid prototyping process of the small composite material rotary body to be processed.

[0026] Preferably, the outer contour of the central core column matches the inner hole shape of the small composite material rotating body to be processed, and the central core column is used to fix the inner position of the small composite material rotating body to be processed.

[0027] Preferably, the inner valve is attached to the outer surface of the small composite material rotating body to be processed. Specifically, the inner side of the inner valve is in close contact with the outer surface of the small composite material rotating body to be processed, and the outer side of the inner valve forms a matching inclined surface contact with the inner side of the outer valve. The length of the lower bottom surface of the inner valve is a first variable parameter, and the length of the upper top surface of the inner valve is uniquely determined by the first variable parameter and the contact surface inclination angle between the inner valve and the outer valve.

[0028] Preferably, the outer side of the outer valve contacts the pressure application mechanism of the pre-set molding machine to apply pressure to the composite material raw material, the inner side of the outer valve is a sloping structure that matches the inner valve; and the length of the upper top surface of the outer valve is a second variable parameter, the length of the lower bottom surface of the outer valve is a fixed parameter, and the contact surface inclination angle is the contact surface inclination angle between the inner valve and the outer valve.

[0029] As a preferred method, during the rapid prototyping process of the small composite material rotating body to be processed, temperature probes are set at different heights on its inner and outer surfaces to measure the inner and outer surface temperatures at different heights.

[0030] Preferably, the fixed parameters include the bottom radius and base height of the central core, the minimum processing thickness of the inner valve and the minimum processing thickness of the outer valve, the total height, inner diameter, and thickness of the small composite material rotating body to be processed, as well as the height and tilt angle of each segment of the rotating body, and the material thermophysical properties of the mold and each component of the small composite material rotating body to be processed.

[0031] Preferably, the optimal variable parameters include a first variable parameter corresponding to the length of the lower bottom surface of the inner valve, a second variable parameter corresponding to the length of the upper top surface of the outer valve, and an optimal combination corresponding to the contact surface inclination angle between the inner and outer valves.

[0032] Beneficial effects: The mold design method and mold for rapid prototyping of small composite rotary bodies disclosed in this application can flexibly design the mold structure according to the shape parameters of multi-segment rotary body products, realize uniform pressure transmission, ensure uniform stress distribution on the outer surface of the product and a high overall stress level, and effectively reduce the mold volume, realizing the miniaturization and lightweighting of the mold. Furthermore, through an efficient parameter optimization strategy, the optimal combination of mold parameters can be quickly found. In terms of mold design, it overcomes the defects of existing composite rotary body molding molds, such as poor versatility, uneven pressure transmission, large mold volume, and low parameter optimization efficiency, ultimately improving molding efficiency and product quality. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 A flowchart illustrating a mold design method for rapid prototyping of small composite rotating bodies provided in an embodiment of this application;

[0035] Figure 2 A three-dimensional exploded view of a small composite material rotary rapid prototyping mold provided in an embodiment of this application;

[0036] Figure 3 A two-dimensional cross-sectional engineering drawing of a rapid prototyping mold for small composite material rotating bodies provided in the embodiments of this application;

[0037] Figure 4 The Bayesian optimized hypervolume convergence graph provided in the embodiments of this application;

[0038] Figure 5 The Bayesian optimization Pareto front diagram provided for the embodiments of this application; in the diagram: (a) is the relationship between mold volume and mean stress; (b) is the relationship between mold volume and stress coefficient of variation; (c) is the relationship between heat transfer efficiency and mean stress; (d) is the relationship between temperature coefficient of variation and mold volume; (e) is the relationship between stress coefficient of variation and mean stress; (f) is the relationship between temperature coefficient of variation and heat transfer efficiency;

[0039] Figure 6 The Bayesian optimization 3D design space mapping diagram provided for the embodiments of this application; in the figure: (a) is the mold volume; (b) is the average stress; (c) is the stress uniformity; (d) is the heat transfer efficiency;

[0040] Figure 7 Radar charts of Bayesian optimization best candidate solutions provided for examples in this application; in the figure: (a) is length=11, length2=10, theta=79; (b) is length=29, length2=10, theta=76; (c) is length=13, length2=100, theta=79; (d) is length=70, length2=100, theta=69; (e) is length=79, length2=98, theta=76; (f) is length=83, length2=63, theta=84;

[0041] Figure 8The figure shows a comparison of the pressurization efficiency and heat transfer efficiency of the embodiment of this application and the unoptimized mold; in the figure: (a), (b) and (c) are length=11, length2=10, theta=79; (d), (e) and (f) are length=31, length2=60, theta=80; (g), (h) and (i) are length=30, length2=26, theta=80;

[0042] Figure 9 A comparison chart of heating rate and energy consumption per unit mass provided in the embodiments of this application; in the figure: (a) is a comparison chart of heating rate; (b) is a comparison chart of energy consumption per unit mass.

[0043] The implementation, functional features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0044] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0045] In this document, the term "comprising" is intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0046] This embodiment specifically describes a mold design method and mold for rapid prototyping of small composite rotating bodies, providing a mold design method and a mold suitable for this design method. This embodiment is particularly suitable for the efficient and high-precision molding of multi-segment rotating composite material components, and can be widely used in aerospace, equipment manufacturing, and other fields with high requirements for the dimensional accuracy and mechanical properties of composite material components.

[0047] Reference Figure 1 , Figure 1 A flowchart illustrating a mold design method for rapid prototyping of small composite rotating bodies provided in an embodiment of this application.

[0048] like Figure 1As shown, this embodiment discloses a mold design method for rapid prototyping of small composite material rotating bodies. This design method responds to the demand for rapid prototyping of small composite material rotating bodies by designing and optimizing the corresponding mold. The design method includes:

[0049] S10: Obtain the design parameters of the small composite material rotating body to be processed.

[0050] S20: Based on the design parameters, define the structural parameters of the mold, which include fixed parameters and variable parameters.

[0051] S30: Based on the structured parameters, model the mold, perform finite element analysis on the modeling results, and obtain the analysis results.

[0052] Specifically, the finite element analysis of the modeling results includes:

[0053] The modeling results are processed as follows: component disassembly, assembly, translation instance, attribute and section assignment, analysis step creation, contact settings, application of mechanical loads and heat source boundary conditions, and mesh generation.

[0054] Submit a finite element analysis task to obtain the mechanical response parameters of the small composite material rotating body to be processed, and record the corresponding mold volume data; among which, the mechanical response parameters include the stress distribution data of the outer surface of the small composite material rotating body to be processed and the overall stress level data;

[0055] Submit a thermal finite element analysis task to obtain the thermal response parameters of the small composite material rotating body to be processed, and record the corresponding mold volume data; among them, the thermal response parameters correspond to the processing index parameters, including the time to reach the curing temperature, the temperature uniformity index during the heating process, and the energy utilization efficiency.

[0056] S40: Based on the analysis results, optimize the variable parameters to obtain the optimal variable parameters. The optimization process is constrained by the external surface stress of the small composite material rotating body to be processed, the mold volume, and the processing index parameters.

[0057] Specifically, the optimization process is constrained by the external surface stress of the small composite material rotating body to be processed, the mold volume, and the processing parameters, including:

[0058] A Bayesian optimization model is constructed with multiple optimization objectives, including more uniform stress distribution on the outer surface of the small composite material rotating body to be processed, higher overall stress level on the outer surface of the small composite material rotating body to be processed, smaller mold volume, shorter time to reach the standard, better temperature uniformity, and higher energy utilization efficiency.

[0059] Using variable parameters as optimization variables and the analysis results as training samples, a Gaussian surrogate model is established.

[0060] The optimal variable parameters are determined by iteratively optimizing the Gaussian surrogate model using the Bayesian optimization algorithm.

[0061] S50: Molds for rapid prototyping of small composite rotating bodies based on fixed parameters and optimal variable parameters.

[0062] Reference Figure 2 and Figure 3 , Figure 2 This is a three-dimensional exploded view of the rapid prototyping mold for small composite material rotating bodies provided in the embodiments of this application. Figure 3 A two-dimensional cross-sectional engineering drawing of a rapid prototyping mold for a small composite material rotating body provided in an embodiment of this application.

[0063] like Figure 2 and Figure 3 This embodiment also discloses a mold, which is manufactured based on the mold design method for rapid prototyping of small composite material rotating bodies. The mold is a coaxially nested tile-like structure, which includes a central core, an inner valve, and an outer valve from the inside out. Specifically, the coaxial nesting means that the central core, the inner valve, and the outer valve are coaxially arranged and all coincide with the axis of the small composite material rotating body to be processed. A cavity is formed between the central core and the inner valve to place the composite material raw material corresponding to the small composite material rotating body to be processed. The central core integrates a heating device for heating during the rapid prototyping process of the small composite material rotating body to be processed.

[0064] Specifically, the outer contour of the central core column matches the inner hole shape of the small composite material rotating body to be processed, and the central core column is used to fix the inner position of the small composite material rotating body to be processed.

[0065] Specifically, the inner valve is attached to the outer surface of the small composite material rotating body to be processed. Specifically, the inner side of the inner valve is in close contact with the outer surface of the small composite material rotating body to be processed, and the outer side of the inner valve forms a matching inclined surface contact with the inner side of the outer valve. The length of the lower bottom surface of the inner valve is a first variable parameter, and the length of the upper top surface of the inner valve is uniquely determined by the first variable parameter and the contact surface inclination angle between the inner and outer valves.

[0066] Specifically, the outer side of the outer valve contacts the pressure application mechanism of the pre-set molding machine to apply pressure to the composite material raw material, the inner side of the outer valve is a sloping structure that matches the inner valve; and the length of the upper top surface of the outer valve is a second variable parameter, the length of the lower bottom surface of the outer valve is a fixed parameter, and the contact surface inclination angle is the contact surface inclination angle between the inner valve and the outer valve.

[0067] Specifically, in the rapid prototyping process of the small composite material rotating body to be processed, temperature probes are set at different heights on its inner and outer surfaces to measure the inner and outer surface temperatures at different heights.

[0068] Specifically, the fixed parameters include the bottom radius and base height of the central core, the minimum processing thickness of the inner valve and the minimum processing thickness of the outer valve, the total height, inner diameter, and thickness of the small composite material rotating body to be processed, as well as the height and tilt angle of each segment of the rotating body, and the material thermophysical properties of the mold and each component of the small composite material rotating body to be processed.

[0069] Specifically, the optimal variable parameters include the first variable parameter corresponding to the length of the lower bottom surface of the inner valve, the second variable parameter corresponding to the length of the upper top surface of the outer valve, and the optimal combination corresponding to the contact surface inclination angle between the inner and outer valves.

[0070] The mold design method and mold for rapid prototyping of small composite material rotary bodies disclosed in this embodiment will now be described in detail with reference to specific embodiments of this embodiment.

[0071] In the specific application of this embodiment, the specific structure and function of the small composite material rotary rapid prototyping mold are as follows:

[0072] The central core column serves as the core support and positioning reference of the mold. It is made of elastic steel and its outer contour matches the inner hole shape of the product to be processed. It is used to fix the inner position of the composite material product to be processed, ensuring the coaxiality and dimensional stability of the product during the molding process.

[0073] The inner valve is a tile-shaped flexible transmission structure made of elastic steel. It adheres to the outer surface of the product to be processed, with its inner side in close contact with the outer surface and its outer side forming a matching inclined contact with the outer valve. Its function is to evenly distribute and apply the pressure transmitted by the outer valve to the outer surface of the product. In terms of shape, the length of its lower base is the first variable parameter, and the length of its upper top surface is uniquely determined by the length of the lower base and the inclination angle (theta) of the contact surface between the inner and outer valves.

[0074] Outer valve: As a pressure receiving and initial transmission component, it is made of high-strength steel. Its outer side connects to the pressure application mechanism of the molding machine, while its inner side has a beveled structure that matches the inner valve. This structure receives the external pressure applied by the molding machine and transmits the pressure to the inner valve through the beveled contact. In terms of shape, the length of its upper top surface is the second variable parameter length2, and the length of its lower bottom surface is fixed at the minimum achievable thickness of 5mm. The contact surface inclination angle is the same as the inner valve contact surface inclination angle theta.

[0075] The heating device uses a central heating tube: as the core component of the heat source, it is coaxially nested within the internal cavity of the central core column. Its outer diameter is considered to be in close contact with the inner diameter of the central core column to ensure efficient heat conduction. The central heating tube is made of a high thermal conductivity metal material and is responsible for rapidly transferring the generated heat to the central core column through heat conduction.

[0076] Small composite material rotating body to be processed: Located between the central core and the inner valve, it is a multi-segment rotating body structure. Its shape is uniquely determined by the height and tilt angle of each segment of the rotating body. It is formed under external pressure. The material is a composite material, such as a metal particle sandwich fiber reinforced resin matrix composite material.

[0077] The temperature measuring device uses temperature probes: during the product molding process, the product can be heated by the central heating tube inside the central core column. At the same time, three temperature probes are inserted at equal intervals along the height direction of the inner and outer surfaces of the product to measure the inner and outer surface temperatures at different heights during the mold molding process.

[0078] Combination Figure 1 , Figure 2 and Figure 3 In this embodiment, the rapid prototyping principle of the small composite material rotary body to be processed is as follows: the molding machine applies pressure to the upper surface of the outer valve. This pressure is transmitted and guided to the inner valve through the interaction of the inclined surfaces between the inner and outer valves, and finally the inner valve evenly applies the pressure to the outer surface of the small composite material rotary body to be processed. At the same time, during the pressurization process, the internal heating tube can quickly transfer heat from the central core to the outer valve, improving the curing efficiency of the composite material and reducing energy consumption.

[0079] Based on the rapid prototyping process described above, the following three core evaluation indicators were established to assess mold performance: the uniformity of stress distribution on the product's outer surface, the overall stress level on the product's outer surface, and the total volume of the inner and outer valves. Based on these evaluation indicators, this embodiment optimized the mold design method.

[0080] In the specific application of this embodiment, the corresponding design method revolves around the aforementioned core evaluation indicators, namely the uniformity of stress distribution on the outer surface of the product, the overall stress level on the outer surface of the product, and the total volume of the inner and outer valves, and is carried out as follows:

[0081] Mold structure parameterization definition: Determine the fixed and variable parameters of the mold; the fixed parameters include the bottom radius of the central core, the base height, the minimum thickness (5mm) of the inner and outer valves, the total height, inner diameter, thickness of the composite material product to be processed, and the height segment_list and tilt angle alpha_list of each segment of the rotating body; the variable parameters include the length of the lower bottom surface of the inner valve as the first variable parameter, the length2 of the upper top surface of the outer valve as the second variable parameter, and the tilt angle theta of the contact surface between the inner and outer valves.

[0082] Parametric Modeling and Finite Element Analysis Based on ABAQUS: Using Python scripts to call ABAQUS finite element simulation software, a parametric 3D model of the mold is established based on the aforementioned fixed and variable parameters; the model is then subjected to component disassembly, assembly, translation instances, attribute and section assignment, analysis step creation, contact settings, load and boundary condition application, and mesh generation; a finite element analysis job is submitted to obtain stress distribution data on the outer surface of the composite material product to be processed, overall stress level data, and the sum of inner and outer valve volumes.

[0083] Bayesian parameter optimization based on Gaussian surrogate model: A Bayesian optimization model is constructed with the optimization objectives of more uniform stress distribution on the outer surface of the product, higher overall stress level on the outer surface of the product, and smaller sum of inner and outer valve volumes. A Gaussian surrogate model is established with the variable parameters of the mold as optimization variables and the data obtained from finite element analysis as training samples. The Gaussian surrogate model is iteratively optimized using the Bayesian optimization algorithm to quickly find the optimal combination of variable parameters of the mold.

[0084] Based on the above, the mold design method and mold for rapid prototyping of small composite material rotating bodies in this embodiment have at least the following advantages and beneficial effects:

[0085] High versatility: Through parametric modeling, the variable parameters of the mold can be flexibly adjusted according to the different shape parameters (height and tilt angle of each segment) of the multi-segment rotating product to be processed, so that one mold design method can correspond to multiple product specifications, which greatly improves the versatility of the mold and reduces production costs.

[0086] Uniform pressure transmission and high stress level: By optimizing the structural parameters of the inner and outer valves, pressure can be uniformly transmitted from the outer valve to the inner valve and then to the product, ensuring uniform stress distribution on the outer surface of the product. At the same time, it improves the overall stress level on the outer surface of the product, which is beneficial to improving the mechanical properties and molding quality of the product.

[0087] Miniaturization and weight reduction: Taking the sum of the inner and outer valve volumes as one of the optimization objectives, parameter optimization can effectively reduce the mold volume while ensuring the molding effect, thereby achieving mold miniaturization and weight reduction, which facilitates the layout and operation of the production site.

[0088] High parameter optimization efficiency: By using Bayesian optimization to establish a Gaussian surrogate model, only a small amount of finite element calculation results are needed to fit the complex nonlinear relationship between variable parameters and optimization objectives. This avoids the large amount of computational resources consumed by enumeration strategies, significantly improves parameter optimization efficiency, and can quickly find the optimal combination of mold parameters, shortening product development and production cycles.

[0089] High energy efficiency: The heating rod heats up quickly, shortening the heating and holding time required for resin curing and reducing total heating energy consumption. This provides core process support for achieving rapid, energy-saving, and high-quality external molding of small rotating components.

[0090] The mold design method and mold for rapid prototyping of small composite material rotary bodies in this embodiment will now be verified and explained in conjunction with specific implementation.

[0091] In the specific implementation process, this embodiment selects a typical multi-segment composite rotating body component with different segment inclination angle distribution as the small composite rotating body to be processed. The specific shape parameters are set as follows: the height of each segment in the example is [100mm, 100mm, 100mm], the total height is 300.0mm, the inner diameter is 120.0mm, and the thickness is 5.0mm; the inclination angle of each segment is [85.0°, 80.0°, 75.0°].

[0092] Based on ABAQUS finite element simulation software, parametric modeling and finite element analysis of the mold were implemented using Python scripts. The specific steps are as follows:

[0093] A10: Create 3D models of each component:

[0094] Central core pillar: Draw a sketch, including the bottom edge, height, rotation axis, top edge, multiple inclined edges, horizontal edges, and vertical edges, and generate a 3D solid by rotating it 360° using the BaseSolidRevolve command.

[0095] Small composite material rotating body to be processed: Draw a sketch, including the bottom edge, multiple inclined edges, top edge, etc., and generate a three-dimensional solid by rotating it 360° using the BaseSolidRevolve command.

[0096] Inner valve: Draw a sketch based on the first variable parameter length and theta, including the bottom edge, the inclined edge, the top edge, etc., and generate a three-dimensional solid by rotating it 360° using the BaseSolidRevolve command.

[0097] External valve: Draw a sketch based on the second variable parameter length2 and theta, including the bottom edge, the inclined edge, the top edge, etc., and generate a three-dimensional solid by rotating it 360° using the BaseSolidRevolve command.

[0098] Central heating tube: Based on the preset heating power density requirements and the size of the central core column, draw a circular cross-section sketch and generate a cylindrical three-dimensional solid by using the extrusion command.

[0099] A20: Split components for easier mesh generation: Perform the PartitionCellByDatumPlane operation on each component to split it into appropriate elements, which facilitates subsequent mesh generation and finite element analysis.

[0100] A30: Assembly and Translation Example: Create instances of each component in rootAssembly to ensure that the positional relationship of each component conforms to the actual forming requirements, and align the reference planes of each component using the FaceToFace command.

[0101] A40: Attribute and Section Assignment: Create Material-CFRP (elastic modulus 180000.0, Poisson's ratio 0.35, thermal conductivity 8.0, density 1.5e-09, specific heat capacity 9.5e+08), Material-Steel (elastic modulus 210000.0, Poisson's ratio 0.28, thermal conductivity 50.0, density 7.85e-09, specific heat capacity 4.5e+08), and Material-Heat (thermal conductivity 28.0, density 8.96e-09, specific heat capacity...). Three materials (3.85e+08) were used, and corresponding HomogeneousSolidSection sections were created using Material-CFRP, Material-Steel, and Material-Heat respectively. The Section-CFRP section was assigned to the composite material to be processed, the Section-Steel section was assigned to the central core, inner valve, and outer valve, and the Section-Heat section was assigned to the central heating tube integrated in the central core.

[0102] A50: Create Analysis Steps: Create the ExplicitDynamicsStep analysis step and the HeatTransferStep analysis step. The two analysis steps are based on the mold model generated under the same parameter combination, but the calculation process is independent of each other.

[0103] A60: Contact settings: Create ContactProperty (IntProp-1), set TangentialBehavior to PENALTY formula, friction coefficient 0.1, NormalBehavior to HARD pressure closure; create ContactExp contact, set useAllstar to ON, and assign IntProp-1 to the contact pair.

[0104] A70: Heat source and boundary condition settings: Set the heating tube inside the central core column as the bulk heat source with a heating power of 400W. Apply convective heat transfer boundary conditions to the outer surface of the mold with a membrane exchange coefficient of 0.005 to simulate the convective heat transfer between the outer surface of the mold and the air during the heating process.

[0105] A80: Mesh Generation: Set the mesh control parameters for each component. Part-1, Part-3, and Part-4 use WEDGE cell shapes and SWEEP meshing technology, with SeedPart size of 4. In Part-2, SeedPart size is 1.5. Then generate the mesh.

[0106] Based on the finite element analysis samples, multi-objective Bayesian optimization is used to optimize the mold parameters. The specific process is as follows:

[0107] B10: Determine the optimization variables and objective function: The optimization variables are the length of the lower surface of the inner valve (range 10-100mm), the length of the upper surface of the outer valve (range 10-100mm), and the inclination angle of the inner and outer valve contact surfaces (range 0-90°). The objective function includes mechanical and thermal indicators: Mechanical indicators include: uniformity of stress distribution on the outer surface of the product (measured by stress stratification index, the higher the better); overall stress level on the outer surface of the product (measured by average stress, the higher the better); and the sum of the volumes of the inner and outer valves (the smaller the better). Thermal indicators include: time to reach the preset curing temperature (the shorter the better); temperature uniformity of the product area (the smaller the temperature difference the better); and energy efficiency of the heating process (the lower the better or the higher the percentage the better).

[0108] B20: Initialize sample points: Using the Latin hypercube sampling method, 30 initial sample points are extracted within the range of values ​​of the optimization variables. For each sample point, the above finite element analysis function is called to obtain the corresponding objective function value.

[0109] B30: Establish a multi-output Gaussian surrogate model: Using the optimization variables of effective sample points as input and six physical indicators as output, establish a multi-task Gaussian process regression (GPR) model to fit the complex mapping relationship between design parameters and mechanical and thermal performance, and quantify the uncertainty of prediction.

[0110] B40: Multi-Objective Iterative Optimization (qEHVI): Computes the Constrained Restricted Hypervolume Improved Acquisition Function (Constrained qEHVI). This algorithm automatically finds the next sample point with the most "trade-off value" in the variable space by maximizing the hypervolume increment covered by the current Pareto solution set in the objective space, while also considering the probability of fulfilling the constraints. The new sample is added to the training set, and the surrogate model is updated in real time. This process is repeated until 500 iterations are completed.

[0111] B50: Extracting the Pareto Optimal Set: After the iteration terminates, the Pareto optimal set is selected from all training samples through non-dominated sorting. This set represents the "best trade-off" combination of mechanical and thermal properties that cannot be further surpassed within the current design space.

[0112] After the above Bayesian optimization process, the mold optimization results for the composite material rotating component in this embodiment are: length=11mm, length2=10mm, theta=79°.

[0113] Reference Figure 4 , Figure 4 The Bayesian optimized hypervolume convergence graph provided for the embodiments of this application.

[0114] To further verify the effectiveness of the optimization process and intuitively demonstrate the nonlinear relationship between design variables and various indicators, this embodiment conducts an in-depth analysis of the optimization results through multi-dimensional data analysis. Firstly, through... Figure 4 The hypervolume convergence graph shown illustrates the evolution of the optimization algorithm. The results show that the curve exhibits a significant step-like upward trend and eventually plateaus. This convergence characteristic strongly demonstrates that the multi-objective Bayesian optimization algorithm, under complex geometric and time constraints, can effectively identify the performance boundaries of the design space and successfully converge from the initial random search state to the high-dimensional Pareto front, ensuring the representativeness and optimality of the final sample.

[0115] Reference Figure 5 , Figure 5 The Bayesian optimization Pareto front diagram provided for the embodiments of this application; in the diagram: (a) is the relationship between mold volume and mean stress; (b) is the relationship between mold volume and stress coefficient of variation; (c) is the relationship between heat transfer efficiency and mean stress; (d) is the relationship between temperature coefficient of variation and mold volume; (e) is the relationship between stress coefficient of variation and mean stress; (f) is the relationship between temperature coefficient of variation and heat transfer efficiency.

[0116] Regarding the correlation analysis of core objectives, embodiments of this application provide, as follows: Figure 5The Bayesian optimization Pareto front plot shown intuitively illustrates the multidimensional trade-off between the mechanical properties, thermal properties, and geometric volume of the mold. Analysis of subplots (a) to (f) reveals that the gray scatter points represent the overall trajectory of the algorithm during the iterative search process, while the black stepped broken lines distributed along the coordinate edges constitute the Pareto front curve of this problem. In particular, plot (c) shows a negative correlation between heat transfer efficiency and mean stress. The smaller the mean stress, the higher the heat transfer efficiency, indicating that thermal performance is improved to some extent while optimizing mechanical properties. Simultaneously, plots (a) and (b) reveal the antagonistic relationship between mold volume, mean stress, and stress variation coefficient. As the mold volume decreases, the mean stress (absolute value) increases, and the stress variation coefficient also rises, indicating that pursuing excessively small volumes exacerbates stress concentration and deteriorates mechanical properties. This non-dominant distribution pattern fully verifies the necessity of the multi-objective joint optimization method adopted in this embodiment, providing data support for the comprehensive evaluation of molds under complex working conditions.

[0117] Reference Figure 6 and Figure 7 . Figure 6 The Bayesian optimization 3D design space mapping diagram provided in the embodiments of this application; in the figure: (a) is the mold volume; (b) is the average stress; (c) is the stress uniformity; (d) is the heat transfer efficiency. Figure 7 Radar chart of the best candidate Bayesian optimization solution provided for the example of this application; in the figure: (a) is length=11, length2=10, theta=79; (b) is length=29, length2=10, theta=76; (c) is length=13, length2=100, theta=79; (d) is length=70, length2=100, theta=69; (e) is length=79, length2=98, theta=76; (f) is length=83, length2=63, theta=84.

[0118] To further achieve full-dimensional mapping and decision-making from design variables to performance indicators, this embodiment introduces, for example... Figure 6 The 3D design space mapping diagram shown and as follows Figure 7 The radar chart showing the best candidate solutions is shown. Figure 6 It clearly illustrates the driving mechanism of the three design parameters, length, length2, and theta, on the performance field, and compares them. Figure 6 The color distribution of (a) mold volume and (d) heat transfer efficiency shows that the high-efficiency region and the low-volume region have a high degree of overlap in parameter space, but exhibit nonlinear discrete characteristics in stress uniformity distribution. Based on this, through Figure 7 The radar chart was used to perform a multi-dimensional visualization evaluation of six typical Pareto optimal solutions. It was found that the polygon area enclosed by scheme (f) is the most balanced in terms of heat transfer efficiency and stress uniformity, avoiding the performance imbalance caused by excessive pursuit of a single index as in scheme (b), thus determining the optimal parameter design domain.

[0119] Reference Figure 8 , Figure 8 The figure shows a comparison of the pressurization efficiency and heat transfer efficiency of the embodiment of this application and the unoptimized mold; in the figure: (a), (b) and (c) are length=11, length2=10, theta=79; (d), (e) and (f) are length=31, length2=60, theta=80; (g), (h) and (i) are length=30, length2=26, theta=80.

[0120] Finally, the optimized mold design scheme of this embodiment is compared with the unoptimized mold and the mold with extreme parameters in terms of pressurization efficiency and heat transfer efficiency, and the results are obtained. Figure 8 .like Figure 8 As shown: In terms of pressurization, compared to the initial random scheme shown in (a), the optimized mold significantly improves the product stress distribution uniformity index, with the stress uniformity value decreasing from approximately 0.35 before optimization to approximately 0.26 (the smaller the value, the more uniform), an improvement of approximately 25.7%. This indicates that the precise matching of the tilt angle theta and the contact surface length effectively eliminates local pressure dead zones. In terms of heat transfer, the temperature field distribution (h) of the optimized mold is more uniform compared to the extreme large volume scheme (e). In terms of energy utilization efficiency, thanks to the intelligent optimization of the volume of the inner and outer valves of the mold (as shown in (i), the volume is controlled at a reasonable level of 1.65e7 mm³), ineffective heat capacity is effectively reduced, resulting in a heat transfer efficiency increase from approximately 0.24 in the basic scheme to approximately 0.31, a relative improvement of over 29%. In summary, the optimized mold in this embodiment achieves effective improvements based on data-driven principles in both force transmission balance and heat transfer efficiency.

[0121] Reference Figure 9 , Figure 9 A comparison chart of heating rate and energy consumption per unit mass provided in the embodiments of this application; in the figure: (a) is a comparison chart of heating rate; (b) is a comparison chart of energy consumption per unit mass.

[0122] On the other hand, by utilizing a high-efficiency heating device integrated into the mold center, this embodiment achieves rapid, uniform curing and precise temperature control of the composite material rotation body. To further quantify and evaluate the energy efficiency advantages of this process, its heating rate and energy consumption per unit mass were compared with those of the traditional autoclave process. The results are as follows: Figure 9As shown in the figure. The results indicate that, with a power setting of 800W, the heating rate of this embodiment can reach 3.47°C / min, significantly higher than the 2.00°C / min of the traditional autoclave process, verifying its rapid curing capability. Simultaneously, in terms of energy consumption per unit mass, this process (approximately 1.51~1.56 MJ / kg) is only about 18% of that of the traditional autoclave (8.50 MJ / kg). This data strongly demonstrates that this embodiment significantly reduces energy consumption while ensuring molding quality, and significantly improves molding efficiency and green manufacturing level.

[0123] This embodiment ultimately designs a mold for rapid prototyping of small composite rotating bodies. Through the proposed mold design method, excellent pressurization efficiency is ensured while achieving a lightweight mold volume. On the other hand, with the help of a high-efficiency heating device integrated into the center of the mold, rapid and uniform curing and precise temperature control of small composite rotating bodies are achieved, significantly improving molding quality and energy efficiency.

[0124] In summary, this embodiment overcomes the shortcomings of existing molds used for rapid prototyping of small composite rotary bodies, such as poor versatility, uneven pressure transmission, large mold volume, and low parameter optimization efficiency. It provides a mold design method for rapid prototyping of small composite rotary bodies. This mold design method can flexibly design the mold structure according to the parameters of multi-segment rotary body products, achieve uniform pressure transmission, ensure uniform stress distribution on the outer surface of the product and a high overall stress level, effectively reduce the mold volume, achieve mold miniaturization and lightweighting, and quickly find the optimal mold parameter combination through an efficient parameter optimization strategy, thereby improving molding efficiency and product quality.

[0125] In the embodiments provided in this application, it should be understood that the embodiments described herein can be implemented in hardware, software, firmware, middleware, code, or any suitable combination thereof. For hardware implementation, the processor may be implemented in one or more of the following: application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to implement the functions described herein, or combinations thereof. For software implementation, some or all of the processes of the embodiments may be performed by a computer program instructing the associated hardware. During implementation, the program may be stored in a computer-readable storage medium or transmitted as one or more instructions or code on a computer-readable storage medium. Computer-readable storage media include computer storage media and communication media, wherein communication media include any medium that facilitates the transmission of a computer program from one place to another. Storage media may be any available medium accessible to a computer. Computer-readable storage media may include, but are not limited to, RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code having the form of instructions or data structures and accessible to a computer.

[0126] Finally, it should be noted that the above description is only a preferred embodiment of this application and is not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A mold design method for rapid prototyping of small composite material rotary bodies, characterized in that, This design method responds to the need for rapid prototyping of small composite rotary bodies by designing and optimizing corresponding molds; the design method includes: Obtain the design parameters for the small composite material rotating body to be processed; Based on the design parameters, the structured parameters of the mold are defined, which include fixed parameters and variable parameters; Based on the structured parameters, the mold is modeled, and the modeling results are subjected to finite element analysis to obtain the analysis results. The finite element analysis and the corresponding analysis results include the mechanical response parameters and corresponding mold volume data obtained from the mechanical finite element analysis and the thermal response parameters and corresponding mold volume data obtained from the thermal finite element analysis. Based on the analysis results, the variable parameters were optimized to obtain the optimal variable parameters. The optimization process was constrained by the external surface stress of the small composite material rotating body to be processed, the mold volume, and the processing index parameters. Based on fixed parameters and optimal variable parameters, molds are fabricated for rapid prototyping of small composite rotating bodies.

2. The mold design method for rapid prototyping of small composite material rotary bodies according to claim 1, characterized in that, The finite element analysis of the modeling results includes: The modeling results are processed as follows: component disassembly, assembly, translation instance, attribute and section assignment, analysis step creation, contact settings, application of mechanical loads and heat source boundary conditions, and mesh generation. Submit a finite element analysis task to obtain the mechanical response parameters of the small composite material rotating body to be processed, and record the corresponding mold volume data; among which, the mechanical response parameters include the stress distribution data of the outer surface of the small composite material rotating body to be processed and the overall stress level data; Submit a thermal finite element analysis task to obtain the thermal response parameters of the small composite material rotating body to be processed, and record the corresponding mold volume data; among them, the thermal response parameters correspond to the processing index parameters, including the time to reach the curing temperature, the temperature uniformity index during the heating process, and the energy utilization efficiency.

3. The mold design method for rapid prototyping of small composite material rotary bodies according to claim 2, characterized in that, The optimization process is constrained by the external surface stress of the small composite material rotating body to be processed, the mold volume, and the processing parameters, including: A Bayesian optimization model is constructed with multiple optimization objectives, including more uniform stress distribution on the outer surface of the small composite material rotating body to be processed, higher overall stress level on the outer surface of the small composite material rotating body to be processed, smaller mold volume, shorter time to reach the standard, better temperature uniformity, and higher energy utilization efficiency. Using variable parameters as optimization variables and the analysis results as training samples, a Gaussian surrogate model is established. The optimal variable parameters are determined by iteratively optimizing the Gaussian surrogate model using the Bayesian optimization algorithm.

4. A mold for rapid prototyping of small composite material rotary bodies, characterized in that, The mold is manufactured based on the mold design method for rapid prototyping of small composite material rotary bodies according to any one of claims 1 to 3. The mold is a coaxially nested tile-like structure, which includes a central core, an inner valve, and an outer valve from the inside out. Specifically, the coaxial nesting means that the central core, the inner valve, and the outer valve are coaxially arranged and all coincide with the axis of the small composite material rotary body to be processed. A cavity is formed between the central core and the inner valve to place the composite material raw material corresponding to the small composite material rotary body to be processed. The central core integrates a heating device for heating during the rapid prototyping process of the small composite material rotary body to be processed.

5. The mold for rapid prototyping of small composite material rotary bodies according to claim 4, characterized in that, The outer contour of the central core column matches the inner hole shape of the small composite material rotating body to be processed, and the central core column is used to fix the inner position of the small composite material rotating body to be processed.

6. The mold for rapid prototyping of small composite material rotary bodies according to claim 4, characterized in that, The inner valve is attached to the outer surface of the small composite material rotating body to be processed. Specifically, the inner side of the inner valve is in close contact with the outer surface of the small composite material rotating body to be processed, and the outer side of the inner valve forms a matching inclined surface contact with the inner side of the outer valve. The length of the lower bottom surface of the inner valve is a first variable parameter, and the length of the upper top surface of the inner valve is uniquely determined by the first variable parameter and the contact surface inclination angle between the inner and outer valves.

7. The mold for rapid prototyping of small composite material rotary bodies according to claim 4, characterized in that, The outer side of the outer valve contacts the pressure application mechanism of the pre-set molding machine to apply pressure to the composite material raw material. The inner side of the outer valve is a sloping structure that matches the inner valve. The length of the upper top surface of the outer valve is a second variable parameter, the length of the lower bottom surface of the outer valve is a fixed parameter, and the contact surface inclination angle is the contact surface inclination angle between the inner and outer valves.

8. The mold for rapid prototyping of small composite material rotary bodies according to claim 4, characterized in that, During the rapid prototyping process of small composite material rotating bodies, temperature probes are set at different heights on the inner and outer surfaces to measure the inner and outer surface temperatures at different heights.

9. The mold for rapid prototyping of small composite material rotary bodies according to claim 4, characterized in that, The fixed parameters include the bottom radius and base height of the central core, the minimum processing thickness of the inner valve and the minimum processing thickness of the outer valve, the total height, inner diameter, and thickness of the small composite material rotating body to be processed, as well as the height and tilt angle of each segment of the rotating body, and the material thermophysical properties of the mold and each component of the small composite material rotating body to be processed.

10. The mold for rapid prototyping of small composite material rotary bodies according to claim 4, characterized in that, The optimal variable parameters are the first variable parameter corresponding to the length of the lower bottom surface of the inner valve, the second variable parameter corresponding to the length of the upper top surface of the outer valve, and the optimal combination corresponding to the contact surface inclination angle between the inner and outer valves.

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