A composite material nozzle design method based on online monitoring and simulation verification

Abstract

The present application belongs to the technical field of engine nozzle performance optimization, and specifically discloses a composite nozzle design method based on online monitoring and simulation verification, comprising the following steps: S1, establishing a preliminary design model; S2, identifying key control parameters to obtain a sample level online monitoring scheme; S3, correcting the simulation parameters of the preliminary design model obtained in S1; S4, carrying out nozzle structure curing simulation analysis and preliminary optimization design to obtain a nozzle preliminary optimization model; and S5, nozzle production, online data collection analysis and simulation verification, if the online monitoring test data and the final product performance indicators both meet the design requirements, the optimization design model is completed. The composite nozzle design method based on online monitoring and simulation verification is adopted, which does not increase the weight of the nozzle structure, and at the same time, multiple parameters in the nozzle curing process are monitored online, which provides support for mastering the temperature and strain change law in the nozzle curing process.

Description

Technical Field

[0001] This invention relates to the field of engine nozzle performance optimization technology, and in particular to a composite material nozzle design method based on online monitoring and simulation verification. Background Technology

[0002] In recent years, with the development of advanced composite materials, structural design, and simulation technologies, and the urgent need for improved solid rocket engine nozzle performance due to advanced propulsion, nozzle technology has gradually evolved towards lightweight, integrated structural and functional design, high reliability, and strong environmental adaptability. Based on this, a one-piece molded all-composite material nozzle technology, which undergoes multiple curing processes, has been developed. Compared to traditional solid rocket engine nozzles (composed of individually molded components with different functions and then assembled), this technology eliminates the macroscopic assembly interface of traditional nozzles, simplifies the process flow, significantly reduces production materials such as tooling and molds, improves nozzle quality reliability, and lowers production costs. However, the following shortcomings still need to be addressed:

[0003] (1) The one-piece molded all-composite material nozzle is a typical multi-material composite functional structure. According to its functional zones, different types of fibers and resins are used to make prepregs, which are then wound or laid up and then cured under pressure, requiring multiple curing processes. During the curing process, due to factors such as resin curing shrinkage and the mismatch of thermal expansion coefficients between the fibers and the matrix resin, the structural strength increases, and the generation and distribution of residual stress continuously accumulate and change, resulting in residual stress and curing deformation. This residual stress affects the mechanical properties of the composite material structure and may even cause structural defects such as delamination and matrix cracking, affecting the structural performance of the nozzle throughout its product life.

[0004] (2) Due to the complex physicochemical process of composite material nozzle curing, the existing material data and curing process parameters are relatively lacking, resulting in insufficient simulation calculation accuracy and low reliability of simulation results, which cannot effectively guide the design. At present, the traditional design method based on experience and simulation is usually adopted in nozzle structure design. The structural reliability is ensured by increasing the safety margin and making conservative design, which results in high manufacturing costs and low structural efficiency. In the face of the urgent need to improve nozzle performance, it is necessary to develop more accurate and efficient optimization design methods to reduce the waste of structural safety redundancy costs and improve the performance of nozzles.

[0005] To obtain a precise and efficient optimization design method for nozzles, it is necessary to change the current situation where material data and curing parameters for the nozzle curing process are incomplete. By using online monitoring, key control parameters in the nozzle curing process can be identified, and on this basis, the simulation calculation model can be checked and verified, the simulation calculation model can be corrected, the accuracy of simulation analysis can be improved, and finally an optimized nozzle design scheme can be obtained.

[0006] In existing technologies, methods for online monitoring of parameters during the curing process of multilayer composite materials are mainly divided into fiber optic methods, ultrasonic methods, electrical methods, and thermal methods. Each method can only monitor a portion of the parameters, and the appropriate method must be selected and evaluated based on specific conditions. Moreover, most of these testing methods are still in the laboratory research stage, primarily targeting flat samples of composite layer layups. Since integrally molded nozzles are formed by wrapping fabric tape during manufacturing, there is a lack of relevant methods for online monitoring of parameters during multiple curing processes of irregularly shaped nozzle components. Summary of the Invention

[0007] The purpose of this invention is to provide a composite material nozzle design method based on online monitoring and simulation verification, which, without increasing the weight of the nozzle structure, enables online monitoring of multiple parameters during the nozzle curing process, providing support for understanding the temperature and strain changes during the nozzle curing process.

[0008] To achieve the above objectives, this invention provides a composite material nozzle design method based on online monitoring and simulation verification, comprising the following steps:

[0009] S1. Establish a preliminary design model;

[0010] S2. Identify key control parameters and obtain an online monitoring scheme for the sample level;

[0011] S3. Online monitoring, data acquisition, analysis and simulation verification of representative basic sample levels, and correction of simulation parameters of the preliminary design model obtained in S1;

[0012] S4. Conduct solidification simulation analysis and preliminary optimization design of the nozzle structure to obtain a preliminary optimized model of the nozzle;

[0013] S5. Based on the initial optimization model of the nozzle, conduct nozzle production, online data acquisition and simulation verification. If the online monitoring test data and the performance indicators of the final product meet the design requirements, the optimization design model is completed. Otherwise, repeat S3-S5 for iterative optimization until the design requirements are met.

[0014] Preferably, S1 is as follows:

[0015] Based on the structural parameters designed with experience and traditional finite element simulation, a preliminary design model of the nozzle scheme is obtained.

[0016] Preferably, S2 is as follows:

[0017] Based on the preliminary design model, key control parameters affecting product performance were identified, and representative basic specimens were prepared. The representative basic specimens include Class A specimens and Class B specimens. Class A specimens are made individually from various composite materials that make up the nozzle structure, while Class B specimens are made by combining and layering various composite materials that make up the nozzle structure in pairs.

[0018] Preferably, the representative basic specimen is one of a flat plate, an L-shaped specimen, or a conical specimen.

[0019] Preferably, S3 is as follows:

[0020] A fiber optic grating sensor was implanted in a Class A specimen to collect real internal temperature and strain change data of the specimen under the same curing process as the nozzle. Simultaneously, a curing simulation model of the Class A specimen was established, and simulation calculations were performed on the specimen under the same molding process to obtain internal temperature and strain change data of the Class A specimen under simulated conditions.

[0021] The location for implanting the fiber Bragg grating sensor can be selected from a representative part obtained through preliminary simulation calculation. The online monitoring data measured in the Class A sample is compared with the finite element simulation results, and the relevant physical property parameters of the Class A sample in the finite element simulation are corrected.

[0022] Preferably, the relevant physical properties include resin curing kinetic parameters, resin chemical shrinkage coefficient, and composite material thermophysical parameters.

[0023] Preferably, S3 is as follows:

[0024] A fiber optic grating sensor was implanted in the type B sample to collect real temperature and strain data at the material interior and interface of the type B sample in a curing environment with the same curing process as the nozzle. At the same time, a curing simulation model of the type B sample was established, and simulation calculations were performed on the type B sample under the same molding process to obtain temperature and strain data inside the material under the simulated conditions. The online monitoring data measured in the type B sample was compared with the finite element simulation results to correct the errors in the design parameters coupled to the type B sample.

[0025] Preferably, the design parameters for coupling of the type B sample include the interfacial thermal conductivity and interfacial contact properties.

[0026] Preferably, in S4, the preliminary optimization design adopts the Taguchi optimization method.

[0027] Preferably, in S5, during the nozzle production process, sensors are implanted into the interlayer of the composite material of the nozzle structure. Sensors are also implanted into key parts with large internal stress and high risk of structural failure corresponding to the curing simulation analysis results, so as to obtain online monitoring test data during the nozzle pressure curing molding process. The test data includes the actual temperature and strain change data inside the material.

[0028] Based on the test data of the implanted fiber optic grating sensor, the errors in the composite material thermal property parameters, interface contact properties, and interface thermal conductivity input error in the initial optimization model of the nozzle were corrected again. The optimization design was carried out by combining measured parameters with finite element simulation to form an optimized design model.

[0029] If the online monitoring test data and the final product performance indicators both meet the design requirements, the optimized design model is complete; otherwise, repeat S3-S5 for iterative optimization until the design requirements are met.

[0030] Therefore, the present invention employs the above-mentioned composite material nozzle design method based on online monitoring and simulation verification, which has the following beneficial effects:

[0031] (1) This invention proposes for the first time an optimized design method for all-composite material nozzle structures that combines online monitoring with simulation verification. This method improves the accuracy of the simulation model without increasing the weight of the nozzle structure. Based on fiber optic sensing technology, the method monitors multiple parameters of the nozzle curing process online by inserting optical fibers into the in-plane direction and interlayer interface direction of the multi-layer composite material structure of the nozzle during the nozzle preparation process. This provides support for understanding the temperature and strain change laws during the nozzle curing process.

[0032] (2) The present invention can achieve full coverage of the nozzle curing process. According to the structural design requirements, the sensor can be arranged in the key areas of each component of the nozzle without significantly affecting the mechanical properties of the composite material nozzle.

[0033] (3) This invention can be extended to the optimization design method of existing irregular composite material components that require multiple curing and molding. It is applicable to the structural optimization of integrally molded nozzles prepared by winding (or other methods to replace tape winding), and is applicable to the optimization design of all-composite material nozzle structures (or irregular multi-layer composite material structures similar to nozzle structures) that have undergone multiple curing processes. It is also low in cost and easy to apply and promote.

[0034] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0035] Figure 1This is a flowchart of Embodiment 1 of the composite material nozzle design method based on online monitoring and simulation verification of the present invention;

[0036] Figure 2 This is a schematic diagram of the nozzle structure in Embodiment 2 of the composite material nozzle design method based on online monitoring and simulation verification of the present invention;

[0037] Figure 3 This is a schematic diagram of the sensor layout of the composite material plate in Embodiment 2 of the composite material nozzle design method based on online monitoring and simulation verification of the present invention;

[0038] Figure 4 This is a schematic diagram of the lead wires of Embodiment 2 of the composite material nozzle design method based on online monitoring and simulation verification of the present invention;

[0039] Figure 5 This is a schematic diagram of lead wire connection in Embodiment 2 of the composite material nozzle design method based on online monitoring and simulation verification of the present invention;

[0040] Figure 6 This is a process and final effect diagram of Embodiment 2 of the composite material nozzle design method based on online monitoring and simulation verification of the present invention, wherein (a) is a schematic diagram of interlayer sensor layout, (b) is a schematic diagram of interlayer filling, (c) is a schematic diagram of interlayer sensor lead wire lead-out, and (d) is a schematic diagram of overall packaging. Detailed Implementation

[0041] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0042] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0043] This invention was funded by the "2023 Hubei Provincial Major Research Project (JD)(2023BAA004)".

[0044] Example 1

[0045] like Figure 1 As shown, a composite material nozzle design method based on online monitoring and simulation verification includes the following steps:

[0046] S1. Establish a preliminary design model. Specifically:

[0047] Based on the structural parameters designed with experience and traditional finite element simulation, a preliminary design model of the nozzle scheme is obtained.

[0048] S2. Identify key control parameters to obtain an online monitoring scheme for the sample level. Specifically:

[0049] Based on the preliminary design model, key control parameters affecting product performance were identified, and representative basic specimens were prepared. These representative basic specimens included Type A specimens and Type B specimens. Type A specimens were made individually from various composite materials that make up the nozzle structure, while Type B specimens were made by layering and combining two of the various composite materials that make up the nozzle structure. In this embodiment, the representative basic specimens are one of the following: flat plate, L-shaped, or conical.

[0050] S3 involves online monitoring, data acquisition, analysis, and simulation verification of representative basic sample levels to correct the simulation parameters of the preliminary design model obtained in S1.

[0051] A fiber optic grating sensor was implanted in a Class A specimen to collect real internal temperature and strain change data of the specimen under the same curing process as the nozzle. Simultaneously, a curing simulation model of the Class A specimen was established, and simulation calculations were performed on the specimen under the same molding process to obtain internal temperature and strain change data of the Class A specimen under simulated conditions.

[0052] The location for implanting the fiber Bragg grating sensor can be selected from representative areas obtained through preliminary simulation calculations. The online monitoring data measured in the Class A samples is compared with the finite element simulation results to correct the relevant physical property parameters of the Class A samples from the finite element simulation. These relevant physical property parameters include resin curing kinetic parameters, resin chemical shrinkage coefficient, and composite material thermophysical parameters.

[0053] A fiber optic grating sensor was implanted in the Class B specimen to collect real temperature and strain data at the material interior and interface of the Class B specimen in a curing environment with the same curing process as the nozzle. At the same time, a curing simulation model of the corresponding Class B specimen was established, and simulation calculations were performed on the Class B specimen under the same molding process to obtain temperature and strain data inside the material under the simulated conditions. The online monitoring data measured in the Class B specimen was compared with the finite element simulation results to correct the errors of the coupling design parameters of the Class B specimen. The coupling design parameters of the Class B specimen include the interface thermal conductivity and interface contact properties.

[0054] S4. Conduct simulation analysis of nozzle structure solidification and preliminary optimization design using Taguchi optimization method to obtain preliminary optimized nozzle model.

[0055] S5. During the nozzle production process, sensors are implanted into the interlayer of the composite material of the nozzle structure. Sensors are also implanted into key parts with large internal stress and high risk of structural failure corresponding to the curing simulation analysis results to obtain online monitoring test data during the nozzle pressure curing molding process. The test data includes the actual temperature and strain change data inside the material.

[0056] Based on the test data of the implanted fiber optic grating sensor, the errors in the composite material thermal property parameters, interface contact properties, and interface thermal conductivity input error in the initial optimization model of the nozzle were corrected again. The optimization design was carried out by combining measured parameters with finite element simulation to form an optimized design model.

[0057] If the online monitoring test data and the final product performance indicators both meet the design requirements, the optimized design model is complete; otherwise, repeat S3-S5 for iterative optimization until the design requirements are met.

[0058] Example 2

[0059] Using the optimized design method of Example 1, taking the nozzle prototype as an example, the steps are as follows:

[0060] S1. Based on the structural parameters and working load boundary conditions designed with experience, the structural schematic diagram of the nozzle prototype is shown below. Figure 2 As shown, the ablation layer is a 20° oblique stacked winding, the heat insulation layer is a 0° flat stacked winding, and the composite material structural layer is a unidirectional tape laid up with a laying angle of [45° / -45° / 0° / -45° / 45° / 90°]s.

[0061] S2. Identify key control parameters to obtain an online monitoring scheme for the sample level.

[0062] Both the ablation layer and the heat insulation layer were formed by winding fabric tape and required simultaneous curing. The composite material structural layer was formed by unidirectional tape laying and was cured again on top of the ablation layer and the heat insulation layer, resulting in 3 Class A samples and 2 Class B samples. Key control parameters for nozzle structure reliability were identified.

[0063] a) Interlaminar stresses during the curing process of the ablation layer and the insulation layer. This includes interlaminar tensile stress, interlaminar shear stress, interlaminar tensile stress, and interlaminar shear stress of the insulation layer, as well as interlaminar tensile stress and shear stress of the ablation / insulation layer. High stress values ​​can lead to interlaminar cracking and structural failure.

[0064] b) The internal stress of the composite structural layer during the curing process and its interfacial deformation matching performance with the insulation layer. This includes the curing internal stress of the composite structural layer itself, the interfacial tensile stress between the composite structure and the insulation layer, and the interfacial shear stress between the composite structure and the insulation layer.

[0065] If the layup angle of the composite structural layer results in a large stress value, the composite structural layer will crack and lose its load-bearing capacity. Furthermore, the mismatch in interface deformation between the composite structural layer and the insulation layer due to differences in materials and processes may lead to interfacial debonding during the curing process, resulting in structural failure. Therefore, the identified key control parameters are the interlayer stress generated in the nozzle ablation layer, insulation layer, and composite structural layer during the curing process.

[0066] S3 involves online monitoring, data acquisition, analysis, and simulation verification of representative basic sample levels to correct the simulation parameters of the preliminary design model obtained in S1.

[0067] A fiber optic grating sensor was implanted in a Class A sample to collect real temperature and strain data within the sample material under the same curing process as the nozzle. Simultaneously, a corresponding curing simulation model for the Class A sample was established, and simulation calculations were performed on the sample under the same molding process to obtain temperature and strain data within the material under simulated conditions. The location of the fiber optic grating sensor was selected from representative areas identified through preliminary simulation calculations. Based on the online monitoring data measured in the sample, the results were compared with the finite element simulation results, and the relevant physical properties of the elemental composite material (including resin curing kinetic parameters, resin chemical shrinkage coefficient, and composite material thermophysical parameters) were corrected.

[0068] Fiber Bragg grating sensors were implanted in type B samples to collect real temperature and strain change data at the material interior and interfaces of the type B samples in a curing environment with the same curing process as the nozzle. Simultaneously, a corresponding curing simulation model of the type B samples was established, and simulation calculations were performed on the samples under the same molding process to obtain temperature and strain change data within the material under simulated conditions. The location of the implanted fiber Bragg grating sensors can be selected from representative locations identified through preliminary simulation calculations. Based on the online monitoring data measured in the samples, the results were compared with the finite element simulation results to correct errors in the integrated coupling parameters of various composite materials (including interfacial thermal conductivity and interfacial contact properties).

[0069] The representative basic specimens are flat composite material structural components. In order to obtain the variation law of temperature, interlaminar shear stress and interlaminar tensile stress during the curing process of composite material structural components, and to provide a basis for the curing simulation verification and structural reliability assessment of composite material structural components, fiber optic online monitoring tests were carried out on the curing process of the flat composite material specimens. The working conditions of the specimens are shown in Table 1.

[0070] Table 1 Sample Conditions

[0071]

[0072]

[0073] Curing monitoring was conducted on composite material plates under various curing conditions. Fiber Bragg grating sensors were used to monitor interlayer shear stress, interlayer tensile stress, and temperature field changes. The placement of the fiber Bragg grating sensors was designed, with one fiber strain sensor and one fiber temperature sensor placed between the two composite material plates of each curing test specimen. A fiber strain sensor was also placed along the Z-axis at the center of the two plates. Sensor placement for monitoring composite material plates under all conditions followed this method.

[0074] The sensor deployment needs to monitor interlayer lateral and longitudinal stresses, and must ensure that the sensor deployment does not cause crosstalk. The sensor routing needs to be optimized. A schematic diagram of the sensor deployment is shown below. Figure 3 As shown in the diagram. The interlayer sensors are mainly concentrated at the center of the composite material plate. Because the grating temperature sensor has a stress-isolation structure, its size is significantly larger than that of the grating strain sensor. Therefore, its placement is moved outwards to ensure that the sensor leads extend along the designed positions. The actual sensor placement on the composite material plate is as follows: Figure 6 As shown in (a), after the X and Y temperature sensors and strain sensors are installed, the leads are all led out along the Y direction. The Z-direction sensor is installed at the center of the contact surface of the two composite material plates, and the sensor is kept between the two layers, and is led out vertically along the Z direction of the center hole.

[0075] Because the grating temperature sensor is relatively large, directly covering the top of the sensor with the upper composite material plate would create a large cavity at the interlayer contact surface, affecting the curing effect. Therefore, the same material as the composite material plate used in the corresponding working condition is used for filling, ensuring a smooth interlayer and good curing effect of the composite material plate. Using the same material for filling, the final result is flush with the edge of the grating temperature sensor. The interlayer structure after filling is as follows: Figure 6 As shown in (b) in the diagram. The composite material flat plates are laid out in this manner under all working conditions.

[0076] like Figure 4 The diagram shows the sensor leads at various locations on the composite material flat plate. Each sensor lead is led out along the Y direction. The sensor leads are symmetrically arranged in the XOY plane. At the Y-direction lead-out positions, each lead is symmetrically led out with the center line as the axis of symmetry. The corresponding sensor is labeled on the sensor lead on one side of the center line.

[0077] based on Figure 4 This diagram illustrates the lead wire layout of an optical fiber sensor. It shows the design of a series connection for the optical fiber sensors. Due to the increased melting point of the fiber optic cable and considering signal loss, the number of sensors in each series connection should not exceed three. The series connection method for the sensor lines is as follows: Figure 5 As shown. Comparison Figure 5As shown in the schematic diagram of the sensors corresponding to the center lead, the red line includes an X-axis temperature sensor, a Y-axis temperature sensor, and an X-axis strain sensor, while the blue line includes a Y-axis strain sensor and a Z-axis strain sensor. Each set of test pieces is tested by connecting the sensors in series with the demodulator in this manner.

[0078] After the fiber optic sensor is deployed between the composite material layers, a vacuum bag extraction process is required during the composite material curing process. Since the fiber optic sensor is located between the two composite material layers and the lead wire is suspended, it needs to be secured and protected. A flexible ramp is constructed using silicone sheets, allowing the fiber optic cable to extend along the ramp to the outside of the vacuum bag. The extension method is as follows: Figure 6 As shown in (c) in the figure.

[0079] Since the Z-axis sensor is vertically led out, a crease can be created at the Z-axis sensor lead-out point in the vacuum bag. This ensures the Z-axis sensor lead remains vertically led out during vacuum extraction. The overall sensor lead package is as follows: Figure 6 As shown in (d) in the figure.

[0080] S4. Conduct solidification simulation analysis of the nozzle structure and perform preliminary optimization design using the Taguchi optimization design method to obtain a preliminary optimized nozzle model. The preliminary optimized nozzle model includes the structural layer layup angle scheme and the interlayer elastic layer parameter design scheme. For key parts with high internal stress and high structural failure risk corresponding to the solidification simulation calculation, multiple sensors can be implanted.

[0081] S5. Nozzle Online Monitoring, Data Acquisition, Analysis, and Simulation Verification. Based on the preliminary nozzle optimization model, nozzle production and online data acquisition are conducted. During nozzle production, sensors implanted in the interlayer of the composite material structure acquire real temperature and strain changes within the material during pressurization and curing. Based on the sensor test data, errors in the thermophysical parameters and interfacial contact parameters of various composite materials, as well as input errors in environmental heat conduction, are corrected in the preliminary optimization model. If the test data monitored by the fiber optic sensors and the performance indicators of the final product both meet expectations, the optimized design model is considered complete.

[0082] Therefore, the present invention adopts the above-mentioned composite material nozzle design method based on online monitoring and simulation verification, which, without increasing the weight of the nozzle structure, performs online monitoring of multiple parameters during the nozzle curing process, providing support for understanding the temperature and strain change laws during the nozzle curing process.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for composite nozzle design based on online monitoring and simulation validation, characterized in that, Includes the following steps: S1. Establish a preliminary design model; S2. Identify key control parameters and obtain an online monitoring scheme for the sample level; S3. Online monitoring, data acquisition, analysis and simulation verification of representative basic sample levels, and correction of simulation parameters of the preliminary design model obtained in S1; S4. Conduct solidification simulation analysis and preliminary optimization design of the nozzle structure to obtain a preliminary optimized model of the nozzle; S5. Based on the initial optimization model of the nozzle, conduct nozzle production, online data acquisition and simulation verification. If the online monitoring test data and the performance indicators of the final product meet the design requirements, the optimization design model is completed. Otherwise, repeat S3-S5 for iterative optimization until the design requirements are met. S2 specifically refers to: Based on the preliminary design model, key control parameters affecting product performance were identified, and representative basic specimens were prepared. The representative basic specimens include Class A specimens and Class B specimens. Class A specimens are made individually from various composite materials that make up the nozzle structure, while Class B specimens are made by combining and layering various composite materials that make up the nozzle structure in pairs. S3 specifically refers to: A fiber optic grating sensor is implanted in a Class A sample to collect real internal temperature and strain change data of the Class A sample in a curing environment with the same curing process as the nozzle. At the same time, a curing simulation model of the corresponding Class A sample is established, and simulation calculations are performed on the Class A sample under the same molding process to obtain the internal temperature and strain change data of the Class A sample under the simulation conditions. The location of the fiber optic grating sensor can be selected from a representative part obtained through preliminary simulation calculations. The online monitoring data measured in the Class A sample is compared with the finite element simulation results to correct the relevant physical property parameters of the Class A sample in the finite element simulation. The relevant physical properties include resin curing kinetic parameters, resin chemical shrinkage coefficient, and composite material thermophysical parameters. A fiber optic grating sensor is implanted in the B-type sample to collect real temperature and strain change data at the material interior and interface of the B-type sample in a curing environment with the same curing process as the nozzle. At the same time, a curing simulation model of the corresponding B-type sample is established, and simulation calculations are performed on the B-type sample under the same molding process to obtain temperature and strain change data inside the material under the simulation conditions. The online monitoring data measured in the B-type sample is compared with the finite element simulation results to correct the error of the coupled design parameters of the B-type sample. The design parameters for coupling of the type B specimens include the interfacial thermal conductivity and interfacial contact properties. In S4, the preliminary optimization design adopts the Taguchi optimization method.

2. The composite material nozzle design method based on online monitoring and simulation verification according to claim 1, characterized in that, S1 specifically refers to: Based on the structural parameters designed with experience and traditional finite element simulation, a preliminary design model of the nozzle scheme is obtained.

3. The composite material nozzle design method based on online monitoring and simulation verification according to claim 1, characterized in that, The representative basic specimen is one of the following: flat plate, L-shaped, or conical.

4. The composite material nozzle design method based on online monitoring and simulation verification according to claim 1, characterized in that, In S5, during the nozzle production process, sensors are implanted into the interlayer of the composite material of the nozzle structure. Sensors are also implanted into key parts with large internal stress and high risk of structural failure corresponding to the curing simulation analysis results to obtain online monitoring test data during the nozzle pressure curing molding process. The test data includes the actual temperature and strain change data inside the material. Based on the test data of the implanted fiber optic grating sensor, the errors in the composite material thermal property parameters, interface contact properties, and interface thermal conductivity input error in the initial optimization model of the nozzle were corrected again. The optimization design was carried out by combining measured parameters with finite element simulation to form an optimized design model. If the online monitoring test data and the final product performance indicators both meet the design requirements, the optimized design model is complete; otherwise, repeat S3-S5 for iterative optimization until the design requirements are met.

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