A bolt arrangement design method for a nozzle heat-insulation assembly based on topology optimization

Abstract

This application provides a bolt arrangement design method for nozzle heat insulation components based on topology optimization, belonging to the field of aero-engine technology. Specifically, it includes establishing a simplified analysis model of the heat insulation component, which comprises an impact layer, a bulge layer, and a film gas layer. The bulge layer and the film gas layer are welded together to form the heat insulation layer. Bolts are welded to the bulge layer to connect the impact layer and hooks on the impact layer, simplifying the bolts into beam elements. A multi-condition topology optimization method based on weighted compliance response is used to determine the initial bolt layout of the simplified analysis model. The initial bolt layout is then optimized based on assembly constraints to obtain the optimal bolt layout. This application's approach improves the computational efficiency of bolt optimization design, as well as the sealing reliability and cooling efficiency of the nozzle heat insulation component. This design scheme combines optimal performance with engineering practicality.

Description

Technical Field

[0001] This application relates to the field of aero-engine technology, and in particular to a method for designing the bolt arrangement of a nozzle heat insulation component based on topology optimization. Background Technology

[0002] In recent years, with the rapid increase in parameters such as the working pressure and combustion temperature of engine combustion chambers, the heat load on nozzles has increased dramatically, posing a severe cooling challenge. Adopting a combination of impact cooling and film cooling is one effective method to protect the nozzle casing from high-temperature damage. Specifically, the cooling chamber is designed as a double-layer structure: the first layer is an impact plate with small holes perpendicular to the wall surface. Cool air first impacts and exchanges heat with the insulation layer wall through these holes; subsequently, the cool air enters the main flow through oblique holes in the insulation layer, forming a film cooling layer. This cooling method makes the nozzle structure design more complex. The connection method between the insulation layer and the impact plate, as well as the flow characteristics of the airflow in the cooling chamber, directly affect the structural strength and reliability, posing numerous design challenges.

[0003] The current design uses a single large impact plate for the heat insulation layer, which is a segmented structure. The heat insulation layer and the impact plate are primarily connected by bolts. However, the arrangement of the bolts (such as spacing and position) largely relies on engineering experience, failing to fully consider the structural differences (including curved and straight sections with varying lengths and shapes) and load differences (significant load variations across sections, and different loads under different testing conditions). This typically results in redundant bolts, making it difficult to effectively control the structure's weight. Furthermore, in critical areas requiring sealing, excessive structural deformation can severely impact sealing reliability and cooling efficiency. Summary of the Invention

[0004] In view of this, this application provides a bolt arrangement design method for nozzle heat insulation components based on topology optimization. This method can minimize the number of bolts by optimizing the force transmission path, while ensuring the structural strength, stiffness, assembly feasibility, and sealing requirements of the heat insulation components, and ensuring a more uniform distribution of bolt loads. Ultimately, it improves the sealing reliability and cooling efficiency of the heat insulation components, while reducing the structural weight.

[0005] This application provides a method for designing the bolt arrangement of a nozzle heat insulation component based on topology optimization, including:

[0006] A simplified analysis model is established for the thermal insulation component, which includes an impact layer, a bulge layer, and an air film layer. The bulge layer and the air film layer are welded together to form the thermal insulation layer. Bolts are welded onto the bulge layer to connect the impact layer and the hooks on the impact layer. The bolts are simplified as beam elements.

[0007] The initial bolt layout of the simplified analysis model is determined by a multi-condition topology optimization method based on weighted compliance response.

[0008] The initial bolt layout is optimized based on assembly constraints to obtain the optimal bolt layout.

[0009] According to a specific implementation of an embodiment of this application, establishing a simplified analysis model for the thermal insulation component includes:

[0010] The impact plate is simplified to a constrained position;

[0011] The insulation layer is simulated using shell elements.

[0012] According to a specific implementation of an embodiment of this application, the step of determining the initial bolt layout of the simplified analysis model using a multi-condition topology optimization method based on weighted compliance response includes:

[0013] Define a designable domain and use the relative density of beam elements within the designable domain as an optimization design variable;

[0014] Based on a simplified analysis model, under optimization constraints, the optimization objective is to minimize the weighted compliance of the thermal insulation components under all test conditions. Topology optimization is then performed on the relative density of beam elements within the design domain to obtain the initial bolt layout.

[0015] According to a specific implementation of an embodiment of this application, the definition of the designable domain includes:

[0016] Based on the function and assembly requirements of the thermal insulation components, the areas between bulges where bolts cannot be placed and the areas between bulges where bolts must be placed are defined as undesignable areas, and the remaining areas between bulges are defined as designable areas.

[0017] According to a specific implementation of an embodiment of this application, the step of using the relative density of beam elements within the designable domain as an optimization design variable includes:

[0018] The mapping relationship between design variables and material properties is established based on the interpolation model of materials. By controlling the density and stiffness relationship of beam elements, the relative density of beam elements is made to approach 0 or 1.

[0019] When the relative density of a beam element approaches 1, it indicates that a bolt needs to be placed at that location; when the relative density of a beam element approaches 0, it indicates that a bolt does not need to be placed at that location.

[0020] According to a specific implementation of an embodiment of this application, the optimization constraints include:

[0021] The maximum tensile load that a single bolt can withstand satisfies the following relationship:

[0022] ≤ , of which F z The maximum tensile load is given by d, where d is the bolt diameter. The buckling strength limit of the material;

[0023] The maximum displacement of the insulation layer shall not exceed the design allowable value;

[0024] Apply structural symmetric constraints.

[0025] According to a specific implementation of an embodiment of this application, the step of performing topology optimization on the relative density of beam elements within the designable domain, with the goal of minimizing the weighted compliance of the thermal insulation component under all test conditions, includes:

[0026] Calculate the initial compliance of the thermal insulation component under each test condition i. and the total tensile load borne by all bolts ;

[0027] Calculate the total tensile load for each test condition i. Total tensile load compared to the preset reference working condition Ratio K Fi ;

[0028] Based on the ratio K Fi Initial compliance for each test condition i Make corrections to obtain the corrected compliance C for each test condition i. mi ;

[0029] Determine the compliance weighting coefficient for each assessment condition i. ;

[0030] Based on the modified compliance C mi Compliance weighting coefficient The optimization objective is to minimize the weighted compliance of the thermal insulation components under all test conditions, and to perform topology optimization on the relative density of beam elements within the design domain.

[0031] According to a specific implementation of an embodiment of this application, the modified compliance C mi The expression is:

[0032] .

[0033] According to a specific implementation of an embodiment of this application, the expression for the weighted compliance is:

[0034] ,

[0035] Among them, C w For weighted compliance.

[0036] According to a specific implementation of an embodiment of this application, the detailed optimization of the initial bolt layout based on assembly constraints includes:

[0037] In the initial bolt layout, regions where the relative density of beam elements approaches 1 are identified as candidate bolt locations.

[0038] Define assembly constraints, including that bolts at hook positions must appear in pairs, and adjacent bolts must be spaced apart by a row of bulges to ensure assembly space.

[0039] Based on assembly constraints, the candidate bolt locations are redefined into designable and non-designable domains.

[0040] Topology optimization is performed on the redefined designable domain to obtain the optimal bolt layout that satisfies strength, stiffness, and assembly feasibility.

[0041] Beneficial effects:

[0042] The topology-optimized bolt arrangement design method for nozzle heat insulation components in this application has the following significant advantages and positive effects compared to existing design methods that rely on engineering experience:

[0043] a) High computational efficiency: By reasonably simplifying the modeling of the impact plate, bolts, and insulation layer, the model complexity is significantly reduced, and the computational efficiency of topology optimization is improved;

[0044] b) Improved Design: A multi-condition topology optimization method based on weighted compliance response is adopted, using the relative density of bolt elements as the design variable. Under the strict constraints of bolt strength (maximum tensile load) and insulation layer stiffness (maximum displacement), the overall weighted compliance of the insulation component is minimized. This is equivalent to optimizing the force transmission path of the structure, making load transfer more direct and efficient.

[0045] c) Improved reliability: The optimized bolt arrangement results in a more uniform distribution of bolt load, avoiding stress concentration; at the same time, it effectively controls the deformation of the sealing area, significantly reduces the risk of cold air leakage, and significantly improves the sealing reliability and cooling efficiency of the nozzle heat insulation component.

[0046] d) Comprehensive consideration: Innovatively adopting a two-order optimization strategy, firstly, the bolt layout prototype with optimal force transmission is obtained through topology optimization, and then detailed optimization is carried out in combination with specific assembly constraints to ensure that the design scheme has both optimal performance and engineering practicality. Attached Figure Description

[0047] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments 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.

[0048] Figure 1 This is a flowchart of a topology-optimized bolt arrangement design method for a nozzle heat insulation assembly according to an embodiment of the present invention;

[0049] Figure 2 This is a schematic diagram of a heat insulation component structure according to an embodiment of the present invention;

[0050] Figure 3 This is a schematic diagram of an initial model of a thermal insulation component according to an embodiment of the present invention;

[0051] Figure 4 This is an optimization analysis model according to an embodiment of the present invention;

[0052] Figure 5 This is a schematic diagram of the relative density distribution of beam units in a thermal insulation component according to an embodiment of the present invention;

[0053] Figure 6 This is an optimized model according to an embodiment of the present invention;

[0054] Figure 7 This is a comparative schematic diagram of the deformation results of the sealing area of ​​a heat insulation component according to an embodiment of the present invention.

[0055] In the diagram: 1. Impact layer; 2. Bolt; 3. Bulging layer; 4. Air film layer; 5. Hook; 11. First column bulging area; 12. Symmetry plane; 13. Front sealing area; 14. Rear sealing area; 15. Second column bulging area; 16. Third column bulging area; 17. Fourth column bulging area; 18. Undesignable area; 19. First designable area; 20. Second designable area; 21. First bolt; 22. Second bolt. Detailed Implementation

[0056] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0057] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0058] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0059] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0060] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0061] This application provides a method for designing the bolt arrangement of a nozzle heat insulation component based on topology optimization. The following refers to... Figures 1 to 7 Provide a detailed description.

[0062] In one embodiment, refer to Figure 1 A method for designing the bolt arrangement of a nozzle heat insulation component based on topology optimization is provided, which specifically includes the following steps:

[0063] Step S101: Establish a simplified analysis model for the thermal insulation component. The thermal insulation component includes an impact layer 1, a bulge layer 3, and an air film layer 4. The bulge layer 3 and the air film layer 4 are welded together to form a thermal insulation layer. Bolt 2 is welded onto the bulge layer 3 and is used to connect the impact layer 1 and the hook 5 on the impact layer 1. The bolt 2 is simplified as a beam element.

[0064] Step S102: Determine the initial layout of bolt 2 in the simplified analysis model using a multi-condition topology optimization method based on weighted compliance response;

[0065] Step S103: Perform detailed optimization based on assembly constraints on the initial layout of bolt 2 to obtain the optimal layout of bolt 2.

[0066] In specific implementation, refer to Figure 2 The thermal insulation component structure mainly consists of three layers: impact layer 1, bulge layer 3, and air film layer 4. Based on the structural rigidity and load characteristics of the thermal insulation component, the model is reasonably simplified.

[0067] Furthermore, the establishment of a simplified analysis model for the thermal insulation component includes:

[0068] The impact plate is simplified to a constrained position;

[0069] The insulation layer is simulated using shell elements.

[0070] In practice, the impact plate is a single large plate, while the insulation layer is a segmented structure. The impact plate can be simplified to a constrained position; the connecting bolt 2 is simplified to a beam element to simulate its connection and force transmission behavior; the size of the insulation layer in the thickness direction is much smaller than the size in the two in-plane directions, so shell elements can be used for simulation.

[0071] In this embodiment, the bulge layer 3 and the air film layer 4 are welded together to form a complete thermal insulation layer structure. Bolt 2 is welded and fixed at a specific position on the bulge layer 3, its main function being to achieve a reliable connection between the impact layer 1 and the hook 5 on the impact layer 1. During model construction, to improve analysis efficiency while ensuring computational accuracy, bolt 2 is abstracted and simplified into a beam element to simulate the force and transmission characteristics of bolt 2 under actual working conditions. An initial model of a thermal insulation component is shown below. Figure 3 See optimization analysis model Figure 4 .

[0072] In one embodiment, determining the initial layout of bolt 2 in the simplified analysis model using a multi-condition topology optimization method based on weighted compliance response includes:

[0073] Define a designable domain and use the relative density of beam elements within the designable domain as an optimization design variable;

[0074] Based on the simplified analysis model, under optimization constraints, with the goal of minimizing the weighted compliance of the thermal insulation components under all test conditions, topology optimization is performed on the relative density of beam elements in the design domain to obtain the initial layout of bolt 2.

[0075] In this embodiment, to achieve precise optimization of the bolt 2 layout, the scope of the designable domain must first be clearly defined. This scope must cover all areas on the thermal insulation component where bolts 2 may be installed to ensure the comprehensiveness of the optimization results. The relative density of beam elements within the designable domain is set as the optimization design variable. Regarding optimization constraints, the main considerations are the quantity limitations of bolts 2, structural strength requirements, and installation space limitations, to ensure the engineering feasibility of the optimization results. Based on a simplified analysis model, the compliance of the thermal insulation component under various operating conditions, such as high-temperature operation, vibration, and impact, is calculated for each condition. By assigning corresponding weight coefficients to different conditions, the compliance under all operating conditions is weighted and summed to obtain the weighted compliance, which is then used as the optimization objective, i.e., minimizing the weighted compliance. During topology optimization, an optimization algorithm is used to iteratively update the relative density of beam elements within the designable domain, continuously adjusting the existence state of each element until the weighted compliance reaches its minimum value. At this point, the positions corresponding to the beam elements with a relative density of 1 within the designable domain constitute the initial layout of bolts 2. This initial layout can optimize the overall stiffness of the thermal insulation components while meeting various operating conditions, providing a reliable basis for the subsequent detailed design of the bolt 2 layout.

[0076] Furthermore, the defined designable domain includes:

[0077] Based on the function and assembly requirements of the thermal insulation components, the area between the bulges where bolts 2 cannot be placed and the area between the bulges where bolts 2 must be placed are defined as undesignable areas 18, and the remaining area between the bulges is defined as designable areas.

[0078] In specific implementation, refer to Figure 3Taking a certain thermal insulation component as an example, a symmetrical plane 12 is set. Taking the right side region of the symmetrical plane 12 as an example, the first column of bulges 11 starting from the right is located at the edge. Due to sealing requirements, bolts 2 must be arranged. This type of bolt 2 is defined as the first bolt 21, and the corresponding region is defined as the undesignable region 18. The second column of bulges 15 and the fourth column of bulges 17 cannot be equipped with bolts 2 because sufficient space needs to be reserved for the installation of hooks 5. The corresponding regions are also undesignable regions 18. The designable regions can be further divided into the first designable region 19 and the second designable region 20. For example, the third column of bulges 16 requires bolts 2 to be arranged because of the assembly requirements of hooks 5 (the position of hooks 5 is determined first). This type of bolt 2 is defined as the second bolt 22, and the corresponding region is defined as the first designable region 19. Bolts 2 can also be established between the bulges from the fifth column of bulges to the symmetrical plane. This type of region is defined as the second designable region 20. Bolts 2 can be arranged in both the first designable region 19 and the second designable region 20.

[0079] In practical implementation, dividing the designable and non-designable domains 18 using the above method effectively eliminates areas where bolts 2 cannot be placed due to functional limitations or assembly conflicts, ensuring that topology optimization is performed only within the feasible space and avoiding invalid calculations. This domain partitioning method based on actual engineering constraints lays an important foundation for the accuracy and engineering practicality of subsequent topology optimization.

[0080] In one embodiment, using the relative density of beam elements within the designable domain as an optimization design variable includes:

[0081] The interpolation model based on materials establishes a mapping relationship between design variables and material properties (such as Young's modulus and density). By controlling the density and stiffness relationship of beam elements, the relative density of beam elements is made to approach 0 or 1.

[0082] When the relative density of the beam element approaches 1, it indicates that bolt 2 needs to be placed at that location; when the relative density of the beam element approaches 0, it indicates that bolt 2 does not need to be placed at that location.

[0083] In one embodiment, the optimization constraints include:

[0084] The maximum tensile load that a single bolt 2 can withstand does not exceed the allowable value, as shown in the following formula:

[0085] ≤ , of which F z The maximum tensile load is given by d, where d is the diameter of bolt 2. The buckling strength limit of the material;

[0086] The maximum displacement of the insulation layer shall not exceed the design allowable value;

[0087] Apply structural symmetric constraints, such as Figure 3 The symmetry plane of the YZ plane is 12.

[0088] Furthermore, the optimization objective is to minimize the weighted compliance of the thermal insulation component under all test conditions, and topology optimization is performed on the relative density of beam elements within the designable domain, including:

[0089] Based on the initial model, the initial compliance of the thermal insulation component under each test condition i is calculated. and the total tensile load borne by all bolts 2 ;

[0090] Calculate the total tensile load for each test condition i. Total tensile load compared to a preset reference condition (e.g., design point condition) Ratio K Fi ;

[0091] Based on the ratio K Fi Initial compliance for each test condition i Make corrections to obtain the corrected compliance C for each test condition i. mi The aim is to balance the contribution of compliance under different load levels;

[0092] Determine the compliance weighting coefficient for each assessment condition i. Weights can be assigned based on the importance of the working condition or the probability of its occurrence.

[0093] Based on the modified compliance C mi Compliance weighting coefficient With the goal of minimizing the weighted compliance of the thermal insulation components under all test conditions, topology optimization is performed on the relative density of beam elements within the designable domain to obtain the topology-optimized configuration of the bolt 2 layout, i.e., the relative density distribution cloud map of the beam elements, as shown below. Figure 5 As shown, Figure 5 The model results for one side of symmetry plane 12 are shown in the figure.

[0094] Furthermore, the corrected compliance C mi The expression is:

[0095] .

[0096] Furthermore, the expression for the weighted compliance is:

[0097] ,

[0098] Among them, C w For weighted compliance.

[0099] In one embodiment, the detailed optimization of the initial layout of bolt 2 based on assembly constraints includes:

[0100] In the initial layout of bolt 2, regions where the relative density of beam elements approaches 1 are identified as candidate points for the location of bolt 2;

[0101] Determine the assembly constraints, including that the bolts 2 at the hook 5 position must appear in pairs, and that adjacent bolts 2 must be separated by a row of bulges to ensure assembly space;

[0102] Based on assembly constraints, the candidate points for bolt 2 are re-divided into designable and non-designable domains 18.

[0103] Topology optimization is performed on the newly partitioned designable domain to obtain the optimal bolt 2 layout that satisfies strength, stiffness, and assembly feasibility.

[0104] In practice, the detailed optimization based on assembly constraints includes the following:

[0105] Based on the topology optimization results of step S102, high-density regions are identified as potential candidate locations for bolt 2.

[0106] Since the connecting bolt 2 needs to be reliably connected to the hook 5, the bolts 2 at the hook 5 position need to appear in pairs, and there should be a row of bulges between adjacent bolts 2 to ensure assembly space.

[0107] Based on the assembly constraints mentioned above and the topology optimization results, the designable and non-designable domains are redefined.

[0108] Within the redefined designable domain, the optimization process of step S102 is executed again to optimize the dimensions of bolt 2. This ultimately yields the optimal arrangement of bolt 2 that meets requirements for strength, stiffness, and assembly feasibility. The final optimization result is as follows: Figure 6 As shown.

[0109] The optimized bolt arrangement in this embodiment results in a more uniform load distribution on the bolts, avoiding stress concentration; it also effectively controls deformation of the sealing area. For example... Figure 7 As shown, without increasing the number of bolts 2, the deformation of the front sealing area 13 is reduced by 48% after optimization, and the deformation of the rear sealing area 14 is reduced by 62% after optimization. It can be seen that the risk of cold air leakage is greatly reduced, and the sealing reliability and cooling efficiency of the nozzle heat insulation component are significantly improved.

[0110] The embodiments provided by this invention achieve precise optimization of the bolt 2 layout of the nozzle heat insulation component through a multi-stage design process combining topology optimization and assembly constraints. First, by establishing a simplified analysis model and employing a multi-condition topology optimization method based on weighted compliance response, the initial bolt 2 layout is determined to ensure optimal overall component stiffness under various operating conditions. Subsequently, based on assembly constraints such as the paired arrangement of hooks 5 and the bulge spacing between adjacent bolts 2, the initial layout is further optimized in detail, adjusting the position and number of bolts 2. The resulting optimal bolt 2 layout not only achieves a more uniform load distribution and effectively avoids stress concentration but also significantly reduces deformation in the sealing areas. For example, the deformation of the front sealing area 13 is reduced by 48%, and the deformation of the rear sealing area 14 is reduced by 62%. Without increasing the number of bolts 2, this significantly improves the sealing reliability and cooling efficiency of the heat insulation component, providing an efficient and engineering-practical solution for the structural design of the nozzle heat insulation system.

[0111] This method also has the following advantages: high computational efficiency: by reasonably simplifying the modeling of the impact plate, bolt 2, and insulation layer, the model complexity is significantly reduced and the computational efficiency of topology optimization is improved;

[0112] Better design: By adopting a multi-condition topology optimization method based on weighted compliance response, and taking the relative density of bolt 2 element as the design variable, the overall weighted compliance of the thermal insulation component is minimized under the strict constraints of bolt 2 strength (maximum tensile load) and insulation layer stiffness (maximum displacement). This is equivalent to optimizing the force transmission path of the structure, making load transmission more direct and efficient.

[0113] Comprehensive consideration: An innovative two-order optimization strategy is adopted. First, the bolt 2 layout prototype with optimal force transmission is obtained through topology optimization. Then, detailed optimization is carried out in combination with specific assembly constraints to ensure that the design scheme has both optimal performance and engineering practicality.

[0114] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for designing the bolt arrangement of a nozzle heat insulation assembly based on topology optimization, characterized in that, include: A simplified analysis model is established for the thermal insulation component, which includes an impact layer, a bulge layer, and an air film layer. The bulge layer and the air film layer are welded together to form the thermal insulation layer. Bolts are welded onto the bulge layer to connect the impact layer and the hooks on the impact layer. The bolts are simplified as beam elements. The initial bolt layout of the simplified analysis model is determined by a multi-condition topology optimization method based on weighted compliance response. The initial bolt layout is optimized based on assembly constraints to obtain the optimal bolt layout. The method of determining the initial bolt layout of the simplified analysis model using a multi-condition topology optimization method based on weighted compliance response includes: Define a designable domain and use the relative density of beam elements within the designable domain as an optimization design variable; Based on a simplified analysis model, under optimization constraints, with the goal of minimizing the weighted compliance of the thermal insulation components under all test conditions, topology optimization is performed on the relative density of beam elements within the design domain to obtain the initial bolt layout. The optimization constraints include: The maximum tensile load that a single bolt can withstand satisfies the following relationship: ≤ , of which F z The maximum tensile load is given by d, where d is the bolt diameter. The buckling strength limit of the material; The maximum displacement of the insulation layer shall not exceed the design allowable value; Apply structural symmetric constraints; The optimization objective is to minimize the weighted compliance of the thermal insulation components under all test conditions. Topology optimization is then performed on the relative density of beam elements within the designable domain, including: Calculate the initial compliance of the thermal insulation component under each test condition i. and the total tensile load borne by all bolts ; Calculate the total tensile load for each test condition i. Total tensile load compared to the preset reference working condition Ratio K Fi ; Based on the ratio K Fi Initial compliance for each test condition i Make corrections to obtain the corrected compliance C for each test condition i. mi ; Determine the compliance weighting coefficient for each assessment condition i. ; Based on the modified compliance C mi Compliance weighting coefficient The optimization objective is to minimize the weighted compliance of the thermal insulation components under all test conditions, and to perform topology optimization on the relative density of beam elements within the design domain.

2. The method for designing the bolt arrangement of a nozzle heat insulation assembly based on topology optimization according to claim 1, characterized in that, The establishment of a simplified analysis model for the thermal insulation component includes: The impact plate is simplified to a constrained position; The insulation layer is simulated using shell elements.

3. The method for designing the bolt arrangement of a nozzle heat insulation assembly based on topology optimization according to claim 1, characterized in that, The defined designable domain includes: Based on the function and assembly requirements of the thermal insulation components, the areas between bulges where bolts cannot be placed and the areas between bulges where bolts must be placed are defined as undesignable areas, and the remaining areas between bulges are defined as designable areas.

4. The bolt arrangement design method for nozzle heat insulation components based on topology optimization according to claim 1, characterized in that, The method of using the relative density of beam elements within the designable domain as an optimization design variable includes: The mapping relationship between design variables and material properties is established based on the interpolation model of materials. By controlling the density and stiffness relationship of beam elements, the relative density of beam elements is made to approach 0 or 1. When the relative density of a beam element approaches 1, it indicates that a bolt needs to be placed at that location; when the relative density of a beam element approaches 0, it indicates that a bolt does not need to be placed at that location.

5. The bolt arrangement design method for nozzle heat insulation assembly based on topology optimization according to claim 1, characterized in that, The corrected compliance C mi The expression is: 。 6. The bolt arrangement design method for nozzle heat insulation assembly based on topology optimization according to claim 1, characterized in that, The expression for the weighted compliance is: ， Among them, C w For weighted compliance.

7. The bolt arrangement design method for nozzle heat insulation components based on topology optimization according to claim 4, characterized in that, The initial bolt layout optimization based on assembly constraints includes: In the initial bolt layout, regions where the relative density of beam elements approaches 1 are identified as candidate bolt locations. Define assembly constraints, including that bolts at hook positions must appear in pairs, and adjacent bolts must be spaced apart by a row of bulges to ensure assembly space. Based on assembly constraints, the candidate bolt locations are redefined into designable and non-designable domains. Topology optimization is performed on the redefined designable domain to obtain the optimal bolt layout that satisfies strength, stiffness, and assembly feasibility.

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