Parameter optimization method based on digital twin aero-engine disc-drum bolt connection structure

Abstract

The invention relates to the technical field of aero-engine bolt optimization, in particular to a digital twin aero-engine-based disc-drum bolt connection structure parameter optimization method, which comprises the following steps of S1, performing systematic modeling from geometric, physical, behavioral and regular dimensions, and constructing a digital twin of a disc-drum bolt connection structure; s2, the geometric model describes geometric parameters of the size, the shape and the assembly relation, and the geometric model of the aero-engine disc-drum bolt connection structure is established. According to the method, geometric, physical, behavior and rule models are established, the digital twin of the disc-drum bolt connection structure is formed, the influence of each parameter of the disc-drum bolt connection structure on the connection performance is comprehensively considered, the optimal parameter combination with the maximum connection rigidity is obtained, the optimization result is accurate and reliable, and the method is suitable for large-scale popularization and application. And a reference basis can be provided for the optimization design of the connection performance of the disc-drum bolt connection structure.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engine bolt optimization, and particularly to a method for optimizing the structural parameters of a disk-drum bolt connection of a digital twin aero-engine. Background Art

[0002] Bolt connections are widely used in aero-engine structures due to their advantages such as convenient assembly and disassembly and flexible design. With the continuous development of aero-engine technology, the requirements for the performance and stability of bolt connections are getting higher and higher. Although the proportion of bolt connections in the whole structure is not high, their impact on the reliability of the whole structure is crucial. Facing the challenges of engine modification and replacement, traditional design methods are difficult to meet the needs of bolt connection structures of modern high-performance engines, and there is an urgent need to study and establish more efficient and accurate design and optimization methods for bolt connections. The optimal design of aero-engine bolt connection structures involves multi-disciplinary and multi-objective problems, and multiple factors need to be comprehensively considered. At the same time, there may be mutually restrictive relationships among these factors, requiring multi-objective optimization in the design process to achieve the maximum improvement of overall performance. However, traditional simulation analysis methods often rely on empirical models or structurally simplified models as the basis, and it is difficult to comprehensively reflect the true characteristics of complex systems. The design decisions obtained therefrom may cause significant differences between virtual products and actual products. Moreover, traditional design methods rely heavily on experience and trial-and-error methods, often requiring a large amount of time and computing resources, and having problems such as low design efficiency, high cost, and imperfect auxiliary decision-making functions. Summary of the Invention

[0003] The purpose of the present invention is to solve the disadvantages existing in the prior art, and to propose a method for optimizing the structural parameters of a disk-drum bolt connection of a digital twin aero-engine.

[0004] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0005] A method for optimizing the structural parameters of a disk-drum bolt connection of a digital twin aero-engine includes the following steps:

[0006] S1. Systematically model from the dimensions of geometry, physics, behavior, and rules to construct a digital twin of the disk-drum bolt connection structure;

[0007] S2. The geometric model describes the geometric parameters of the size, shape, and assembly relationship, and establishes a geometric model of the disk-drum bolt connection structure of the aero-engine;

[0008] S3. The physical model analyzes the physical characteristics of structural stress, fatigue, and strain, and further introduces relevant information on constraints on the basis of the geometric model. Use the commercial software Workbench 2023R1 to establish a finite element model of the disk-drum bolt connection structure and solve the physical properties of the model;

[0009] S4. The behavior model describes the external environment and interference of physical entities at different granularities and different spatial scales, as well as the responses and behaviors triggered by the internal operating mechanism. The thin layer element method is used to characterize the contact stiffness, and a behavior model is established to truly reflect the mapping of physical entities.

[0010] S5. The rule model models the laws or rules of the operation of physical entities, including the laws and rules related to historical data, the experience summarized from knowledge, etc., enabling the digital twin to have multiple functions such as prediction, evaluation, assessment, and optimization, so as to guide the physical space, determine the main structural parameters affecting the performance of the disc-drum bolt connection and their value ranges, and based on the adaptive genetic algorithm of population dissimilarity, perform coding transformation to generate an initial population and establish a rule model.

[0011] S6. Establish a hierarchical structure model, split the comprehensive optimization problem into sub-goals, use the method of solving the eigenvector of the judgment matrix to calculate the weight of each layer of elements relative to the upper layer of elements, and finally perform weighted summation to obtain the weight for the comprehensive optimization of the total goal.

[0012] S7. According to the digital twin of the disc-drum bolt connection structure, combined with the parameter weights obtained by the analytic hierarchy process, comprehensively optimize the bolt connection structure to obtain the optimal parameter combination scheme.

[0013] Compared with the prior art, the present application establishes geometric, physical, behavior, and rule models, constitutes a digital twin of the disc-drum bolt connection structure, comprehensively considers the influence of various parameters of the disc-drum bolt connection structure on its connection performance, obtains the optimal parameter combination with the largest connection stiffness, and the optimization result is accurate and reliable, which can provide a reference basis for the optimal design of the connection performance of the disc-drum bolt connection structure.

[0014] Establish a geometric model of the aero-engine disc-drum bolt connection structure, use the commercial software Workbench2023R1 to establish a finite element model of the disc-drum bolt connection structure, and solve the physical properties of the model; use the thin layer element method to characterize the contact stiffness and establish a behavior model to truly reflect the mapping of physical entities; determine the main structural parameters affecting the performance of the disc-drum bolt connection and their value ranges, perform coding transformation to obtain the test factor level coding table, generate an initial population, and perform operations such as adaptive crossover and mutation based on population dissimilarity to establish a rule model, so that the digital twin has an optimization function; finally, with the minimum equivalent stress, the lightest structural mass, and the largest connection stiffness as the optimization goals, establish a digital twin and perform multi-objective structural optimization using the analytic hierarchy process.

[0015] Preferably, the parameters of the disc-drum bolt connection structure to be optimized include the thickness of the mounting edge, the number of bolts, the height of the mounting edge, and the bolt pre-tightening force.

[0016] Furthermore, accurately obtain the structural parameters of the disk-drum bolt connection to understand the situation of the disk-drum bolt connection.

[0017] Preferably, establish a geometric model of the disk-drum bolt connection structure according to the actual size of the aero-engine rotor; use the Workbench 2023R1 software to mesh the geometric model, set boundary conditions and contact solutions to obtain a physical model; use the thin-layer element method to characterize the contact stiffness, establish a behavior model, truly reflect the mapping of the physical entity, calculate the contact stiffness at each grid node according to the magnitude of the contact stress, and then calculate the elastic modulus of the thin-layer element by the average value of the contact stiffness at each grid node through the following formula, and then obtain a complete model of the bolt connection structure using the thin-layer element method;

[0018]

[0019] k = 0.9933p 0.6736

[0020] Establish a rule model using an adaptive genetic algorithm based on population dissimilarity; establish a digital twin of the disk-drum bolt connection structure.

[0021] Furthermore, fully establish a rule model to effectively realize the establishment of a digital twin of the disk-drum bolt connection structure, so as to optimize the parameters of the aero-engine disk-drum bolt connection through this digital twin model.

[0022] Preferably, the S5 adaptive genetic algorithm based on population dissimilarity adaptively adjusts the crossover and mutation probabilities through population dissimilarity. The dissimilarity between individuals and the overall dissimilarity of the population are expressed by the following formula:

[0023]

[0024] where d i，j represents the dissimilarity between individuals x i and x j , x ik , x jk are the k-th genes of individuals x i and x j respectively.

[0025] Furthermore, fully understand the differences between individual and overall situations in the case of the adaptive genetic algorithm based on population dissimilarity

[0026] The beneficial effects of the present invention are:

[0027] 1. By establishing geometric, physical, behavioral, and rule models, a digital twin of the disk-drum bolt connection structure is constructed. Considering the influence of various parameters of the disk-drum bolt connection structure on its connection performance, the optimal parameter combination with the maximum connection stiffness is obtained. The optimization results are accurate and reliable, providing a reference for the optimal design of the connection performance of the disk-drum bolt connection structure.

[0028] 2. By establishing the geometric model of the aero-engine disk-drum bolt connection structure, using commercial software Workbench2023R1 to establish the finite element model of the disk-drum bolt connection structure, and solving the physical properties of the model; using the thin layer element method to characterize the contact stiffness and establish a behavioral model to truly reflect the mapping of the physical entity; determining the main structural parameters affecting the connection performance of the disk-drum bolt and their value ranges, and performing coding transformation to obtain the test factor level coding table, generating the initial population, and establishing a rule model through operations such as adaptive crossover and mutation based on population dissimilarity, so that the digital twin has an optimization function; finally, taking the minimum equivalent stress, the lightest structural mass, and the maximum connection stiffness as the optimization goals, establishing a digital twin, and performing multi-objective structural optimization using the analytic hierarchy process. Description of the Drawings

[0029] Figure 1 is the flowchart of the present invention;

[0030] Figure 2 is the schematic diagram of the digital twin of the disk-drum bolt connection structure of the present invention;

[0031] Figure 3 is the geometric model of the disk-drum bolt connection structure of the present invention;

[0032] Figure 4 is the physical model of the disk-drum bolt connection structure of the present invention;

[0033] Figure 5 is the hierarchical structure model of the present invention;

[0034] Figure 6 is the optimization flowchart of the disk-drum bolt connection structure of the present invention. Detailed Embodiments

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0036] Based on the digital twin aero-engine disk-drum bolt connection structure parameter optimization method, as Figure 1 shown, it includes the following steps:

[0037] S1. Systematically model from the dimensions of geometry, physics, behavior, and rules to construct a digital twin of the disk-drum bolt connection structure;

[0038] S2. The geometric model describes the geometric parameters of the size, shape, and assembly relationship. Establish a geometric model of the aero-engine disk-drum bolt connection structure, which includes the geometric parameters of the size, shape, and assembly relationship of the research object. As Figure 3 shown, in the present invention, the parameters of the disk-drum bolt connection structure are shown in Table 1;

[0039] Table 1 Geometric properties of the disk-drum bolt connection structure

[0040] Item Dimension / Quantity Length of single-side drum (mm) 40 Diameter of center circle (mm) 279 Inner diameter of drum (mm) 327 Outer diameter of drum (mm) 332 Thickness of drum (mm) 2.5 Thickness of wheel disc (mm) 10 Thickness of mounting edge (mm) 6 Total height (mm) 21.8 Number of bolts 48 Model of bolts M8

[0041] S3. Use the commercial software Workbench 2023R1 to establish a finite element model of the disk-drum bolt connection structure. Set the circumferential cyclic symmetry for the model to achieve full-week calculation. Set the boundary conditions. Set the material of the drum and the disk as 45 steel, and the material of the bolt as GH4169. The material characteristic parameters are shown in Table 2, and solve the physical properties of the model;

[0042] Table 2 Material characteristic parameters

[0043]

[0044] S4. Use the thin layer element method to characterize the contact stiffness, establish a behavior model, truly reflect the mapping of the physical entity, calculate the contact stiffness at each grid node according to the magnitude of the contact stress, and then calculate the elastic modulus of the thin layer element from the average value of the contact stiffness at each grid node through the following formula, and then obtain the complete model of the bolt connection structure using the thin layer element method;

[0045]

[0046] k = 0.9933p 0.6736

[0047] S5. Determine the main structural parameters affecting the performance of the disk-drum bolt connection and their value ranges, and perform coding transformation to generate an initial population and establish a rule model; The optimization parameters include the thickness of the mounting edge, the number of bolts, the height of the mounting edge, and the bolt pre-tightening force;

[0048] In the present invention, the structural parameters of the casing mounting edge are selected as the thickness of the mounting edge, the number of bolts, the height of the mounting edge, and the bolt pre-tightening force, and their variation ranges are shown in Table 3;

[0049] Table 3 Variation ranges of the optimization parameters

[0050]

[0051] Perform operations such as adaptive crossover and mutation to generate a new population. Change the crossover and mutation probabilities based on the population dissimilarity, calculate the fitness values of individuals, and calculate the population dissimilarity according to the following formula:

[0052]

[0053] where \(d_{i,j}\) represents the dissimilarity between individuals \(x_i\) and \(x_j\), and \(x_{ik}\), \(x_{jk}\) are the \(k\)-th genes of individuals \(x_i\) and \(x_j\) respectively;

[0054] S6. Establish a hierarchical structure model, split the comprehensive optimization problem into sub-goals, use the method of solving the eigenvector of the judgment matrix to calculate the weight of an element in a certain layer with respect to the upper-layer element, and finally perform weighted summation to obtain the weight for the comprehensive optimization of the overall goal;

[0055] S7. According to the digital twin of the disk-drum bolt connection structure, combined with the parameter weights obtained by the analytic hierarchy process, comprehensively optimize the bolt connection structure to obtain the optimal parameter combination scheme; obtain the optimal parameter combination scheme, and the composition and optimization process of the digital twin are as Figure 6 shown; among them Figure 4 in, (a) is the mesh diagram of the disk-drum bolt connection structure, (b) is the schematic diagram of the boundary conditions of the disk-drum bolt connection structure, and (c) is the stress diagram of the disk-drum bolt connection structure.

[0056] In this embodiment, the finally obtained optimal scheme is that the installation edge thickness is 6 mm, the number of bolts is 44, the installation edge height is 10 mm, and the bolt pre-tightening force is 9000 N. The bolt connection stiffness of the initial model is \(258.52\times10 7 N / m, the equivalent stress is 3369.03 MPa, the structural mass is 201.90 kg. The connection stiffness of the installation edge structure under the optimal parameter combination is increased by 74.21% compared with the initial model, the equivalent stress is decreased by 115.67%, and the structural mass is reduced by 7.25%. According to the analytic hierarchy process, the weights of the disk-drum bolt connection structure parameters for the comprehensive optimization of the overall goal can be obtained as \(w = [0.4737, 0.3233, 0.2030]\).

[0057] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. A method for optimizing the structural parameters of a disk-drum bolt connection of an aero-engine based on digital twin, characterized in that: The following steps are involved: S1. Conduct systematic modeling from the dimensions of geometry, physics, behavior, and rules to build a digital twin of the disc-drum bolt connection structure; S2. The geometric model describes the geometric parameters of the size, shape and assembly relationship, and establishes the geometric model of the aircraft engine disc-drum bolt connection structure; S3. The physical model analyzes the physical characteristics of structural stress, fatigue, and strain, and further introduces relevant information of constraints based on the geometric model. The commercial software Workbench 2023R1 is used to establish a finite element model of the drum bolt connection structure, and the physical properties of the model are solved; S4. The behavior model describes the external environment and interference of physical entities at different granularities and spatial scales, as well as the responses and behaviors caused by the internal operating mechanism. The thin layer element method is used to characterize the contact stiffness, establish a behavior model, and truly reflect the mapping of the physical entity. S5. The rule model models the laws or rules of the operation of physical entities, including the laws and rules related to historical data, the experience of knowledge summary, etc., so that the digital twin has multiple functions such as prediction, evaluation, assessment, and optimization, so as to guide the physical space, determine the main structural parameters and their value ranges that affect the performance of the drum bolt connection, and use an adaptive genetic algorithm based on the population dissimilarity, perform coding transformation, generate the initial population, and establish a rule model; S6. Establish a hierarchical model, split the comprehensive optimization problem into sub-goals, use the method of solving the eigenvector of the judgment matrix to calculate the weight of a certain layer of elements to the upper layer elements, and finally perform weighted sum to obtain the weight of the comprehensive optimization of the overall goal; S7. Based on the digital twin of the drum bolt connection structure and the parameter weights obtained by the hierarchical analysis method, the bolt connection structure is comprehensively optimized to obtain the optimal parameter combination scheme.

2. The method for optimizing the structural parameters of a disk-drum bolt connection of a digital twin aircraft engine according to claim 1 is characterized in that: The disc-drum bolt connection structural parameters to be optimized include the thickness of the mounting edge, the number of bolts, the height of the mounting edge and the bolt preload.

3. The method for optimizing the structural parameters of a disk-drum bolt connection of a digital twin aircraft engine according to claim 1 is characterized in that: The geometric model of the disc-drum bolt connection structure is established according to the actual size of the aircraft engine rotor; the geometric model is meshed using Workbench2023R1 software, boundary conditions and contact solutions are set, and the physical model is obtained; the contact stiffness is characterized by the thin layer element method, and a behavioral model is established to truly reflect the mapping of the physical entity. The contact stiffness on each grid node is calculated according to the magnitude of the contact stress, and then the elastic modulus of the thin layer element is calculated from the average value of the contact stiffness on each grid node through the following formula, thereby obtaining a complete model of the bolt connection structure using the thin layer element method; <h2 style=";text-align:left;direction:ltr">k = 0.9933p<h2 style=";text-align:left;direction:ltr"> 0.6736 A rule model is established using an adaptive genetic algorithm based on population dissimilarity; a digital twin of the disc-drum bolt connection structure is established.

4. The method for optimizing the structural parameters of a disk-drum bolt connection of a digital twin aircraft engine according to claim 1 is characterized in that: The S5 is an adaptive genetic algorithm based on population dissimilarity, which adaptively adjusts the crossover and mutation probabilities through population dissimilarity. The dissimilarity between individuals and the overall dissimilarity of the population are expressed by the following formula: Among them, d i，j Represents individual x i With x j The dissimilarity, x ik 、x jk For each individual x i With x j The kth gene of .

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