Robust design method for sleeve-tooth connection structure of high-pressure cantilever rotor system of aero-engine

Abstract

The present invention belongs to the field of aircraft engine rotor design, and specifically relates to a robust design method for a sleeve tooth connection structure of an aircraft engine high-pressure cantilever rotor system, including: conducting modal analysis to evaluate the robustness of the sleeve tooth connection structure; establishing a finite element model of the sleeve tooth connection structure; determining design parameters, design goals and constraints to form a robust design optimization function; selecting an optimization algorithm to screen the optimal solution of assembly-structure parameters based on the finite element model of the sleeve tooth connection structure and the robust design optimization function; and forming a robust design scheme for the sleeve tooth connection structure through structural design using the optimal solution of assembly-structure parameters. The present invention can effectively suppress the change of the interface contact state of the sleeve tooth connection structure under the action of external loads, reduce interface damage and stiffness loss, reduce the influence of the dispersion of the mechanical characteristics of the sleeve tooth connection structure on the dynamic characteristics of the rotor system, improve the robustness of the high-pressure cantilever rotor system, and help ensure the reliability and safety of aircraft engines.

Description

Technical Field

[0001] The invention belongs to the field of aeroengine rotor design, and in particular relates to a robust design method for a sleeve-tooth connection structure of a high-pressure cantilever rotor system of an aeroengine. Background Art

[0002] The high-pressure cantilever rotor system of advanced aircraft engines often adopts a 1-1-0 cantilever support scheme, which can reduce the number of load-bearing frames and the overall weight of the engine, and is conducive to improving the overall thrust-to-weight ratio of the engine. Affected by the DN value and temperature of the rear pivot bearing, the diameter size of the high-pressure shaft is limited; due to the small diameter and strong torque transmission capacity of the sleeve gear connection structure, it is suitable for transmitting large driving power and torque from the turbine to the compressor end. Therefore, the sleeve gear connection structure is often used for the shaft connection between the compressor and the turbine of the high-pressure cantilever rotor system. Generally, the spline teeth transmit torque, the end face axial positioning, the front and rear cylindrical centering, and the large nut behind the disc is tightened to apply preload. At this time, the high-pressure tie rod at the center of the disc is deformed, and multiple related structures such as the turbine disc and bearing are pressed to form a structural whole. Under external loads, especially rotational inertia bending loads, the inner and outer shafts of the sleeve gear produce non-coordinated bending deformation, which leads to changes in the interface contact state of each mating surface. Under full-cycle operation, it is easy to cause the connection structure stiffness loss and irreversible interface damage, making the dynamic characteristics of the rotor system show strong dispersion.

[0003] In traditional aircraft engine rotor systems and their connection structures, the focus of related design methods is mainly on strength and assembly, ignoring the damage to the contact interface of the sleeve-tooth connection structure and the change in stiffness characteristics and their impact on the robustness of the dynamic characteristics of the rotor system. Corresponding robustness design methods have been proposed in the prior art, but most of them are aimed at flange-bolt and simple mechanism rotor systems. For the high-pressure cantilever rotor sleeve-tooth connection structure of aircraft engines, there is a lack of systematic robust design processes and methods, which leads to poor robustness of the cantilever rotor system designed in the past. During the engine test and use, the rotor and even the whole machine frequently show large vibration dispersion and excessive amplitude, affecting the reliability and safety of the whole machine.

[0004] Therefore, in order to reduce the impact of changes in the interface contact state of the sleeve-tooth connection structure on the dynamic characteristics of the high-pressure cantilever rotor system and improve the robustness of the rotor system, it is urgent to establish a robust design method for the sleeve-tooth connection structure of the high-pressure cantilever rotor system of an aero-engine. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a robust design method for the sleeve-tooth connection structure of a high-pressure cantilever rotor system of an aircraft engine. This method can be used to quickly and efficiently perform robustness evaluation and design on the sleeve-tooth connection structure, so as to suppress changes in the interface contact state of the sleeve-tooth connection structure under external loads, reduce interface damage and stiffness loss, and reduce the influence of the dispersion of the mechanical properties of the sleeve-tooth connection structure on the dynamic characteristics of the rotor system, thereby ensuring the reliability and safety of the aircraft engine.

[0006] The present invention is implemented by providing a robust design method for a sleeve-tooth connection structure of a high-pressure cantilever rotor system of an aircraft engine, comprising the following steps:

[0007] S1): Carry out modal analysis on the high-pressure cantilever rotor system of the aircraft engine, and conduct robustness assessment on the sleeve-tooth connection structure based on the strain energy distribution of the high-pressure cantilever rotor to determine whether robust design is needed;

[0008] S2): Based on the variable parameter function of the finite element analysis software, a finite element model of the sleeve gear connection structure with variable assembly-structure parameters and considering the interface contact state is established;

[0009] S3): By calculating the finite element model of the sleeve gear connection structure in S2), and according to the interface contact characteristics and stiffness characteristics of the sleeve gear connection structure under external loads, the design parameters, design objectives and constraints are determined to form a robust design optimization function;

[0010] S4): Select an optimization algorithm, based on the finite element model of the gear connection structure in S2) and the robust design optimization function in S3), to screen the optimal solution of assembly-structure parameters;

[0011] S5): The optimal solution of assembly-structure parameters is used to form a robust design scheme for the sleeve tooth connection structure through structural design.

[0012] Preferably, the step S1) specifically includes:

[0013] S1.1): Using finite element analysis software, on the basis of ensuring the mechanical properties, the actual complex structure is simplified, and the dynamic model of the aircraft engine high-pressure cantilever rotor system is established. The front and rear bearing positions are located, and the spring unit is used to simulate the elastic support stiffness;

[0014] S1.2): For the dynamic model of the high-voltage cantilever rotor system, the gyroscopic torque effect is considered and the QRDAMP method is used to calculate the first three modes and strain energy at the maximum speed;

[0015] S1.3): Select the area between the front and rear centering surfaces to extract the strain energy of the gear connection structure at each modal level , extract the strain energy of the rotor structure , calculate the strain energy distribution ratio of the sleeve gear connection structure under each mode , used to make a preliminary assessment of the robustness of the sleeve tooth connection structure. The higher the strain energy ratio, the worse the robustness of the sleeve tooth connection structure.

[0016] If the modal strain energy of the first two quasi-rigid vibration modes accounts for All are greater than 10% or the third-order bending vibration mode modal strain energy ratio If it is greater than 20%, it is necessary to continue to carry out robust design of the sleeve tooth connection structure.

[0017] Preferably, the step S2) specifically includes:

[0018] S2.1): If the robustness of the sleeve-tooth connection structure of the rear cantilever rotor system does not meet the requirements as evaluated in step S1), a finite element model of the disc-shaft sleeve-tooth connection structure considering the interface contact state is established. The model includes four mating surfaces with three-dimensional contact elements, namely, the positioning end surface, the front centering surface, the rear centering surface and the nut clamping surface;

[0019] S2.2): Based on the parameter adjustable function of the finite element analysis software, the assembly-structure parameters are set to a variable state. The variable assembly parameters include: front and rear centering surface tightness, preload; the structural parameters include: high-pressure shaft tie rod diameter and thickness, bearing constraint axial position, clamping structure stiffness, etc.;

[0020] S2.3): Select the restraint position, apply the centrifugal load, and apply the bending moment at the turbine disk rim;

[0021] S2.4): Under the conditions of S2.3), some parameters are adjusted and the calculation is performed under two conditions. One is to consolidate the contact surfaces of the model established in S2.1). Under the above constraints and external load conditions, the continuous structural stiffness is calculated. ; Another state is to set the matching surfaces of the model in S1.1) to the standard contact state and calculate the connection structure stiffness , according to the formula , obtain the stiffness loss under specific external load, structure and assembly parameters , verifying that the finite element model of the sleeve tooth connection structure has the function of adjustable parameters.

[0022] Preferably, the step S3) specifically includes:

[0023] S3.1): According to the actual situation, select the design parameters, which are a subset of the variable assembly-structure parameters in step S2), including the structure parameters , assembly parameters ;

[0024] S3.2): The design target is determined as the loss of connection structural stiffness under maximum load Friction work between the front and rear centering surfaces , used to normalize the maximum friction work , is the maximum friction work that may be generated by a single slip of the interface, selected based on engineering experience and actual conditions, and is a function of the structure and assembly parameters; while the friction work Then through the formula Calculate, where is the average shear stress on the cylinder, is the average slip distance of the interface, S is the cylindrical area; the standardized friction work of the front and rear centering surfaces is obtained by division. , the design objective function is constructed as , It is a weight coefficient for robust design determined based on engineering experience and actual conditions;

[0025] S3.3): The constraint condition is the maximum contact stress of each interface With tie rod structure Both are less than the material yield stress 1.5 times, and the maximum contact stress Subscript i So 1~n Variables represent different interface numbers;

[0026] S3.4): Combine the design parameters of S3.1), the design objective function of S3.2) and the constraints of S3.3) to form a robust design optimization function, expressed as:

[0027] .

[0028] Preferably, the step S4) specifically includes:

[0029] S4.1): According to the actual situation, considering the computational efficiency and global convergence, the genetic algorithm is selected as the optimization algorithm;

[0030] S4.2): The finite element model of the sleeve gear connection structure in S2) and the robust design optimization function in S3) are introduced into the optimization algorithm. According to the optimization algorithm process, the optimal solution is obtained by iterative screening. The main process is to determine the design parameters required for input according to the optimization algorithm; and bring the parameters into the sleeve gear connection structure model for calculation to obtain relevant physical quantities; when the constraints are met, the optimization target value is calculated by bringing the relevant physical quantities into the robust design optimization function; and the optimal solution is obtained by screening based on the judgment and termination conditions.

[0031] Preferably, the step S5) specifically includes:

[0032] S5.1): Structural design is performed according to the optimal solution of structural parameters. Adjustments in structural parameters include but are not limited to adjusting the structural transition mode and the thread size of the large nut according to the thickness and outer diameter of the tie rod; adjusting the structure of the outer shaft of the sleeve gear and the position of the relevant clamping structure according to the bearing position; structural design of the clamping parts to meet the stiffness requirements, etc.;

[0033] S5.2): Adjust the structural design according to the optimal solution of assembly parameters, that is, select the shaft hole tolerance matching parameters according to the optimal solution of centering surface tightness, so as to form a complete robust design scheme for the sleeve gear connection structure.

[0034] Compared with the prior art, the advantages of the present invention are:

[0035] The present invention proposes a robust design method for the sleeve-tooth connection structure of an aircraft engine high-pressure cantilever rotor system, so as to suppress interface damage and stiffness loss of the sleeve-tooth connection structure under external load, thereby reducing the influence of contact state changes of the sleeve-tooth connection structure on the dynamic characteristics of the rotor system and improving the robustness of the rotor system. The robust design of the aircraft engine cantilever rotor using the method proposed in the present invention can suppress the large vibration amplitude and dispersion of the rotor system caused by the unrobust sleeve-tooth connection structure from a design perspective, filling the gap in the robust design of the existing sleeve-tooth connection structure, ensuring the reliability and safety of the aircraft engine, avoiding repeated iterative design, achieving cost reduction and efficiency improvement, and having important engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a flow chart of the robust design method of the sleeve-tooth connection structure of the high-pressure cantilever rotor system of an aircraft engine.

[0037] Figure 2 It is a schematic diagram of the structure of a typical sleeve-tooth-connected cantilever rotor system of an aircraft engine.

[0038] Figure 3 This is a schematic diagram of a typical disc-shaft sleeve gear connection structure.

[0039] Figure 4 It is a schematic diagram of the dynamic model of the high-pressure cantilever rotor system.

[0040] Figure 5 It is a schematic diagram of the strain energy ratio of the sleeve-tooth connection structure of the third-order bending vibration mode of the high-voltage cantilever rotor.

[0041] Figure 6 It is a schematic diagram of the finite element model of the disc-shaft sleeve gear connection structure considering the interface contact state.

[0042] Figure 7 It is a schematic diagram of the stiffness loss of the sleeve gear connection structure under different structural-assembly parameters.

[0043] Figure 8It is a schematic diagram of the genetic algorithm optimization process.

[0044] Fig. 9 Schematic diagram of the robust design of the disc-sleeve tooth connection structure for the high-pressure cantilever rotor system.

[0045] Fig.10 It is a schematic diagram of the stiffness loss of the front and rear sleeve gear connection structure in a robust design.

[0046] Figure 2 middle:

[0047] 2a. Front pivot bearing, 2b. Front journal, 2c. First stage compressor disk, 2d. Second stage centrifugal compressor disk, 2e. First high pressure shaft, 2f. Rear pivot bearing, 2g. Sleeve gear connection structure, 2h. First turbine disk.

[0048] Figure 3 middle:

[0049] 3a. The second high-pressure shaft, 3b. The rear fulcrum bearing, 3c. The clamping structure, 3d. The positioning end face, 3e. The front centering face, 3f. The spline teeth, 3g. The outer shaft with sleeve gears, 3h. The inner shaft with sleeve gears, 3i. The rear centering face, 3j. The second turbine disk, 3k. The pull rod of the high-pressure shaft, 3l. The clamping face of the nut, 3m. The large nut. DETAILED DESCRIPTION

[0050] In order to make the technical scheme and key points of the present invention clearer, the technical scheme of the present invention will be further described in detail with reference to the accompanying drawings and specific examples. The specific embodiments described herein are only some embodiments of the present invention and are not intended to limit the present invention. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

[0051] Figure 1 This is a flow chart of the robust design method for the sleeve gear connection structure of the aircraft engine high pressure cantilever rotor system proposed by the present invention. Figure 2-Figure 10 The present invention is described in further detail. Figure 2 The schematic diagram of a typical aircraft engine high-pressure cantilever rotor system is shown in Figure 2. The sleeve-tooth connection cantilever rotor system is mainly composed of the front journal 2b, the first-stage compressor disc 2c, the second-stage centrifugal compressor disc 2d, the first high-pressure shaft 2e, and the first turbine disc 2h. It is cantilevered on the front pivot bearing 2a and the rear pivot bearing 2f, and the turbine disc and the high-pressure shaft are connected by the sleeve-tooth connection structure 2g. Figure 3As shown, the sleeve gear connection structure is a double-layer shaft structure mainly used to connect the second high-pressure shaft 3a and the second turbine disk 3j, which are the sleeve gear outer shaft 3g and the sleeve gear inner shaft 3h respectively. The torque is mainly transmitted through the spline teeth 3f, the positioning end face 3d is axially positioned, and the front centering surface 3e and the rear centering surface 3i are centered. The large nut 3m is tightened to make the high-pressure shaft tie rod 3k tensilely deformed, and the axial clamping force is applied through the nut clamping surface 3l to clamp the rear fulcrum bearing 3b, the clamping structure 3c and the second turbine disk 3j and other related parts. The sleeve gear connection structure with poor robustness will cause stiffness loss and interface damage due to the change of its interface contact state under the action of external loads, which seriously affects the dynamic characteristics of the high-pressure cantilever rotor system. Therefore, the robust design method of the sleeve gear connection structure of the aircraft engine high-pressure cantilever rotor system proposed in the present invention is adopted to improve the robustness of the sleeve gear connection structure:

[0052] Step S1): According to Figure 2 The typical aero-engine typical sleeve gear connection cantilever rotor system structure shown in the figure simplifies the actual complex structure on the basis of ensuring the mechanical properties, and uses finite element analysis software to establish Figure 4 The dynamic model of the high-pressure cantilever rotor system is shown in Figure 1. At the front and rear bearing positions, spring units are used to simulate the lateral symmetric elastic support stiffness, k 1yy =k 1zz =2e7N / m and k 2yy =k 2zz =5e7N / m; Considering the gyroscopic torque effect, the QRDAMP method is used to calculate the first three modes and strain energy at the maximum speed. The first two quasi-rigid vibration mode modal strain energy accounts for 7% and 8.2%, which is less than 10%; the third-order bending vibration mode modal strain energy accounts for, Figure 5 As shown, the strain energy of the inner and outer shafts of the sleeve gear is 6.32% and 23.76%, that is, the strain energy of the sleeve gear connection structure accounts for 30.08%, which exceeds 20%. According to the set evaluation criteria, robust design is required.

[0053] Step S2): After evaluation in step S1), the robustness of the sleeve gear structure of the cantilever rotor system does not meet the requirements, and further robust design of the sleeve gear connection structure is carried out. Figure 3 The disc-shaft sleeve gear connection structure shown in the figure is established through reasonable simplification. Figure 6 The finite element model of the disc-shaft sleeve gear connection structure considering the interface contact state is shown. The model includes multiple contact unit interfaces such as the positioning end face, the front centering face, the rear centering face and the nut clamping face. The basic parameters of the contact interface are set to 0.2 for the friction coefficient and 1 for the penalty function stiffness. Based on the adjustable parameter function of the finite element software, the assembly-structure parameters are set to a variable state. The variable assembly parameters include: the tightness of the front and rear centering faces, the preload; the structural parameters include: the diameter and thickness of the high-pressure shaft tie rod, the axial position of the bearing constraint, the stiffness of the clamping structure, etc.

[0054] The boundary conditions of the model are also Figure 6 As shown in the figure, full constraint is applied to the front end of the shaft, radial constraint is applied to the bearing position, the speed is given to be 25000RPM, and the bending moment is applied at the turbine disk rim from 100 to 6000 N·m. Under the above conditions, the angular stiffness of 5.2×10 6 N·m / rad; adjust 3 groups of parameters, mainly adjust the preload, parameter 1 preload is 2 tons, parameter 2 preload is 10 tons, parameter 3 preload is 12 tons, and parameter 1 is the original solution. According to the model and the public announcement, the calculation is Figure 7 The change of angular stiffness loss under different parameters is shown in the figure. The above calculation process verifies that the model has the function of adjustable parameters.

[0055] Step S3): According to the actual situation, all the above adjustable assembly and structural parameters are set as design parameters. In the design target structure, the friction work of the front and rear centering surfaces is The required centering surface area is 1705mm 2 and 1464mm 2 The weight coefficient of the objective function Set as , used for standardized is 1000mJ. In terms of constraint setting, this case selects GH4169 alloy at 650℃, that is, the robust optimization function is expressed as:

[0056]

[0057] Stiffness loss , shear stress , slip , each interface contact stress and rod stress Obtained from model calculation.

[0058] Step S4): Due to the complexity of parameter changes, considering the computational efficiency and global convergence, the genetic algorithm is selected as the optimization algorithm for this case. The genetic algorithm flow chart is as follows: Figure 8 As shown. The structure and assembly parameters are initialized randomly. According to step S3), the design objective function is calculated based on the simulation analysis model of the gear connection structure with variable parameters. , and obtain the fitness function , is an arbitrarily small quantity, avoiding division by zero, and taking the constraint into account in the form of a penalty function. The roulette wheel method is used for selection, according to the fitness value Determine the probability of an individual being selected; use uniform crossover bionics to generate offspring; use high-speed mutation to operate on offspring individuals to obtain a new generation of design parameters; use this new generation to calculate the fitness function , the function residual satisfies 10 -3 The result is output. If the requirements are not met, it is repeated. After the above optimization process, the optimal solution of each structure-assembly parameter is calculated, that is, the robust design result. The optimal solution structural parameters are: the diameter of the high-pressure shaft tie rod is 97mm, the tie rod thickness is 1.2mm, the axial constraint position of the bearing is adjusted backward by 45.33mm, and the clamping structure stiffness is 1.2e8N / m; the optimal assembly parameter preload is 16 tons, and the front and rear centering surface tightness is 0.065mm and 0.07mm respectively.

[0059] Step S5): Structural design is performed based on the obtained optimized structure-assembly parameters. The adjustments in this case mainly include the change of the outer diameter of the nut thread from M102 to M100 due to the reduction of the pull rod diameter and outer diameter; to meet the stiffness of the elastic clamp block of 1.2e8N / m, it is changed to a gate-shaped design; because the optimal solution for the axial position of the bearing is located above the outer shaft of the gear, the outer diameter of the bearing and the clamping method are slightly changed. In terms of assembly parameters, the preload is determined to be 16 tons, and the tightness of the front and rear centering surfaces is 0.065mm and 0.07mm. According to the assembly situation, the matching relationship of the front and rear centering surfaces of the inner and outer shafts of the gear in this case is determined to be H6 / p7.

[0060] After the above structural process, the final Fig. 9 The robust design method of the typical high-pressure cantilever rotor system tooth connection structure is shown in Figure 1. Fig.10 As shown in the figure, compared with the original solution (parameter 1), the robust design solution has a significant reduction in stiffness loss, with a maximum reduction of 36%; in addition, the friction work of the front centering surface is reduced from 360mJ to 215mJ, and the friction work of the rear centering surface is reduced from 447mJ to 156mJ. The above results show that:

[0061] 1) The robust design method for the sleeve-tooth connection structure of the high-pressure cantilever rotor system of an aircraft engine proposed in the present invention can be used to evaluate the robustness of the sleeve-tooth connection structure of the existing high-pressure cantilever rotor system, and preliminarily determine whether further robust design optimization is needed, thereby reducing design costs and improving design efficiency.

[0062] 2) By utilizing the robust design method for the sleeve-tooth connection structure of the aircraft engine high-pressure cantilever rotor system proposed in the present invention, it is possible to carry out optimization design of the structure-assembly parameters for the sleeve-tooth connection structure design scheme with poor robustness during the aircraft engine rotor design stage, thereby avoiding the frequent occurrence of connection structure stiffness loss and interface damage caused by the poor robustness of the sleeve-tooth connection structure during use; reducing the influence of changes in the interface contact state on the dynamic characteristics of the high-pressure cantilever rotor system; and improving the robustness of the rotor system, thereby ensuring the reliability and safety of the entire engine, which has important engineering application value.

[0063] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A robust design method for the sleeve-tooth connection structure of a high-pressure cantilever rotor system of an aircraft engine, characterized in that: The following steps are involved: S1): Carry out modal analysis on the high-pressure cantilever rotor system of the aircraft engine, and based on the strain energy distribution of the high-pressure cantilever rotor, conduct a robustness assessment on the sleeve-tooth connection structure to determine whether a robust design is needed; Step S1) specifically includes: S1.1): Use finite element analysis software to establish a dynamic model of the aircraft engine high pressure cantilever rotor system; S1.2): For the dynamic model of the high-voltage cantilever rotor system, considering the gyroscopic torque effect, calculate the first three modes and strain energy at the maximum speed; S1.3): If the modal strain energy of the first two quasi-rigid vibration modes accounts for All are greater than 10% or the third-order bending vibration mode modal strain energy ratio If it is greater than 20%, it is necessary to continue to carry out robust design of the sleeve tooth connection structure; S2): Establish a finite element model of the sleeve-tooth connection structure with variable assembly-structure parameters and considering the interface contact state; S3): By calculating the finite element model of the sleeve gear connection structure in S2), and according to the interface contact characteristics and stiffness characteristics of the sleeve gear connection structure under external load, the design parameters, design objectives and constraints are determined to form a robust design optimization function; S4): Select an optimization algorithm, based on the finite element model of the gear connection structure in S2) and the robust design optimization function in S3), to screen the optimal solution of assembly-structure parameters; S5): The optimal solution of assembly-structure parameters is used to form a robust design scheme for the sleeve tooth connection structure through structural design.

2. The robust design method for the sleeve-tooth connection structure of the high-pressure cantilever rotor system of an aircraft engine according to claim 1 is characterized in that: The step S2) specifically includes: S2.1): Establish a finite element model of the disc-shaft sleeve gear connection structure considering the interface contact state. The model includes four mating surfaces with three-dimensional contact elements, namely the positioning end surface, the front centering surface, the rear centering surface and the nut pressing surface; S2.2): Based on the parameter adjustable function of the finite element analysis software, the assembly-structure parameters are set to a variable state; S2.3): Select the restraint position, apply the centrifugal load, and apply the bending moment at the turbine disk rim; S2.4): Simulate and calculate the stiffness loss under specific external loads, structure and assembly parameters , verifying that the finite element model of the sleeve tooth connection structure has the function of adjustable parameters.

3. The robust design method for the sleeve-tooth connection structure of the high-pressure cantilever rotor system of an aircraft engine according to claim 1, characterized in that: The step S3) specifically includes: S3.1): According to the actual situation, select the design parameters, which are a subset of the variable assembly-structure parameters in step S2), including the structure parameters , assembly parameters ; S3.2): The design target is determined as the loss of connection structural stiffness under maximum load Friction work between the front and rear centering surfaces , using the maximum friction work , standardized to obtain the standardized friction work of the front and rear centering surfaces , the design objective function is constructed as , It is a weight coefficient for robust design determined based on engineering experience and actual conditions; S3.3): The constraint condition is the maximum contact stress of each interface With tie rod structure Both are less than the material yield stress 1.5 times of the maximum contact stress Subscript i So 1~n Variables represent different interface numbers; S3.4): Combine the design parameters of S3.1), the design objective function of S3.2) and the constraints of S3.3) to form a robust design optimization function, expressed as: 。 4. The robust design method for the sleeve-tooth connection structure of the aircraft engine high-pressure cantilever rotor system according to claim 1 is characterized in that: The step S4) specifically includes: S4.1): According to the actual situation, considering the computational efficiency and global convergence, the genetic algorithm is selected as the optimization algorithm; S4.2): The finite element model of the sleeve gear connection structure in S2) and the robust design optimization function in S3) are introduced into the optimization algorithm, and the optimal solution is obtained by iterative screening according to the optimization algorithm process.

5. The robust design method for the sleeve-tooth connection structure of the aircraft engine high-pressure cantilever rotor system according to claim 1 is characterized in that: The step S5) specifically includes: S5.1): Perform structural design based on the optimal solution of structural parameters; S5.2): Adjust the structural design according to the optimal solution of assembly parameters, that is, select the shaft hole tolerance matching parameters according to the optimal solution of centering surface tightness, so as to form a complete robust design scheme for the sleeve gear connection structure.

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