Method for evaluating mechanical characteristics of aero-engine force bearing frame

Abstract

This application belongs to the field of aero-engines, and specifically relates to a method for evaluating the mechanical properties of aero-engine load-bearing frames. The method includes: S10, performing parametric modeling of the load-bearing frame structural scheme to obtain a finite element structural model; S20, performing simulation calculations of the mechanical property parameters of the load-bearing frame based on the finite element structural model to obtain mechanical property results; S30, performing a comprehensive score of the mechanical property parameters of the load-bearing frame based on the mechanical property results. The mechanical property evaluation method for aero-engine load-bearing frames of this application can realize the evaluation of the mechanical properties of load-bearing frame structural schemes, complete the comparative analysis of load-bearing frame structural schemes, and determine the direction of optimization design.

Description

Technical Field

[0001] This application belongs to the field of aero-engines, and specifically relates to a method for evaluating the mechanical properties of aero-engine load-bearing frames. Background Technology

[0002] The load-bearing frame is the most critical load-bearing structure of an aero-engine. Its main function is to provide support and constraint for the engine rotor and stators and accessories, and to transfer engine thrust and other loads to the aircraft through the mounting joints. The design of the load-bearing frame is constrained by the rotor support points, mains ducts, cooling air passages, and lubricating oil passages. It is necessary to improve the structural load-bearing capacity and reduce weight within a limited space. Moreover, it is necessary to carefully consider the complex and variable load environment such as rotor rotation, aerodynamic excitation, and temperature field, and to reduce bearing damage and the transmission of harmful vibrations to the aircraft. Therefore, the mechanical properties of the load-bearing frame need to be rigorously tested during the aero-engine development process.

[0003] Currently, the design of newly developed aero-engine load-bearing frame structures typically references existing models, conducting detailed designs based on principles such as strength verification, resonance avoidance, and weight reduction. However, this approach no longer meets the demands of increasingly lightweight, heavy-duty load-bearing frames for high-performance, high-reliability, and long-life engines. To improve the design level of aero-engine load-bearing frames, it is necessary to evaluate whether the load-bearing capacity, thermal deformation resistance, and vibration transmission attenuation of the load-bearing frame meet design requirements during the engine design phase.

[0004] The shortcomings of existing methods for evaluating the mechanical properties of aero-engine load-bearing frames are:

[0005] 1. The mechanical properties of load-bearing frames are usually related to the location of the structure being measured. Existing methods do not specify how the structural location should be selected, which leads to differences in the mechanical property parameters calculated by different overall structural designers, and may result in errors in the assessment of the mechanical properties of load-bearing frames.

[0006] 2. The calculation results of the mechanical properties of different load-bearing frame structural schemes can only be qualitatively compared to obtain advantages and disadvantages. There is a lack of a unified method for evaluating mechanical property parameters, which makes it impossible for the overall structural designer to determine the optimal scheme that balances various indicators among a large number of structural schemes.

[0007] Therefore, there is an urgent need for a technical solution to overcome or mitigate at least one of the aforementioned defects in the existing technology. Summary of the Invention

[0008] The purpose of this application is to provide a method for evaluating the mechanical properties of the load-bearing frame of an aero-engine, in order to solve at least one problem existing in the prior art.

[0009] The technical solution of this application is:

[0010] A method for evaluating the mechanical properties of aero-engine load-bearing frames includes:

[0011] S10. Perform parametric modeling of the load-bearing frame structure scheme to obtain the finite element structural model, including:

[0012] S11. Obtain the load-bearing frame structure scheme and extract the geometric features of the force transmission structure in the load-bearing frame structure scheme;

[0013] S12. Extract the geometric parameters of the structural elements based on the geometric features, and construct a parameterized structural model of the load-bearing frame structure scheme;

[0014] S13. Construct a finite element structural model of the load-bearing frame structure scheme based on the parametric structural model;

[0015] S14. Encode the structural interfaces in the finite element structural model that participate in the simulation calculation of the mechanical property parameters of the load-bearing frame to obtain the structural interface coding nodes.

[0016] S20. Based on the finite element structural model, perform simulation calculations of the mechanical property parameters of the load-bearing frame to obtain the mechanical property results;

[0017] S30. Based on the mechanical property results, a comprehensive score is given for the mechanical property parameters of the load-bearing frame.

[0018] In at least one embodiment of this application, in S13, constructing a finite element structural model of the load-bearing frame structural scheme based on the parameterized structural model includes:

[0019] The parameterized structure model is meshed;

[0020] Configure material properties for the parameterized structural model;

[0021] In the parametric structural model, fixed constraint boundary conditions are applied to the front and rear mounting sides of the outer bypass casing.

[0022] In at least one embodiment of this application, in S14, the structural interfaces participating in the simulation calculation of the mechanical property parameters of the load-bearing frame in the finite element structural model are encoded to obtain structural interface encoding nodes, including:

[0023] The inner ring surface of the bearing housing is encoded to obtain the encoded nodes of the inner ring surface of the bearing housing;

[0024] The annular surfaces of the front and rear mounting edges of the outer bypass casing are encoded to obtain the mounting edge annular surface encoding nodes.

[0025] In at least one embodiment of this application, in step S20, the mechanical property parameters of the load-bearing frame are simulated and calculated based on the finite element structural model to obtain the mechanical property results, including:

[0026] S21. Based on the finite element structural model, perform simulation calculations of the stiffness characteristic parameters of the load-bearing frame to obtain the stiffness characteristic results;

[0027] S22. Based on the finite element structural model, perform simulation calculations of the constraint modal characteristic parameters of the load-bearing frame to obtain the constraint modal characteristic results;

[0028] S23. Based on the finite element structural model, perform simulation calculations of the vibration transmission characteristic parameters of the load-bearing frame to obtain the vibration transmission characteristic results;

[0029] S24. Based on the finite element structural model, perform simulation calculations of the thermal deformation characteristic parameters of the load-bearing frame to obtain the thermal deformation characteristic results.

[0030] In at least one embodiment of this application, in step S21, the stiffness characteristic parameters of the load-bearing frame are simulated and calculated based on the finite element structural model to obtain stiffness characteristic results, including:

[0031] Based on the finite element structural model, the static stiffness characteristic parameters of the load-bearing frame are simulated and calculated to obtain the static stiffness array:

[0032] ;

[0033] Among them, K s,i For static stiffness arrays, F s To apply a static, uniformly distributed force to the coded nodes on the inner ring surface of the bearing housing, u i Let be the deformation amplitude of the coded node on the surface of the i-th bearing housing inner ring under the first simulation condition;

[0034] Based on the finite element structural model, the dynamic stiffness characteristic parameters of the load-bearing frame are simulated and calculated to obtain the dynamic stiffness matrix:

[0035] ;

[0036] in, Let A be the dynamic stiffness matrix at the excitation frequency f0. d y represents the amplitude of the uniformly distributed force with varying vibration frequency applied to the coding nodes on the inner ring surface of the bearing housing. i This represents the deformation amplitude of the coded node on the inner ring surface of the i-th bearing housing under the second simulation condition.

[0037] In at least one embodiment of this application, in step S22, the constraint modal characteristic parameters of the load-bearing frame are simulated and calculated based on the finite element structural model to obtain the constraint modal characteristic results, including:

[0038] Based on the finite element structural model, simulation calculations were performed on the constrained modal characteristic parameters of the load-bearing frame. The constrained modal frequencies of the load-bearing frame within the rotor rotation frequency and aerodynamic excitation frequency were extracted to obtain the constrained modal frequency array f. n , where n is the order.

[0039] In at least one embodiment of this application, in step S23, the vibration transmission characteristic parameters of the load-bearing frame are simulated and calculated based on the finite element structural model to obtain the vibration transmission characteristic results, including:

[0040] Based on the finite element structural model, the vibration transmission characteristic parameters of the load-bearing frame are simulated and calculated to obtain the vibration displacement transmission matrix:

[0041] ;

[0042] in, p is the vibration displacement transfer matrix. i Let q be the vibration displacement amplitude of the coded node on the inner ring surface of the i-th bearing housing. i Let be the vibration displacement amplitude of the i-th mounting edge annular surface coding node.

[0043] In at least one embodiment of this application, in step S24, the thermal deformation characteristic parameters of the load-bearing frame are simulated and calculated based on the finite element structural model to obtain the thermal deformation characteristic results, including:

[0044] Based on the finite element structural model, the thermal deformation characteristic parameters of the load-bearing frame are simulated and calculated. The thermal deformation displacements at the coded nodes on the inner ring surface of the bearing housing and the coded nodes on the ring surface of the mounting edge are extracted to obtain the thermal deformation displacement array X. i .

[0045] In at least one embodiment of this application, in step S30, a comprehensive score of the mechanical property parameters of the load-bearing frame is performed based on the mechanical property results, including:

[0046] Calculate the static stiffness fraction based on the static stiffness array:

[0047] ;

[0048] ;

[0049] Among them, R s,i R represents the static stiffness fraction of the array elements for different static stiffnesses. s K represents the total static stiffness fraction. bearing For the stiffness of the fulcrum bearing;

[0050] Calculate the dynamic stiffness fraction based on the dynamic stiffness matrix:

[0051] ;

[0052] ;

[0053] Among them, R d,i R represents the dynamic stiffness fractions of different dynamic stiffness matrix elements. d This represents the total score for dynamic stiffness.

[0054] Calculate the constraint mode score based on the constraint mode frequency array:

[0055] ;

[0056] Among them, R modal To constrain modal scores, f k For the constrained modal frequency array f n The frequency of the most recent constraint mode is the frequency of the excitation frequency f0.

[0057] Calculate the vibration transmission fraction based on the vibration displacement transmission matrix:

[0058] ;

[0059] Among them, R trans For the vibration transmission fraction, Vibration displacement transfer matrix The average;

[0060] Calculate the thermal deformation fraction based on the thermal deformation displacement array:

[0061] ;

[0062] ;

[0063] Among them, R tempi R represents the thermal deformation fraction of different thermal deformation displacement array elements. temp L0 represents the total thermal deformation fraction, and L0 represents the original geometric dimensions of the structure.

[0064] Calculate the total score for the mechanical properties of the load-bearing frame:

[0065] ;

[0066] Where R is the total score of the mechanical properties of the load-bearing frame, and α1, α2, α3, α4, and α5 are weights.

[0067] The invention has at least the following beneficial technical effects:

[0068] The mechanical property evaluation method for the load-bearing frame of an aero-engine disclosed in this application can evaluate the mechanical properties of load-bearing frame structural schemes, and complete the comparative analysis of load-bearing frame structural schemes and determine the direction of optimization design. Attached Figure Description

[0069] Figure 1 This is a flowchart of a method for evaluating the mechanical properties of an aero-engine load-bearing frame according to one embodiment of this application;

[0070] Figure 2 This is a schematic diagram of the intermediate casing load-bearing frame structure of one embodiment of this application;

[0071] Figure 3 This is a schematic diagram of a turbine load-bearing frame structure according to one embodiment of this application;

[0072] Figure 4 This is a schematic diagram of the coded nodes on the inner ring surface of the bearing housing according to one embodiment of this application;

[0073] Figure 5 This is a schematic diagram of the mounting edge annular surface coding node according to one embodiment of this application. Detailed Implementation

[0074] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0075] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this application.

[0076] The following is in conjunction with the appendix Figures 1 to 5 This application will be described in further detail.

[0077] This application provides a method for evaluating the mechanical properties of aero-engine load-bearing frames, such as... Figure 1 As shown, it includes the following steps:

[0078] S10. Perform parametric modeling of the load-bearing frame structure scheme to obtain the finite element structure model;

[0079] S20. Based on the finite element structural model, perform simulation calculations of the mechanical property parameters of the load-bearing frame to obtain the mechanical property results;

[0080] S30. Based on the mechanical property results, conduct a comprehensive evaluation of the mechanical property parameters of the load-bearing frame.

[0081] The mechanical property evaluation method for the load-bearing frame of the aero-engine of this application firstly involves, in step S10, the geometric features of the main force transmission structure are extracted based on the load-bearing frame structure scheme obtained from the aero-engine design scheme, a parametric structural model is constructed, a finite element structural model for mechanical property calculation is constructed using finite element software, and the structural interfaces that need to be evaluated for mechanical properties are encoded, thus completing the parametric modeling of the load-bearing frame structure scheme with structural interface encoding nodes.

[0082] Preferably, in S10, parametric modeling of the load-bearing frame structure is performed to obtain a finite element structural model, specifically including the following processes:

[0083] S11. Obtain the load-bearing frame structure scheme and extract the geometric features of the force transmission structure in the load-bearing frame structure scheme;

[0084] S12. Extract the geometric parameters of the structural elements based on the geometric features, and construct a parametric structural model of the load-bearing frame structure scheme;

[0085] S13. Construct a finite element structural model of the load-bearing frame structure scheme based on the parametric structural model;

[0086] S14. Encode the structural interfaces involved in the simulation calculation of the mechanical property parameters of the load-bearing frame in the finite element structural model to obtain the structural interface coding nodes.

[0087] In one embodiment of this application, a structural scheme for the intermediate casing load-bearing frame is obtained, such as... Figure 2 As shown, the intermediate casing load-bearing frame includes an outer bypass casing 1, a support plate 2, a diverter ring 3, an inner load-bearing ring 4, a load-bearing cone shell 5, and a bearing seat 6. The outer bypass casing 1 of the intermediate casing load-bearing frame has a front mounting edge 11 and a rear mounting edge 12. The load-bearing cone shell 5 includes a front load-bearing cone shell and a rear load-bearing cone shell. The bearing seat 6 includes a front bearing seat and a rear bearing seat.

[0088] In another embodiment of this application, a turbine load-bearing frame structure scheme is obtained, such as... Figure 3As shown, the turbine load-bearing frame includes an outer bypass casing 1, a tie rod 7, an outer load-bearing ring 8, a support plate 2, an inner load-bearing ring 4, a load-bearing cone shell 5, and a bearing seat 6.

[0089] In S11, based on the function of the bearing frame of the aero-engine constraining and supporting the rotor, the force transmission path of the rotor support reaction force from the pivot bearing seat to the outer bypass casing is obtained through static analysis. The force transmission path is extracted through the force transmission structure related to the bearing frame, and the geometric features related to the mechanical properties in the force transmission structure are retained.

[0090] In S12, the force transmission structure is simplified into a general structural element based on geometric features, and the geometric parameters of the structural element are extracted, such as the length and thickness of the force transmission structure along the force transmission path, the included angle of the rotor axis, etc., and a parametric structural model of the load-bearing frame structure scheme is constructed based on the geometric parameters.

[0091] In S13, the finite element structural model of the load-bearing frame structure scheme is constructed based on the parametric structural model, including:

[0092] Mesh the parametric structure model;

[0093] Configure material properties for the parametric structural model;

[0094] In the parametric structural model, fixed constraint boundary conditions are applied to the front and rear mounting sides of the outer bypass casing.

[0095] In this embodiment, the parametric structural model is meshed using finite element software, and material properties, including density, elastic modulus, thermal conductivity, and coefficient of thermal expansion, are configured. Fixed constraint boundary conditions are applied to the front and rear mounting edges of the outer casing to obtain the finite element structural model of the load-bearing frame structure.

[0096] In S14, nodal forces need to be applied to the inner ring surface of the bearing housing in the finite element structural model to participate in the subsequent simulation calculations of stiffness characteristics and vibration transmission characteristics. The inner ring surface of the bearing housing is encoded to obtain the encoded nodes of the inner ring surface, such as... Figure 4 As shown. Fixed constraint boundary conditions are applied to the annular surfaces of the front and rear mounting edges of the outer bypass casing in the finite element structural model. These conditions are then used in subsequent simulation calculations of stiffness characteristics, constraint modal characteristics, vibration transmission characteristics, and thermal deformation characteristics. The annular surfaces of the front and rear mounting edges of the outer bypass casing are encoded to obtain the encoded nodes of the mounting edge annular surfaces, as shown below. Figure 5 As shown.

[0097] In the mechanical property evaluation method for the load-bearing frame of the aero-engine of this application, in S20, the finite element structural model is simulated and calculated based on the load characteristics of the load-bearing frame of the aero-engine, including rotor rotation load, aerodynamic load and thermal load, and the mechanical properties between the input and output structural interfaces are extracted to form an array or matrix of mechanical property parameters.

[0098] Preferably, in S20, the mechanical property parameters of the load-bearing frame are simulated and calculated based on the finite element structural model to obtain the mechanical property results, including:

[0099] S21. Based on the finite element structural model, perform simulation calculations of the stiffness characteristic parameters of the load-bearing frame to obtain the stiffness characteristic results;

[0100] S22. Based on the finite element structural model, perform simulation calculations of the constraint modal characteristic parameters of the load-bearing frame to obtain the constraint modal characteristic results;

[0101] S23. Based on the finite element structural model, perform simulation calculations of the vibration transmission characteristic parameters of the load-bearing frame to obtain the vibration transmission characteristic results;

[0102] S24. Based on the finite element structural model, perform simulation calculations of the thermal deformation characteristic parameters of the load-bearing frame to obtain the thermal deformation characteristic results.

[0103] In S21, the load-bearing frame is subjected to dynamic loads at the support points transmitted from the rotor bearings. The ability of the load-bearing frame to resist static and dynamic deformation is evaluated. The static stiffness and dynamic stiffness from the coded node on the inner ring surface of the bearing housing to the coded node on the ring surface of the mounting edge are simulated and calculated to obtain the static stiffness array and the dynamic stiffness matrix.

[0104] In this embodiment, when simulating the static stiffness characteristic parameters of the load-bearing frame, the boundary conditions and loads applied to the finite element structural model are as follows: fixed constraints are applied to the coded nodes of the annular surface of the mounting edge of the front and rear mounting edges of the outer casing, and static uniformly distributed force is applied to the coded nodes of the inner ring surface of the bearing housing.

[0105] The static stiffness characteristics of the load-bearing frame are simulated and calculated based on the finite element structural model. The deformation amplitude of the coded nodes on the inner ring surface of the bearing housing is extracted from the simulation results, and the static stiffness array of the load-bearing frame is calculated.

[0106] ;

[0107] Among them, K s,i For static stiffness arrays, F s To apply a static, uniformly distributed force to the coded nodes on the inner ring surface of the bearing housing, u i Let be the deformation amplitude of the coded node on the surface of the i-th bearing housing inner ring under the first simulation condition;

[0108] In this embodiment, when simulating the dynamic stiffness characteristic parameters of the load-bearing frame, the boundary conditions and loads applied to the finite element structural model are as follows: fixed constraints are applied to the coded nodes of the annular surface of the mounting edge of the front and rear mounting edges of the outer casing, and a uniformly distributed force with varying vibration frequency is applied to the coded nodes of the inner ring surface of the bearing housing.

[0109] The uniformly distributed force F with varying vibration frequency applied to the coding node on the inner ring surface of the bearing housing d for:

[0110] ;

[0111] Among them, A d ω represents the amplitude of the uniformly distributed force with varying vibration frequency applied to the coding nodes on the inner ring surface of the bearing housing, where ω is the angular frequency and t is the time.

[0112] The dynamic stiffness characteristics of the load-bearing frame are simulated and calculated based on the finite element structural model. The deformation amplitude of the coded nodes on the inner ring surface of the bearing housing is extracted from the simulation results. The dynamic stiffness array of the load-bearing frame at the excitation frequency f0 is calculated, and the dynamic stiffness matrix of the load-bearing frame is constructed according to different applied vibration frequencies.

[0113] ;

[0114] in, Let A be the dynamic stiffness matrix at the excitation frequency f0. d y represents the amplitude of the uniformly distributed force with varying vibration frequency applied to the coding nodes on the inner ring surface of the bearing housing. i This represents the deformation amplitude of the coded node on the inner ring surface of the i-th bearing housing under the second simulation condition.

[0115] In S22, for the deformation modes of the load-bearing frame caused by rotor rotational load and aerodynamic load excitation, during the simulation calculation of the load-bearing frame constraint modal characteristic parameters, fixed constraints are applied to the annular surface coding nodes of the mounting edges on the front and rear mounting edges of the outer casing. The finite element structural model of the load-bearing frame structure is then used to perform simulation calculations of the load-bearing frame constraint modal characteristic parameters. From the simulation results, the load-bearing frame constraint modal frequencies within the rotor rotational frequency and aerodynamic excitation frequency are extracted to obtain the constraint modal frequency array f. n , where n is the order.

[0116] In S23, to evaluate the impact of the load-bearing frame structure scheme on the attenuation of vibration transmitted from the rotor support to the outer casing, during the simulation calculation of the load-bearing frame vibration transmission characteristic parameters, fixed constraints are applied to the annular surface coding nodes of the mounting edges on the front and rear mounting edges of the outer casing. A uniformly distributed force with varying vibration frequency is applied to the inner ring surface coding nodes of the bearing housing. Based on the finite element structural model, the vibration transmission characteristic parameters of the load-bearing frame are simulated and calculated. The vibration displacement amplitudes of the inner ring surface coding nodes of the bearing housing and the annular surface coding nodes of the mounting edges are extracted from the simulation results, and the vibration displacement transmission matrix is ​​calculated.

[0117] ;

[0118] in, p is the vibration displacement transfer matrix. i Let q be the vibration displacement amplitude of the coded node on the inner ring surface of the i-th bearing housing. i Let be the vibration displacement amplitude of the i-th mounting edge annular surface coding node.

[0119] In S24, to address the impact of thermal loads on the load-bearing frame, during the simulation calculation of the load-bearing frame's thermal deformation characteristic parameters, fixed constraints are applied to the annular surface coding nodes of the mounting edges on the front and rear mounting edges of the outer culvert casing. A specific temperature field is applied to the load-bearing frame to achieve temperature load loading. Based on the finite element structural model, the thermal deformation characteristic parameters of the load-bearing frame are simulated and calculated. The thermal deformation displacements at the inner ring surface coding nodes of the bearing housing and the annular surface coding nodes of the mounting edges are extracted from the simulation results to obtain the thermal deformation displacement array X. i .

[0120] The mechanical property evaluation method for the load-bearing frame of an aero-engine disclosed in this application, in step S30, involves a comprehensive scoring of the mechanical property parameters of the load-bearing frame based on the mechanical property results, including:

[0121] The static deformation resistance of the load-bearing frame is evaluated based on the design stiffness of the support bearings. The ratio of the static stiffness of the load-bearing frame to the stiffness of the support bearings is used as the static stiffness score; a higher score indicates stronger static stiffness.

[0122] Calculate the static stiffness fraction based on the static stiffness array:

[0123] ;

[0124] ;

[0125] Among them, R s,i R represents the static stiffness fraction of the array elements for different static stiffnesses. s K represents the total static stiffness fraction. bearing For the stiffness of the fulcrum bearing;

[0126] Dynamic stiffness reflects the deformation resistance and natural frequency characteristics of a load-bearing frame. It should be evaluated based on the dynamic stiffness corresponding to the excitation frequency of the rotor rotation load acting on the load-bearing frame. The ratio of the dynamic stiffness of the load-bearing frame at the excitation frequency to the stiffness of the support bearings is taken as the dynamic stiffness score; a higher score indicates stronger dynamic stiffness.

[0127] Calculate the dynamic stiffness fraction based on the dynamic stiffness matrix:

[0128] ;

[0129] ;

[0130] Among them, R d,i R represents the dynamic stiffness fractions of different dynamic stiffness matrix elements. d This represents the total score for dynamic stiffness.

[0131] To evaluate the quality of the constraint modal characteristics of the load-bearing frame with the goal of avoiding resonance, the percentage deviation between the excitation frequency of the load-bearing frame and the most recent constraint modal frequency is used as the constraint modal score. The higher the score, the further the natural modal frequency of the load-bearing frame is from the excitation frequency, and the better its anti-resonance ability.

[0132] Calculate the constraint mode score based on the constraint mode frequency array:

[0133] ;

[0134] Among them, R modal To constrain modal scores, f k For the constrained modal frequency array f n The frequency of the most recent constraint mode is the frequency of the excitation frequency f0.

[0135] The vibration transmission characteristics are evaluated with the goal of reducing the transmission of vibration from the bearing housing to the outer casing. The difference between 1 and the average of the vibration displacement transmission matrix at the excitation frequency of the load-bearing frame under the rotor rotation load is taken as the vibration transmission score. The higher the score, the more effectively the load-bearing frame can reduce vibration transmission.

[0136] Calculate the vibration transfer fraction based on the vibration displacement transfer matrix:

[0137] ;

[0138] Among them, R trans For the vibration transmission fraction, Vibration displacement transfer matrix The average.

[0139] The thermal deformation characteristics are evaluated with the goal of reducing the thermal deformation of the load-bearing frame. The ratio of thermal deformation displacement to the original geometric dimensions of the structure is used as the thermal deformation score. The higher the score, the stronger the load-bearing frame's ability to resist thermal deformation.

[0140] Calculate the thermal deformation fraction based on the thermal deformation displacement array:

[0141] ;

[0142] ;

[0143] Among them, R tempi R represents the thermal deformation fraction of different thermal deformation displacement array elements. temp L0 represents the total thermal deformation fraction, and L0 represents the original geometric dimensions of the structure.

[0144] In order to comprehensively and accurately evaluate the mechanical properties of the load-bearing frame structure scheme and facilitate comparative analysis with existing aero-engine load-bearing frame structure schemes, a weighted average algorithm is used to obtain the total score of the mechanical properties of the load-bearing frame.

[0145] The total score for the mechanical properties of the load-bearing frame is:

[0146] ;

[0147] Where R is the total score of the mechanical properties of the load-bearing frame, and α1, α2, α3, α4, and α5 are weights.

[0148] This application presents a method for evaluating the mechanical properties of aero-engine load-bearing frames. Based on finite element modeling, it divides and encodes the structural interfaces related to the calculation of mechanical property parameters. After extracting simulation results, it constructs an array or matrix of mechanical property parameters, which yields more standardized mechanical parameter calculation results compared to traditional methods. A general comprehensive evaluation method for the mechanical properties of load-bearing frames is constructed. For each mechanical property parameter, a normalized method for calculating the mechanical property parameter score is proposed. Finally, a weighted average algorithm is used to obtain the total mechanical property score of the load-bearing frame, facilitating comparison between different load-bearing frame structural schemes and optimizing the design of load-bearing frames.

[0149] The mechanical property evaluation method for the load-bearing frame of aero-engines proposed in this application can more quickly and accurately evaluate the load-bearing frame's ability to withstand rotor rotation loads, aerodynamic loads, and thermal loads during the overall structural design phase of aero-engines. This allows for the comparative analysis of structural schemes and the determination of optimization design objectives in the early design stage, effectively avoiding the need to test the mechanical properties of the load-bearing frame through mechanical tests, significantly shortening the R&D cycle of the aero-engine load-bearing frame structure, and saving costs.

[0150] 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 evaluating the mechanical properties of aero-engine load-bearing frames, characterized in that, include: S10. Perform parametric modeling of the load-bearing frame structure scheme to obtain the finite element structural model, including: S11. Obtain the load-bearing frame structure scheme and extract the geometric features of the force transmission structure in the load-bearing frame structure scheme; S12. Extract the geometric parameters of the structural elements based on the geometric features, and construct a parameterized structural model of the load-bearing frame structure scheme; S13. Construct a finite element structural model of the load-bearing frame structure scheme based on the parametric structural model; S14. Encode the structural interfaces in the finite element structural model that participate in the simulation calculation of the mechanical property parameters of the load-bearing frame to obtain the structural interface coding nodes. S20. Based on the finite element structural model, perform simulation calculations of the mechanical property parameters of the load-bearing frame to obtain the mechanical property results; S30. Based on the mechanical property results, perform a comprehensive score of the mechanical property parameters of the load-bearing frame; In S13, the finite element structural model of the load-bearing frame structure scheme is constructed based on the parametric structural model, including: The parameterized structure model is meshed; Configure material properties for the parameterized structural model; In the parametric structural model, fixed constraint boundary conditions are applied to the front and rear mounting sides of the outer bypass casing. In S14, the structural interfaces participating in the simulation calculation of the mechanical property parameters of the load-bearing frame in the finite element structural model are encoded to obtain structural interface encoding nodes, including: The inner ring surface of the bearing housing is encoded to obtain the inner ring surface encoded nodes of the bearing housing. These inner ring surface encoded nodes are used to apply forces during simulation calculations. The annular surfaces of the front and rear mounting edges of the outer bypass casing are encoded to obtain mounting edge annular surface encoding nodes, and fixed constraints are applied to the mounting edge annular surface encoding nodes during simulation calculations.

2. The method for evaluating the mechanical properties of the load-bearing frame of an aero-engine according to claim 1, characterized in that, In S20, the mechanical property parameters of the load-bearing frame are simulated and calculated based on the finite element structural model to obtain the mechanical property results, including: S21. Based on the finite element structural model, perform simulation calculations of the stiffness characteristic parameters of the load-bearing frame to obtain the stiffness characteristic results; S22. Based on the finite element structural model, perform simulation calculations of the constraint modal characteristic parameters of the load-bearing frame to obtain the constraint modal characteristic results; S23. Based on the finite element structural model, perform simulation calculations of the vibration transmission characteristic parameters of the load-bearing frame to obtain the vibration transmission characteristic results; S24. Based on the finite element structural model, perform simulation calculations of the thermal deformation characteristic parameters of the load-bearing frame to obtain the thermal deformation characteristic results.

3. The method for evaluating the mechanical properties of the load-bearing frame of an aero-engine according to claim 2, characterized in that, In S21, the stiffness characteristic parameters of the load-bearing frame are simulated and calculated based on the finite element structural model to obtain stiffness characteristic results, including: Based on the finite element structural model, the static stiffness characteristic parameters of the load-bearing frame are simulated and calculated to obtain the static stiffness array: ； in, K s,i This is the static stiffness array. F s This refers to the static, uniformly distributed force applied to the coded nodes on the inner ring surface of the bearing housing. u i For the first simulation condition i Deformation amplitude of the coded nodes on the inner ring surface of the bearing housing; Based on the finite element structural model, the dynamic stiffness characteristic parameters of the load-bearing frame are simulated and calculated to obtain the dynamic stiffness matrix: ； in, To the excitation frequency f 0 The dynamic stiffness matrix under the following conditions A d The amplitude of the uniformly distributed force with varying vibration frequency applied to the coding nodes on the inner ring surface of the bearing housing. y i For the second simulation condition i The deformation amplitude of the coded nodes on the inner ring surface of the bearing housing.

4. The method for evaluating the mechanical properties of the load-bearing frame of an aero-engine according to claim 3, characterized in that, In S22, the constraint modal characteristic parameters of the load-bearing frame are simulated and calculated based on the finite element structural model to obtain the constraint modal characteristic results, including: Based on the finite element structural model, simulation calculations were performed on the constrained modal characteristic parameters of the load-bearing frame. The constrained modal frequencies of the load-bearing frame within the rotor rotation frequency and aerodynamic excitation frequency were extracted to obtain a constrained modal frequency array. f n , where n is the order.

5. The method for evaluating the mechanical properties of the load-bearing frame of an aero-engine according to claim 4, characterized in that, In S23, the vibration transmission characteristic parameters of the load-bearing frame are simulated and calculated based on the finite element structural model to obtain the vibration transmission characteristic results, including: Based on the finite element structural model, the vibration transmission characteristic parameters of the load-bearing frame are simulated and calculated to obtain the vibration displacement transmission matrix: ； in, φ i,j The vibration displacement transfer matrix, p i For the first i Vibration displacement amplitude of the coded nodes on the inner ring surface of the bearing housing q i For the first i The vibration displacement amplitude of each mounted edge ring surface coding node.

6. The method for evaluating the mechanical properties of the load-bearing frame of an aero-engine according to claim 5, characterized in that, In S24, the thermal deformation characteristic parameters of the load-bearing frame are simulated and calculated based on the finite element structural model to obtain the thermal deformation characteristic results, including: Based on the finite element structural model, the thermal deformation characteristic parameters of the load-bearing frame are simulated and calculated. The thermal deformation displacements at the coded nodes on the inner ring surface of the bearing housing and the coded nodes on the annular surface of the mounting edge are extracted to obtain a thermal deformation displacement array. X i .

7. The method for evaluating the mechanical properties of the load-bearing frame of an aero-engine according to claim 6, characterized in that, In S30, a comprehensive score is calculated based on the mechanical property results of the load-bearing frame, including: Calculate the static stiffness fraction based on the static stiffness array: ； ； in, R s,i This represents the static stiffness fraction of each element in the array with different static stiffness values. R s This represents the total static stiffness score. K bearing For the stiffness of the fulcrum bearing; Calculate the dynamic stiffness fraction based on the dynamic stiffness matrix: ； ； in, R d,i These represent the dynamic stiffness fractions of different dynamic stiffness matrix elements. R d This represents the total score for dynamic stiffness. Calculate the constraint mode score based on the constraint mode frequency array: ； in, R modal To constrain modal scores, f k constrained modal frequency array f n Intermediate excitation frequency f 0 Most recent first-order constrained mode frequency; Calculate the vibration transmission fraction based on the vibration displacement transmission matrix: ； in, R trans For the vibration transmission fraction, φ k Vibration displacement transfer matrix φ i,j The average; Calculate the thermal deformation fraction based on the thermal deformation displacement array: ； ； in, R tempi The thermal deformation fractions for different thermal deformation displacement array elements. R temp This represents the total thermal deformation fraction. L 0 These are the original geometric dimensions of the structure; Calculate the total score for the mechanical properties of the load-bearing frame: ； Where R is the total score of the mechanical properties of the load-bearing frame. α 1. α 2. α 3. α 4. α 5 is the weight.

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