Impeller mechanical blade vibration fatigue simulation piece and design method thereof

Abstract

The application provides a kind of impeller mechanical blade vibration fatigue simulation piece and its design method, belong to impeller mechanical blade vibration and fatigue test technical field, this simulation piece includes clamping section, the clamping section is in turn for rim section, fillet transition section and blade section; The top of blade section is provided with mass block; Mass block replaces the cut section of real blade blade; The method comprises: carrying out frequency test to the real blade to be analyzed, and obtaining the frequency characteristics of the real blade; According to the frequency characteristics of the real blade, a numerical fusion vibration analysis finite element model is constructed; A parameterized model of the structural characteristics of the blade vibration fatigue simulation piece is constructed; Search the structural characteristic parameter space of the blade vibration fatigue simulation piece, and obtain the blade vibration fatigue simulation piece closest to the vibration characteristics of the real blade. The application has wide applicability for impeller mechanical blades, has the advantages of simple design scheme, good simulation degree, small modeling and testing difficulty, etc.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of impeller mechanical blade vibration and fatigue test, and particularly relates to an impeller mechanical blade vibration fatigue simulation piece and a design method thereof. BACKGROUND

[0002] Blades are core components for energy conversion in heavy gas turbines, steam turbines and other impeller machines. In the operation process of impeller machines, there are non-uniform excitation sources in structure and flow, such as structural factors such as exhaust pipes, manufacturing and installation deviations, partial inlet, and stator wake, which can easily cause forced vibration of the blades, and high-cycle fatigue caused thereby is one of the most common failure forms of the blades. Since the blades are usually in a cantilever beam state during operation, the bending vibration is a typical vibration form caused by the transverse action of the aerodynamic load. The bending vibration fatigue problem is more significant at the transition feature between the blade body and the rim plate. If the blade is subjected to fatigue fracture, it can cause unplanned shutdown of the unit, and even secondary damage to the downstream components or even destruction of the entire unit. Therefore, it is of great significance to accurately master the vibration and fatigue characteristics of the real blade in order to ensure the stable and safe operation of the impeller machine.

[0003] In the field of blade vibration fatigue analysis, the main research methods include numerical methods and test methods. Since the numerical methods have defects such as model errors and dependence on artificial experience, the effectiveness of the results needs to be discussed; and for the test method, the test piece is a key element for studying the vibration fatigue performance of the blade, and the scheme can be divided into two categories:

[0004] 1) Directly using full-size real blades as test pieces, which can directly reflect the actual material, process and structural characteristics of the blades, but a large number of tests need to be carried out for quantitative evaluation of the vibration fatigue reliability of the blades. Since the real blades are complex to process, the cost of using a large number of real blades as vibration fatigue test pieces is extremely high; and the size of the real blades along the height direction is large, which has high requirements for experimental equipment and installation space.

[0005] 2) Using blade feature simulation pieces as test pieces. Since the fatigue problem has local characteristics, the use of feature simulation pieces to quantitatively study the detailed mechanical behavior of the local structure of the blade has attracted widespread attention from researchers in the field. The traditional feature simulation piece only represents the local characteristics of the real blade with a few geometric parameters, such as the transition fillet radius between the blade and the rim plate. In the design process, there are a large number of assumptions and simplifications, and it is difficult to reflect the actual vibration characteristics of the blade with complex modeling in the complete examination site.

[0006] Therefore, it is an urgent problem to develop an effective blade vibration simulation piece design method and design a simulation piece that can represent the typical site geometry, stress state and other characteristics of the blade. SUMMARY

[0007] In order to solve the problem that the traditional feature simulation piece is too simple and it is difficult to reflect the actual vibration characteristics of the blade with complex shape in the complete examination position, the application provides a turbomachinery blade vibration fatigue simulation piece and a design method thereof.

[0008] In order to achieve the above-mentioned purpose, the application provides the following technical scheme:

[0009] A turbomachinery blade vibration fatigue simulation piece comprises a clamping section, a mass block and a blade holding section arranged on the clamping section.

[0010] The blade holding section comprises a rim plate section, a fillet transition section and a blade body section arranged in sequence on the top of the clamping section, and a part of the original structure is cut off from one end of the blade body section away from the fillet transition section; in addition to the length of the blade body section being reduced, the blade holding section is the original structure of the real turbomachinery blade, and the mass block is arranged at one end of the blade body section away from the fillet transition section instead of the cut-off section of the real blade body.

[0011] Preferably, the clamping section adopts an integral dovetail structure, the cross-sectional shape of the mass block is rectangular, oval or airfoil-shaped, and the shape and size of the mass block are matched with the blade height of the blade body section so that the first-order bending natural frequency of the blade vibration fatigue simulation piece is the same as that of the real blade.

[0012] Preferably, the clamping section and the rim plate section and the blade body section and the mass block are connected through a fillet smooth transition, and the dynamic stress gradient at the fillet transition section is similar to that at the transition feature of the rim plate of the blade body of the real blade.

[0013] The application further provides a design method of a turbomachinery blade vibration fatigue simulation piece, comprising the following steps:

[0014] A frequency test is carried out on the real blade to be analyzed to obtain the test value f0 of the first-order bending natural frequency of the free vibration of the real blade;

[0015] The finite element model of the real blade to be analyzed is corrected through the test value f0 of the first-order bending natural frequency of the free vibration of the real blade to obtain a numerical fusion vibration analysis finite element model;

[0016] Constructing a parameterized model of the structural features of a blade vibration fatigue simulation component specifically includes: replacing the tenon in the three-dimensional geometric model of the real blade to be analyzed with a clamping segment; cutting off the blade body near the blade tip in the three-dimensional geometric model; preserving the transition features between the rim plate, the blade body and the rim plate, and the remaining blade body portion, corresponding to the rim plate segment, the rounded transition segment, and the blade body segment, respectively; adding a mass block to the top end face of the blade body segment to replace the cut-off segment; the structural feature parameters of the constructed vibration fatigue simulation component are {S}. i}, i = 1, 2, 3, ..., n, where n is the number of parameters in the blade vibration fatigue simulation component; {S i The corresponding design space is denoted as Ω;

[0017] The first-order bending natural frequency f0 of the real blade was obtained by calculation based on the finite element model of vibration analysis fused with numerical and physical parameters. b With dynamic stress field And the first-order bending natural frequency f0 of the blade vibration fatigue simulation component s With dynamic stress field Search in the design space Ω of structural characteristic parameters for a value f0. s With f0 b Same, and and The structural feature parameter combination {S} with the most similar gradient at the rounded corner transition section. i *}, based on the combination of structural characteristic parameters {S i * The final impeller blade vibration fatigue simulation part was obtained.

[0018] Preferably, the blade height parameter retained in the blade section is denoted as L, the cross-sectional shape of the mass block is rectangular, one side length of the rectangular cross-section along the blade chord direction is denoted as a, the other side length parameter is denoted as b, the height of the mass block along the blade height direction is denoted as c, and the structural characteristic parameters {S} of the constructed vibration fatigue simulation component are... i} = (L, a, b, c).

[0019] Preferably, the step of conducting frequency testing on the real blade to be analyzed to obtain the experimental value f0 of the first-order bending natural frequency of the real blade's free vibration specifically involves: for the real blade to be analyzed, measuring in physical space using the natural vibration method or resonance method to obtain the experimental value f0 of the first-order bending natural frequency of the real blade's free vibration.

[0020] Preferably, the finite element model of the actual blade to be analyzed is corrected using the experimental value f0 of the first-order bending natural frequency of the real blade's free vibration to obtain a finite element model for vibration analysis based on the fusion of data and matter, specifically including:

[0021] With the experimental value f0 of the first order bending natural frequency of the real blade free vibration as the benchmark, a set of optimal numerical parameter values applied to the numerical space finite element model calculation is selected through a parameter identification method, so that the first order bending natural frequency f0 of the blade calculated by the numerical method is consistent with f0 b The numerical parameters include tangential stiffness of the contact surface, nonlinear parameters, and material parameters.

[0022] Preferably, the parameter identification method is an iterative optimization method, and a set of optimal numerical parameter values applied to the numerical space finite element model calculation is selected through the iterative optimization method, so that the first order bending natural frequency f0 of the blade calculated by the numerical method is consistent with f0 b Specifically, f0 is consistent with f0

[0023] From a set of structural characteristic parameter values, the first order bending natural frequency f0 of the blade vibration fatigue simulation piece corresponding to the set of structural characteristic parameters is calculated by the numerical vibration analysis finite element model. s The dynamic stress field According to the gap between f0 s And f0 b The gap between f0 And f0 The gradient of the fillet transition section is adjusted to the similar degree of the value of the repeated structural characteristic parameter {S i};

[0024] After the structural characteristic parameter L is determined, the values of the mass block structural characteristic parameters a, b, and c are iteratively updated to adjust the size and mass of the mass block, and then the first order bending natural frequency f0 of the blade vibration fatigue simulation piece is adjusted. s ;

[0025] The values of (L, a, b, and c) are iteratively adjusted until f0 s Is consistent with f0 b And f0 Is consistent with f0 When the gradient of the fillet transition section 3 is similar, the iteration is ended, and the design of the blade vibration fatigue simulation piece is completed.

[0026] Preferably, the parameter identification method is an iterative optimization method, and a set of optimal numerical parameter values applied to the numerical space finite element model calculation is selected through the iterative optimization method, so that the first order bending natural frequency f0 of the blade calculated by the numerical method is consistent with f0 b Specifically, f0 is consistent with f0

[0027] A sampling method is used to collect N0 blade vibration fatigue simulation piece samples in the design space Ω of the blade vibration fatigue simulation piece structural characteristic parameters, to form a sample set Each sample corresponds to a set of structural characteristic parameters of the blade vibration fatigue simulation piece;

[0028] The sample set The input numerical fusion vibration analysis finite element model, obtains The corresponding first-order bending natural frequency set And the dynamic stress field set

[0029] The sample set The first-order bending natural frequency set And the dynamic stress field set The agent model is trained, and the mapping relationship from the structural characteristic parameters {S i} of the blade vibration fatigue simulation piece to the first-order bending natural frequency f0 s And the dynamic stress field of the blade vibration fatigue simulation piece are obtained The mapping relationship and And Namely:

[0030]

[0031] By solving the equation One or more structural characteristic parameter combinations satisfying the requirement that the first-order bending natural frequency of the blade vibration fatigue simulation piece and the real blade is the same are obtained, and then input In, the dynamic stress distribution of the corresponding structural characteristic parameter combination is obtained, from which the structural characteristic parameter combination that makes the dynamic stress gradient at the fillet transition section similar to that of the real blade is screened out, so that the blade vibration fatigue simulation piece scheme closest to the vibration characteristics of the real blade is obtained.

[0032] The impeller mechanical blade vibration fatigue simulation piece and the design method thereof provided by the application have the following beneficial effects:

[0033] In the design of the blade vibration fatigue simulation piece, the transition characteristics between the real blade body and the rim plate to be analyzed and the adjacent part of the rim plate and the part of the blade body are retained, so that the simulation of the geometric modeling near the key structural characteristics and the dynamic stress gradient is better realized. In the design of the structural characteristic scheme of the blade vibration fatigue simulation piece, the cut-off section of the blade body is replaced by a mass block, the natural frequency of the simulation piece is adjusted by changing the size or mass of the mass block, the first-order bending vibration frequency of the simulation piece is ensured to be the same as that of the real blade, and the size of the test piece in the blade height direction is shortened, which is beneficial to the development of the test. Further, the original tenon structure which has little effect on the vibration characteristics of the real blade but is complex to process is simplified, and the simulation piece is clamped and fixed by using a simpler structure, which helps to reduce the processing difficulty of the simulation piece.

[0034] The design method provided by the application realizes full interaction of numerical simulation and physical test by constructing a numerical fusion vibration analysis finite element model, taking test measured data as a benchmark, and correcting the finite element model through a parameter identification method, so that a simulation model with higher accuracy and reliability is obtained, and the precision and effect of the design method are improved. Different design schemes of the blade vibration fatigue simulation piece are represented by changing parameter values, the flexibility, repeatability and maintainability of the model are improved, and the search efficiency of the blade vibration fatigue simulation piece scheme is improved. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the application and the design scheme thereof, the drawings required by the embodiments will be briefly introduced as follows. The drawings in the following description are only part of the embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0036] Figure 1 A structural schematic diagram of the impeller mechanical blade vibration fatigue simulation piece of the embodiment 1 of the application;

[0037] Figure 2 A design method flowchart of the impeller mechanical blade vibration fatigue simulation piece of the embodiment of the application;

[0038] Figure 3 A blade vibration fatigue simulation piece structure feature parameterization scheme schematic diagram of the embodiment of the application.

[0039] Explanation of reference signs:

[0040] 1-clamping section; 2-rib section; 3-round corner transition section; 4-blade section; 5-mass block. DETAILED DESCRIPTION

[0041] In order to make those skilled in the art better understand the technical scheme of the application and can be implemented, the application will be described in detail below in conjunction with the drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical scheme of the application, and cannot be used to limit the protection scope of the application.

[0042] In the description of the application, it should be understood that the orientation or positional relationship indicated by the terms “center”, “longitudinal”, “transverse”, “length”, “width”, “thickness”, “upper”, “lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer”, “axial”, “radial”, “circumferential” and the like are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the technical scheme of the application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0043] Furthermore, the terms "first", "second", etc. are used only for descriptive purposes and should not be construed as indicating or implying relative importance. In the description of the present application, it should be noted that unless otherwise explicitly specified or limited, the terms "connected" and "linked" should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more, which will not be described here.

[0044] Embodiment 1

[0045] The present application provides a kind of impeller blade vibration fatigue simulation piece, specifically as Figure 1 As shown, including clamping section 1, mass 5 and the blade holding section being set on clamping section 1.

[0046] Specifically, the blade holding section includes rim section 2, fillet transition section 3 and blade section 4 arranged in clamping section 1 top in turn, except that the length of blade section 4 is reduced, the blade holding section is the original structure of real impeller blade, that is to say, the transition characteristics between the blade of real blade to be analyzed and rim and adjacent part of rim and part of blade are retained. The end of blade section 4 away from fillet transition section 3 is cut off part of the original structure, mass 5 replaces the cut-off section of real blade and is arranged at the end of blade section 4 away from fillet transition section 3, and the size of clamping section 1 can contain rim section 2.

[0047] The present application simplifies the original tenon structure which has little effect on the vibration characteristics of real blade but is complex in processing when designing the structural feature scheme of blade vibration fatigue simulation piece, and uses more simple structure form clamping section 1 to fix the impeller blade vibration fatigue simulation piece, which helps to reduce the processing difficulty of simulation piece.

[0048] Clamping section 1 and rim section 2, blade section 4 and mass 5 are connected through fillet smooth transition. The core of the simulation piece is to replace the cut-off section of blade with mass 5 to ensure the dangerous position, and adjust the size of mass to adjust the frequency of simulation piece.

[0049] Specifically, clamping section 1 is simplified from the original complex tenon feature which has little effect on the vibration characteristics of blade but is complex in processing. In the present embodiment, clamping section 1 adopts dovetail structure in whole, which simplifies the throat of real blade dovetail tenon, avoids the additional processing cost caused by structural mutation, and is conducive to the design and processing of corresponding tooling.

[0050] The edge plate section 2, the fillet transition section 3 and the blade section 4 all retain the geometric modeling of the real blade, which is beneficial to guarantee the geometric similarity and stress gradient similarity of the blade vibration fatigue simulation piece to the key parts of the real blade, i.e. the blade edge plate transition feature, so as to realize the effective simulation of the vibration fatigue behavior of the real blade. The part above the blade section 4 of the real blade is cut off.

[0051] The mass block 5 is used to replace the cut-off section of the real blade blade, which helps to shorten the size of the blade vibration fatigue simulation piece and adjust the natural frequency. The cross-sectional shape of the mass block 5 is rectangular, elliptical or airfoil-shaped. The height of the blade section 4 and the shape and size of the mass block 5 should be such that the first-order bending natural frequency of the blade vibration fatigue simulation piece is the same as that of the real blade, and the dynamic stress gradient at the fillet transition section 3 of the blade vibration fatigue simulation piece is similar to that at the transition feature of the real blade edge plate. The height of the blade section 4 and the shape and size of the mass block 5 can be obtained by iterative optimization method or proxy model method analysis in the design stage.

[0052] The impeller mechanical blade vibration fatigue simulation piece designed in the embodiment retains the key parts of the original real blade, i.e. the transition feature between the blade and the edge plate and the adjacent part of the edge plate and the blade, for the bending vibration fatigue problem of the blade; the mass block is designed to replace the cut-off section of the blade, which is used to adjust the natural frequency of the blade vibration fatigue simulation piece; the original tenon structure which has little effect on the vibration characteristics of the real blade but is complex to process is simplified, which shortens the size of the test piece, reduces the design and processing difficulty and realizes the effective simulation of the key structure and vibration characteristics of the real blade.

[0053] Referring to Figure 2 The present application further provides a design method of an impeller mechanical blade vibration fatigue simulation piece, which comprises the following steps:

[0054] S1: The frequency test is carried out on the real blade to be analyzed to obtain the test value f0 of the first-order bending natural frequency of the free vibration of the real blade.

[0055] For the real blade to be analyzed, the self-vibration method, resonance method and the like are used to measure the first-order bending vibration natural frequency in the physical space.

[0056] Specifically, taking the self-vibration method as an example, one real blade to be analyzed is fixed at the tenon, the force hammer knocking method which is easy to carry out is used to measure the response curve of the free decay vibration of the blade, and the test value f0 of the first-order bending natural frequency of the free vibration of the real blade is obtained through frequency spectrum analysis.

[0057] S2: Correct the finite element model of the real blade to be analyzed by the test value f0 of the first-order bending natural frequency of the free vibration of the real blade, and obtain the numerical-physical fusion vibration analysis finite element model.

[0058] In view of the defects of the model error of the finite element model of the real blade to be analyzed and the strong dependence on artificial experience, the test value f0 of the first-order bending natural frequency of the real blade obtained in step S1 is used to correct the finite element model of the real blade to be analyzed, and a numerical-physical fusion vibration analysis finite element model is obtained.

[0059] Specifically, based on the three-dimensional geometric model of the real blade to be analyzed, a corresponding high-fidelity finite element analysis model is established in the numerical space, and multi-field coupled nonlinear finite element analysis is carried out to obtain the numerical solution of the vibration characteristics of the blade, including the first-order bending vibration natural frequency and the corresponding dynamic stress field.

[0060] In order to correct the error existing in the solving process of the finite element method and make the calculation result of the numerical method approach the real mechanical behavior of the blade, the numerical-physical fusion method is used to realize the full interaction between numerical simulation and physical test, so as to obtain a finite element simulation model with higher accuracy and reliability. Taking the test value f0 of the first-order bending natural frequency of the real blade obtained in step S1 as the reference, a set of optimal numerical parameter values applied to the calculation of the finite element model in the numerical space is selected by the parameter identification method, so that the first-order bending natural frequency f0 of the blade calculated by the numerical method b is basically consistent with f0, thereby completing the construction of the numerical-physical fusion vibration analysis finite element model. The numerical parameters to be identified can be selected according to sensitivity analysis to be the variables that have the most significant influence on the vibration characteristics but have uncertain values, including but not limited to contact surface tangential stiffness, nonlinear parameters, material parameters, etc. The parameter identification method can use iterative optimization method or proxy model method, etc.

[0061] S3: Construct a parameterized model of the structural characteristics of the blade vibration fatigue simulation piece, specifically:

[0062] Taking the geometric modeling of the real blade as the reference, the structural forms and key test positions that affect the vibration characteristics of the blade are retained, the geometric structures that have little influence on the vibration characteristics of the real blade but are complex to process are simplified, and the structural characteristic scheme of the blade vibration fatigue simulation piece is determined. The different structural characteristic schemes of the blade vibration fatigue simulation piece are represented by parameterized design, wherein the structural characteristic parameters of the blade vibration fatigue simulation piece can be denoted as {S i}, i = 1, 2, 3, …, n, n is the number of parameters of the blade vibration fatigue simulation piece, the structural characteristic parameters are the related dimensions of each component, and the design space corresponding to {S i} is Ω.

[0063] Specifically, please refer to the structure characteristic parameterization scheme diagram of the blade vibration fatigue simulation piece in the embodiment Figure 3 . For the three-dimensional geometric model of the real blade to be analyzed, first, the tenon feature is simplified, and the simulation piece is clamped and fixed by using a clamping section 1 with a simpler structure, which helps to reduce the processing cost of the simulation piece. The structure of the clamping section should match the tooling. In this embodiment, the clamping section 1 adopts an overall dovetail structure.

[0064] Secondly, the blade body near the tip part of the three-dimensional geometric model of the real blade to be analyzed is cut off, and the remaining blade body part, the transition feature between the rim plate and the blade body, and the rim plate are reserved, corresponding to the rim plate section 2, the fillet transition section 3, and the blade body section 4 in Figure 1 . Reserving the above structures from the real blade can make the key parts of the blade vibration fatigue simulation piece the same as the real blade, thereby better simulating the dynamic stress gradient near the key structural features. The blade height parameter reserved by the blade body section 4 is denoted as L.

[0065] Finally, a mass block 5 is added to the top end face of the blade body section 4 to replace the cut-off section of the blade body, adjust the natural frequency of the blade vibration fatigue simulation piece, and excite the first-order bending mode. The cross-sectional shape of the mass block 5 includes but is not limited to rectangular, elliptical, airfoil, etc., and its spatial position is determined according to the cross-sectional properties of the top end face of the blade body section 4. In this embodiment, the cross-sectional shape of the mass block 5 adopts a rectangular scheme, the edge length parameter of the rectangular cross section along the chord length direction is denoted as a, the other edge length parameter of the rectangular cross section is denoted as b, and the height parameter of the mass block 5 along the blade height direction is denoted as c.

[0066] At this point, the construction of the structure characteristic parameterization model of the blade vibration fatigue simulation piece in this embodiment is completed, and a set of parameters {S i}=(L,a,b,c) corresponds to a blade vibration fatigue simulation piece scheme.

[0067] S4: Search the structure characteristic parameter space of the blade vibration fatigue simulation piece to obtain the blade vibration fatigue simulation piece scheme closest to the vibration characteristics of the real blade, specifically:

[0068] The first-order bending natural frequency f0 b of the real blade is obtained from the numerical fusion vibration analysis finite element model in step S2 , and the dynamic stress field s of the blade vibration fatigue simulation piece is obtained from the numerical fusion vibration analysis finite element model in step S3 . The first-order bending natural frequency f0 s of the blade vibration fatigue simulation piece can be searched in the design space Ω of the structure characteristic parameters by an iterative optimization method or a surrogate model method to make f0 b the same as f0 b , and the same as The combination of structural feature parameters {S i *} is the closest to the real blade vibration characteristics.

[0069] Specifically, the iterative optimization method can be expressed as follows: starting from a certain set of structural feature parameters, the first-order bending natural frequency f0 s of the blade vibration fatigue simulation piece corresponding to the set of structural feature parameters is calculated by the numerical-physical fusion vibration analysis finite element model in step S2 s According to the gap between f0 s and f0 b , and and The value of the repeated structural feature parameters {S i} at the round corner transition section 3 is adjusted.

[0070] For the structural feature parameters (L, a, b, c) of the present embodiment, L should not be too short, otherwise it is difficult to ensure that the dynamic stress gradient at the round corner transition section 3 is similar to that of the real blade, nor should it be too long, otherwise it will lead to the size of the blade vibration fatigue simulation piece in the blade height direction being too large, which is not conducive to the development of the test; after the structural feature parameter L is determined, the values of the mass block structural feature parameters a, b, and c are updated by iteration to adjust the size and mass of the mass block, and then the first-order bending natural frequency f0 s of the blade vibration fatigue simulation piece is adjusted, for example, increasing the mass or size of the frequency-adjusting mass can reduce f0 s , and vice versa, which will increase f0 s . The values of (L, a, b, c) are repeatedly adjusted until f0 s is the same as f0 b and and When the gradient at the round corner transition section 3 is similar, the iteration is ended, and the design of the blade vibration fatigue simulation piece is completed.

[0071] The surrogate model method can be expressed as follows: using Latin hypercube sampling (LHS) or other sampling methods, N0 blade vibration fatigue simulation piece samples are collected in the design space Ω of the blade vibration fatigue simulation piece structural feature parameters to form a sample set Each sample corresponds to a set of blade vibration fatigue simulation piece structural feature parameters. The sample set is input into the numerical-physical fusion vibration analysis finite element model obtained in step S2 to obtain a corresponding first-order bending natural frequency set and a dynamic stress field set The first-order bending natural frequency set of the sample set A dynamic stress field set Training an agent model, such as a deep learning model, to obtain a mapping relationship from structural characteristic parameters {S i} of a blade vibration fatigue simulation piece to a first-order bending natural frequency f0 s and a dynamic stress field of the blade vibration fatigue simulation piece and That is:

[0072]

[0073] By solving the equation One or more combinations of structural characteristic parameters that meet the requirement that the first-order bending natural frequency of the blade vibration fatigue simulation piece is the same as that of the real blade can be obtained, and then input into In which, the dynamic stress distribution of the corresponding combination of structural characteristic parameters is obtained, from which the combination of structural characteristic parameters that makes the dynamic stress gradient at the fillet transition section 3 similar to that of the real blade is screened, thereby obtaining a blade vibration fatigue simulation piece scheme that is closest to the vibration characteristics of the real blade. Thus, the design of the blade vibration fatigue simulation piece is completed.

[0074] The design method of the blade vibration fatigue simulation piece of the turbomachinery provided in the embodiment takes the real blade geometry as a reference, retains the structural form and key test positions that affect the vibration characteristics of the blade, simplifies the geometric structures that have little effect on the vibration characteristics of the real blade but are complex to process, and determines the structural characteristic scheme of the blade vibration fatigue simulation piece; the different structural characteristic schemes of the blade vibration fatigue simulation piece are represented by using a parameterized design method, a numerical-physical fusion vibration analysis finite element model is constructed, and the accuracy of the simulation model is improved; the parameterized model of the structural characteristics of the blade vibration fatigue simulation piece is established, the flexibility, repeatability and maintainability of the model are improved, and at the same time, in combination with the iterative optimization method or the agent model method, the search efficiency of the blade vibration fatigue simulation piece scheme can be significantly improved.

[0075] It should be noted that the specific embodiments described above can enable those skilled in the art to more fully understand the present invention, but in no way limit the present invention. Therefore, although the present invention has been described in detail in the specification and examples, those skilled in the art should understand that modifications or equivalent replacements can still be made to the present invention; and all technical solutions and improvements that do not depart from the spirit and scope of the present invention are encompassed in the protection scope of the patent of the present invention. Any reference signs in the claims should not be considered as limiting the claims involved.

Claims

1. A method of designing a bladed-vibration fatigue mockup for a turbomachinery blade, characterized in that, comprising the steps of: A frequency test is carried out on the real blade to be analyzed to obtain the test value of the first-order bending natural frequency of the free vibration of the real blade f 0; through the first order bending natural frequency of the real blade free vibration test value f 0correct the finite element model of the real blade to be analyzed to obtain the numerical fusion vibration analysis finite element model; The structure characteristic parameterization model of the blade vibration fatigue simulation piece is constructed, specifically including: replacing a tenon in a three-dimensional geometric model of a real blade to be analyzed with a clamping section (1), performing cutting treatment on a blade body close to a blade tip part of the three-dimensional geometric model, and reserving a rim plate, a transition feature between the rim plate and the blade body, and a remaining blade body part, corresponding to a rim plate section (2), a round corner transition section (3), and a blade body section (4) respectively; adding a mass block (5) to a top end face of the blade body section (4) to replace a cut section of the blade body; and structure characteristic parameters of the vibration fatigue simulation piece constructed are S i}, i =1,2,3,……, n , n is a number of parameters of the blade vibration fatigue simulation piece; { S i}The corresponding design space is denoted by ; The first-order bending natural frequency of the real blade was calculated based on the finite element model of vibration analysis fused with numerical and physical parameters. With dynamic stress field And the first-order bending natural frequency of the blade vibration fatigue simulation component. With dynamic stress field In the design space of structural characteristic parameters Search Engine and Same, and and The structural feature parameter combination with the most similar gradient at the rounded transition section (3) { S i * }, based on the combination of structural characteristic parameters { S i * The final impeller blade vibration fatigue simulation part was obtained.

2. The method of designing a bladed vibration fatigue mockup for an impeller machine of claim 1, wherein, The blade height parameter of the blade section (4) is denoted as L, the cross section shape of the mass block (5) is rectangular, one side length of the rectangular cross section along the chord length direction of the blade is denoted as a , another side length parameter is denoted as b , and the height of the mass block (5) along the blade height direction is denoted as c， The structural characteristic parameters of the vibration fatigue simulation piece are constructed as S i} = (L, a , b , c ).

3. The method of designing a bladed vibration fatigue mockup for an impeller machine of claim 2, wherein, The real blade to be analyzed is subjected to frequency testing to obtain the test value of the first-order bending natural frequency of the free vibration of the real blade f 0, specifically: for the real blade to be analyzed, the self-vibration method or the resonance method is used to measure in the physical space to obtain the test value of the first-order bending natural frequency of the free vibration of the real blade f 0.

4. The method of designing a bladed vibration fatigue mockup for an impeller machine of claim 3, wherein, The test value of the first order bending natural frequency of the real blade through free vibration f 0correcting the finite element model of the real blade to be analyzed to obtain a numerical fusion vibration analysis finite element model, specifically comprising: The experimental value of the first order bending natural frequency of the real blade free vibration f 0 is the reference, a set of optimal numerical parameter values applied to the numerical space finite element model calculation is selected by parameter identification method, so that the first order bending natural frequency of the blade calculated by the numerical method With Consistent, complete the construction of the numerical fusion vibration analysis finite element model; the numerical parameters include the tangential stiffness of the contact surface, the nonlinear parameters and the material parameters.

5. The method of designing a bladed vibration fatigue mockup for an impeller machine of claim 4, wherein, The parameter identification method is an iterative optimization method, and a set of optimal numerical parameter values applied to the numerical space finite element model calculation is selected by the iterative optimization method, so that the first-order bending natural frequency of the blade calculated by the numerical method is consistent with the first-order bending natural frequency of the blade calculated by the analytical method With consistent, specifically: From a set of structural characteristic parameter values, the first order bending natural frequency of the blade vibration fatigue simulation piece corresponding to the set of structural characteristic parameters is calculated by the numerical and physical fusion vibration analysis finite element model with dynamic stress field , according to the gap between and and The value of the repeated structural characteristic parameter is adjusted in the similar degree of the gradient at the fillet transition section (3) S i} After the structural characteristic parameter L is determined, the structural characteristic parameter of the mass block is updated through iteration a, b, c The value of the mass block is adjusted to adjust the size and mass of the mass block, and then the first-order bending natural frequency of the blade vibration fatigue simulation piece is adjusted ; The value of the repeated iteration adjustment (L, a , b , c ) is adjusted until the requirements of The same as and The same as The gradient at the rounded transition section 3, the iteration ends, and the design of the blade vibration fatigue simulation piece is completed.

6. The method of designing a bladed vibration fatigue mockup for an impeller machine of claim 4, wherein, The parameter identification method is a surrogate model method, and a set of optimal numerical parameter values applied to calculation of a numerical space finite element model is selected through the surrogate model method, so that the first-order bending natural frequency of the blade calculated by the numerical method is consistent with specifically: A sample method is adopted to collect a plurality of blade vibration fatigue simulation piece samples, to form a sample set wherein each sample corresponds to a set of structural characteristic parameters of the blade vibration fatigue simulation piece​ The sample set Input the number of material fusion vibration analysis finite element model, get The corresponding first-order bending natural frequency set With the dynamic stress field set ; a set of samples a set of first order bending natural frequencies a set of dynamic stress fields training the agent model to obtain a mapping relationship from the structural characteristic parameters of the blade vibration fatigue simulation piece S i to the first order bending natural frequencies of the blade vibration fatigue simulation piece and the dynamic stress fields and that is:​ by solving equation obtain one or more structural characteristic parameter combinations satisfying the requirement that the first order bending natural frequency of the blade vibration fatigue simulation piece and the real blade are the same, and then input In the method, the dynamic stress distribution of the corresponding structural characteristic parameter combination is obtained, and the structural characteristic parameter combination that makes the dynamic stress gradient at the fillet transition section (3) similar to that of the real blade is screened from the dynamic stress distribution, so that the blade vibration fatigue simulation piece scheme closest to the vibration characteristics of the real blade is obtained.

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