A method for extracting and optimizing design of key structural parameters of an elastic ring

Abstract

The application relates to the technical field of aero-engines, in particular to a method for extracting and optimizing key structural parameters of an elastic ring, which comprises the following steps: obtaining elastic ring supporting stiffness parameters and oil film dynamic characteristic parameters according to parameters of the elastic ring; obtaining relative sensitivities of the supporting stiffness parameters and the oil film dynamic characteristic parameters about structural parameters according to a mapping function; dividing key stiffness parameters and key damping parameters of the elastic ring design from the structural parameters of the elastic ring according to the relative sensitivities; and designing the divided key stiffness parameters and then the divided key damping parameters according to design requirements, a target function and constraint conditions. The application solves the practical problems of trial and error, repeated design and iterative design of the same structural parameters of the elastic ring by taking the design idea that the key stiffness parameters of the elastic ring have absolute priority.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aero-engines, and particularly relates to a method for extracting and optimizing key structural parameters of an elastic ring. BACKGROUND

[0002] With the increasing requirements of the maneuverability of modern aircraft and the thrust-to-weight ratio of engines, the characteristics of aero-engines, such as high speed, high temperature, high load, variable working conditions, complex structure and lightness, are becoming more and more prominent, and the vibration problem is prominent. The vibration reduction design has become a “bottleneck” problem to be solved in the development process of the next generation of engines. The elastic ring type extruded oil film damper (hereinafter referred to as “elastic ring”) is an important component of aero-engine vibration control, and has the functions of frequency modulation and vibration control. Compared with other types of dampers, the elastic ring can avoid the collision between the inner and outer rings of the oil film under extreme working conditions, improve the nonlinearity of the oil film, reduce the risk of bearing fatigue fracture and save the axial space of the engine, and therefore has a broad application prospect in the vibration control of aero-engines.

[0003] The elastic ring is located in the rotor support structure and is a support element with the inner and outer bosses staggered and uniformly distributed. The inner boss is matched with the inner bushing of the elastic ring, and the outer boss is matched with the outer bushing of the elastic ring. The working principle is as follows: lubricating oil is supplied to the above structure, the oil film in the gap surrounded by adjacent inner bosses, elastic rings and bearing outer rings is called inner oil film, and the oil film in the gap surrounded by adjacent outer bosses, elastic rings and bearing seats is called outer oil film. There is a radial oil passage between the inner and outer oil films to allow partial intercommunication of lubricating oil. When the rotor rotates, the rotor journal deviates from the center under the excitation of unbalance and the like, the elastic ring deforms to provide support stiffness; the inner and outer oil films form dynamic pressure oil films under the extrusion of the shaft journal and the elastic ring to provide oil film stiffness and oil film damping. The main structural parameters affecting the dynamic characteristics of the elastic ring include the elastic ring radius, the elastic ring width, the elastic ring thickness, the boss height, the boss width and the number of bosses.

[0004] In order to avoid critical speed drift and vibration problems, the prior art proposes an elastic ring structural parameter optimization method with stiffness effect as the optimization target, establishes a relatively comprehensive elastic ring structural parameter design process, and improves the design accuracy and operation stability of the rotor system. However, this design method does not consider the oil film, and cannot be applied to the elastic ring structural parameter design work with vibration reduction design as the target.

[0005] The prior art also discloses that the number of the bosses of the elastic ring should correspond to the rigidity value which meets the support rigidity requirement and maximally meets the requirement of improving the oil film force characteristics. In addition, the oil film gap of the elastic ring should also be controlled within a suitable range. The person skilled in the art analyzes the basic law of the rigidity and damping force characteristics of the elastic ring varying with the number of bosses, the boss height and the boss width. However, the influence law of the structural parameters obtained by the prior art is a qualitative law, and no quantitative design suggestion of the structural parameters of the elastic ring is given.

[0006] The prior art also discloses that the structural parameters influence the support rigidity and the oil film characteristics of the elastic ring, thereby influencing the critical speed and the unbalance response of the elastic ring-rotor system. The damping effect of the elastic ring with the same set of structural parameters is different under different modes, and the structural parameters influencing the effect of the elastic ring are numerous, and the parameter optimization design of the elastic ring and the rotor system needs to be performed. However, the research does not give the parameter optimization design flow of the elastic ring-rotor system which can be directly applied to the engineering design link.

[0007] In summary, there is no quantitative design method of the structural parameters of the elastic ring which can be directly applied in the prior art. In the actual design process, several rounds of iteration of "design-processing-test-design" are needed. Therefore, how to extract the key structural parameters of the elastic ring, and establish the optimization design method of the elastic ring based on the same, solve the practical problems of the iterative design of the elastic ring in the engineering application, and reduce the vibration risk, are the key technical problems to be solved in the design of the support and damper in the field of rotor dynamics of the aero-engine and the gas turbine. SUMMARY

[0008] In order to solve the above technical problems, the present application provides an extraction and optimization design method of the key structural parameters of the elastic ring in view of the fact that there is no design method of the structural parameters of the elastic ring which can be directly applied to the engineering application and aims at the vibration reduction design of the rotor in the prior art. The method decouples and separates the rigidity related parameters and the damping related parameters of the structural parameters of the elastic ring, divides the key rigidity parameters and the key damping parameters through the related sensitivity, and proposes the design idea that the key rigidity parameters of the elastic ring have absolute priority, thereby avoiding the practical problems of the trial and error, repeated design and iterative design of the same structural parameter of the elastic ring.

[0009] The purpose of the present application is to provide an extraction and optimization design method of the key structural parameters of the elastic ring, which is used for the structural parameter design of the elastic ring arranged on the support of the rotor system in the aero-engine, and comprises the following steps:

[0010] Obtaining the parameters of the elastic ring;

[0011] Obtaining the support rigidity parameters and the oil film dynamics characteristic parameters of the elastic ring according to the parameters of the elastic ring; wherein the oil film dynamics characteristic parameters comprise the equivalent oil film rigidity and the equivalent oil film damping;

[0012] constructing a mapping function of the structure parameters to the bearing stiffness parameters and the oil film dynamic characteristic parameters based on different structure parameters of the elastic ring, and corresponding bearing stiffness parameters and oil film dynamic characteristic parameters;

[0013] obtaining relative sensitivities of the bearing stiffness parameters and the oil film dynamic characteristic parameters to the structure parameters according to the mapping function;

[0014] dividing key stiffness parameters and key damping parameters of the elastic ring design from the structure parameters of the elastic ring according to the relative sensitivities;

[0015] defining design requirements of the structure parameters of the elastic ring, and constructing an objective function and constraint conditions of the structure parameters of the elastic ring;

[0016] designing the divided key stiffness parameters first and then the divided key damping parameters according to the design requirements, the objective function and the constraint conditions;

[0017] wherein, some of the structure parameters of the elastic ring belong to both the key stiffness parameters and the key damping parameters, in the design process, the stiffness design requirements are satisfied first, and then the single key damping parameter is adjusted to make the elastic ring meet the damping design requirements.

[0018] In an embodiment, the defining the design requirements of the structure parameters of the elastic ring, and constructing the objective function and the constraint conditions of the structure parameters of the elastic ring comprises:

[0019] establishing a dynamic model of the elastic ring-rotor system, and calculating modal characteristics and response characteristics of the elastic ring-rotor system;

[0020] determining design requirements of the key structure parameters of the elastic ring according to the modal characteristics and the response characteristics, and constructing the objective function and the constraint conditions of the structure parameters of the elastic ring.

[0021] In an embodiment, the mapping function of the structure parameters to the bearing stiffness parameters and the oil film dynamic characteristic parameters is:

[0022]

[0023] wherein, is the bearing stiffness of the elastic ring; is the equivalent oil film stiffness of the elastic ring; is the equivalent oil film damping; is the mapping function of the structure parameters to the bearing stiffness parameters; is the mapping function of the structure parameters to the equivalent oil film stiffness; is the mapping function of the structure parameters to the equivalent oil film damping; n is the number of bosses;R The radius of the elastic ring; h The thickness of the elastic ring; L The width of the elastic ring; b This is the width of the boss; c This is the height of the boss;

[0024] The relative sensitivity is:

[0025]

[0026] In the formula, S i Relative sensitivity; For the dependent variable parameter, take ; For the independent variable parameter, take ; To control the change in the dependent variable parameter caused by a change in a single independent variable parameter during the process; To control the change of a single independent variable parameter during the process.

[0027] In one embodiment, the key stiffness parameters of the partition are optimized, including:

[0028] Define the design value of the elastic ring stiffness according to the design requirements;

[0029] Based on the design value of the elastic ring stiffness and the objective function, key stiffness parameters are designed.

[0030] The key stiffness parameters for the division include the number of bosses, the radius of the elastic ring, the thickness of the elastic ring, the width of the elastic ring, and the width of the bosses.

[0031] Select bearings based on the rotational speed range of the rotor system, and design the elastic ring radius based on the selected bearings;

[0032] The number and width of the bosses are determined based on the design value of the elastic ring stiffness.

[0033] The thickness and width of the elastic ring are optimized based on the objective function.

[0034] The objective function is:

[0035]

[0036] In the formula, For the first The objective function for stiffness optimization of a single-support elastic ring; For parameters and The first under the influence Stiffness values ​​of the elastic rings at each fulcrum; For the first The rigidity design value of the fulcrum elastic ring.

[0037] In an embodiment, the key damping parameters of the division are designed, including:

[0038] According to the design requirements, the elastic ring damping design value is defined;

[0039] According to the elastic ring damping design value, the key damping parameters are designed based on the constraint conditions;

[0040] The constraint conditions are the key measurement point vibration displacement limit value, the key measurement point support external force limit value, and the design unbalance amplitude and phase of the elastic ring-rotor system obtained according to the structural characteristics of the rotor.

[0041] In an embodiment, it further includes: based on the designed key stiffness parameters and key damping parameters, modal checking and response checking of the elastic ring-rotor system are carried out, if the design requirements are met, the key parameter design of the elastic ring is completed; if the design requirements are not met, the optimization design range of the elastic ring structure parameters is adjusted, and the design is iterated.

[0042] In an embodiment, the elastic ring support rigidity parameters are obtained according to the following steps:

[0043] Based on the finite element method, a solid domain model of the elastic ring is established according to the structure parameters, material parameters and grid parameters of the elastic ring, and a deformation control equation of the elastic ring is obtained;

[0044] The boundary conditions of the solid domain of the elastic ring are defined, the deformation control equation of the elastic ring is solved, and the deformation function and support rigidity parameters of the elastic ring are obtained.

[0045] In an embodiment, the boundary conditions of the solid domain of the elastic ring are:

[0046]

[0047] In the formula, is the radial displacement of the elastic ring unit node; is the journal eccentricity of the elastic ring outer bushing; is the circumferential coordinate of the elastic ring; is the journal eccentricity phase angle of the elastic ring outer bushing; is the radial force acting on the elastic ring unit node; is the circumferential force acting on the elastic ring unit node; Region I refers to the elastic ring inner boss on the side pressed by the journal; Region II refers to the elastic ring outer boss on the side pressed by the journal; Region III refers to all elastic ring segments, elastic ring inner bosses on the side not pressed by the journal, and elastic ring outer bosses on the side not pressed by the journal.

[0048] In an embodiment, the oil film dynamic characteristic parameters are obtained according to the following steps:

[0049] Based on the structure parameters of the elastic ring, the oil parameters and the grid parameters, the elastic ring fluid domain gap function is constructed in combination with the elastic ring deformation function result, and is substituted into the generalized Reynolds equation to establish the elastic ring oil film pressure field control equation;

[0050] The boundary conditions of the elastic ring fluid domain are defined, the elastic ring oil film pressure field control equation is solved, and the oil film dynamic characteristic parameters are obtained;

[0051] The elastic ring fluid domain gap function is:

[0052]

[0053] In the formula, is the deformation of the elastic ring, is the height of the outer boss of the elastic ring; is the height of the inner boss of the elastic ring; is the gap function of the inner oil film of the elastic ring; is the gap function of the outer oil film of the elastic ring; is the journal eccentricity of the outer bushing of the elastic ring; is the circumferential coordinate of the elastic ring.

[0054] In an embodiment, the elastic ring oil film pressure field control equation is:

[0055]

[0056] In the formula, is the radius of the elastic ring; is the axial coordinate of the elastic ring model; is the gap function of the inner oil film of the elastic ring; is the gap function of the outer oil film of the elastic ring; is the inner oil film pressure of the elastic ring; is the outer oil film pressure of the elastic ring; is the viscosity of the lubricating oil; is the circumferential velocity boundary of the inner bushing end of the inner oil film of the elastic ring; is the circumferential velocity boundary of the elastic ring end of the inner oil film of the elastic ring; is the radial velocity boundary of the inner bushing end of the inner oil film of the elastic ring; is the radial velocity boundary of the elastic ring end of the inner oil film of the elastic ring; is the circumferential velocity boundary of the elastic ring end of the outer oil film of the elastic ring; is the circumferential velocity boundary of the outer bushing end of the outer oil film of the elastic ring; is the radial velocity boundary of the elastic ring end of the outer oil film of the elastic ring; is the radial velocity boundary of the outer bushing end of the outer oil film of the elastic ring; is the circumferential coordinate of the elastic ring;

[0057] The boundary condition of the elastic ring fluid domain is:

[0058]

[0059] In the formula, is the angular velocity of the journal whirl; is the time; is the journal eccentricity of the elastic ring outer bushing; is the first order derivative of the journal eccentricity of the elastic ring outer bushing with respect to time.

[0060] The present application has at least the following beneficial effects:

[0061] The present application provides a kind of extraction and optimization design method of elastic ring key structure parameter, the present application is directed to the characteristics of numerous elastic ring structure parameters, relative sensitivity parameter for the decoupling analysis of elastic ring structure parameter is proposed, the decoupling and separation of key stiffness parameter and key damping parameter of elastic ring structure parameter are realized, and from the supporting and damping function of elastic ring, in order to avoid the significant change of the elastic ring-rotor system mode caused by the change of elastic ring supporting stiffness, the design idea that elastic ring key stiffness parameter has absolute priority is proposed, the design order of " key stiffness parameter-key damping parameter " is established, and the practical problems such as trial and error, repeated design and iterative design in the design process of the same structure parameter of elastic ring are solved.

[0062] The present application establishes the damping design process and method of rotor system with elastic ring, after the completion of key stiffness parameter design, the damping effect of multiple elastic rings on multiple modal responses in the full speed range can be considered comprehensively, the response of rotor system is taken as optimization target, the systematic positive design of elastic ring is realized, and technical support is provided for elastic ring design. DETAILED DESCRIPTION

[0063] Figure 1 It is a flow chart of the extraction and optimization design method of elastic ring key structure parameter of the present application.

[0064] Figure 2 It is a schematic diagram of elastic ring component structure of the present application.

[0065] Figure 3 It is a schematic diagram of the structure of a single rotor system with elastic ring in the embodiment of the present application.

[0066] Figure 4 It is a schematic diagram of the calculation result of deformation function of a certain elastic ring in the embodiment of the present application.

[0067] Figure 5 It is a schematic diagram of the calculation result of oil film pressure field of a certain elastic ring in the embodiment of the present application.

[0068] Figure 6 Mode shape of the rotor system in the embodiment of the present application.

[0069] Figure 7 Response of the elastic ring-rotor system under the condition of no damping and being excited by the designed unbalance in the embodiment of the present application.

[0070] Figure 8 Response of the elastic ring-rotor system under the condition of damping and being excited by the designed unbalance in the embodiment of the present application.

[0071] In the drawings, 1 is an elastic ring; 2 is an inner bushing of the elastic ring; 3 is an outer bushing of the elastic ring; 4 is a bearing; 5 is a journal; 6 is an inner oil film; 7 is an outer oil film; 8 is an oil hole; 9 is an inner boss; 10 is an outer boss; 11 is a first-stage compressor disc; 12 is a second-stage compressor disc; 13 is a third-stage compressor disc; 14 is a grid disc; 15 is a turbine disc; 16 is a high-pressure compressor shaft; 17 is a first-stage drum; 18 is a second-stage drum; 19 is a third-stage drum; 20 is a high-pressure shaft; 21 is a high-pressure turbine shaft; 22 is a third elastic support point; 23 is a three-support-point elastic ring; 24 is a fourth elastic support point; 25 is a four-support-point elastic ring; 26 is an inner bushing of the three-support-point elastic ring; 27 is an outer bushing of the three-support-point elastic ring; 28 is an inner bushing of the four-support-point elastic ring; 29 is an outer bushing of the four-support-point elastic ring. DETAILED DESCRIPTION

[0072] In order to illustrate the technical means and effects adopted by the present application to achieve the predetermined object, the following will be described in detail in combination with embodiments.

[0073] The object of the present application is to overcome the problem of lacking a systematic design method of elastic ring structure parameters aiming at vibration reduction design which can be directly applied to engineering application in the prior art, and to provide an extraction and optimization design method of key structure parameters of an elastic ring. The method realizes decoupling and separation of stiffness-related parameters and damping-related parameters of the structure parameters of the elastic ring, and on this basis, proposes a design idea that the key stiffness parameters of the elastic ring have absolute priority, thereby avoiding the practical problems of trial and error, repeated design and iterative design of the same structure parameters of the elastic ring.

[0074] In order to achieve the above object, referring to Figure 1 , an extraction and optimization design method of key structure parameters of an elastic ring is proposed, which is used for the design of structure parameters of an elastic ring arranged on a rotor system in an aero-engine, and includes the following steps:

[0075] S1, obtaining parameters of the elastic ring;

[0076] The parameters of the elastic ring are used to establish its dynamic characteristic model, including structural parameters, material parameters, lubricating oil parameters, and mesh parameters. The structural parameters of the elastic ring include its radius, thickness, width, boss width, boss height, number of bosses, and oil passage diameter. The material parameters include density, Young's modulus, and Poisson's ratio. The lubricating oil parameter is its viscosity. The mesh parameters include the number of nodes in the circumferential and axial directions. For a specific elastic ring, its structural parameters are directly read from engineering drawings or measured using specialized equipment (such as vernier calipers). Material and lubricating oil parameters are obtained from material handbooks. The mesh parameters are selected appropriately based on the elastic ring's structural parameters, ensuring that nodes exist at the axial edges of the elastic ring, the circumferential edges of the bosses, and at the oil passages.

[0077] S2. Based on the structural parameters of the elastic ring, obtain the support stiffness parameters and oil film dynamic characteristic parameters of the elastic ring; among which, the oil film dynamic characteristic parameters include the equivalent oil film stiffness and the equivalent oil film damping.

[0078] In this invention, a model for calculating the support stiffness of an elastic ring is established based on its structural, material, and mesh parameters. According to the generalized Hooke's law, the deformation function of the elastic ring under journal force is calculated, and the support stiffness parameters are obtained. Based on the structural, lubricating oil, and mesh parameters of the elastic ring, and combined with the elastic ring deformation function results, a fluid domain clearance function for the elastic ring is constructed. This function is then substituted into the generalized Reynolds equation to establish a model for calculating its oil film dynamics. By solving for the pressure field distribution within and outside the elastic ring's oil film, numerical integration yields the equivalent oil film stiffness parameters and equivalent oil film damping parameters of the elastic ring.

[0079] In this embodiment, the stiffness parameters of the elastic ring support are obtained according to the following steps:

[0080] Based on the finite element method, a solid domain model of the elastic ring is established according to the structural parameters, material parameters and mesh parameters of the elastic ring, and the deformation control equation of the elastic ring is obtained.

[0081] Define the boundary conditions of the elastic ring solid domain, solve the deformation control equation of the elastic ring, and obtain the deformation function and support stiffness parameters of the elastic ring.

[0082] The governing equation for the deformation of the elastic ring is:

[0083]

[0084] In the formula, It is the generalized displacement vector of the elastic link, that is, the deformation of the elastic ring; Let be the generalized force vector of the journal on the elastic ring. Let be the stiffness matrix of the elastic ring solid domain.

[0085] The boundary conditions for the elastic ring solid domain are:

[0086]

[0087] wherein, is the radial displacement of the elastic ring unit node; is the journal eccentricity of the elastic ring outer bushing; is the circumferential coordinate of the elastic ring; is the phase angle of the journal eccentricity of the elastic ring outer bushing; is the radial force acting on the elastic ring unit node; is the circumferential force acting on the elastic ring unit node; Region I refers to the elastic ring inner boss on the side pressed by the journal; Region II refers to the elastic ring outer boss on the side pressed by the journal; Region III refers to all elastic ring ring segments, the elastic ring inner boss on the side not pressed by the journal, and the elastic ring outer boss on the side not pressed by the journal.

[0088] The expression of the elastic ring support stiffness is:

[0089]

[0090] wherein, is the elastic ring support stiffness, is the resultant radial force of the elastic ring under the action of the journal pressing.

[0091] In the embodiment, the oil film dynamic characteristic parameters are obtained according to the following steps:

[0092] Based on the structural parameters, oil parameters and grid parameters of the elastic ring, the elastic ring fluid domain gap function is constructed in combination with the elastic ring deformation function result, and is substituted into the generalized Reynolds equation to establish the elastic ring oil film pressure field control equation;

[0093] The boundary conditions of the elastic ring fluid domain are defined, the elastic ring oil film pressure field control equation is solved, and the oil film dynamic characteristic parameters are obtained;

[0094] The elastic ring fluid domain gap function is:

[0095] wherein, is the deformation of the elastic ring, is the height of the elastic ring outer boss; is the height of the elastic ring inner boss; is the gap function of the elastic ring inner oil film; is the gap function of the elastic ring outer oil film; is the journal eccentricity of the elastic ring outer bushing; is the circumferential coordinate of the elastic ring.

[0096] The elastic ring oil film pressure field control equation is:

[0097]

[0098] wherein, is the elastic ring radius; is the axial coordinate of the elastic ring model; is the gap function of the inner oil film of the elastic ring; is the gap function of the outer oil film of the elastic ring; is the inner oil film pressure of the elastic ring; is the outer oil film pressure of the elastic ring; is the viscosity of the lubricant; is the circumferential velocity boundary at the inner bushing end of the inner oil film of the elastic ring; is the circumferential velocity boundary at the elastic ring end of the inner oil film of the elastic ring; is the radial velocity boundary at the inner bushing end of the inner oil film of the elastic ring; is the radial velocity boundary at the elastic ring end of the inner oil film of the elastic ring; is the circumferential velocity boundary at the elastic ring end of the outer oil film of the elastic ring; is the circumferential velocity boundary at the outer bushing end of the outer oil film of the elastic ring; is the radial velocity boundary at the elastic ring end of the outer oil film of the elastic ring; is the radial velocity boundary at the outer bushing end of the outer oil film of the elastic ring; is the circumferential coordinate of the elastic ring;

[0099] The boundary conditions for the elastic ring fluid domain are:

[0100]

[0101] wherein, is the angular velocity of the journal whirl; is the time; is the journal eccentricity of the outer bushing of the elastic ring; is the first derivative of the journal eccentricity of the outer bushing of the elastic ring with respect to time.

[0102] The expressions for the equivalent oil film stiffness and equivalent oil film damping of the elastic ring are:

[0103]

[0104] wherein, integrating the oil film pressure field, the radial oil film support reaction force and the circumferential oil film support reaction force are obtained.

[0105] S3, constructing a mapping function of the structure parameter pointing to the supporting stiffness parameter and the oil film dynamic characteristic parameter based on different structure parameters of the elastic ring and corresponding elastic ring supporting stiffness parameters and oil film dynamic characteristic parameters;

[0106] According to the mapping function, the relative sensitivity of the supporting stiffness parameter and the oil film dynamic characteristic parameter with respect to the structure parameter is obtained;

[0107] According to the relative sensitivity, the key stiffness parameter and the key damping parameter of the elastic ring design are divided from the structure parameters of the elastic ring;

[0108] In the present application, according to the structure characteristics and stress characteristics of the elastic ring, based on the idea of control variable, the structure parameters of the elastic ring are changed, the supporting stiffness parameter, the equivalent oil film stiffness parameter and the equivalent oil film damping parameter are calculated, and on this basis, the mapping function of the structure parameter pointing to the dynamic characteristic parameter is constructed , and the relative sensitivity is defined to evaluate the influence of the structure parameter of the elastic ring on the dynamic characteristic.

[0109] Among them, the steps of extracting the key stiffness parameter and the key damping parameter are:

[0110] Based on the idea of control variable, the number of bosses n , the radius of the elastic ring R , the thickness of the elastic ring h , the width of the elastic ring L , the width of the boss b , the height of the boss c and other structure parameters are changed, and the supporting stiffness k , the equivalent oil film stiffness and the equivalent oil film damping are calculated.

[0111] The mapping function Ξ is constructed, and the relative sensitivity S i The concept of key stiffness parameter and key damping parameter is defined.

[0112] The optimization design range of the structure parameter of the elastic ring is analyzed.

[0113] The influence of the structure parameter of the elastic ring on the dynamic characteristic is evaluated, and the key stiffness parameter and the key damping parameter are determined.

[0114] In this embodiment, the expression of the mapping function is:

[0115]

[0116] In the formula, is the supporting stiffness of the elastic ring; is the equivalent oil film stiffness of the elastic ring. is the equivalent oil film damping; is a mapping function from the structural parameters to the support stiffness parameter; is a mapping function from the structural parameters to the equivalent oil film stiffness; is a mapping function from the structural parameters to the equivalent oil film damping; n is the number of bosses; R is the elastic ring radius; h is the elastic ring thickness; L is the elastic ring width; b is the boss width; c is the boss height;

[0117] relative sensitivity S i is expressed as:

[0118]

[0119] wherein, is the dependent variable parameter, which can be taken as ; is the independent variable parameter, which can be taken as ; is the change of the dependent variable parameter caused by the change of the single independent variable parameter in the process of controlling the variable; is the change of the single independent variable parameter in the process of controlling the variable.

[0120] The concepts of the key stiffness parameter and the key damping parameter are defined according to Table 1:

[0121] Table 1 Definition of the key parameters of the elastic ring

[0122]

[0123] According to the relative sensitivity in Table 1, the key stiffness parameter and the key damping parameter of the elastic ring design are divided from the structural parameters of the elastic ring by the relative sensitivity;

[0124] In this embodiment, by dividing from the structural parameters of the elastic ring by the relative sensitivity, the elastic ring radius and the elastic ring width are both the key stiffness parameter and the key damping parameter, the number of bosses, the elastic ring thickness and the boss width are the key stiffness parameter, and the boss height is the key damping parameter.

[0125] When determining the structural parameters of the elastic ring, the value range of the structural parameters of the elastic ring is defined as:

[0126]

[0127] wherein, and are the lower limit and the upper limit of the value range of the number of bosses of the elastic ring, respectively. and are respectively the lower limit and upper limit of the elastic ring radius value; and are respectively the lower limit and upper limit of the elastic ring thickness value; and are respectively the lower limit and upper limit of the elastic ring width value; and are respectively the lower limit and upper limit of the elastic ring boss width value; and are respectively the lower limit and upper limit of the elastic ring boss height value.

[0128] In particular, the elastic ring serves as a supporting component of the rotor system, and its supporting stiffness is a key parameter for determining the modal of the rotor system. In the analysis process, if the supporting stiffness parameter is too sensitive to a slight change in a certain structural parameter (a change in the order of magnitude occurs), the rotor modal will deviate significantly from the design value. At this time, the influence of the structural parameter on the equivalent oil film stiffness parameter and the equivalent oil film damping parameter is no longer analyzed.

[0129] S4, defining the design requirements of the structural parameters of the elastic ring, and constructing the objective function and constraint conditions of the structural parameters of the elastic ring;

[0130] In the present application, according to the installation conditions and structural characteristics of the elastic ring on the rotor system, a dynamic model of the elastic ring-rotor system is established, and the modal characteristics and response characteristics of the elastic ring-rotor system are calculated, on the basis of which the design requirements of the key structural parameters of the elastic ring are determined, the objective function and constraint conditions of the key structural parameters of the elastic ring are constructed, and an optimization design process of the key structural parameters of the elastic ring in the elastic ring-rotor system is formed.

[0131] The definition of the design requirements of the structural parameters of the elastic ring, and the construction of the objective function and constraint conditions of the structural parameters of the elastic ring, comprise:

[0132] A dynamic model of the elastic ring-rotor system is established, and the modal characteristics and response characteristics of the elastic ring-rotor system are calculated;

[0133] The design requirements of the key structural parameters of the elastic ring are determined according to the modal characteristics and response characteristics, and the objective function and constraint conditions of the structural parameters of the elastic ring are constructed.

[0134] S5, according to the design requirements and the objective function and constraint conditions, first design the divided key stiffness parameters, and then design the divided key damping parameters;

[0135] The structure parameters of the partial elastic ring belong to both key stiffness parameters and key damping parameters, in the design process, the key damping parameters are adjusted to meet the damping design requirements after meeting the stiffness design requirements.

[0136] The divided key stiffness parameters are optimized and designed, including:

[0137] The elastic ring stiffness design value is defined according to the design requirements;

[0138] The key stiffness parameters are designed based on the objective function according to the elastic ring stiffness design value.

[0139] The divided key stiffness parameters include the number of bosses, the elastic ring radius, the elastic ring thickness, the elastic ring width and the boss width;

[0140] The bearing is selected according to the speed range of the rotor system, and the elastic ring radius is designed according to the selected bearing;

[0141] The number of bosses and the boss width are determined according to the elastic ring stiffness design value;

[0142] The thickness and width of the elastic ring are optimized and designed based on the objective function;

[0143] The objective function is:

[0144]

[0145] In the formula, is the stiffness optimization objective function of the jth support elastic ring; is the stiffness value of the jth support elastic ring under the influence of parameters and is the stiffness design value of the jth support elastic ring. The divided key damping parameters are designed, including: The elastic ring damping design value is defined according to the design requirements;

[0146] The key damping parameters are designed based on the constraint conditions according to the elastic ring damping design value;

[0147] The constraint conditions are the key measurement point vibration displacement limit value, the key measurement point support external force limit value and the design unbalance amplitude and phase of the elastic ring-rotor system obtained according to the structural characteristics of the rotor.

[0148] The constraint conditions are the key measurement point vibration displacement limit value, the key measurement point support external force limit value and the design unbalance amplitude and phase of the elastic ring-rotor system obtained according to the structural characteristics of the rotor.

[0149] The constraint conditions are the key measurement point vibration displacement limit value, the key measurement point support external force limit value and the design unbalance amplitude and phase of the elastic ring-rotor system obtained according to the structural characteristics of the rotor.

[0150] ​​Further comprising: based on the key stiffness parameters and the key damping parameters of the design, carrying out modal checking and response checking of the elastic ring-rotor system, if the design requirements are met, the key parameter design of the elastic ring is completed, if the design requirements are not met, adjusting the optimization design range of the structure parameters of the elastic ring, and iteratively designing.

[0151] In the application, the steps of establishing the elastic ring key structure parameter design process are:

[0152] Based on the finite element method, according to the structure characteristics of the rotor system, an elastic ring-rotor system model and a motion equation of the elastic ring-rotor system are established;

[0153] Solving the homogeneous and non-homogeneous motion equations of the system, the modal characteristics and response characteristics of the elastic ring-rotor system are obtained;

[0154] Combining the characteristics of the rotor system, the design requirements of the structure parameters of the elastic ring are determined, including the modal design target and the response design target;

[0155] According to the modal design target, the key stiffness parameters of the elastic ring are determined; it is worth noting that the stiffness design of the elastic ring has absolute priority, if a certain structure parameter is both a key stiffness parameter and a key damping parameter, the value of the parameter should be ensured to meet the stiffness design requirements, that is, to meet the modal design target in the design process;

[0156] According to the response design target, the key damping parameters of the elastic ring are determined;

[0157] Based on the key stiffness parameters and the key damping parameters of the design, the modal checking and response checking of the elastic ring-rotor system are carried out, if the design requirements are met, the key parameter design of the elastic ring is completed, if the design requirements are not met, the optimization design range is adjusted, and the design is iterated.

[0158] Wherein, the motion equation of the elastic ring-rotor system is:

[0159]

[0160] In the formula, is the mass matrix of the elastic ring-rotor system, is the support damping matrix of the elastic ring-rotor system, is the gyroscopic effect matrix of the elastic ring-rotor system, is the support stiffness matrix of the elastic ring-rotor system, and are the generalized displacement vector, the generalized velocity vector and the generalized acceleration vector of the elastic ring-rotor system, is the external force vector of the elastic ring-rotor system.

[0161] The state vector method is used to solve homogeneous motion equations of the system, and the modal characteristics of the elastic ring-rotor system are calculated. The equivalent oil film stiffness and the supporting stiffness of the elastic ring are connected in parallel to form the supporting stiffness of the rotor system. In the small eccentricity ratio interval, the equivalent oil film stiffness of the elastic ring is much smaller than the supporting stiffness, and the modal can be directly calculated by using the supporting stiffness.

[0162] The state vector method is used to solve the non-homogeneous motion equations of the system, and the unbalance response characteristics of the elastic ring-rotor system are calculated. Since the elastic ring is a nonlinear element, its equivalent oil film parameters are functions of the shaft neck eccentricity e and the angular velocity Ω . The oil film pressure field of the elastic ring is related to its deformation function, and the deformation function is obtained by numerical calculation according to the finite element method. Therefore, the radial support reaction force F r and the circumferential support reaction force F τ must be obtained by numerical calculation. The equivalent oil film stiffness K and the equivalent oil film damping C are superimposed in the corresponding supporting matrix to realize the unit introduction of the elastic ring, and the new overall motion equation is solved iteratively to obtain the rotor response.

[0163] According to the structural characteristics, stress characteristics and working speed range of the rotor system, the modal requirements and response requirements of the elastic ring-rotor system are determined, so as to determine the design value of the supporting point stiffness and the design value of the supporting point damping;

[0164] According to the bearing type, the structure and size of the elastic ring inner bushing are determined, that is, the radius of the elastic ring is determined; according to the order of magnitude of the supporting point stiffness design value, the number of bosses is determined, and then the key stiffness parameters of the elastic ring are designed by using the optimization algorithm.

[0165] According to the structural characteristics of the rotor, the key vibration displacement limit value of the elastic ring-rotor system at the key measuring point, the key supporting external force limit value at the key measuring point, and the amplitude and phase of the unbalance are determined, and the key damping parameters of the elastic ring are determined in combination with the design value of the supporting point damping.

[0166] After completing the parameter optimization design, the design results are applied to the rotor system to carry out analysis and checking, and the effectiveness of the design results is verified.

[0167] In order to illustrate the extraction and optimization design method of the key structural parameters of the elastic ring provided by the present application, it is described in combination with the drawings. In this embodiment, the structure of a single-rotor system with an elastic ring is taken as an example for description.

[0168] Referring to Figure 2As shown, the elastic ring component structure diagram, the elastic ring 1 is set on the bearing 4, and the elastic ring 1 and the bearing 4 are provided with the elastic ring inner bushing 2, the outer side of the elastic ring 1 is provided with the elastic ring outer bushing 3, the elastic ring inner side is provided with a plurality of inner bosses 9 along the equidistant circumferential direction, the elastic ring outer side is provided with a plurality of outer bosses 10 along the equidistant circumferential direction, the inner oil film 6 is further provided between the adjacent inner bosses 9 on the elastic ring inner side, and the outer oil film 7 is further provided between the adjacent outer bosses 10 on the elastic ring outer side, wherein the inner oil film and the outer oil film are sequentially connected and dredged through the oil hole 8 penetrating the elastic ring, and in addition, the bearing 4 is set on the shaft journal 5.

[0169] Referring to Figure 3 As shown, the structure diagram of the single rotor system with elastic ring, the single rotor system with elastic ring includes a rotor disc shaft system and a supporting system. The rotor disc shaft system includes a first stage compressor disc 11, a second stage compressor disc 12, a third stage compressor disc 13, a grid disc 14 and a turbine disc 15 arranged in sequence and coaxially, wherein the first stage compressor disc 11 and the second stage compressor disc 12 are connected through a first stage drum 17, the second stage compressor disc 12 and the third stage compressor disc 13 are connected through a second stage drum 18, the third stage compressor disc 13 and the grid disc 14 are connected through a third stage drum 19, and the grid disc 14 and the turbine disc 15 are connected through a high pressure shaft 20.

[0170] The second stage compressor disc 12 is connected with one end of the high pressure compressor shaft 16 on the side away from the third stage compressor disc 13, and the other end of the high pressure compressor shaft 16 extends to the outside through the first stage compressor disc 11 to form a connecting end; the turbine disc 15 is connected with a high pressure turbine shaft 21 on the side away from the high pressure shaft 20.

[0171] The supporting system includes a third elastic support point 22 and a fourth elastic support point 24 arranged on the high pressure compressor shaft 16 and the high pressure turbine shaft 21 respectively; the third elastic support point 22 and the fourth elastic support point 24 are respectively provided with a three-point elastic ring 23 and a four-point elastic ring 25, and correspondingly, a three-point elastic ring inner bushing 26, a three-point elastic ring outer bushing 27, a four-point elastic ring inner bushing 28 and a four-point elastic ring outer bushing 29 need to be designed.

[0172] The elastic ring key structure parameter extraction and optimization design method provided in the embodiment includes:

[0173] Step one, obtain the elastic ring supporting stiffness and oil film dynamic characteristic parameters;

[0174] The solid domain and the fluid domain of the elastic ring component are modeled respectively. In this embodiment, the input parameters shown in Table 2 are substituted into the elastic ring deformation control equation to obtain the deformation function and the support stiffness of the elastic ring; on this basis, the deformation function result of the elastic ring is substituted into the elastic ring oil film pressure field control equation, and the equivalent oil film stiffness and equivalent oil film damping parameters of the elastic ring are obtained through numerical integration. It should be noted that the elastic ring is a nonlinear element, and its equivalent oil film parameters are functions of the shaft journal eccentricity e and angular velocity Ω . The shaft journal eccentricity e and angular velocity Ω are boundary parameters. In the analysis process, different shaft journal eccentricity parameters or different angular velocity parameters are substituted into the model to obtain a family of equivalent oil film parameter curves under different shaft journal eccentricities or different angular velocities.

[0175] Table 2 Parameters of the elastic ring

[0176]

[0177] In this embodiment, the finite element method proposed in “Maria A N, Ana A, Luis R, et al, Engineering Computation of Structures: The Finite Element Method, Springer International Publishing Switzerland, 2015.” is used to construct the arc plate element, obtain the deformation function of the elastic ring, and analyze the support stiffness characteristics of the elastic ring. Figure 4 The deformation function calculation results of a certain elastic ring in this embodiment are shown in the schematic diagram. Figure 4 In the schematic diagram, the horizontal axis of the coordinate system is the circumferential coordinate θ of the elastic ring, the vertical axis is the axial coordinate z of the elastic ring, and the vertical axis is the deformation r of the elastic ring. For ease of representation, the elastic ring is unfolded along the circumferential direction, θ and the change range of π is [0, 2 ). According to the deformation function calculation results of the elastic ring boss, combined with the force boundary conditions at the boss of the elastic ring, the support stiffness of the elastic ring can be calculated according to Hooke's law.

[0178] H In this embodiment, the parameters h = c , ε = e and c =2 p are introduced. ΩμR 2 P / c 2 , the oil film gap h , the journal eccentricity e , and the nodal pressure value p are non-dimensionalized. The governing equations of the elastic ring fluid domain are discretized by using the finite difference method, and are solved by using the successive over-relaxation iteration method to obtain the non-dimensional oil film pressure field.

[0179] Figure 5 is a schematic diagram of the non-dimensional oil film pressure field calculation result of an elastic ring in this embodiment. In the diagram, the horizontal axis of the coordinate system is the circumferential coordinate θ of the elastic ring, the vertical axis is the axial coordinate z of the elastic ring, and the vertical axis is the non-dimensional inner oil film pressure P in and the non-dimensional outer oil film pressure P out of the elastic ring, respectively. Similarly, for the convenience of representation, the elastic ring is unfolded along the circumferential direction, θ , and the range of variation of π is [0, 2 p in ΩμR 2 P in / c 2 in , and p out ΩμR 2 P out / c 2 out , the non-dimensional pressure can be converted into the dimensional pressure (actual pressure). In this embodiment, Simpson integration is used to numerically integrate the non-dimensional oil film pressure field calculation result to obtain the equivalent oil film stiffness and the equivalent oil film damping under the current journal eccentricity. Further, the journal eccentricity e is changed, the above work is repeated to obtain the variation law of the equivalent oil film stiffness and the equivalent oil film damping parameter with the eccentricity ratio, until e / c =1.

[0180] Step two, divide the key stiffness parameter and the key damping parameter;

[0181] ​​Specifically, by controlling the structural parameters of the elastic ring, its support stiffness parameters, equivalent oil film stiffness parameters, and equivalent oil film damping parameters, as well as the relative sensitivity of its dynamic characteristic parameters with respect to the structural parameters, are calculated. This yields the influence mechanism of key structural parameters on the dynamic parameters, determining the key stiffness and damping parameters for the elastic ring design, which serve as the theoretical basis and design foundation for step three. Table 3 shows the results of the relative sensitivity analysis.

[0182] Table 3. Results of relative sensitivity analysis

[0183]

[0184] Step 3: Establish the design process for key structural parameters of the elastic ring;

[0185] In this embodiment, the operating speed range of the single-rotor system with elastic rings is 0~5800 r / min. Based on the structural and stress characteristics of the rotor system, the design unbalance is determined as follows: 20 g∙cm unbalance on the first-stage compressor disk and 30 g∙cm unbalance on the turbine disk, both in phase. The key vibration displacement measurement points are the first-stage compressor disk and the turbine disk. The design constraints for the three-point and four-point elastic rings are:

[0186] Modal limitation: The simulated rotor tester has two modes within the operating speed range, and each elastic ring can reduce vibration in each mode.

[0187] Response Limitation: Under the design unbalance, the vibration displacement amplitude of the key measuring points of the simulated rotor tester within the operating speed range shall never exceed the limit of 50μm.

[0188] Step 31: Determine the design value of the elastic ring stiffness;

[0189] The modal characteristics of the rotor system in this embodiment were obtained using the finite element method proposed in "Rotor Dynamics of Aero-engines". When the stiffness of the three supports is 6 × 10⁻⁶... 6 N / m, four-point stiffness is 7.5×10 6 At N / m, the critical speeds of the rotor system are 2670 r / min and 5096 r / min, respectively, and the two-order mode shapes are as follows: Figure 6 As shown. The first-order mode shape is a translational mode shape, the second-order mode shape is a pitching mode shape, and the three- and four-support modes are located at... Figure 6 At the triangular node, the support points are far from the elastic centerline in both modes, indicating that the vibration displacement at the support points is large in both modes. This provides the necessary conditions for vibration reduction of the elastic ring and satisfies the modal constraint conditions. The design stiffness value of the three-support elastic ring. 6×10 6 N / m, design stiffness value of a four-point elastic ring 7.5 x 10 6 N / m.

[0190] Step 32, design key stiffness parameters;

[0191] In this embodiment, the bearing is selected according to the speed range of the rotor system, and the elastic ring radius is designed accordingly; the bearing selection result shows that the outer radius of the third elastic support point bearing is 55 mm, and the width is 16 mm; the outer radius of the fourth elastic support point bearing is 65 mm, and the width is 22 mm. Considering the design factors such as structural strength, the inner radii of the three-point elastic ring and the four-point elastic ring are designed to be 65.5 mm and 75.5 mm, respectively.

[0192] In this embodiment, the number of bosses and the boss width are determined according to the order of magnitude of the designed support stiffness; generally, in order to ensure uniformity of the support stiffness in all directions, the number of bosses is even. When the number of bosses increases from 10 to 12, the support stiffness of the elastic ring changes dramatically in order of magnitude, so the number of bosses is 10. Too large boss width will lead to dramatic changes in the support stiffness of the elastic ring, and too small boss width will lead to stress concentration at the boss. Generally, the boss width accounts for no more than 30% of the arc length of the elastic ring substructure; therefore, the boss width of the three-point elastic ring and the four-point elastic ring is 5 mm.

[0193] In this embodiment, the particle swarm optimization algorithm is used to optimize the thickness of the three-point elastic ring h 3, width L 3 and the thickness of the four-point elastic ring h 4, width L 4, the optimization objective function expression is:

[0194] (1)

[0195] In the formula, is the stiffness optimization objective function of the three-point elastic ring, is the stiffness value of the three-point elastic ring under the influence of parameters h 3 and L 3, is the stiffness optimization objective function of the four-point elastic ring, is the stiffness value of the four-point elastic ring under the influence of parameters h 4 and L 4. Specifically, the value range of the parameters to be optimized is shown in Table 4. Taking the particle vector dimension as 2 and the number of individuals in the population as 30, the optimization design results of the elastic ring thickness and the elastic ring width shown in Table 4 can be obtained.

[0196] Table 4 Optimization design results of elastic ring thickness and elastic ring width

[0197]

[0198] Step 33: Determine the design value of the elastic ring damping;

[0199] The response characteristics of the rotor system in this embodiment are obtained using the finite element method proposed in "Rotor Dynamics of Aero-engines". The response of the rotor system under undamped conditions when excited by a designed unbalance is as follows: Figure 7 As shown, the maximum amplitude of vibration displacement at key measuring points of the rotor system is 100.6 μm, which does not meet the response constraint conditions. Based on the additional damping proportional function of the rotor system and combined with the mode shapes of the rotor system, the design value of the three-support elastic ring damping is calculated. and the design value of the four-point elastic ring damping The proportional relationship. Specifically, the expression for the proportional function of the additional damping of the rotor system is:

[0200] (2)

[0201] In the formula, These are the weighting coefficients for the first-order mode. These are the weighting coefficients for the second-order modes. These weighting coefficients represent the degree of emphasis placed on each mode when allocating damping design values. It should be equal to 1. This represents the relative displacement values ​​of the nodes containing the three-supported elastic rings in the first-order mode. These represent the relative displacements of the nodes containing the four-point elastic rings in the first-order mode. These represent the relative displacement values ​​at the nodes containing the three-supported elastic rings in the second-order modal vibration mode. This represents the relative displacement values ​​of the nodes containing the four-point elastic rings in the second-order modal vibration. In this embodiment, =0.4, =0.6, =1.1336:1. According to the proportional relationship... Adding additional damping to the rotor system yields... ≈ 1700 N∙s / m, ≈1500N∙s / m, at which point the rotor response satisfies the response constraint condition.

[0202] Step 34: Design key damping parameters;

[0203] With the oil passage diameter set to 0.5mm and other parameters kept constant, only the single key damping parameter—the boss height—is changed. c Calculate the equivalent oil film damping parameters of the elastic ring extrusion oil film damper under different boss heights; due to the equivalent oil film damping... CWith the increase of the eccentricity ratio, the damping value in the small eccentricity ratio range of 0.1 is selected as the actual design value in the design process, so as to ensure that the designed damper can provide sufficient oil film damping in the whole eccentricity ratio range (0, 1]. In the embodiment, c 3=0.2mm, c 4=0.3mm, = 1626N∙s / m, =1496N∙s / m.

[0204] Step 35, accounting of the optimization design result

[0205] The key stiffness parameters and the key damping parameters of the design are substituted into the elastic ring component model and the rotor system model with the elastic ring to account the key stiffness parameters and the key damping parameters of the three-support-point elastic ring and the four-support-point elastic ring, and whether the modal limit condition and the response limit condition are met is checked. The actual support stiffness of the three-support-point elastic ring is 6.18*10 6 N / m, and the actual support stiffness of the four-support-point elastic ring is 7.58*10 6 N / m. The response of the rotor system excited by the unbalance under the condition of damping is shown in Figure 8 . Figure 8 In the embodiment, the two-order critical speeds of the rotor system with the elastic ring in the working speed range change little compared with the state without damping, and the modal limit condition is met; the vibration displacement of the key measuring point is 48.17 μm, the damping ratio can reach 52.1%, and the response limit condition is met. Thus, the optimization design of the key structure parameters of the elastic ring in the rotor system is completed.

[0206] The above only describes the preferred embodiments of the present application, and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for extracting and optimizing the key structural parameters of an elastic ring, characterized in that, The structural parameter design for the elastic ring installed on the rotor system support in aero-engines includes: Obtain the parameters of the elastic ring; Based on the parameters of the elastic ring, the support stiffness parameters and oil film dynamic characteristic parameters of the elastic ring are obtained; among them, the oil film dynamic characteristic parameters include the equivalent oil film stiffness and the equivalent oil film damping. Based on the structural parameters of different elastic rings, and the corresponding elastic ring support stiffness parameters and oil film dynamic characteristic parameters, a mapping function is constructed from the structural parameters to the support stiffness parameters and oil film dynamic characteristic parameters. The relative sensitivity of the support stiffness parameters and oil film dynamics parameters with respect to the structural parameters is obtained based on the mapping function; Based on relative sensitivity, the key stiffness parameters and key damping parameters of the elastic ring design are divided from the structural parameters of the elastic ring. Define the design requirements for the structural parameters of the elastic ring, and construct the objective function and constraints for the structural parameters of the elastic ring; Based on the design requirements, objective function, and constraints, the key stiffness parameters of the partition are designed first, and then the key damping parameters of the partition are designed. Some of the structural parameters of the elastic ring are both critical stiffness parameters and critical damping parameters. In the design process, after determining that the stiffness design requirements are met, the single critical damping parameter is adjusted to make the elastic ring meet the damping design requirements.

2. The method for extracting and optimizing the key structural parameters of an elastic ring according to claim 1, characterized in that, The design requirements for the structural parameters of the elastic ring are defined, and the objective function and constraints for the structural parameters of the elastic ring are constructed, including: A dynamic model of the elastic ring-rotor system was established, and the modal characteristics and response characteristics of the elastic ring-rotor system were calculated. The design requirements for the key structural parameters of the elastic ring are determined based on the modal and response characteristics, and the objective function and constraints for the structural parameters of the elastic ring are constructed.

3. The method for extracting and optimizing the key structural parameters of an elastic ring according to claim 1, characterized in that, The mapping function between structural parameters and support stiffness parameters and oil film dynamic characteristic parameters is constructed as follows: In the formula, For the stiffness of the elastic ring support; The equivalent oil film stiffness of the elastic ring; This is equivalent to oil film damping; This is a mapping function from structural parameters to support stiffness parameters; This is a mapping function for structural parameters pointing to the equivalent oil film stiffness; This is a mapping function for structural parameters pointing to the equivalent oil film damping; n This represents the number of bosses; R The radius of the elastic ring; h The thickness of the elastic ring; L The width of the elastic ring; b This is the width of the boss; c This is the height of the boss; The relative sensitivity is: In the formula, S i Relative sensitivity; For the dependent variable parameter, take ; For the independent variable parameter, take ; To control the change in the dependent variable parameter caused by a change in a single independent variable parameter during the process; To control the change of a single independent variable parameter during the process.

4. The method for extracting and optimizing the key structural parameters of an elastic ring according to claim 1, characterized in that, The key stiffness parameters of the partition are optimized, including: Define the design value of the elastic ring stiffness according to the design requirements; Based on the design value of the elastic ring stiffness and the objective function, key stiffness parameters are designed. The key stiffness parameters for the division include the number of bosses, the radius of the elastic ring, the thickness of the elastic ring, the width of the elastic ring, and the width of the bosses. Select bearings based on the rotational speed range of the rotor system, and design the elastic ring radius based on the selected bearings; The number and width of the bosses are determined based on the design value of the elastic ring stiffness. The thickness and width of the elastic ring are optimized based on the objective function. The objective function is: In the formula, For the first The objective function for stiffness optimization of a single-support elastic ring; For parameters and The first under the influence Stiffness values ​​of the elastic rings at each fulcrum; For the first The design value of the stiffness of the elastic ring at each fulcrum.

5. The method for extracting and optimizing the key structural parameters of an elastic ring according to claim 1, characterized in that, The key damping parameters for the division are designed, including: Define the design value of the elastic ring damping according to the design requirements; Based on the design value of the elastic ring damping and the constraints, the key damping parameters are designed. The constraints are the vibration displacement limit values ​​of the key measuring points of the elastic ring-rotor system, the external force limit values ​​of the support of the key measuring points, and the amplitude and phase of the design unbalance, obtained based on the structural characteristics of the rotor.

6. The method for extracting and optimizing the key structural parameters of an elastic ring according to claim 1, characterized in that, Also includes: Based on the key stiffness and key damping parameters of the design, modal verification and response verification of the elastic ring-rotor system are carried out. If the design requirements are met, the design of the key parameters of the elastic ring is completed. If the design requirements are not met, the optimization design range of the elastic ring structure parameters is adjusted, and the design is iterated.

7. The method for extracting and optimizing the key structural parameters of an elastic ring according to claim 1, characterized in that, The stiffness parameters of the elastic ring support are obtained according to the following steps: Based on the finite element method, a solid domain model of the elastic ring is established according to the structural parameters, material parameters and mesh parameters of the elastic ring, and the deformation control equation of the elastic ring is obtained. Define the boundary conditions of the elastic ring solid domain, solve the deformation control equation of the elastic ring, and obtain the deformation function and support stiffness parameters of the elastic ring.

8. The method for extracting and optimizing the key structural parameters of an elastic ring according to claim 7, characterized in that, The boundary conditions for the elastic ring solid domain are: In the formula, For the radial displacement of the nodes of the elastic ring element; The journal eccentricity of the outer bushing of the elastic ring; For the circumferential coordinates of the elastic ring; The journal eccentricity phase angle of the outer bushing of the elastic ring; This refers to the radial force acting on the nodes of the elastic ring element; The force is the circumferential force acting on the nodes of the elastic ring element; Region I refers to the inner boss of the elastic ring on the side compressed by the journal; Region II refers to the outer boss of the elastic ring on the side compressed by the journal; Region III refers to all elastic ring segments, the inner boss of the elastic ring on the side not compressed by the journal, and the outer boss of the elastic ring on the side not compressed by the journal.

9. The method for extracting and optimizing the key structural parameters of an elastic ring according to claim 1, characterized in that, The oil film dynamics parameters are obtained according to the following steps: Based on the structural parameters, lubricating oil parameters, and mesh parameters of the elastic ring, the fluid domain gap function of the elastic ring is constructed by combining the deformation function results of the elastic ring, and then substituted into the generalized Reynolds equation to establish the control equation of the oil film pressure field of the elastic ring. Define the boundary conditions of the elastic annular fluid domain, solve the governing equations of the elastic annular oil film pressure field, and obtain the oil film dynamic characteristic parameters; The gap function of the elastic annular fluid domain is: In the formula, This is the deformation of the elastic ring. The height of the outer boss of the elastic ring; The height of the inner boss of the elastic ring; This is a function of the gap in the oil film within the elastic ring; The gap function of the outer oil film of the elastic ring; The journal eccentricity of the outer bushing of the elastic ring; Let be the circumferential coordinates of the elastic ring.

10. The method for extracting and optimizing the key structural parameters of an elastic ring according to claim 9, characterized in that, The governing equation for the pressure field of the elastic annular oil film is: In the formula, The radius of the elastic ring; For the axial coordinates of the elastic ring model; This is a function of the gap in the oil film within the elastic ring; The gap function of the outer oil film of the elastic ring; This refers to the oil film pressure inside the elastic ring. This refers to the pressure of the elastic ring outer oil film. The viscosity of the lubricating oil; The circumferential velocity boundary of the inner bushing end of the oil film inside the elastic ring; The circumferential velocity boundary at the end of the elastic ring is the oil film inside the elastic ring. The radial velocity boundary of the inner bushing end of the oil film inside the elastic ring; The radial velocity boundary at the elastic ring end of the oil film inside the elastic ring; The circumferential velocity boundary of the elastic ring end of the outer oil film of the elastic ring; The circumferential velocity boundary of the outer bushing end of the elastic ring outer oil film; The radial velocity boundary of the elastic ring end of the outer oil film of the elastic ring; The radial velocity boundary at the outer bushing end of the elastic ring outer oil film; For the circumferential coordinates of the elastic ring; The boundary conditions for the elastic annular fluid domain are: In the formula, The angular velocity of the journal whirl; For time; The journal eccentricity of the outer bushing of the elastic ring; Let be the first derivative of the journal eccentricity of the elastic ring outer bushing with respect to time.

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