CN-121302826-B - Mechanical property evaluation method for aeroengine load-bearing frame

CN121302826BCN 121302826 BCN121302826 BCN 121302826BCN-121302826-B

Abstract

The application belongs to the field of aero-engines, and particularly relates to a mechanical property evaluation method of a bearing frame of an aero-engine. The method comprises the steps of S10, carrying out parameterized modeling on a force-bearing frame structure scheme to obtain a finite element structure model, S20, carrying out simulation calculation on mechanical characteristic parameters of the force-bearing frame according to the finite element structure model to obtain a mechanical characteristic result, and S30, carrying out comprehensive scoring on the mechanical characteristic parameters of the force-bearing frame according to the mechanical characteristic result. The mechanical property evaluation method of the aeroengine force-bearing frame can realize the mechanical property evaluation of the force-bearing frame structure scheme, and complete the comparison analysis of the force-bearing frame structure scheme and determine the optimal design direction.

Inventors

LIANG TIANYU
LIU YONGQUAN
WANG DONG
SONG YANG
FANG HAO
JIANG HONGWEI
BAO YU

Assignees

中国航发沈阳发动机研究所

Dates

Publication Date: 20260505
Application Date: 20251212

Claims (7)

1. The mechanical property evaluation method of the aeroengine bearing frame is characterized by comprising the following steps of: S10, carrying out parameterized modeling on a force-bearing frame structure scheme to obtain a finite element structure model, wherein the method comprises the following steps of: S11, acquiring a force bearing frame structure scheme, and extracting geometric features of a force transmission structure in the force bearing frame structure scheme; S12, extracting geometric parameters of structural elements according to the geometric features, and constructing a parameterized structural model of the bearing frame structural scheme; S13, constructing a finite element structure model of the bearing frame structure scheme according to the parameterized structure model; S14, coding a structural interface which participates in simulation calculation of mechanical characteristic parameters of the bearing frame in the finite element structural model to obtain a structural interface coding node; S20, carrying out simulation calculation on mechanical characteristic parameters of the bearing frame according to the finite element structure model to obtain a mechanical characteristic result; S30, comprehensively scoring mechanical characteristic parameters of the bearing frame according to the mechanical characteristic result; in S13, constructing a finite element structure model of the force-bearing frame structure scheme according to the parameterized structure model, including: Performing grid division on the parameterized structure model; configuring material properties for the parameterized structural model; applying a fixed constraint boundary condition on the front mounting edge and the rear mounting edge of the outer culvert casing in the parameterized structural model; s14, coding a structural interface which participates in simulation calculation of mechanical characteristic parameters of the bearing frame in the finite element structural model to obtain a structural interface coding node, wherein the method comprises the following steps: Coding the inner ring surface of the bearing pedestal to obtain a bearing pedestal inner ring surface coding node, wherein the bearing pedestal inner ring surface coding node is a node for applying force during simulation calculation; And coding annular surfaces of the front mounting edge and the rear mounting edge of the outer culvert casing to obtain mounting edge annular surface coding nodes, wherein the mounting edge annular surface coding nodes apply fixed constraint in simulation calculation.
2. The method for evaluating mechanical properties of an aircraft engine load-bearing frame according to claim 1, wherein in S20, performing simulation calculation on mechanical properties parameters of the load-bearing frame according to the finite element structure model to obtain mechanical properties results, comprises: s21, carrying out simulation calculation on the stiffness characteristic parameters of the bearing frame according to the finite element structure model to obtain a stiffness characteristic result; S22, carrying out simulation calculation on constrained modal characteristic parameters of the bearing frame according to the finite element structure model to obtain a constrained modal characteristic result; s23, carrying out simulation calculation on the vibration transmission characteristic parameters of the bearing frame according to the finite element structure model to obtain a vibration transmission characteristic result; S24, carrying out simulation calculation on thermal deformation characteristic parameters of the bearing frame according to the finite element structure model to obtain a thermal deformation characteristic result.
3. The method for evaluating mechanical properties of an aircraft engine load-bearing frame according to claim 2, wherein in S21, the stiffness property result is obtained by performing a simulation calculation of the stiffness property parameter of the load-bearing frame according to the finite element structure model, including: And carrying out simulation calculation on the static stiffness characteristic parameters of the bearing frame according to the finite element structure model to obtain a static stiffness array: ; Wherein K s,i is a static stiffness array, F s is static uniform force applied to the surface coding node of the inner ring of the bearing, and u i is deformation amplitude of the surface coding node of the i-th inner ring of the bearing under the first simulation working condition; According to the finite element structure model, carrying out simulation calculation on dynamic stiffness characteristic parameters of the bearing frame to obtain a dynamic stiffness matrix: ; Wherein, the For the dynamic stiffness matrix at the excitation frequency f 0 , a d is the amplitude of the uniformly distributed force of the vibration frequency change applied to the bearing seat inner ring surface coding node, and y i is the deformation amplitude of the ith bearing seat inner ring surface coding node under the second simulation working condition.
4. The method for evaluating mechanical properties of an aircraft engine load-bearing frame according to claim 3, wherein in S22, performing simulation calculation on constraint modal property parameters of the load-bearing frame according to the finite element structure model to obtain constraint modal property results, includes: And carrying out simulation calculation on the constrained modal characteristic parameters of the bearing frame according to the finite element structure model, extracting the constrained modal frequencies of the bearing frame within the rotation frequency and the pneumatic excitation frequency of the rotor, and obtaining a constrained modal frequency array f n , wherein n is the order.
5. The method for evaluating mechanical properties of an aircraft engine load-bearing frame according to claim 4, wherein in S23, performing simulation calculation of vibration transmission characteristic parameters of the load-bearing frame according to the finite element structure model to obtain a vibration transmission characteristic result comprises: According to the finite element structure model, carrying out simulation calculation on the vibration transmission characteristic parameters of the bearing frame to obtain a vibration displacement transmission matrix: ; Wherein phi i,j is a vibration displacement transmission matrix, p i is the vibration displacement amplitude of the coding node of the inner ring surface of the ith bearing seat, and q i is the vibration displacement amplitude of the coding node of the annular surface of the ith mounting side.
6. The method for evaluating mechanical properties of an aircraft engine load-bearing frame according to claim 5, wherein in S24, performing thermal deformation property parameter simulation calculation of the load-bearing frame according to the finite element structure model to obtain a thermal deformation property result comprises: and carrying out thermal deformation characteristic parameter simulation calculation of the bearing frame according to the finite element structure model, and extracting thermal deformation displacement at the inner ring surface coding node of the bearing seat and the mounting edge annular surface coding node to obtain a thermal deformation displacement array X i .
7. The method for evaluating mechanical properties of an aircraft engine load-bearing frame according to claim 6, wherein in S30, the comprehensive scoring of mechanical property parameters of the load-bearing frame is performed according to the mechanical property result, including: calculating a static stiffness fraction according to the static stiffness array: ; ; wherein R s,i is the static stiffness fraction of different static stiffness array elements, R s is the total static stiffness fraction, and K bearing is the pivot bearing stiffness; Calculating the dynamic stiffness fraction according to the dynamic stiffness matrix: ; ; Wherein R d,i is the dynamic stiffness fraction of different dynamic stiffness matrix elements, and R d is the total dynamic stiffness fraction; calculating constraint mode scores according to the constraint mode frequency array: ; Wherein, R modal is the constraint mode fraction, f k is the first-order constraint mode frequency closest to the excitation frequency f 0 in the constraint mode frequency array f n ; calculating a vibration transfer fraction according to the vibration displacement transfer matrix: ; wherein R trans is a vibration transmission fraction, and phi k is an average number of a vibration displacement transmission matrix phi i,j ; calculating a thermal deformation fraction according to the thermal deformation displacement array: ; ; Wherein R tempi is the thermal deformation fraction of the array elements with different thermal deformation displacement, R temp is the total thermal deformation fraction, and L 0 is the original geometric dimension of the structure; Calculating the total score of mechanical properties of the bearing frame: ; Wherein R is the total fraction of mechanical properties of the bearing frame, and alpha 1 、α 2 、α 3 、α 4 、α 5 is the weight.

Description

Mechanical property evaluation method for aeroengine load-bearing frame Technical Field The application belongs to the field of aero-engines, and particularly relates to a mechanical property evaluation method of a bearing frame of an aero-engine. Background The bearing frame is the most critical bearing structure of the aeroengine, and has the main function of providing support and restraint for engine rotors and accessories and transmitting engine thrust and other loads to the aircraft through the mounting joints. The design of the bearing frame is limited by a rotor fulcrum, a main runner, a cooling air circuit, a lubricating oil circuit and the like, the bearing capacity of the structure must be improved in a limited space, the weight is reduced, and the complex and changeable load environments such as rotor rotation, pneumatic excitation, a temperature field and the like are required to be considered in detail, so that the damage of a bearing and the transmission of harmful vibration to an aircraft are reduced, and the mechanical characteristics of the bearing frame are required to be strictly checked in the development process of an aeroengine. At present, the newly developed structural design of the aeroengine bearing frame is generally referred to the existing model, and on the basis, the detailed design is developed on the basis of checking strength, avoiding resonance and reducing weight, so that the requirements of increasingly light weight and heavy load bearing frames of high-performance, high-reliability and long-service-life engines can not be met. In order to improve the design level of the aeroengine bearing frame, whether the bearing capacity, the heat deformation resistance and the vibration transmission attenuation of the bearing frame meet the design requirements needs to be judged in the design stage of the engine scheme. The existing mechanical property evaluation method of the aeroengine load-bearing frame has the following defects: 1. The mechanical property values of the force-bearing frame are usually related to the measured structure positions, and the prior method does not specify how the structure positions should be selected, so that the mechanical property parameters calculated by different overall structure designers are different, and thus the mechanical property evaluation errors of the force-bearing frame can be caused. 2. The mechanical characteristic calculation results of different bearing frame structure schemes can only be qualitatively compared to obtain advantages and disadvantages, and a unified mechanical characteristic parameter judging method is lacked, so that an overall structure designer cannot determine an optimal scheme for balancing indexes in all aspects in a large number of structure schemes. Accordingly, there is a need for a solution that overcomes or mitigates at least one of the above-mentioned drawbacks of the prior art. Disclosure of Invention The application aims to provide a mechanical property evaluation method of an aeroengine bearing frame, which aims to solve at least one problem existing in the prior art. The technical scheme of the application is as follows: A mechanical property evaluation method of an aeroengine bearing frame comprises the following steps: S10, carrying out parameterized modeling on a force-bearing frame structure scheme to obtain a finite element structure model, wherein the method comprises the following steps of: S11, acquiring a force bearing frame structure scheme, and extracting geometric features of a force transmission structure in the force bearing frame structure scheme; S12, extracting geometric parameters of structural elements according to the geometric features, and constructing a parameterized structural model of the bearing frame structural scheme; S13, constructing a finite element structure model of the bearing frame structure scheme according to the parameterized structure model; S14, coding a structural interface which participates in simulation calculation of mechanical characteristic parameters of the bearing frame in the finite element structural model to obtain a structural interface coding node; S20, carrying out simulation calculation on mechanical characteristic parameters of the bearing frame according to the finite element structure model to obtain a mechanical characteristic result; S30, comprehensively scoring mechanical characteristic parameters of the bearing frame according to the mechanical characteristic results. In at least one embodiment of the present application, in S13, constructing a finite element structure model of the force-bearing framework structure scheme according to the parameterized structure model includes: Performing grid division on the parameterized structure model; configuring material properties for the parameterized structural model; And applying fixed constraint boundary conditions on the front mounting edge and the rear mounting edge of the outer culvert casing