CN117113583A - Quantitative assessment method for contact damage of aviation gas turbine connecting interface - Google Patents

Quantitative assessment method for contact damage of aviation gas turbine connecting interface Download PDF

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Publication number
CN117113583A
CN117113583A CN202311151776.9A CN202311151776A CN117113583A CN 117113583 A CN117113583 A CN 117113583A CN 202311151776 A CN202311151776 A CN 202311151776A CN 117113583 A CN117113583 A CN 117113583A
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contact
engine
stress
evaluation
parameters
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王东
田静
洪杰
程荣辉
洪昊然
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AECC Shenyang Engine Research Institute
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AECC Shenyang Engine Research Institute
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    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00Computer-aided design [CAD]
    • G06F30/10Geometric CAD
    • G06F30/17Mechanical parametric or variational design
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00Computer-aided design [CAD]
    • G06F30/20Design optimisation, verification or simulation
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F2119/00Details relating to the type or aim of the analysis or the optimisation
    • G06F2119/04Ageing analysis or optimisation against ageing
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F2119/00Details relating to the type or aim of the analysis or the optimisation
    • G06F2119/14Force analysis or force optimisation, e.g. static or dynamic forces
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T90/00Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation

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Abstract

The application belongs to the field of aero-engine design, and relates to a quantitative assessment method for contact damage of an aero-gas turbine connecting interface, which comprises the steps of firstly establishing a simulation model corresponding to an engine by acquiring structural parameters of the engine to be assessed, then respectively inputting a plurality of groups of operation data into the simulation model, collecting operation results of the data in the simulation model, respectively calculating quantitative assessment parameters corresponding to different input data, and respectively setting assessment tables of different parameters according to the result distribution of the quantitative assessment parameters obtained by calculation; the evaluation tables can directly complete qualitative evaluation of the working performance of the engine, obtain quantitative results of quantitative evaluation parameters in the actual working process of the engine for the engine in a parameter calculation mode, and are used for visually representing the influence of interface damage on the contact state of the connecting interface and the loss of the connecting rigidity, and can be also used for evaluation analysis of structural mechanics.

Description

Quantitative assessment method for contact damage of aviation gas turbine connecting interface
Technical Field
The application belongs to the field of aero-engine design, and particularly relates to a quantitative assessment method for contact damage of a connecting interface of an aero-gas turbine.
Background
The connecting interface in the structural system refers to a joint of two objects which are pressed by a physical way and is used for transmitting the load between the two objects or playing a role in restraining displacement. According to the load and deformation conditions of the contact surfaces on the connecting interface, the contact state can be qualitatively divided into four modes of viscous contact, sliding contact, quasi-contact and separation, wherein only the connecting interface is in the viscous and sliding contact states, the force and the load can be transmitted, and the force effect is generated between the contact surfaces.
The structural damage refers to the phenomenon that structural members and matching interfaces deform, break, fatigue, wear, corrosion and the like due to the action of a load environment in the use process of the structure, and the mechanical properties of a structural system are changed in a range capable of completing a specified function, so that the initial performance is not benefited. Structural damage is essentially different from structural failure, which generally refers to the loss of a structure from its intended function under intended use conditions. The phenomenon in which a structure loses its ability to withstand a prescribed load due to separation, breakage, destabilization, excessive deformation, and abnormal distortion of the structure and its constituent parts is referred to as structural failure.
When the working state of the rotor of the gas turbine engine changes, the working load applied to the connecting structure also changes correspondingly, and interface stress and slippage are inevitably caused to fluctuate within a certain range, so that the connecting interface is caused to change in a manner that the bearing/restraining function of the connecting interface is not facilitated, namely, interface damage occurs. Interface damage can be classified into fatigue damage, friction damage, and slip damage according to the function change caused.
The gas turbine engine interface connection rotor structure system can divide the connection interface contact damage failure into three types of contact fatigue damage, interface sliding (constraint failure) and interface abrasion according to the structural characteristics and the working load environment characteristics. In the practical use of the interface connection rotor structure system, certain dispersity exists in the assembly/process/load characteristic parameters such as assembly pretightening force, assembly interference magnitude, interface friction coefficient, external load amplitude, cycle number and the like, and the interface contact characteristic parameters are changed, so that the damage of the rotor connection interface is obviously nondeterminacy. In the past, the degree of damage of a connecting interface is mainly represented by qualitative description, the degree of contact damage of the interface cannot be represented by quantitative parameters, and the interface damage cannot be used for evaluating and analyzing the mechanical characteristics of the structure.
Disclosure of Invention
The application aims to provide a quantitative assessment method for contact damage of an aviation gas turbine connecting interface, which aims to solve the problem that the contact degree of a section cannot be represented by quantitative parameters in the prior art.
The technical scheme of the application is as follows: a quantitative assessment method for contact damage of an aviation gas turbine connection interface comprises the following steps:
obtaining structural parameters of an engine to be evaluated, and establishing a simulation model corresponding to the engine;
acquiring multiple sets of operation data corresponding to different working nodes of an engine and respectively inputting the multiple sets of operation data into a simulation model, wherein the same working node also has the multiple sets of operation data, acquiring operation results of the data in the simulation model and respectively calculating quantitative evaluation parameters corresponding to the different input data, and the method comprises the following steps: the contact state coefficient, the contact stress, the elastoplastic deformation energy and the contact friction work of the connecting interface;
setting a contact state coefficient evaluation table, a contact stress evaluation table, an elastoplastic deformation energy evaluation table and a connection interface contact friction work evaluation table according to the calculated multiple groups of contact state coefficients, contact stress, elastoplastic deformation energy and connection interface contact friction work result distribution;
after the engine works, acquiring real machine data of the engine, respectively calculating a contact state coefficient, a contact stress, elastoplastic deformation energy and a connection interface contact friction work, and respectively evaluating the contact state coefficient, the contact stress, the elastoplastic deformation energy and the connection interface contact friction work through a contact state coefficient evaluation table, a contact stress evaluation table, an elastoplastic deformation energy evaluation table and a connection interface contact friction work grade table to obtain an evaluation result.
Preferably, the contact state coefficient C conta The calculation formula of (2) is as follows:
wherein A is sticking 、A sliding Viscous contact area and sliding contact area, respectively; a is that total Is the total area of the contact surface;
the contact stress is calculated by boundary conditions;
the elastic plasticity variable performance is irreversible dissipation energy D, and the calculation formula of the irreversible dissipation energy D is as follows:
D=k p k s σ a Δε
wherein k is s Is of the form factor, sigma a To contact normal stress amplitude, k p Is plastic deformation, and delta epsilon is the normal deformation vector of the contact surface node;
the calculation formula of the friction work of the contact interface in unit area is as follows:
dw=μ|σ n ||δ|dA
wherein mu is the friction coefficient of the contact surface; sigma (sigma) n Is normal contact stress; delta is the relative slippage of the contact nodes.
Preferably, the contact state coefficient evaluation table, the contact stress evaluation table, the elastoplastic deformation energy evaluation table and the connection interface contact friction work grade table are all good, general, poor and poor, wherein when the corresponding parameters are in good and general states, the engine is normal under the parameters, and different judgment thresholds are respectively set at different grades.
According to the quantitative assessment method for the contact damage of the connection interface of the aviation gas turbine, a simulation model corresponding to the engine is built by acquiring structural parameters of the engine to be assessed, then a plurality of groups of operation data are respectively input into the simulation model, operation results of the data in the simulation model are acquired, quantitative assessment parameters corresponding to different input data are respectively calculated, and assessment tables of different parameters are respectively set according to the result distribution of the calculated quantitative assessment parameters; the evaluation tables can directly complete qualitative evaluation of the working performance of the engine, obtain quantitative results of quantitative evaluation parameters in the actual working process of the engine for the engine in a parameter calculation mode, and are used for visually representing the influence of interface damage on the contact state of the connecting interface and the loss of the connecting rigidity, and can be also used for evaluation analysis of structural mechanics.
Drawings
In order to more clearly illustrate the technical solution provided by the present application, the following description will briefly refer to the accompanying drawings. It will be apparent that the figures described below are merely some embodiments of the application.
FIG. 1 is a schematic overall flow chart of the present application.
Detailed Description
The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
A quantitative assessment method for contact damage of an aviation gas turbine connecting interface is shown in fig. 1, and comprises the following steps:
step S100, obtaining structural parameters of the engine to be evaluated to establish a simulation model corresponding to the engine, or directly using the existing simulation model, wherein different models of engines need to be established, or using the existing simulation model, or creating a simulation model;
step S200, obtaining multiple groups of operation data corresponding to different working nodes of the engine and respectively inputting the multiple groups of operation data into the simulation model, wherein the same working node also has the multiple groups of operation data, collecting operation results of the data in the simulation model and respectively calculating quantitative evaluation parameters corresponding to the different input data, and the method comprises the following steps: the contact state coefficient, the contact stress, the elastoplastic deformation energy and the contact friction work of the connecting interface;
coefficient of contact state
The contact state coefficient is used as a characteristic parameter for evaluating the contact state of the interface and is used for reflecting the relative size of the bearing contact area to the total area of the matching surface, and the larger the magnitude of the contact state coefficient is, the more stable the contact surface is. Coefficient of contact state C conta Summing the percentage of the area in the viscous contact state and the sliding contact state to the total area of the contact surface; coefficient of contact state C conta The calculation formula of (2) is as follows:
wherein A is sticking 、A sliding Viscous contact area and sliding contact area, respectively; a is that total Is the total area of the contact surface. The viscous contact area, the sliding contact area, and the total contact area can be obtained by checking bytes by decomposition of the engine.
For specific structures and using load conditions, the contact state coefficients required for ensuring the stable matching of the connecting interfaces can be determined according to design experience. The connection interface can also be evaluated by comparing the change of the distribution coefficient of the contact state under different states.
Contact stress
Contact stress is a major parameter used to describe the contact damage that produces stress control at the connection interface, which can be divided into maximum contact stress and average contact stress due to the non-uniformity of interface contact stress distribution. The maximum contact stress is used for evaluating the damage degree of the interface, and the average contact stress is used for evaluating the stress reserve of the connecting interface and the stress state of the connecting interface.
The maximum contact stress-as the mating surfaces of the mechanical components are rough surfaces, the actual contact area is much smaller than the macroscopic contact area. Under the action of contact pressure, microscopic plastic deformation is generated on the microscopic contact surface, and the deformation and the surface fatigue are generatedThe initiation of fatigue cracks is related. By calculation of boundary conditions, the local stress value of the material surface is the weakest part of the whole component, so that the material surface is only provided that the material surface has the largest contact stress sigma n Not exceeding the surface micro yield strength sigma ms The surface of the material is not subject to fatigue failure, namely:
σ n <σ ms
wherein the surface micro yield strength sigma ms Is a mechanical parameter of the resistance of the surface of the reaction material to plastic deformation. Related researches show that the yield strength value and the symmetrical tensile and compressive fatigue limit sigma of the material -1 Proximity. Maximum contact stress sigma of material surface n The calculation adopts the existing formula, and detailed description is omitted.
Average contact stress-when designing the stress degree of the connecting interface, the mating surface needs to be ensured to be kept in a pressed state under any state so as to meet the technical requirements of centering/positioning. The contact stress distribution of the mating surface is generally strongly non-uniform, so that the average contact stress sigma is initially adopted in the study aver The state of compression of the contact surface will be described.
In addition, the average contact stress may reflect the amount of mating pressure reserve on the active contact surface, with the larger the magnitude the more difficult the connection interface to loosen and the higher the connection structure robustness. Since the average stress can describe the pressure distribution over the whole contact surface, it is used for a robust design of the connection structure.
Elastic plastic deformation energy
The elastoplastic deformation energy is the basis for quantitative analysis of fatigue damage by energy, and the sum of the dissipated energy generated by each stress cycle is constant during the fatigue life. Irreversible dissipation energy D and stress amplitude sigma a Nonelastic deformation (non-recoverable deformation) Δε n Is proportional to the product of (a), namely:
D=k s σ a Δε n
in the above, k s The shape factor can be selected according to actual test conditions.
For one stress cycle, the material undergoes inelastic deformation deltaε n It is difficult to measure, and therefore, the irreversible deformation energy density e of the contact surface is defined to represent the irreversible dissipation energy D. Assuming a proportion k in each contact deformation p The non-recoverable deformation energy density e is the contact normal stress amplitude sigma a The product of the normal deformation vector delta epsilon of the contact surface node, namely:
e=σ a Δε
at this time, the irreversible dissipation energy D can be expressed as:
D=k p k s σ a Δε
wherein k is s Is of the form factor, sigma a To contact normal stress amplitude, k p For plastic deformation, Δε is the normal deformation vector of the contact surface node.
Connection interface contact friction work
The contact friction work of the connecting interface reflects the damage degree of the fretting wear process to the interface. The contact friction work and the inching damage life have inverse proportion relation, can be used as parameters for evaluating interface abrasion, and the friction work of unit area is defined as:
the calculation formula of the friction work of the contact interface in unit area is as follows:
dw=μ|σ n ||δ|dA
wherein mu is the friction coefficient of the contact surface; sigma (sigma) n Is normal contact stress; delta is the relative slippage of the contact nodes. The parameters in the above calculation formula can be obtained through decomposition inspection, direct acquisition or calculation.
Through the step, the damage degree of the connecting interface in the engine is quantitatively simulated, and then the damage degree of the actual connecting interface of the engine can be obtained only by comparing and calculating corresponding parameters in the actual working process of the engine.
Step S300, setting a contact state coefficient evaluation table, a contact stress evaluation table, an elastoplastic deformation energy evaluation table and a connection interface contact friction work evaluation table according to the calculated multiple groups of contact state coefficients, contact stress, elastoplastic deformation energy and connection interface contact friction work result distribution;
the distribution of the results of different quantitative evaluation parameters is different, but the numerical range of the corresponding quantitative evaluation parameters can be directly obtained, and then the judgment threshold value is quantitatively given according to the current design experience which parameters belong to the parameters with normal performance and which parameters belong to the parameters with abnormal performance and which parameters belong to the parameters with good surface.
The contact state coefficient evaluation table, the contact stress evaluation table, the elastoplastic deformation energy evaluation table and the connection interface contact friction work grade table are all provided with excellent, general, poor and poor, wherein when corresponding parameters are in excellent and general states, the engine is normally operated under the parameters, and different judgment thresholds are respectively set at different grades.
Taking a contact state coefficient as an example, the sum of the bonding contact area and the sliding contact area of the engine under two different working nodes is A and B respectively, judging that the evaluation grade of A is good through a threshold value, if the evaluation grade of B is poor, the corresponding structure of the engine does not need to be optimized when the evaluation grade is good, and the corresponding structure of the engine needs to be optimized when the evaluation grade is poor, and carrying out a simulation test again until the general requirement of evaluation is met.
And S400, after the engine works, collecting real machine data of the engine, respectively calculating a contact state coefficient, contact stress, elastoplastic deformation energy and connection interface contact friction work, and respectively evaluating the contact state coefficient, the contact stress, elastoplastic deformation energy and the connection interface contact friction work through a contact state coefficient evaluation table, a contact stress evaluation table, an elastoplastic deformation energy evaluation table and a connection interface contact friction work grade table to obtain an evaluation result.
According to the application, a simulation model corresponding to the engine is built by acquiring structural parameters of the engine to be evaluated, then a plurality of groups of operation data are respectively input into the simulation model, operation results of the data in the simulation model are acquired, quantitative evaluation parameters corresponding to different input data are respectively calculated, and evaluation tables of different parameters are respectively set according to the result distribution of the calculated quantitative evaluation parameters; the evaluation tables can directly complete qualitative evaluation of the working performance of the engine, obtain quantitative results of quantitative evaluation parameters in the actual working process of the engine for the engine in a parameter calculation mode, and are used for visually representing the influence of interface damage on the contact state of the connecting interface and the loss of the connecting rigidity, and can be also used for evaluation analysis of structural mechanics.
The last points to be described are: first, in the description of the present application, it should be noted that, unless otherwise specified and defined, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be mechanical or electrical, or may be a direct connection between two elements, and "upper," "lower," "left," "right," etc. are merely used to indicate relative positional relationships, which may be changed when the absolute position of the object being described is changed;
secondly: in the drawings of the disclosed embodiments, only the structures related to the embodiments of the present disclosure are referred to, and other structures can refer to the common design, so that the same embodiment and different embodiments of the present disclosure can be combined with each other under the condition of no conflict;
finally: the foregoing description of the preferred embodiments of the application is not intended to limit the application to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and principles of the application are intended to be included within the scope of the application.

Claims (3)

1. The quantitative assessment method for the contact damage of the connection interface of the aviation gas turbine is characterized by comprising the following steps of:
obtaining structural parameters of an engine to be evaluated, and establishing a simulation model corresponding to the engine;
acquiring multiple sets of operation data corresponding to different working nodes of an engine and respectively inputting the multiple sets of operation data into a simulation model, wherein the same working node also has the multiple sets of operation data, acquiring operation results of the data in the simulation model and respectively calculating quantitative evaluation parameters corresponding to the different input data, and the method comprises the following steps: the contact state coefficient, the contact stress, the elastoplastic deformation energy and the contact friction work of the connecting interface;
setting a contact state coefficient evaluation table, a contact stress evaluation table, an elastoplastic deformation energy evaluation table and a connection interface contact friction work evaluation table according to the calculated multiple groups of contact state coefficients, contact stress, elastoplastic deformation energy and connection interface contact friction work result distribution;
after the engine works, acquiring real machine data of the engine, respectively calculating a contact state coefficient, a contact stress, elastoplastic deformation energy and a connection interface contact friction work, and respectively evaluating the contact state coefficient, the contact stress, the elastoplastic deformation energy and the connection interface contact friction work through a contact state coefficient evaluation table, a contact stress evaluation table, an elastoplastic deformation energy evaluation table and a connection interface contact friction work grade table to obtain an evaluation result.
2. The quantitative assessment method for contact damage of aviation gas turbine connection interface according to claim 1, wherein the contact state coefficient C conta The calculation formula of (2) is as follows:
wherein A is sticking 、A sliding Viscous contact area and sliding contact area, respectively; a is that total Is the total area of the contact surface;
the contact stress is calculated by boundary conditions;
the elastic plasticity variable performance is irreversible dissipation energy D, and the calculation formula of the irreversible dissipation energy D is as follows:
D=k p k s σ a Δε
wherein k is s Is of the form factor, sigma a To contact normal stress amplitude, k p Is plastic deformation, and delta epsilon is the normal deformation vector of the contact surface node;
the calculation formula of the friction work of the contact interface in unit area is as follows:
dw=μ|σ n ||δ|dA
wherein mu is the friction coefficient of the contact surface; sigma (sigma) n Is normal contact stress; delta is the relative slippage of the contact nodes.
3. The quantitative assessment method for contact damage of an aviation gas turbine connection interface of claim 1, wherein the method comprises the following steps: the contact state coefficient evaluation table, the contact stress evaluation table, the elastoplastic deformation energy evaluation table and the connection interface contact friction work grade table are all provided with excellent, general, poor and poor, wherein when corresponding parameters are in excellent and general states, the engine is normally operated under the parameters, and different judgment thresholds are respectively set at different grades.
CN202311151776.9A 2023-09-07 2023-09-07 Quantitative assessment method for contact damage of aviation gas turbine connecting interface Pending CN117113583A (en)

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CN202311151776.9A CN117113583A (en) 2023-09-07 2023-09-07 Quantitative assessment method for contact damage of aviation gas turbine connecting interface

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Application Number Priority Date Filing Date Title
CN202311151776.9A CN117113583A (en) 2023-09-07 2023-09-07 Quantitative assessment method for contact damage of aviation gas turbine connecting interface

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