A life evaluation method and system for rotor connecting bolts

Abstract

The present invention relates to the field of aero-engine technology and discloses a life evaluation method and system for rotor connecting bolts. By comprehensively considering the stress concentration factor of the connecting bolts, the nominal stress of the connecting bolt threads under working load, and the load conditions of the axial mating end faces of the connected parts under standard contact conditions and non-separation contact conditions, the method accurately identifies weak points in the connecting bolts, better guides the precise analysis of the high-cycle fatigue reserve coefficient of the connecting bolts, and thus enables the high-cycle fatigue life evaluation of the connecting bolts. The present invention can effectively avoid the risk of high-cycle fatigue failure of the rotor connecting bolts, providing support for the safety and reliability of the rotor connecting bolts during their life.

Description

Technical Field

[0001] The invention relates to the technical field of aero-engines and discloses a life evaluation method and system for rotor connecting bolts. Background Art

[0002] Aero-engine rotor bolts are widely used in rotor structures to connect the discs. Currently, conventional methods for evaluating the strength reserve of rotor bolts are primarily based on material mechanics. However, due to the inherent threaded structure of rotor bolts, significant stress concentration occurs within the bolts. Conventional methods are unable to analyze and evaluate stress concentration areas, effectively identifying weak spots and determining the risk of low-cycle fatigue failure, resulting in insufficient design guidance.

[0003] In addition, conventional methods are unable to analyze the alternating loads borne by the connecting bolts due to the high-frequency opening and closing of the mounting edges of the connected parts caused by factors such as rotor vortex during operation. There is a risk of fatigue failure of the connecting bolts during operation, which poses a major hidden danger to the safe operation of the engine. Summary of the Invention

[0004] The purpose of the present invention is to provide a life evaluation method and system for rotor connecting bolts, which can effectively avoid the risk of high-cycle fatigue failure of rotor connecting bolts and provide support for the safety and reliability of rotor connecting bolts during their service life.

[0005] In order to achieve the above technical effects, the technical solution adopted by the present invention is:

[0006] A method for evaluating the life of a rotor connecting bolt comprises:

[0007] Constructing a geometric model of a connected sector of an aircraft engine rotor connection portion, wherein the geometric model of the connected sector includes a connecting member, and the connecting member includes a connecting bolt with threaded teeth and a nut matched with the connecting bolt;

[0008] A linear elastic finite element simulation analysis method is used to simulate and analyze the geometric model of the connected segment to obtain the maximum elastic stress of the connecting bolt under the initial bolt preload. Based on the cross-sectional area of ​​the bolt at the location of the maximum elastic stress, the nominal stress of the bolt cross section and the stress concentration factor of the connecting bolt are analyzed and obtained.

[0009] Under the condition that the axial mating end faces of the connected parts adopt standard contact, the linear elastic finite element simulation analysis method is used to perform stress analysis on the connecting bolts under working loads. The maximum elastic stress of the connecting bolts under working loads, the nodes and node temperatures corresponding to the maximum elastic stress under working loads, and the total axial support reaction load on the connecting bolt end faces at the node temperatures are obtained.

[0010] According to the maximum elastic stress of the connecting bolt under the working load and the stress concentration factor, the nominal stress of the thread of the connecting bolt under the working load is obtained by analysis;

[0011] Under the condition that the axial mating end faces of the connected parts are in non-separation contact, a linear elastic finite element simulation analysis method is used to calculate the stress of the connecting bolt when the installation side of the connected parts is not axially expanded under the working load, and combined with the stress concentration factor analysis, the nominal stress of the node of the connecting bolt when the installation side of the connected parts is not axially expanded under the working load is obtained;

[0012] According to the connection bolt material at the node temperature tensile strength under working load, nominal stress of thread teeth of connecting bolts under working load, nominal stress of nodes when the mounting side of the connecting bolts is not axially opened under working load, and stress ratio of connecting bolt materials at the node temperature of -1 and number of cycles of 10 7 The corresponding fatigue strength is analyzed to obtain the high-cycle fatigue reserve coefficient of the connecting bolt. If the high-cycle fatigue reserve coefficient is greater than a preset coefficient threshold, it is determined that the high-cycle fatigue life of the connecting bolt meets the design requirements.

[0013] Furthermore, the high cycle fatigue reserve factor of the connecting bolts Calculated, where is the stress concentration factor of the connecting bolts, is the nominal stress of the thread of the connecting bolt under working load, It is the nominal stress of the node when the connecting bolt is not axially expanded by the installation side of the connected part under the working load. The temperature of the connecting bolt material at the node The tensile strength under The temperature of the connecting bolt material at the node The stress ratio is -1 and the number of cycles is 10 7 times the corresponding fatigue strength.

[0014] Furthermore, the central angle of the geometric model of the connected sector ,in The number of connecting bolts at the connection parts of the aircraft engine rotor.

[0015] Furthermore, the nominal stress of the bolt cross section ,in is the initial bolt preload, is the maximum elastic stress of the connecting bolt The cross-sectional area of ​​the bolt at the connection point; the stress concentration factor of the connecting bolt .

[0016] Furthermore, it also includes:

[0017] According to the tensile test load of the connection bolts at room temperature and typical high temperature in the acceptance technical conditions, the node temperature is obtained by linear interpolation. The tensile load of the connecting bolt under the known room temperature; according to the tensile test load at room temperature, the node temperature The tensile load of the connecting bolts under the known temperature is converted into the axial force load at the room temperature;

[0018] Based on the known room temperature fatigue test peak load and valley load parameters as described in the technical conditions for connection bolt acceptance, as well as the initial bolt preload and the known room temperature axial load, analyze and obtain the peak conversion load that has the same ratio as the known room temperature fatigue test load;

[0019] Compare the peak conversion load with the fatigue test peak load. If the peak conversion load is less than or equal to the fatigue test peak load, it is judged that the low-cycle fatigue life of the connecting bolt meets the design requirements.

[0020] Furthermore, the axial force load at the known room temperature ,in, is the node temperature The tensile load of the connecting bolts under The room temperature of the connecting bolts is known in the acceptance technical conditions. Tensile test load under is the node temperature Total axial support reaction load on the end face of the lower connecting bolt; and the known room temperature Peak conversion load when the fatigue test load ratio is the same ,in The room temperature is known in the technical conditions for the acceptance of connecting bolts. Under the fatigue test peak load, The room temperature is known in the technical conditions for the acceptance of connecting bolts. The valley load of the fatigue test is is the initial bolt preload.

[0021] To achieve the above technical effects, the present invention further provides a life evaluation system for rotor connecting bolts, which is used to implement the above life evaluation method, comprising:

[0022] A model building module is used to build a geometric model of a connected sector of an aircraft engine rotor connection portion, wherein the geometric model of the connected sector includes a connecting member, and the connecting member includes a connecting bolt with threaded teeth and a nut that cooperates with the connecting bolt;

[0023] A first simulation analysis module is configured to simulate and analyze the geometric model of the connected segment using a linear elastic finite element simulation analysis method to obtain the maximum elastic stress of the connecting bolt under the initial bolt preload, and to obtain the nominal stress of the bolt cross section and the stress concentration factor of the connecting bolt based on the cross-sectional area of ​​the bolt at the location of the maximum elastic stress;

[0024] The second simulation analysis module is used to perform stress analysis on the connecting bolts under working loads using a linear elastic finite element simulation analysis method under the condition that the axial mating end faces of the connected parts adopt standard contact. The module obtains the maximum elastic stress of the connecting bolts under working loads, the nodes and node temperatures corresponding to the maximum elastic stress under working loads, and the total axial support reaction load on the end faces of the connecting bolts at the node temperatures.

[0025] A thread nominal stress analysis module is used to analyze and obtain the thread nominal stress of the connecting bolt under the working load based on the maximum elastic stress of the connecting bolt under the working load and the stress concentration factor;

[0026] A third simulation analysis module is configured to calculate the stress of the connecting bolt when the mounting side of the connected parts is not axially expanded under the working load using a linear elastic finite element simulation analysis method, under the condition that the axial mating end faces of the connected parts are in non-separation contact, and to obtain the nominal stress of the node of the connecting bolt when the mounting side of the connected parts is not axially expanded under the working load in combination with the stress concentration factor analysis;

[0027] The first judgment module is used to determine the connection bolt material at the node temperature. tensile strength under working load, nominal stress of thread teeth of connecting bolts under working load, nominal stress of nodes when the mounting side of the connecting bolts is not axially opened under working load, and stress ratio of connecting bolt materials at the node temperature of -1 and number of cycles of 10 7 The corresponding fatigue strength is analyzed to obtain the high-cycle fatigue reserve coefficient of the connecting bolt. If the high-cycle fatigue reserve coefficient is greater than a preset coefficient threshold, it is determined that the high-cycle fatigue life of the connecting bolt meets the design requirements.

[0028] Furthermore, in the first discrimination module, the high cycle fatigue reserve coefficient of the connecting bolt Calculated, where is the stress concentration factor of the connecting bolts, is the nominal stress of the thread of the connecting bolt under working load, It is the nominal stress of the node when the connecting bolt is not axially expanded by the installation side of the connected part under the working load. The temperature of the connecting bolt material at the node The tensile strength under The temperature of the connecting bolt material at the node The stress ratio is -1 and the number of cycles is 10 7 times the corresponding fatigue strength.

[0029] Furthermore, in the model building module, the central angle of the geometric model of the connected sector ,in The number of connecting bolts at the connection parts of the aircraft engine rotor.

[0030] Furthermore, it also includes:

[0031] Axial force load analysis module is used to obtain the node temperature by linear interpolation based on the tensile test load of the connection bolts at room temperature and typical high temperature in the acceptance technical conditions The tensile load of the connecting bolt under the known room temperature; according to the tensile test load at room temperature, the node temperature The tensile load of the connecting bolts under the known temperature is converted into the axial force load at the room temperature;

[0032] A peak conversion load analysis module is used to analyze and obtain a peak conversion load with the same ratio as the fatigue test load at known room temperature according to the known peak load and valley load parameters of the fatigue test at known room temperature as described in the technical conditions for acceptance of the connecting bolts, as well as the initial bolt preload and the axial force load at known room temperature;

[0033] The second judgment module is used to compare the peak conversion load with the fatigue test peak load. If the peak conversion load is less than or equal to the fatigue test peak load, it is judged that the low-cycle fatigue life of the connecting bolt meets the design requirements.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention comprehensively considers the stress concentration coefficient of the connecting bolt and the nominal stress of the thread of the connecting bolt under the working load, as well as the load conditions of the axial mating end faces between the connected parts under the standard contact conditions and the non-separation contact conditions, so as to accurately identify the weak parts of the connecting bolt, better guide the precise analysis of the high-cycle fatigue reserve coefficient of the connecting bolt, thereby realizing the evaluation of the high-cycle fatigue life of the connecting bolt, and can effectively avoid the risk of high-cycle fatigue failure of the rotor connecting bolt. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a flow chart of the life evaluation method for the rotor connecting bolts in Example 1;

[0036] Figure 2 Schematic diagram of the connection structure of the rotor connection portion of the aircraft engine in Example 1 or 2;

[0037] Figure 3 This is a structural block diagram of the life evaluation system for the rotor connecting bolts in Example 1;

[0038] Among them, 1. Connecting bolts; 2. Nuts; 3. Model construction module; 4. First simulation analysis module; 5. Second simulation analysis module; 6. Thread nominal stress analysis module; 7. Third simulation analysis module; 8. First discrimination module; 9. Axial force load analysis module; 10. Peak conversion load analysis module; 11. Second discrimination module. DETAILED DESCRIPTION

[0039] The present invention will be described in further detail below with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the present invention to the following embodiments, as all technologies implemented based on the present invention fall within the scope of the present invention.

[0040] Example 1

[0041] See also Figures 1 to 3 , a life evaluation method for rotor connecting bolts, comprising:

[0042] Constructing a geometric model of a connected sector of an aircraft engine rotor connection portion, wherein the geometric model of the connected sector includes a connecting member, wherein the connecting member includes a connecting bolt 1 with threaded teeth and a nut 2 matched with the connecting bolt 1;

[0043] A linear elastic finite element simulation analysis method is used to simulate and analyze the geometric model of the connected sector to obtain the maximum elastic stress of the connecting bolt 1 under the initial bolt preload. Based on the cross-sectional area of ​​the bolt at the location of the maximum elastic stress of the connecting bolt 1, the nominal stress of the bolt cross section and the stress concentration factor of the connecting bolt 1 are analyzed and obtained.

[0044] Under the condition that the axial mating end faces of the connected parts adopt standard contact, a linear elastic finite element simulation analysis method is used to perform stress analysis on the connecting bolt 1 under the working load, and the maximum elastic stress of the connecting bolt 1 under the working load, the node and node temperature corresponding to the maximum elastic stress under the working load, and the total axial support reaction load on the end face of the connecting bolt 1 at the node temperature are obtained;

[0045] According to the maximum elastic stress of the connecting bolt 1 under the working load and the stress concentration factor, the nominal stress of the thread of the connecting bolt 1 under the working load is analyzed and obtained;

[0046] Under the condition that the axial mating end faces of the connected parts are in non-separation contact, the stress of the connecting bolt 1 when the installation side of the connected parts is not axially expanded under the working load is calculated using the linear elastic finite element simulation analysis method, and the nominal stress of the node of the connecting bolt 1 when the installation side of the connected parts is not axially expanded under the working load is obtained in combination with the stress concentration factor analysis;

[0047] According to the material of the connecting bolt 1 at the node temperature tensile strength under working load, nominal stress of thread of connecting bolt 1 under working load, nominal stress of node when connecting bolt 1 is not axially opened on the installation side of the connected part under working load, and stress ratio of connecting bolt 1 material at the node temperature of -1 and number of cycles of 10 7 The corresponding fatigue strength is analyzed to obtain the high cycle fatigue reserve coefficient of the connecting bolt 1. If the high cycle fatigue reserve coefficient is greater than the preset coefficient threshold, it is determined that the high cycle fatigue life of the connecting bolt 1 meets the design requirements.

[0048] In this embodiment, by comprehensively considering the stress concentration factor of the connecting bolt 1 and the nominal stress of the thread of the connecting bolt 1 under the working load, as well as the load conditions of the axial mating end faces between the connected parts under the standard contact conditions and the non-separation contact conditions, the weak parts of the connecting bolt 1 can be accurately identified, and the precise analysis of the high-cycle fatigue reserve coefficient of the connecting bolt 1 can be better guided, thereby realizing the evaluation of the high-cycle fatigue life of the connecting bolt 1, which can effectively avoid the risk of high-cycle fatigue failure of the rotor connecting bolt 1 and provide support for the safety and reliability of the rotor connecting bolt 1 during its service life.

[0049] Based on the same inventive concept, this embodiment further provides a life evaluation system for rotor connecting bolts, which is used to implement the life evaluation method, including:

[0050] Model building module 3, for building a geometric model of a connected sector of an aircraft engine rotor connection portion, wherein the geometric model of the connected sector includes a connecting member, wherein the connecting member includes a connecting bolt 1 with threaded teeth and a nut 2 that cooperates with the connecting bolt 1;

[0051] The first simulation analysis module 4 is configured to simulate and analyze the geometric model of the connected sector using a linear elastic finite element simulation analysis method to obtain the maximum elastic stress of the connecting bolt 1 under the initial bolt preload, and to obtain the nominal stress of the bolt cross section and the stress concentration factor of the connecting bolt 1 based on the bolt cross-sectional area at the location of the maximum elastic stress of the connecting bolt 1;

[0052] The second simulation analysis module 5 is used to perform stress analysis on the connecting bolt 1 under the working load using a linear elastic finite element simulation analysis method under the condition that the axial mating end faces of the connected parts adopt standard contact, to obtain the maximum elastic stress of the connecting bolt 1 under the working load, the node and node temperature corresponding to the maximum elastic stress under the working load, and the total axial support reaction load on the end face of the connecting bolt 1 at the node temperature;

[0053] The thread nominal stress analysis module 6 is used to analyze and obtain the thread nominal stress of the connecting bolt 1 under the working load based on the maximum elastic stress of the connecting bolt 1 under the working load and the stress concentration factor;

[0054] The third simulation analysis module 7 is used to calculate the stress of the connecting bolt 1 when the mounting side of the connected parts is not axially expanded under the working load using a linear elastic finite element simulation analysis method under the condition that the axial mating end faces of the connected parts are in non-separation contact, and to obtain the nominal stress of the node of the connecting bolt 1 when the mounting side of the connected parts is not axially expanded under the working load in combination with the stress concentration factor analysis;

[0055] The first judgment module 8 is used to determine the material of the connecting bolt 1 at the node temperature. tensile strength under working load, nominal stress of thread of connecting bolt 1 under working load, nominal stress of node when connecting bolt 1 is not axially opened on the installation side of the connected part under working load, and stress ratio of connecting bolt 1 material at the node temperature of -1 and number of cycles of 10 7 The corresponding fatigue strength is analyzed to obtain the high cycle fatigue reserve coefficient of the connecting bolt 1. If the high cycle fatigue reserve coefficient is greater than the preset coefficient threshold, it is determined that the high cycle fatigue life of the connecting bolt 1 meets the design requirements.

[0056] The life evaluation system for the rotor connecting bolts in this embodiment further includes:

[0057] Axial force load analysis module 9 is used to obtain the node temperature by linear interpolation based on the tensile test load of the connecting bolt 1 at room temperature and typical high temperature in the acceptance technical conditions Tensile load of connecting bolt 1 under the known room temperature tensile test load and node temperature The tensile load of the connecting bolt under the condition of the node temperature is converted into the total axial support reaction load of the end face of the connecting bolt 1 under the condition of the known room temperature;

[0058] The peak conversion load analysis module 10 is used to analyze and obtain the peak conversion load when the ratio is the same as the fatigue test load at known room temperature according to the known peak load and valley load parameters of the fatigue test at known room temperature as described in the technical conditions for acceptance of the connecting bolt 1, as well as the initial bolt preload and the axial load at known room temperature;

[0059] The second judging module 11 is used to compare the peak conversion load with the fatigue test peak load. If the peak conversion load is less than or equal to the fatigue test peak load, it is judged that the low-cycle fatigue life of the connecting bolt 1 meets the design requirements.

[0060] In this embodiment, on the basis of realizing the evaluation of the high-cycle fatigue life of the connecting bolt 1, the peak load and valley load parameters of the fatigue test at known room temperature, as well as the initial bolt preload and the axial force load at the known room temperature, are used in the acceptance technical conditions of the connecting bolt 1 to realize the peak conversion load with the same ratio as the fatigue test load at the known room temperature, thereby realizing an effective evaluation of the low-cycle fatigue life of the connecting bolt 1 based on considering the local stress of the connecting bolt 1.

[0061] Example 2

[0062] In view of the problem that the current method cannot effectively analyze and evaluate the low-cycle and high-cycle fatigue reserves of the rotor connecting bolts 1, and there is a risk of fatigue failure of the connecting bolts 1 during operation, this embodiment provides a life evaluation method for the rotor connecting bolts, including:

[0063] Step 1: Construct a geometric model of the connected sector of the aircraft engine rotor connection part;

[0064] In this embodiment, according to the number of rotor connecting bolts 1 and the periodic symmetric structural characteristics of the connected parts, a geometric model of the connected parts is constructed. The circumferential angle (that is, the central angle) of the geometric model of the connected parts is ,in The number of connecting bolts 1 at the connection part of the aircraft engine rotor. The geometric model of the connected sector includes a connecting part, which includes a connecting bolt 1 with threaded teeth and a nut 2 (such as Figure 2 As shown in the figure), the connecting bolt 1 and the nut 2 need to establish a thread structure, and the meshing threads are not allowed to interfere with each other.

[0065] Step 2: Use a linear elastic finite element simulation analysis method to simulate and analyze the geometric model of the connected sector to obtain the maximum elastic stress of the connecting bolt 1 under the initial bolt preload. According to the cross-sectional area of ​​the bolt at the maximum elastic stress of the connecting bolt 1, the nominal stress of the bolt cross section and the stress concentration factor of the connecting bolt 1 are analyzed and obtained;

[0066] In this embodiment, a finite element simulation analysis model is established based on the constructed geometric model of the connected part sector. In the finite element simulation analysis model, the thread unit type at the meshing point of the connecting bolt 1 and the nut 2 must be the same, and the mesh density must be consistent. In the specific setting process, the bottom unit of the thread should be no less than 6 layers of units, and the unit Jacobian should be no less than 0.7, so as to ensure that no singular points will appear in the subsequent stress results. Contact units must be used for simulation at the contact points between the connector and the connected part, as well as at the contact points between the connected parts. The linear elastic finite element simulation analysis model is used to calculate only the initial bolt preload. The stress of the connecting bolt 1 is obtained at the initial bolt preload Maximum elastic stress of lower connecting bolt 1 , extract the maximum elastic stress of connecting bolt 1 The cross-sectional area of ​​the connecting bolt 1 , according to the formula Calculate the nominal stress of the connecting bolt 1 section ,according to Get the stress concentration factor of connecting bolt 1 .

[0067] Step 3: Under the condition that the axial mating end faces of the connected parts adopt standard contact, a linear elastic finite element simulation analysis method is used to perform stress analysis on the connecting bolt 1 under the working load, and the maximum elastic stress of the connecting bolt 1 under the working load, the node and node temperature corresponding to the maximum elastic stress under the working load, and the total axial support reaction load on the end face of the connecting bolt 1 at the node temperature are obtained;

[0068] In this embodiment, a linear elastic finite element simulation analysis model is used to calculate the stress of the connecting bolt 1 under the working load; the working load must at least include the rotational speed, temperature and axial force; during the finite element simulation analysis, the axial mating end faces of the connected parts are all in standard contact. The maximum elastic stress of the connecting bolt 1 under the working load is obtained. , the node N1 corresponding to the maximum elastic stress under the working load and the temperature of the node , extract node temperature Total axial support reaction load on the end face of the lower single connecting bolt 1 .

[0069] Step 4: Analyze and obtain the nominal stress of the thread of the connecting bolt 1 under the working load based on the maximum elastic stress of the connecting bolt 1 under the working load and the stress concentration factor;

[0070] In this embodiment, The nominal stress of the thread of the connecting bolt 1 under the working load is calculated .

[0071] Step 5: Under the condition that the axial mating end faces of the connected parts are in non-separation contact, a linear elastic finite element simulation analysis method is used to calculate the stress of the connecting bolt 1 when the installation side of the connected parts is not axially expanded under the working load, and the nominal stress of the node of the connecting bolt 1 when the installation side of the connected parts is not axially expanded under the working load is obtained in combination with the stress concentration factor analysis;

[0072] In this embodiment, a linear elastic finite element simulation analysis model is used to calculate the stress of the connecting bolt 1 when the mounting side of the connected part is not axially expanded under the working load; the working load must at least include the rotational speed, temperature and axial force. During the finite element simulation analysis, the axial mating end faces between the connected parts are all in non-separation contact to determine the stress of the connecting bolt 1 when the mounting side is not separated. The stress corresponding to the node N1 of the connecting bolt 1 when the mounting side of the connected part is not axially expanded under the working load is obtained. , which can be determined by The nominal stress of node N1 when the connecting bolt 1 is not axially expanded by the mounting side of the connected part under working load is calculated. .

[0073] In this embodiment, 、 It can also be directly output by finite element analysis software.

[0074] Step 6: According to the material of connecting bolt 1 at the node temperature tensile strength under working load, nominal stress of thread of connecting bolt 1 under working load, nominal stress of node when connecting bolt 1 is not axially opened on the installation side of the connected part under working load, and stress ratio of connecting bolt 1 material at the node temperature of -1 and number of cycles of 10 7 The corresponding fatigue strength is analyzed to obtain the high cycle fatigue reserve coefficient of the connecting bolt 1. If the high cycle fatigue reserve coefficient is greater than a preset coefficient threshold, it is determined that the high cycle fatigue life of the connecting bolt 1 meets the design requirements;

[0075] In this embodiment, the high cycle fatigue reserve factor of the connecting bolt 1 is Calculated, where is the stress concentration factor of connecting bolt 1, is the nominal stress of the thread of the connecting bolt 1 under working load, is the nominal stress of the node when the connecting bolt 1 is not axially expanded by the installation side of the connected part under the working load, The material temperature of the connecting bolt 1 at the node The tensile strength under The material temperature of the connecting bolt 1 at the node The stress ratio is -1 and the number of cycles is 10 7 times the corresponding fatigue strength. In this embodiment, if , it indicates that the high cycle fatigue reserve of connecting bolt 1 meets the requirements, otherwise the design needs to be improved.

[0076] Step 7: Based on the tensile test loads of the connection bolt 1 at room temperature and typical high temperature in the acceptance technical conditions, the node temperature is obtained by linear interpolation. According to the tensile test load and node temperature at room temperature, The tensile load of the connecting bolt under the condition of the node temperature is converted into the total axial support reaction load of the end face of the connecting bolt 1 under the condition of the known room temperature;

[0077] In this embodiment, the room temperature of the connecting bolt 1 is known in the acceptance technical conditions. Tensile test load under , and typical high temperature Tensile test load under , the node temperature is obtained by linear interpolation Tensile load under .according to The node temperature Total axial support reaction load on the end face of lower connecting bolt 1 Converted to the known room temperature Axial force load under .

[0078] Step 8: Based on the known room temperature fatigue test peak load and valley load parameters in the acceptance technical conditions of the connecting bolt 1, as well as the initial bolt preload and the known room temperature axial load, analyze and obtain the peak conversion load that has the same ratio as the known room temperature fatigue test load;

[0079] In this embodiment, the room temperature Peak conversion load when the fatigue test load ratio is the same ,in The room temperature is known in the technical conditions for the acceptance of the connecting bolt 1. Under the fatigue test peak load, The room temperature is known in the technical conditions for the acceptance of the connecting bolt 1. The valley load of the fatigue test is is the initial bolt preload.

[0080] Step 9: Peak conversion load Fatigue test peak load For comparison, if the peak conversion load Less than or equal to the fatigue test peak load , it is judged that the low-cycle fatigue life of the connecting bolt 1 meets the design requirements, otherwise the design needs to be improved.

[0081] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for evaluating the life of a rotor connecting bolt, characterized in that: include: Constructing a geometric model of a connected sector of an aircraft engine rotor connection portion, wherein the geometric model of the connected sector includes a connecting member, and the connecting member includes a connecting bolt with threaded teeth and a nut matched with the connecting bolt; A linear elastic finite element simulation analysis method is used to simulate and analyze the geometric model of the connected segment to obtain the maximum elastic stress of the connecting bolt under the initial bolt preload. Based on the cross-sectional area of ​​the bolt at the location of the maximum elastic stress, the nominal stress of the bolt cross section and the stress concentration factor of the connecting bolt are analyzed and obtained. Under the condition that the axial mating end faces of the connected parts adopt standard contact, the linear elastic finite element simulation analysis method is used to perform stress analysis on the connecting bolts under working loads. The maximum elastic stress of the connecting bolts under working loads, the nodes and node temperatures corresponding to the maximum elastic stress under working loads, and the total axial support reaction load on the connecting bolt end faces at the node temperatures are obtained. According to the maximum elastic stress of the connecting bolt under the working load and the stress concentration factor, the nominal stress of the thread of the connecting bolt under the working load is obtained by analysis; Under the condition that the axial mating end faces of the connected parts are in non-separation contact, a linear elastic finite element simulation analysis method is used to calculate the stress of the connecting bolt when the installation side of the connected parts is not axially expanded under the working load, and combined with the stress concentration factor analysis, the nominal stress of the node of the connecting bolt when the installation side of the connected parts is not axially expanded under the working load is obtained; According to the connection bolt material at the node temperature tensile strength under working load, nominal stress of thread teeth of connecting bolts under working load, nominal stress of nodes when the mounting side of the connecting bolts is not axially opened under working load, and stress ratio of connecting bolt materials at the node temperature of -1 and number of cycles of 10 7 The corresponding fatigue strength is analyzed to obtain the high-cycle fatigue reserve coefficient of the connecting bolt. If the high-cycle fatigue reserve coefficient is greater than a preset coefficient threshold, it is determined that the high-cycle fatigue life of the connecting bolt meets the design requirements.

2. The life evaluation method according to claim 1, characterized in that: High cycle fatigue reserve factor of connecting bolts Calculated, where is the stress concentration factor of the connecting bolts, is the nominal stress of the thread of the connecting bolt under working load, It is the nominal stress of the node when the connecting bolt is not axially expanded by the installation side of the connected part under the working load. The temperature of the connecting bolt material at the node The tensile strength under The temperature of the connecting bolt material at the node The stress ratio is -1 and the number of cycles is 10 7 times the corresponding fatigue strength.

3. The life evaluation method according to claim 1, characterized in that: The central angle of the geometric model of the connected sector ,in The number of connecting bolts at the connection parts of the aircraft engine rotor.

4. The life evaluation method according to claim 1, characterized in that: Nominal stress in the bolt cross section ,in is the initial bolt preload, is the maximum elastic stress of the connecting bolt The cross-sectional area of ​​the bolt at the connection point; the stress concentration factor of the connecting bolt .

5. The life evaluation method according to claim 1, characterized in that: Also includes: According to the tensile test load of the connection bolts at room temperature and typical high temperature in the acceptance technical conditions, the node temperature is obtained by linear interpolation. The tensile load of the connecting bolt under the known room temperature; according to the tensile test load at room temperature, the node temperature The tensile load of the connecting bolts under the known temperature is converted into the axial force load at the room temperature; Based on the known room temperature fatigue test peak load and valley load parameters as described in the technical conditions for connection bolt acceptance, as well as the initial bolt preload and the known room temperature axial load, analyze and obtain the peak conversion load that has the same ratio as the known room temperature fatigue test load; Compare the peak conversion load with the fatigue test peak load. If the peak conversion load is less than or equal to the fatigue test peak load, it is judged that the low-cycle fatigue life of the connecting bolt meets the design requirements.

6. The life evaluation method according to claim 5, characterized in that: The known axial force load at room temperature ,in, is the node temperature The tensile load of the connecting bolts under The room temperature of the connecting bolts is known in the acceptance technical conditions. Tensile test load under is the node temperature Total axial support reaction load on the end face of the lower connecting bolt; and the known room temperature Peak conversion load when the fatigue test load ratio is the same ,in The room temperature is known in the technical conditions for the acceptance of connecting bolts. Under the fatigue test peak load, The room temperature is known in the technical conditions for the acceptance of connecting bolts. The valley load of the fatigue test is is the initial bolt preload.

7. A life evaluation system for rotor connecting bolts, used to implement the life evaluation method according to claim 1, characterized in that: include: A model building module is used to build a geometric model of a connected sector of an aircraft engine rotor connection portion, wherein the geometric model of the connected sector includes a connecting member, and the connecting member includes a connecting bolt with threaded teeth and a nut that cooperates with the connecting bolt; A first simulation analysis module is configured to simulate and analyze the geometric model of the connected segment using a linear elastic finite element simulation analysis method to obtain the maximum elastic stress of the connecting bolt under the initial bolt preload, and to obtain the nominal stress of the bolt cross section and the stress concentration factor of the connecting bolt based on the cross-sectional area of ​​the bolt at the location of the maximum elastic stress; The second simulation analysis module is used to perform stress analysis on the connecting bolts under working loads using a linear elastic finite element simulation analysis method under the condition that the axial mating end faces of the connected parts adopt standard contact. The module obtains the maximum elastic stress of the connecting bolts under working loads, the nodes and node temperatures corresponding to the maximum elastic stress under working loads, and the total axial support reaction load on the end faces of the connecting bolts at the node temperatures. A thread nominal stress analysis module is used to analyze and obtain the thread nominal stress of the connecting bolt under the working load based on the maximum elastic stress of the connecting bolt under the working load and the stress concentration factor; A third simulation analysis module is configured to calculate the stress of the connecting bolt when the mounting side of the connected parts is not axially expanded under the working load using a linear elastic finite element simulation analysis method, under the condition that the axial mating end faces of the connected parts are in non-separation contact, and to obtain the nominal stress of the node of the connecting bolt when the mounting side of the connected parts is not axially expanded under the working load in combination with the stress concentration factor analysis; The first judgment module is used to determine the connection bolt material at the node temperature. tensile strength under working load, nominal stress of thread teeth of connecting bolts under working load, nominal stress of nodes when the mounting side of the connecting bolts is not axially opened under working load, and stress ratio of connecting bolt materials at the node temperature of -1 and number of cycles of 10 7 The corresponding fatigue strength is analyzed to obtain the high-cycle fatigue reserve coefficient of the connecting bolt. If the high-cycle fatigue reserve coefficient is greater than a preset coefficient threshold, it is determined that the high-cycle fatigue life of the connecting bolt meets the design requirements.

8. The life evaluation system according to claim 7, characterized in that: In the first discrimination module, the high cycle fatigue reserve coefficient of the connecting bolt Calculated, where is the stress concentration factor of the connecting bolts, is the nominal stress of the thread of the connecting bolt under working load, It is the nominal stress of the node when the connecting bolt is not axially expanded by the installation side of the connected part under the working load. The temperature of the connecting bolt material at the node The tensile strength under The temperature of the connecting bolt material at the node The stress ratio is -1 and the number of cycles is 10 7 times the corresponding fatigue strength.

9. The life evaluation system according to claim 7, characterized in that: In the model building module, the central angle of the connected sector geometric model ,in The number of connecting bolts at the connection parts of the aircraft engine rotor.

10. The life evaluation system according to claim 7, characterized in that: Also includes: Axial force load analysis module is used to obtain the node temperature by linear interpolation based on the tensile test load of the connection bolts at room temperature and typical high temperature in the acceptance technical conditions The tensile load of the connecting bolt under the known room temperature; according to the tensile test load at room temperature, the node temperature The tensile load of the connecting bolts under the known temperature is converted into the axial force load at the room temperature; A peak conversion load analysis module is used to analyze and obtain a peak conversion load with the same ratio as the fatigue test load at known room temperature according to the known peak load and valley load parameters of the fatigue test at known room temperature as described in the technical conditions for acceptance of the connecting bolts, as well as the initial bolt preload and the axial force load at known room temperature; The second judgment module is used to compare the peak conversion load with the fatigue test peak load. If the peak conversion load is less than or equal to the fatigue test peak load, it is judged that the low-cycle fatigue life of the connecting bolt meets the design requirements.

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