Aerospace floating spline contact stress calculation method, system, device and medium

Abstract

The present invention belongs to the field of aero-engines, relates to the technology of calculating the contact stress of engine parts, and provides a method, a system, a device and a medium for calculating the contact stress of an aviation floating spline. The method includes: establishing a mechanical deformation mechanics model including an internal spline shaft, an external spline shaft and a plurality of bearings; obtaining the radial support stiffness of a radial intermediate bearing according to the spline normal stiffness and the spline structure; using the simulation model to perform mechanical deformation simulation analysis through the radial support stiffness of each bearing of the radial intermediate bearing to obtain the mechanical deformation of the floating spline under mechanical loads; inputting the mechanical deformation into the established contact stress simulation model for contact stress analysis to obtain the contact stress of the floating spline. Through the spline designed by the present invention, the service time before excessive contact fatigue wear occurs during long-term service is increased by about 25% - 30% compared with the traditional design method, the maintenance and replacement cycle of the spline is improved, and the maintenance cost and economic cost are saved.

Description

Technical Field

[0001] The present invention relates to the field of aero-engines, and relates to the technology of calculating the contact stress of engine parts. Specifically, it relates to a method, system, device and medium for calculating the contact stress of an aero floating spline. Background Art

[0002] In engineering practice of aero-engines, in order to facilitate the assembly of the adapter shaft, a floating spline is often used to connect two rotors. It is a common rotor connection structure in the engine. The structure of the floating spline is as Figure 1 shown, which is formed by an internal spline shaft 1, an external spline shaft 2, roller bearings 3 and ball bearings 4. Among them, the spline contact stress is the most important design index affecting the reliable operation of the spline. In order to ensure the operation safety of the aero-engine rotor, it is necessary to conduct a detailed analysis of the contact stress of the aero floating spline.

[0003] At present, the design method of the contact pressure of the spline pair is usually calculated according to aviation standards or national standards. Although the off-axis load coefficient and stress concentration in the work are considered during the calculation, the actually served floating spline is still likely to have problems of contact wear and fatigue failure prematurely, and it is necessary to frequently repair or replace the spline, resulting in a large waste of manpower and financial resources. It is found through research that the main reason for the contact wear of the floating spline is that it is difficult to control the floating amount of the floating spline in actual work. In addition, the floating deformation of the spline caused by assembly, processing errors and working loads will also directly affect the floating amount of the spline. Among them, the maneuver overload during actual flight has a significant impact on the floating amount of the spline. If the influence of maneuver deformation is not considered during the calculation, it may lead to a large difference between the design result and the service state, resulting in problems of premature contact fatigue or wear of the spline.

[0004] Therefore, for the design and analysis of the contact stress of the aero floating spline, it is crucial to propose a design method for the contact stress of the aero floating spline considering the maneuver deformation. Summary of the Invention

[0005] In order to solve the technical problem that when calculating the contact stress of the existing aero floating spline, the influence of maneuver deformation is not considered, resulting in difficult control of the floating amount of the spline, and further there is a large difference between the design result and the service state, resulting in premature contact fatigue or wear of the spline, the present invention discloses a method for calculating the contact stress of an aero floating spline, and the method includes the following steps:

[0006] S1. Establish a mechanical model of maneuver deformation by using a simplified floating spline connection structure. The mechanical model of maneuver deformation includes an internal spline shaft, an external spline shaft, a first radial ground bearing, a second radial ground bearing, a third radial ground bearing, a first axial ground bearing, a second axial ground bearing and a radial intermediate bearing;

[0007] S2. Obtain the radial support stiffness of the radial intermediate bearing according to the spline normal stiffness and the spline structure;

[0008] S3. Establish a simulation model based on the motorized deformation mechanics model, and conduct motorized deformation simulation analysis through the radial support stiffness of the radial intermediate bearing, the support stiffness of the first radial ground bearing, the support stiffness of the second radial ground bearing, the support stiffness of the third radial ground bearing, the support stiffness of the first axial ground bearing, and the support stiffness of the second axial ground bearing to obtain the motorized deformation of the floating spline under motorized loads;

[0009] S4. Based on the spline input shaft length, output shaft length, and spline tooth surface meshing contact length, establish a contact stress simulation model using the floating spline connection structure, input the motorized deformation into the contact stress simulation model for contact stress analysis, and obtain the floating spline contact stress.

[0010] Further, in step S1, establish a motorized deformation mechanics model using a simplified floating spline connection structure, including:

[0011] S11. Conduct a structural analysis of the floating spline, and extract the internal spline shaft and the external spline shaft from the structural analysis results to establish a simplified floating spline connection structure;

[0012] S12. Set the first radial ground bearing at the position on the internal spline shaft that contacts the roller bearing, set the second radial ground bearing and the first axial ground bearing at the position on the internal spline shaft that contacts the ball bearing, set the radial intermediate bearing at the position where the internal spline shaft contacts the external spline shaft, and set the third radial ground bearing and the second axial ground bearing at the position on the external spline shaft that mates with other splines to obtain the motorized deformation mechanics model.

[0013] Further, in step S2, obtain the radial support stiffness of the radial intermediate bearing according to the spline normal stiffness and the spline structure, including:

[0014] S21. According to the rotation angle and contact pressure angle of each tooth in the polar coordinates of the fit between the internal spline and the external spline, calculate the angle between the normal direction of the tooth contact surface of each tooth and the vertical direction;

[0015] S22. Obtain the displacement generated by applying a unit load in the normal direction of the single-tooth model through a simulation method, and take the reciprocal of the displacement to obtain the spline normal stiffness;

[0016] S23. Calculate the radial support stiffness of each tooth through the angle and the spline normal stiffness;

[0017] S24. Sum the radial support stiffness of all the teeth in the fit between the internal spline and the external spline to obtain the radial support stiffness of the radial intermediate bearing.

[0018] Further, in step S3, a simulation model is established based on the mechanical model of maneuvering deformation. Maneuvering deformation simulation analysis is performed through the radial support stiffness of the radial intermediate bearing, the support stiffness of the first radial grounding bearing, the support stiffness of the second radial grounding bearing, the support stiffness of the third radial grounding bearing, the support stiffness of the first axial grounding bearing, and the support stiffness of the second axial grounding bearing to obtain the maneuvering deformation of the floating spline under maneuvering loads, including:

[0019] S31. Obtain the support stiffness of the first radial grounding bearing according to the roller bearing structure, and obtain the support stiffness of the second radial grounding bearing, the support stiffness of the third radial grounding bearing, the support stiffness of the first axial grounding bearing, and the support stiffness of the second axial grounding bearing according to the ball bearing structure;

[0020] S32. Input the unit axial overload or unit radial overload, unit gyroscopic moment, the radial support stiffness of the radial intermediate bearing, the support stiffness of the first radial grounding bearing, the support stiffness of the second radial grounding bearing, the support stiffness of the third radial grounding bearing, the support stiffness of the first axial grounding bearing, and the support stiffness of the second axial grounding bearing into the simulation model established through the mechanical model of maneuvering deformation to obtain the axial deformation, the first angular deformation, and the first radial deformation, or obtain the axial deformation, the second angular deformation, and the second radial deformation;

[0021] S33. Obtain the first maneuvering deformation through the axial deformation, the first angular deformation, and the first radial deformation, obtain the second maneuvering deformation through the axial deformation, the second angular deformation, and the second radial deformation, and use the first maneuvering deformation and the second maneuvering deformation as the maneuvering deformation.

[0022] In an improved embodiment of the above method for calculating the contact stress of an aviation floating spline, the method further includes:

[0023] S5. Evaluate the fatigue reserve of the floating spline according to the contact stress of the floating spline.

[0024] Further, in the above step S5, evaluating the fatigue reserve of the floating spline according to the contact stress of the floating spline includes:

[0025] Evaluating the fatigue reserve of the floating spline according to the contact fatigue limit and the contact stress of the floating spline, or evaluating the fatigue reserve of the floating spline according to the contact stress of the floating spline and the target life.

[0026] The embodiment of the present invention also provides a system for calculating the contact stress of an aviation floating spline, including a mechanical model construction module for maneuvering deformation, a support stiffness calculation module, a floating spline maneuvering deformation calculation module, and a contact stress calculation module.

[0027] Among them, the mobile deformation mechanics model construction module is used to establish a mobile deformation mechanics model by adopting a simplified floating spline connection structure. The mobile deformation mechanics model includes an internal spline shaft, an external spline shaft, a first radial ground bearing, a second radial ground bearing, a third radial ground bearing, a first axial ground bearing, a second axial ground bearing, and a radial intermediate bearing;

[0028] The support stiffness calculation module is used to obtain the radial support stiffness of the radial intermediate bearing according to the spline normal stiffness and the spline structure;

[0029] The floating spline mobile deformation calculation module is used to establish a simulation model based on the mobile deformation mechanics model, and perform mobile deformation simulation analysis through the radial support stiffness of the radial intermediate bearing, the support stiffness of the first radial ground bearing, the support stiffness of the second radial ground bearing, the support stiffness of the third radial ground bearing, the support stiffness of the first axial ground bearing, and the support stiffness of the second axial ground bearing, so as to obtain the mobile deformation of the floating spline under mobile loads;

[0030] The contact stress calculation module is used to establish a contact stress simulation model by adopting the floating spline connection structure according to the length of the spline input shaft, the length of the output shaft, and the meshing contact length of the spline tooth surface, input the mobile deformation into the contact stress simulation model for contact stress analysis, and obtain the floating spline contact stress.

[0031] Furthermore, the system further includes an evaluation module, and the evaluation module is used to evaluate the fatigue reserve of the floating spline according to the floating spline contact stress.

[0032] An embodiment of the present invention further provides a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the above-mentioned arbitrary method for calculating the contact stress of an aviation floating spline, so as to solve the technical problem that when calculating the contact stress of an existing aviation engine floating spline, the influence of mobile deformation is not considered, resulting in difficult control of the spline floating amount, and further there is a large difference between the design result and the service state, resulting in premature contact fatigue or wear of the spline.

[0033] An embodiment of the present invention further provides a computer-readable storage medium, which stores a computer program for executing the above-mentioned arbitrary method for calculating the contact stress of an aviation floating spline, so as to solve the technical problem that when calculating the contact stress of an existing aviation engine floating spline, the influence of mobile deformation is not considered, resulting in difficult control of the spline floating amount, and further there is a large difference between the design result and the service state, resulting in premature contact fatigue or wear of the spline.

[0034] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above technical solutions adopted in the embodiments of this specification at least include: The method of the present invention can quickly establish an aero floating spline maneuvering deformation mechanics model and a contact stress calculation model, forming a design method for the contact stress of an aero floating spline considering maneuvering deformation, which is mainly used in the simulation analysis of the contact stress of the transmission spline of an aeroengine, and can solve the contact fatigue problem of the spline during long-term operation in the maneuvering state during aircraft flight. The service life of the spline designed by the present invention before excessive contact fatigue wear occurs during long-term service is increased by about 25% - 30% compared with the traditional design method, improving the maintenance and replacement cycle of the spline, and saving maintenance costs and economic costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0036] Figure 1 is a schematic structural diagram of a floating spline in the prior art;

[0037] Figure 2 is a flowchart of the method for calculating the contact stress of the aero floating spline disclosed in the embodiments of the present invention;

[0038] Figure 3 is a schematic diagram of the maneuvering deformation mechanics model disclosed in the embodiments of the present invention;

[0039] Figure 4 is a schematic diagram of the meshing of a set of internal and external splines in the floating spline disclosed in the embodiments of the present invention;

[0040] Figure 5 is the spline contact stress - fatigue life curve disclosed in the embodiments of the present invention;

[0041] Figure 6 is an architecture diagram of the calculation of the contact stress of the aero floating spline disclosed in the embodiments of the present invention;

[0042] Among them, 1, internal spline shaft; 2, external spline shaft; 3, roller bearing; 4, ball bearing; 5, first radial ground bearing; 6, second radial ground bearing; 7, first axial ground bearing; 8, radial intermediate bearing; 9, third radial ground bearing; 10, second axial ground bearing; 601, maneuvering deformation mechanics model construction module; 602, support stiffness calculation module; 603, floating spline maneuvering deformation calculation module; 604, contact stress calculation module; 605, evaluation module. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0044] The following specific examples illustrate the implementation manners of the present application. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The present application can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the following embodiments and the features of the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope protected by the present application.

[0045] The present invention discloses a method for calculating the contact stress of an aviation floating spline. Refer to Figure 2 as shown, the method includes the following steps:

[0046] S1. Establish a kinematic deformation mechanics model by using a simplified floating spline connection structure. The kinematic deformation mechanics model includes an internal spline shaft, an external spline shaft, a first radial ground bearing, a second radial ground bearing, a third radial ground bearing, a first axial ground bearing, a second axial ground bearing, and a radial intermediate bearing;

[0047] S2. Obtain the radial support stiffness of the radial intermediate bearing according to the spline normal stiffness and the spline structure;

[0048] S3. Establish a simulation model based on the kinematic deformation mechanics model, and perform kinematic deformation simulation analysis through the radial support stiffness of the radial intermediate bearing, the support stiffness of the first radial ground bearing, the support stiffness of the second radial ground bearing, the support stiffness of the third radial ground bearing, the support stiffness of the first axial ground bearing, and the support stiffness of the second axial ground bearing to obtain the kinematic deformation of the floating spline under kinematic loads;

[0049] S4. Establish a contact stress simulation model by using the floating spline connection structure according to the length of the spline input shaft, the length of the output shaft, and the meshing contact length of the spline tooth surface. Input the kinematic deformation into the contact stress simulation model for contact stress analysis to obtain the floating spline contact stress.

[0050] Further, in step S1, establishing a kinematic deformation mechanics model by using a simplified floating spline connection structure includes:

[0051] S11. Conduct a structural analysis of the floating spline, and extract the internal spline shaft and the external spline shaft from the structural analysis results to establish a simplified floating spline connection structure;

[0052] S12. A first radial ground bearing 5 is arranged at the position of the internal spline shaft in contact with the roller bearing, a second radial ground bearing 6 and a first axial ground bearing 7 are arranged at the position of the internal spline shaft in contact with the ball bearing, a radial intermediate bearing 8 is arranged at the position where the internal spline shaft contacts the external spline shaft, and a third radial ground bearing 9 and a second axial ground bearing 10 are arranged at the position of the external spline shaft in engagement with other splines, obtaining the motorized deformation mechanics model as shown in Figure 3 . In step S3, when establishing the simulation model, each bearing in the motorized deformation mechanics model can be simulated by a spring element.

[0053] Furthermore, in step S2, obtaining the radial support stiffness of the radial intermediate bearing according to the spline normal stiffness and the spline structure includes:

[0054] S21. According to the rotation angle and the contact pressure angle of each tooth in the engagement between the internal spline and the external spline in polar coordinates, calculate the angle between the normal direction of the tooth contact surface of each tooth and the vertical direction;

[0055] S22. Obtain the displacement generated by applying a unit load in the normal direction of the single-tooth model through a simulation method, and take the reciprocal of the displacement to obtain the spline normal stiffness;

[0056] S23. Calculate the radial support stiffness of each tooth through the angle and the spline normal stiffness;

[0057] S24. Sum up the radial support stiffness of all teeth in the engagement between the internal spline and the external spline to obtain the radial support stiffness of the radial intermediate bearing.

[0058] During specific implementation, the engagement schematic diagram of a set of internal and external splines in the floating spline is as shown in Figure 4 . Define as the angle between the normal direction of the tooth contact surface of the i-th tooth and the vertical direction, , see Figure 4 shown, θ i is the rotation angle of the i-th tooth in polar coordinates, is the contact pressure angle of the spline tooth surface, where the contact pressure angle can be positive or negative, The positive or negative of is related to the load transfer method of the front guide surface. When the external spline is the driving tooth, takes a negative value. When the internal spline is the driving tooth, takes a positive value. Each tooth of the spline can be regarded as an individual spring, and the radial support stiffness of the i-th tooth is K i , which can be calculated according to the following formula (1):

[0059] Equation (1), in Equation (1), K n is the normal stiffness of the spline. First, the displacement caused by applying a unit load in the normal direction to the single-tooth model can be obtained through a simulation method, that is, the flexibility, and then the reciprocal of it can be obtained to get the magnitude of the normal stiffness. For example, the calculated result is 8.9×10 8 N / m.

[0060] The total radial stiffness of all contact teeth of a set of splines is , that is, the radial support stiffness of the radial intermediate bearing can be calculated according to the following Equation (2): Equation (2), in Equation (2), m is the total number of spline contact teeth. There are 18 teeth in total for the splines in this implementation case, and the contact pressure angle is 30°. The radial stiffness of the spline obtained by solving according to the above Equation (1) and Equation (2) is 5.3×10 9 N / m.

[0061] Furthermore, in step S3, a simulation model is established based on the mobile deformation mechanics model, and mobile deformation simulation analysis is carried out through the radial support stiffness of the radial intermediate bearing, the first radial ground bearing support stiffness, the second radial ground bearing support stiffness, the third radial ground bearing support stiffness, the first axial ground bearing support stiffness, and the second axial ground bearing support stiffness to obtain the mobile deformation of the floating spline under mobile loads, including:

[0062] S31. Obtain the first radial ground bearing support stiffness K1 according to the roller bearing structure, and obtain the second radial ground bearing support stiffness K2 according to the ball bearing structure R , the third radial ground bearing support stiffness K4 R , the first axial ground bearing support stiffness K2 x and the second axial ground bearing support stiffness K4 x . Specifically, during implementation, the stiffness values of each bearing are shown in Table 1 below:

[0063] Table 1: Support stiffness of each bearing in the mobile deformation mechanics model

[0064]

[0065] S302. Apply a unit axial overload or a unit radial overload, a unit gyroscopic moment, the radial support stiffness K3 of the radial intermediate bearing, the first radial ground bearing support stiffness K1, the second radial ground bearing support stiffness K2 R , the third radial ground bearing support stiffness K4 R , the first axial ground bearing support stiffness K2 x and the second axial ground bearing support stiffness K4 xIn the simulation model established through the mechanical model of flexible deformation, obtain the axial deformation, the first angular deformation, and the first radial deformation, or obtain the axial deformation, the second angular deformation, and the second radial deformation.

[0066] During specific implementation, the unit axial overload is 1g, and the unit gyroscopic moment is a steady-state acceleration of 1 rad / s about any axis in the plane perpendicular to the rotor axis. The axial deformation U is obtained through the axial overload. X The radial deformation U is obtained when the unit gyroscopic moment is applied. ωR and the angular deformation U ωθ . The unit radial overload is 1g, and the second radial deformation U RR and the second angular deformation U Rθ are obtained through the radial overload.

[0067] During specific implementation, perform flexible deformation calculations according to a steady-state angular velocity of ω θ rad / s (a given value) about any axis in the plane perpendicular to the rotor axis and an axial maximum load factor n Xmax or a radial n Rmax maximum load factor. This value is U XZ = ω θ ×U ωθ + ω θ ×U ωR +U X ×n Xmax or U XZ = ω θ ×U ωθ + ω θ ×U ωR +U RR ×n Rmax + U Rθ ×n Rmax . Through analysis, it can be known that this value U XZ is composed of angular displacement and radial or axial translational displacement.

[0068] The calculation results of the unit flexible deformation of the floating spline calculated according to the support stiffness in Table 1 above are shown in Table 2 below:

[0069] Table 2: Calculation Results of Unit Flexible Deformation of Floating Spline

[0070]

[0071] S303. Take the first maneuver deformation amount under the limit load of the spline obtained through the first maneuver deformation as the maneuver deformation U JX .

[0072] Specifically, during implementation, perform maneuver deformation calculation according to a steady-state angular velocity of ω max rad / s at maximum and a radial load of 1 g about any axis in the plane perpendicular to the rotor axis. This value is U JX = ω max ×U ωθ + ω max ×U ωR +U RR ×1+U Rθ × 1 , and it can be known that this value is composed of angular displacement and radial translation displacement together.

[0073] Furthermore, when specifically implementing the above step S4, establish a contact stress calculation model according to the lengths of the spline input shaft and output shaft and the meshing contact length of the spline tooth surface. When establishing the contact stress calculation model, a steady-state working maximum torque load can be applied at the input end, and the output end is fixed and constrained. At the same time, according to Saint-Venant's principle, in order to reduce the influence of the load and boundary on the simulation analysis results of the contact pair, make the lengths of the spline input shaft and output shaft 3 times the meshing contact length of the spline tooth surface. By establishing a standard friction contact on the meshing tooth surfaces of the internal and external splines, the external spline and the internal spline are mutually the contact surface and the target surface. During the assembly process of the internal and external splines, artificially set the geometric state of the maneuver deformation of the spline, and adjust the contact state during the calculation to ensure that no serious interference phenomenon occurs.

[0074] When calculating the contact stress of the floating spline, first, a finite element simulation model of the contact stress can be established for the contact stress calculation model, and contact stress analysis under maneuver deformation calculation can be carried out. Input the maneuver deformation U XZ and the maneuver deformation U JX into the model, and output the contact stress of the spline pair; second, analyze according to the condition of the maneuver deformation U XZ , and the contact stresses under the limit load obtained are σ X and σ R . σ X When the axial overload is the largest (through U XZ = ω θ×U ωθ + ω θ ×U ωR + U X ×n Xmax Calculation), σ R Corresponding to the maximum radial overload (through U XZ = ω θ ×U ωθ + ω θ ×U ωR +U RR ×n Rmax +U Rθ ×n Rmax Calculation); Finally, solve the contact stress under the ultimate load of the spline for the maneuvering deformation U JX The contact stress under the action, according to the maneuvering deformation of U JX Under the condition of analysis, the contact stresses under the ultimate load obtained are respectively σ max .

[0075] Among them, the selection of the limit load and the ultimate load calculated according to Table 2 above and the results of the deformation superposition are shown in Table 3 below:

[0076] Table 3: Selection of Limit Load and Ultimate Load and Results of Deformation Superposition

[0077]

[0078] The results of the contact stresses of the limit load and the ultimate load calculated through Table 3 above are shown in Table 4 below:

[0079] Table 4 Results of Contact Stresses of Limit Load and Ultimate Load

[0080]

[0081] In an improved embodiment of the above method for calculating the contact stress of the aviation floating spline, the method further includes:

[0082] S5. Evaluate the fatigue reserve of the floating spline according to the contact stress of the floating spline.

[0083] Further, in the above step S5, evaluating the fatigue reserve of the floating spline according to the contact stress of the floating spline includes:

[0084] Evaluate the fatigue reserve of the floating spline according to the contact fatigue limit and the contact stress of the floating spline, or evaluate the fatigue reserve of the floating spline according to the contact stress of the floating spline and the target life. During specific implementation, considering that the load borne by each tooth in the circumferential direction of the spline changes after the maneuvering deformation, and one load cycle is experienced for each rotation, it is necessary to evaluate according to the contact fatigue. At the same time, with the help of the spline contact stress-fatigue life curve measured by the test, see Figure 5 as shown Figure 5 The contact fatigue limit in Hlim is σ 7 , generally the contact fatigue strength corresponding to more than 10 HN cycles, and the fatigue strength at a certain determined target life N is σ

[0085] On the one hand, according to the contact stress and the contact fatigue limit under the limiting load, evaluate the contact stress of the spline under the action of the limiting load maneuvering deformation. It can be evaluated according to the infinite life. At this time, the maximum contact stress σ X and σ R should both not be greater than the contact fatigue limit σ Hlim , that is, the contact fatigue reserve coefficient k XZ satisfies the following formulas (3) and (4):

[0086] Formula (3);

[0087] Formula (4);

[0088] If the contact fatigue reserve coefficient < 1, it means that the fatigue reserve of the floating spline is insufficient, and the floating spline needs to be replaced or modified.

[0089] On the other hand, according to the contact stress under the ultimate load and the contact fatigue strength at a certain determined target life N, evaluate the contact stress of the spline under the action of the ultimate load maneuvering deformation. It can be evaluated according to the finite target life N. Under the limiting load, it is required that the spline has the ability to work for a short time under the condition of the steady-state maximum speed n max . The time is determined to be t seconds. The target life N is calculated by the following formula (5):

[0090] Formula (5);

[0091] See Figure 5 as shown. According to formula (5), the fatigue strength at the determined target life N is σ HN . At this time, the maximum contact stress σ max of the spline under the ultimate load is not greater than the contact fatigue limit σ HN , that is, the contact fatigue reserve coefficient kJX Satisfy the following formula (6):

[0092] Formula (6);

[0093] The method of the present invention can quickly establish a mechanical model of the maneuvering deformation of an aviation floating spline and a contact stress calculation model, forming a design method for the contact stress of an aviation floating spline considering maneuvering deformation. It is mainly used for the simulation analysis of the contact stress of the transmission spline of an aeroengine, and can solve the contact fatigue problem of the spline during long-term operation under the maneuvering state during aircraft flight. The service life of the spline designed by the present invention before excessive contact fatigue wear occurs during long-term service is increased by about 25% - 30% compared with the traditional design method, improving the maintenance and replacement cycle of the spline and saving maintenance costs and economic costs.

[0094] Based on the same inventive concept, an aviation floating spline contact stress calculation system is also provided in an embodiment of the present invention, as described in the following embodiments. Since the principle of solving problems by the aviation floating spline contact stress calculation system is similar to that of the aviation floating spline contact stress calculation method described in the above embodiments, the implementation of the aviation floating spline contact stress calculation system can refer to the implementation of the above aviation floating spline contact stress calculation method, and the repeated parts will not be described again. As used hereinafter, the term "unit" or "module" can be a combination of software and / or hardware that can achieve a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0095] Figure 6 is a structural block diagram of an aviation floating spline contact stress calculation system disclosed in an embodiment of the present invention, as Figure 6 shown. The aviation floating spline contact stress calculation system includes a maneuvering deformation mechanics model construction module 601, a support stiffness calculation module 602, a floating spline maneuvering deformation calculation module 603, and a contact stress calculation module 604. The following will explain this structure.

[0096] Among them, the maneuvering deformation mechanics model construction module 601 is used to establish a maneuvering deformation mechanics model by adopting a simplified floating spline connection structure. The maneuvering deformation mechanics model includes an internal spline shaft, an external spline shaft, a first radial ground bearing, a second radial ground bearing, a third radial ground bearing, a first axial ground bearing, a second axial ground bearing, and a radial intermediate bearing;

[0097] The support stiffness calculation module 602 is used to obtain the radial support stiffness of the radial intermediate bearing according to the normal stiffness of the spline and the spline structure;

[0098] The floating spline motorized deformation calculation module 603 is used to establish a simulation model based on the motorized deformation mechanical model, and perform motorized deformation simulation analysis through the radial support stiffness of the radial intermediate bearing, the support stiffness of the first radial grounding bearing, the support stiffness of the second radial grounding bearing, the support stiffness of the third radial grounding bearing, the support stiffness of the first axial grounding bearing, and the support stiffness of the second axial grounding bearing, so as to obtain the motorized deformation of the floating spline under motorized load;

[0099] The contact stress calculation module 604 is used to establish a contact stress simulation model by using the floating spline connection structure according to the length of the spline input shaft, the length of the output shaft, and the meshing contact length of the spline tooth surface, input the motorized deformation into the contact stress simulation model for contact stress analysis, and obtain the floating spline contact stress.

[0100] Further, as shown in Figure 6 the system further includes an evaluation module 605, and the evaluation module 605 is used to evaluate the fatigue reserve of the floating spline according to the floating spline contact stress.

[0101] In this embodiment, a computer device is provided, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the above-mentioned arbitrary method for calculating the contact stress of the aviation floating spline is implemented.

[0102] Specifically, the computer device can be a computer terminal, a server, or a similar computing device.

[0103] In this embodiment, a computer-readable storage medium is provided, and the computer-readable storage medium stores a computer program for executing the above-mentioned arbitrary method for calculating the contact stress of the aviation floating spline.

[0104] Specifically, a computer-readable storage medium includes permanent and non-permanent, removable and non-removable media that can implement information storage by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer-readable storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tapes, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to store information accessible by a computing device. As defined herein, a computer-readable storage medium does not include transitory computer-readable media, such as modulated data signals and carrier waves.

[0105] Obviously, those skilled in the art should understand that the above-mentioned modules or steps of the embodiments of the present invention can be implemented by a general-purpose computing device. They can be concentrated on a single computing device or distributed on a network composed of multiple computing devices. Optionally, they can be implemented by program codes executable by the computing device. Thus, they can be stored in a storage device and executed by the computing device. And in some cases, the steps shown or described can be executed in a different order than here, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module to implement. In this way, the embodiments of the present invention are not limited to any specific combination of hardware and software.

[0106] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, various changes and modifications can be made to the embodiments of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for calculating the contact stress of an aviation floating spline, characterized in that, Including: A simplified floating spline connection structure is adopted to establish a mechanical deformation mechanics model, which includes an internal spline shaft, an external spline shaft, a first radial grounding bearing, a second radial grounding bearing, a third radial grounding bearing, a first axial grounding bearing, a second axial grounding bearing, and a radial intermediate bearing; The radial support stiffness of the radial intermediate bearing is obtained according to the spline normal stiffness and the spline structure; Based on the mechanical deformation mechanics model, a simulation model is established, and the mechanical deformation simulation analysis is carried out through the radial support stiffness of the radial intermediate bearing, the support stiffness of the first radial grounding bearing, the support stiffness of the second radial grounding bearing, the support stiffness of the third radial grounding bearing, the support stiffness of the first axial grounding bearing, and the support stiffness of the second axial grounding bearing to obtain the mechanical deformation of the floating spline under the mechanical load; Based on the length of the spline input shaft, the length of the output shaft, and the meshing contact length of the spline tooth surface, a contact stress simulation model is established by using the floating spline connection structure, and the mechanical deformation is input into the contact stress simulation model for contact stress analysis to obtain the floating spline contact stress, including: applying the maximum steady-state working torque load at the input end, fixing the output end, setting the lengths of the spline input shaft and the output shaft to 3 times the meshing contact length of the spline tooth surface, establishing a standard friction contact on the meshing tooth surfaces of the internal and external splines, and artificially setting the geometric state of the mechanical deformation of the spline during the assembly of the internal and external splines to establish a contact stress simulation model; When calculating the contact stress of the floating spline, the kinematic deformation U is respectively input into the contact stress simulation model XZ and the kinematic deformation U JX , and analyzed under the condition of the kinematic deformation U XZ to obtain the contact stress under the limited load; analyzed under the condition of the kinematic deformation U JX to obtain the contact stress under the ultimate load.

2. The method for calculating the contact stress of the aviation floating spline according to claim 1, characterized in that, A mechanical deformation mechanics model is established by using a simplified floating spline connection structure, including: The structure of the floating spline is analyzed, and the internal spline shaft and the external spline shaft are extracted from the structure analysis results to establish a simplified floating spline connection structure; A first radial grounding bearing is arranged at the position where the internal spline shaft contacts the roller bearing, a second radial grounding bearing and a first axial grounding bearing are arranged at the position where the internal spline shaft contacts the ball bearing, a radial intermediate bearing is arranged at the position where the internal spline shaft contacts the external spline shaft, and a third radial grounding bearing and a second axial grounding bearing are arranged at the position where the external spline shaft cooperates with other splines to obtain a mechanical deformation mechanics model.

3. The method for calculating the contact stress of the aviation floating spline according to claim 1, characterized in that, Obtaining the radial support stiffness of the radial intermediate bearing according to the spline normal stiffness and the spline structure, including: According to the rotation angle and the contact pressure angle of each tooth in the polar coordinates of the fit between the internal spline and the external spline, the rotation angle and the contact pressure angle are used to calculate the angle between the normal direction of the tooth contact surface of each tooth and the vertical direction; The displacement generated by applying a unit load in the normal direction of the single-tooth model is obtained by a simulation method, and the reciprocal of the displacement is obtained to obtain the spline normal stiffness; The radial support stiffness of each tooth is calculated through the angle and the spline normal stiffness; The radial support stiffness of all the teeth in the fit between the internal spline and the external spline is summed to obtain the radial support stiffness of the radial intermediate bearing.

4. The method for calculating the contact stress of the aviation floating spline according to claim 1, wherein A simulation model is established based on the mechanical model of maneuverable deformation. Maneuverable deformation simulation analysis is carried out through the radial support stiffness of the radial intermediate bearing, the support stiffness of the first radial ground bearing, the support stiffness of the second radial ground bearing, the support stiffness of the third radial ground bearing, the support stiffness of the first axial ground bearing, and the support stiffness of the second axial ground bearing to obtain the maneuverable deformation of the floating spline under maneuverable loads, including: The support stiffness of the first radial ground bearing is obtained according to the roller bearing structure, and the support stiffness of the second radial ground bearing, the support stiffness of the third radial ground bearing, the support stiffness of the first axial ground bearing, and the support stiffness of the second axial ground bearing are obtained according to the ball bearing structure; The unit axial overload or unit radial overload, unit gyroscopic moment, the radial support stiffness of the radial intermediate bearing, the support stiffness of the first radial ground bearing, the support stiffness of the second radial ground bearing, the support stiffness of the third radial ground bearing, the support stiffness of the first axial ground bearing, and the support stiffness of the second axial ground bearing are input into the simulation model established by the mechanical model of maneuverable deformation to obtain the axial deformation, the first angular deformation, and the first radial deformation, or to obtain the axial deformation, the second angular deformation, and the second radial deformation; The first maneuverable deformation is obtained through the axial deformation, the first angular deformation, and the first radial deformation, and the second maneuverable deformation is obtained through the axial deformation, the second angular deformation, and the second radial deformation. The first maneuverable deformation and the second maneuverable deformation are used as the maneuverable deformation.

5. The method for calculating the contact stress of the aviation floating spline according to claim 1, characterized in that, It also includes: Evaluating the fatigue reserve of the floating spline according to the contact stress of the floating spline.

6. The method for calculating the contact stress of the aviation floating spline according to claim 5, wherein, Evaluating the fatigue reserve of the floating spline according to the contact stress of the floating spline, including: Evaluating the fatigue reserve of the floating spline according to the contact fatigue limit and the contact stress of the floating spline, or evaluating the fatigue reserve of the floating spline according to the contact stress of the floating spline and the target life.

7. An aviation floating spline contact stress calculation system, characterized in that, It includes: A maneuverable deformation mechanical model construction module, which is used to establish a maneuverable deformation mechanical model by adopting a simplified floating spline connection structure. The maneuverable deformation mechanical model includes an internal spline shaft, an external spline shaft, a first radial ground bearing, a second radial ground bearing, a third radial ground bearing, a first axial ground bearing, a second axial ground bearing, and a radial intermediate bearing; A support stiffness calculation module, which is used to obtain the radial support stiffness of the radial intermediate bearing according to the normal stiffness of the spline and the spline structure; A floating spline maneuverable deformation calculation module, which is used to establish a simulation model based on the maneuverable deformation mechanical model, and carry out maneuverable deformation simulation analysis through the radial support stiffness of the radial intermediate bearing, the support stiffness of the first radial ground bearing, the support stiffness of the second radial ground bearing, the support stiffness of the third radial ground bearing, the support stiffness of the first axial ground bearing, and the support stiffness of the second axial ground bearing to obtain the maneuverable deformation of the floating spline under maneuverable loads; Contact stress calculation module, which is used to establish a contact stress simulation model by using the floating spline connection structure according to the spline input shaft length, output shaft length and spline tooth surface meshing contact length, input the kinematic deformation into the contact stress simulation model for contact stress analysis, and obtain the floating spline contact stress, including: applying the maximum steady-state working torque load at the input end, fixing the output end, setting the lengths of the spline input shaft and output shaft to 3 times the spline tooth surface meshing contact length, establishing a standard friction contact on the meshing tooth surfaces of the internal and external splines, artificially setting the kinematic deformation geometric state of the splines during the assembly of the internal and external splines, and establishing a contact stress simulation model; When calculating the contact stress of the floating spline, the maneuvering deformations U XZ and U JX are respectively input into the contact stress simulation model. Analyze under the condition of the maneuvering deformation U XZ to obtain the contact stress under the limiting load; analyze under the condition of the maneuvering deformation U JX to obtain the contact stress under the ultimate load.

8. The aviation floating spline contact stress calculation system according to claim 7, wherein It further includes an evaluation module, which is used to evaluate the fatigue reserve of the floating spline according to the floating spline contact stress.

9. A computer device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the aviation floating spline contact stress calculation method according to any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program for executing the aviation floating spline contact stress calculation method according to any one of claims 1 to 6.

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