A data-driven-based method for calculating the stiffness of a squirrel-cage elastic support structure

Abstract

The application provides a data-driven squirrel cage elastic supporting structure stiffness calculation method and relates to the technical field of aero-engines. The application relates to the technical field of aero-engines and provides a data-driven squirrel cage elastic supporting structure stiffness calculation method, which comprises the following steps: regarding a squirrel cage bar as an equal cross-section beam with both ends fixed, obtaining an original stiffness calculation formula of the squirrel cage bar, establishing a squirrel cage bar cross-section coordinate system, further considering the influence of the bar camber angle, and obtaining an improved stiffness calculation formula; introducing a correction coefficient into the improved squirrel cage bar stiffness calculation formula to obtain a corrected stiffness calculation formula; and calculating the squirrel cage stiffness according to the corrected squirrel cage bar stiffness calculation formula. The application aims to obtain a squirrel cage elastic supporting structure stiffness formula according to the real cross-section shape of the squirrel cage bar, regard the cross-section shape of the bar as the difference between sectors, consider the influence of the bar camber angle and the process structure on the stiffness, obtain a squirrel cage stiffness calculation formula suitable for the case of a larger camber angle, and improve the accuracy of the aero-engine elastic supporting stiffness calculation result.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engines, and in particular to a data-driven method for calculating the stiffness of a squirrel-cage elastic support structure. Background Art

[0002] The design and research of aircraft engine rotor support systems is a core technology in modern engine design. As engine failures caused by rotor system vibration become increasingly prominent, elastic support structures are a simple and effective way to adjust the critical speeds of the rotor system to minimize resonant speeds or maintain a sufficient safety margin at operating speeds. Typical elastic support structures for engines, such as squirrel cages and elastic rings, are widely used in aircraft engine rotor systems.

[0003] Accurately determining the stiffness of squirrel-cage elastic support structures is essential for studying the dynamic characteristics of aeroengine rotors. Currently, the stiffness of squirrel-cage structures is primarily determined through finite element simulation and analytical calculations. Finite element simulation can more comprehensively account for the influence of details such as cage bar chamfers. However, its accuracy is overly dependent on the quality of the meshing and the correctness of the boundary conditions, leading to low computational efficiency and high costs. Therefore, convenient and rapid analytical calculations offer greater engineering applicability and practical significance.

[0004] There are three main analytical calculation methods for squirrel cage elastic support structures. All of these calculation methods are based on the theory of uniform cross-section beams, that is, the squirrel cage bars are regarded as uniform cross-section beams with fixed supports at both ends. The first method regards the cross section of the cage bar as a square, and derives it based on the moment of inertia of the square section combined with the stiffness calculation formula of the uniform cross-section beam. Typical literature includes Literature 1 ("Aero Engine Design Manual Volume 19 - Rotor Dynamics and Whole Machine Vibration") and Literature 2 ("Several Issues in the Stiffness Calculation of Aero Engine Rotor Support Systems" DOI: 10.16358 / j.issn.1009-1300.2005.02.004); the second method is based on the first method and further considers the characteristics that the main bending direction of each cage bar section is not parallel to the force direction of the cage bar, and regards the cage bar cross section as a rectangle. Typical literatures include literature 3 ("Optimization Design and Experiment of Squirrel Cage Elastic Support Structure Parameters" DOI: 10.13224 / j.cnki.jasp.2011.01.026) and literature 4 ("Step-by-step Optimization Design Method of Squirrel Cage Elastic Support Structure Parameters" DOI: 10.13477 / j.cnki.aeroengine.2016.02.008); the third type further considers the influence of inconsistent upper and lower widths of the cage bar section on stiffness, and regards the cage bar section as a trapezoid. Typical literatures include literature 5 ("Experimental Test and Calculation Analysis of Stiffness of Squirrel Cage Elastic Support").

[0005] While the aforementioned methods for calculating the stiffness of squirrel cage elastic support structures can, to a certain extent, yield analytical stiffness values ​​for the cage, several issues remain. First, none of the three methods consider the impact of the cross-sectional radian angle of the cage bars on the stiffness calculation. Furthermore, the calculation of the total moment of inertia of the cage bar cross section directly uses the product of the number of bars and the average moment of inertia of a single bar in two directions. This can lead to significant errors in the stiffness calculation when the number of bars is small and the bar radian angle is large. On the other hand, all three stiffness calculation methods simplify the radian lines into straight lines when calculating the cross-sectional moment of inertia of individual cage bars. Reference 1 treats the cage bar cross-section as a square, ignoring the fact that the principal bending direction of each cage bar cross-section is not parallel to the direction of force acting on the cage bar. While Reference 3 further considers this characteristic based on Reference 1, it still exhibits significant errors relative to the actual cage bar shape, resulting in inaccurate cross-sectional moment of inertia. Reference 5, inspired by the moment of inertia derivation ideas of References 1 and 3, goes a step further by considering the inconsistent upper and lower widths of the cage bars, further considering the rectangular cage bar cross-section as a trapezoid. While this formula is closer to the actual fan-shaped cage bar cross-section, it still fails to account for the crucial effect of the radian angle, which has a significant impact on the stiffness value when the radian angle is large. More importantly, current aircraft engine squirrel cage elastic support structures in actual engineering practice often have large radian angles. Therefore, to avoid calculation errors in actual engineering design, the calculation formula should further consider the influence of the cage bar radian angle to avoid errors in stiffness calculation when the radian angle is large. Secondly, the three existing cage stiffness calculation formulas all consider only cage bar deformation during their derivation, ignoring the effects of bar chamfers and other process structures. This results in a certain deviation between the calculated results of the analytical formulas and those obtained through simulation or testing, affecting the accuracy of the final calculated stiffness results. Furthermore, the simplifications made during the derivation process also affect the accuracy of the final calculated results. These issues indicate that the current methods for calculating the stiffness of squirrel cage elastic support structures still have flaws and deficiencies in terms of calculation accuracy, making it difficult to accurately calculate the stiffness of squirrel cages with large bar curvature angles. Further research is needed to improve this accuracy. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to propose a data-driven squirrel cage elastic support structure stiffness calculation method, derive the squirrel cage elastic support structure stiffness analytical formula according to the actual cross-sectional shape of the squirrel cage bars, regard the cross-sectional shape of the cage bars as a fan to derive its section moment of inertia, consider the influence of the cage bar radian angle and the process structure on the stiffness, and finally obtain an accurate squirrel cage stiffness calculation formula applicable to the case of larger radian angle, improve the accuracy of the calculation results of the aircraft engine elastic support stiffness, and solve the problem of inaccurate calculation caused by the existing squirrel cage elastic support structure stiffness calculation method ignoring the cage bar cross-sectional radian angle, cage bar chamfer and other process structure influences.

[0007] The technical means adopted in the present invention are as follows:

[0008] A data-driven method for calculating the stiffness of a squirrel-cage elastic support structure comprises the following steps:

[0009] The squirrel cage bars are regarded as beams with equal cross-sections and fixed at both ends, the original stiffness calculation formula of the squirrel cage bars is obtained, and the squirrel cage bar cross-section coordinate system is established, wherein the squirrel cage bar cross-section coordinate system includes a circle center coordinate system and a centroid coordinate system;

[0010] The cross-sectional shape of the squirrel cage bar is regarded as the difference between two concentric sectors with different radii. According to the inertia moment of the sectors about the x-axis of the coordinate system through the center of the circle, the x-axis moment of the cross-sectional shape of the squirrel cage bar about the coordinate system through the center of the circle is obtained. c Axis moment of inertia formula;

[0011] Dividing the cross-sectional shape of the squirrel cage bar into three parts, solving the moment of inertia formulas of the three parts about the y-axis in the cross-sectional coordinate system of the squirrel cage bar respectively, and then adding them together to obtain the section moment of inertia formula of the squirrel cage bar cross-sectional shape about the y-axis in the cross-sectional coordinate system;

[0012] The cross section of the cage bar is about the centroid coordinate system x c Substitute the formula for the moment of inertia of the axis and the formula for the section moment of inertia of the y-axis in the section coordinate system into the original stiffness calculation formula of the squirrel cage bar to obtain the improved stiffness calculation formula of the squirrel cage bar;

[0013] Introducing a correction coefficient into the improved stiffness calculation formula of the squirrel cage bar to obtain a corrected stiffness calculation formula of the squirrel cage bar;

[0014] The cage stiffness is calculated according to the modified cage bar stiffness calculation formula.

[0015] Furthermore, the method for establishing the cross-sectional coordinate system of the squirrel cage bar is as follows: the cross-sectional shape of the squirrel cage bar is regarded as the difference between two concentric sectors with different radii, the centers of the two sectors are taken as the center of the coordinate system, the horizontal line passing through the centers is taken as the x-axis, the vertical line passing through the centroid of the cross-sectional shape of the cage bar is taken as the y-axis, and the horizontal line passing through the centroid of the cross-sectional shape of the cage bar is taken as the x-axis. c axis.

[0016] Furthermore, the cross section of the cage bar is obtained with respect to the centroid coordinate system x c The specific steps of the formula for the moment of inertia of the shaft are:

[0017] According to the squirrel cage bar cross-section coordinate system and the definition of moment of inertia, the formula of the moment of inertia of the sector about the coordinate system passing through the center of the circle is obtained;

[0018] According to the formula for the moment of inertia of the sector about the coordinate system passing through the center of the circle, the cross section of the squirrel cage bar is regarded as the difference between the two sectors, and the formula for the moment of inertia of the cross section of the squirrel cage bar about the coordinate system passing through the center of the circle is obtained;

[0019] The formula of the moment of inertia of the slot section about the coordinate system passing through the center of the circle is obtained according to the parallel axis theorem of the moment of inertia combined with the vertical distance between the x axis and the x axis. c The formula of the moment of inertia of the slot section about the coordinate system passing through the center of the circle is obtained according to the parallel axis theorem of the moment of inertia combined with the vertical distance between the x axis and the x axis.

[0020] Further, the specific steps for obtaining the formula of the moment of inertia of the slot section about the y axis in the section coordinate system are as follows:

[0021] According to the shape characteristics of the slot section of the squirrel cage, the slot section of the squirrel cage is divided into a first part and a third part at both ends and a second part in the middle, so that the number of edges of the first part and the third part is minimized.

[0022] The first part and the third part are regarded as triangles, and the calculation formula of the first part and the calculation formula of the third part are obtained according to the definition of the moment of inertia.

[0023] The formula of the moment of inertia of the second part about the y axis is obtained according to the definition of the moment of inertia.

[0024] The formula of the moment of inertia of the second part about the y axis is obtained according to the definition of the moment of inertia.

[0025] Further, the correction coefficient is obtained by three-dimensional fitting of the stiffness ratio based on a data-driven method.

[0026] Further, the formula of the moment of inertia of the slot section about the coordinate system passing through the center of the circle is:

[0027]

[0028] Wherein: I x represents the moment of inertia of the slot section about the x axis passing through the center of the circle, I xc represents the moment of inertia of the slot section about the x axis passing through the center of the circle, y c represents the vertical offset distance of the center of the slot section from the center of the circle, S A represents the area of the slot section, R represents the outer diameter of the slot, r represents the inner diameter of the slot, and θ represents half of the radian angle of the sector.

[0029] The formula of the moment of inertia of the slot section about the y axis in the section coordinate system is:

[0030]

[0031] The improved formula for calculating the stiffness of the squirrel cage is:

[0032]

[0033] Among them: K1 represents the cage stiffness, E represents the material elastic modulus, L represents the cage length, n represents the number of cage bars, Indicates the angle between the i-th cage bar and the horizontal line starting from the vertical direction (0°﹤φ i ﹤180°).

[0034] Furthermore, the modified stiffness calculation formula of the squirrel cage bar is:

[0035]

[0036] Where,

[0037]

[0038]

[0039] K r =p+p1·(Rr)+p2·θ+p3·(Rr) 2 +p4·(Rr)·θ

[0040] Where: n is the number of cage bars, L is the length of the cage bars, E is the elastic modulus, R is the outer diameter of the cage bars, r is the inner diameter of the cage bars, θ is half of the sector arc angle, Indicates the angle between the i-th cage bar and the horizontal line starting from the vertical direction p, p1, p2, p3, and p4 are fitting parameters to be determined, which are 1.06, -1.93×10-2, -4.2×10-2, -2.9×10-3, and 1.2×10-3, respectively.

[0041] Compared with the prior art, the present invention has the following advantages:

[0042] The present invention truly considers the curvature of the cross-section of the cage bars, derives the cross-sectional moment of inertia of each cage bar based on the fan-shaped cross-section, and then multiplies the cross-sectional moment of inertia of each cage bar by the trigonometric function corresponding to its position to obtain the final overall moment of inertia of the cage structure. The influence of the curvature angle of the cage bars is taken into account, and the error generated when the number of cage bars is small and the curvature angle of the cage bars is large is avoided.

[0043] The present invention adopts a data-driven method to add stiffness correction on the basis of the derived stiffness calculation formula, and obtains the stiffness correction coefficient through three-dimensional fitting based on simulation or experimental data, so that the result obtained by the final corrected stiffness calculation formula is close to the simulation or test value. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0045] Figure 1 Flow chart of the method of the present invention.

[0046] Figure 2 This is a cross-sectional view of the cage bars of the present invention.

[0047] Figure 3 It is a schematic diagram of a fan-shaped cross section of the present invention.

[0048] Figure 4 Schematic diagram of the cross-section of the cage bars of the present invention.

[0049] Figure 5 It is a schematic diagram of the geometric relationship of the present invention.

[0050] Figure 6 This is the fitting result diagram of the present invention.

[0051] Figure 7 This is a diagram showing the changing patterns of the calculation results of the formulas of the present invention. DETAILED DESCRIPTION

[0052] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0053] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0054] like Figure 1 As shown, the present invention provides a data-driven method for calculating the stiffness of a squirrel-cage elastic support structure.

[0055] Schematic diagram of the cage cross section Figure 2 As shown in the figure, according to the "Aero Engine Design Manual", the squirrel cage bars are regarded as beams with equal cross-sections fixed at both ends, and the stiffness calculation formula is as follows:

[0056]

[0057] Where, K0 represents the original calculation formula of cage stiffness, E represents the elastic modulus of the material, L represents the length of the cage bar, n represents the number of cage bars, I x represents the moment of inertia of the cage bar section about the x-axis, I y represents the moment of inertia of the cage bar section about the y-axis, Indicates the angle between the i-th cage bar and the horizontal line in counterclockwise direction starting from the vertical direction

[0058] First, derive the formula for the moment of inertia of the sector section about the x-axis of the coordinate system passing through the center of the circle, and divide the total moment of inertia into two parts according to the characteristics of the section. The section diagram is as follows Figure 3 shown.

[0059] The formula for the moment of inertia of a sector section about the x-axis of the coordinate system passing through the center of the circle is as follows.

[0060] I x =I a +I b (2)

[0061]

[0062]

[0063]

[0064] Where, I a represents the section inertia moment of the triangle about the x-axis, I b represents the section moment of inertia of the remaining part about the x-axis, R represents the diameter of the sector, and θ represents half of the arc angle of the sector.

[0065] When a plane figure is composed of several simple figures, according to the definition of moment of inertia, we can first calculate the moment of inertia of each simple figure about the same axis, and then find the sum of them, which is equal to the moment of inertia of the entire figure about this axis. Therefore, the cross section of the squirrel cage bar is regarded as the difference between two sectors, such as Figure 2 shown.

[0066] According to the formula for the moment of inertia of the sector section about the x-axis of the coordinate system passing through the center of the circle, the formula for the moment of inertia of the cage bar section about the x-axis of the coordinate system passing through the center of the circle is as follows.

[0067]

[0068] Where, I x1 It represents the section inertia moment of the large sector about the x-axis, I x2 represents the section moment of inertia of the small sector about the x-axis, R represents the outer diameter of the cage bar, r represents the inner diameter of the cage bar, and θ represents half of the arc angle of the sector.

[0069] By using a principle similar to the above solution of the cage bar section moment of inertia, the vertical offset distance y between the centroid of the cage bar section and the center of the circle can be obtained. c , the centroid solution formula is as follows:

[0070]

[0071] Where y total Indicates the y coordinate of the centroid of the large sector, S A1 Indicates the cross-sectional area of ​​the cage bar, S A2 Represents the area of ​​the small sector, y1 represents the y-coordinate of the centroid of the cage bar, and y2 represents the y-coordinate of the centroid of the small sector.

[0072] The vertical distance y between the coordinate axis passing through the centroid of the cross section of the cage bar and the coordinate axis passing through the center of the circle is further obtained from formula (7): c as follows:

[0073]

[0074] Combining the moment of inertia parallel axis theorem, we can get the formula of the moment of inertia of the cage bar section about the centroid coordinate system.

[0075]

[0076] Where, I x I represents the moment of inertia of the cage cross section about the x-axis passing through the center of the circle. xc represents the moment of inertia of the cage section about the x-axis passing through the centroid, y c Indicates the vertical offset distance between the centroid of the cage cross section and the center of the circle, S A Represents the cross-sectional area of ​​the cage bars.

[0077] According to the cross-sectional shape characteristics, it can be divided into three parts, as shown in the figure Figure 4 shown.

[0078] The calculation of the moment of inertia of the squirrel cage section about the y-axis was simplified. The first and third sections of the cross section were considered as triangles. The final calculation formula is as follows:

[0079]

[0080]

[0081]

[0082] Where, I y1 represents the moment of inertia of the first part of the division about the y-axis, I y2 The moment of inertia of the second part of the division about the y-axis, I y3 Represents the moment of inertia of the third part of the division about the y-axis.

[0083] When solving the second part of the moment of inertia about the y-axis, we must first obtain the vertical distance of the cage bar section at any x position. This vertical distance has a certain geometric relationship with the inner and outer diameters of the cage bar, such as Figure 5 shown.

[0084] Depend on Figure 5 The geometric relationship can be obtained as:

[0085]

[0086] Where y x represents the vertical distance of the cage bar cross section, and x represents any x position.

[0087] From formula (13), we can further obtain y x expression:

[0088]

[0089] The second part of the section moment of inertia about the y-axis can be obtained from the definition of the moment of inertia:

[0090]

[0091] Substituting equations (11), (12) and (15) into equation (10) yields the section moment of inertia of the cage bar section about the y-axis:

[0092]

[0093] Substituting equations (9) and (16) into equation (1), the improved stiffness calculation formula of the squirrel cage is obtained as follows:

[0094]

[0095] Since some assumptions were made in the derivation of the formula, in order to improve the calculation accuracy of the analytical formula as much as possible and reduce the error, the correction coefficient K is introduced into the final stiffness calculation formula. r, the correction factor is obtained by three-dimensional fitting stiffness ratio based on a data-driven method and is a function of (Rr) and θ:

[0096] K r =f[(Rr),θ] (18)

[0097] The specific expression of the correction coefficient is as follows:

[0098] K r =p+p1·(Rr)+p2·θ+p3·(Rr) 2 +p4·(Rr)·θ (19)

[0099] Where K r is the correction coefficient, and p, p1, p2, p3, and p4 are the fitting parameters to be determined, which are 1.06, -1.93×10-2, -4.2×10-2, -2.9×10-3, and 1.2×10-3, respectively. The fitting function uses a three-dimensional polynomial fitting, and the fitting goodness of fit R2 is 0.9978 and the RMSE is 0.0061, indicating that the fitting effect is good and can accurately predict data in other ranges. The fitting results are shown in the figure below. Figure 6 shown.

[0100] The final stiffness calculation formula after considering the correction coefficient is as follows:

[0101]

[0102] Where,

[0103]

[0104]

[0105] K r =p+p1·(Rr)+p2·θ+p3·(Rr) 2 +p4·(Rr)·θ (23)

[0106] Where n is the number of cage bars, L is the length of the cage bars, E is the elastic modulus, R is the outer diameter of the cage bars, r is the inner diameter of the cage bars, and θ is half of the sector arc angle. Indicates the angle between the i-th cage bar and the horizontal line starting from the vertical direction p, p1, p2, p3, and p4 are fitting parameters to be determined, which are 1.06, -1.93×10-2, -4.2×10-2, -2.9×10-3, and 1.2×10-3, respectively.

[0107] Based on the above formula, the stiffness calculation formulas in Reference 1 and Reference 3 and the stiffness calculation formula in this paper were studied to determine the variation of the results with the arc angle of the cage bar section. The cage structural parameters used are shown in Table 1. The variation is as follows: Figure 7 As shown in Table 2, the calculation results of the stiffness calculation formula in this paper and the two existing stiffness formulas are compared and analyzed for a certain squirrel cage model and five squirrel cage models obtained by changing certain parameters on this basis, as shown in Table 2 and Table 3 below. The relative errors between the stiffness calculated by the formula and the simulation or test values ​​are given in brackets.

[0108] Table 1 Cage parameters

[0109]

[0110] Table 2 Comparison of stiffness calculation results 1

[0111]

[0112] Table 3 Comparison of stiffness calculation results 2

[0113]

[0114]

[0115] Depend on Figure 7 As can be seen, as the radian angle gradually increases, the error between the stiffness calculation formulas in References 1 and 3 and the simulation values ​​increases, while the error of this formula is much smaller than the former, which demonstrates the practical significance of this formula for stiffness calculation. As shown in Tables 2 and 3, the stiffness calculation formula proposed in this paper is more accurate in the calculation results, with a smaller relative error compared to the simulation or experimental values. Therefore, an accurate squirrel cage stiffness calculation formula applicable to larger radian angles is ultimately obtained, improving the accuracy of the calculation results for the elastic support stiffness of aircraft engines while avoiding the computational inefficiencies such as slow speed and high cost associated with the finite element method.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A data-driven method for calculating the stiffness of a squirrel-cage elastic support structure, characterized in that: The steps include: The squirrel cage bars are regarded as beams with equal cross-sections and fixed at both ends, the original stiffness calculation formula of the squirrel cage bars is obtained, and the squirrel cage bar cross-section coordinate system is established, wherein the squirrel cage bar cross-section coordinate system includes a circle center coordinate system and a centroid coordinate system; The cross-sectional shape of the squirrel cage bar is regarded as the difference between two concentric sectors with different radii. According to the inertia moment of the sectors about the x-axis of the coordinate system through the center of the circle, the x-axis moment of the cross-sectional shape of the squirrel cage bar about the coordinate system through the center of the circle is obtained. c Axis moment of inertia formula; Dividing the cross-sectional shape of the squirrel cage bar into three parts, solving the moment of inertia formulas of the three parts about the y-axis in the cross-sectional coordinate system of the squirrel cage bar respectively, and then adding them together to obtain the section moment of inertia formula of the squirrel cage bar cross-sectional shape about the y-axis in the cross-sectional coordinate system; The cross section of the cage bar is about the centroid coordinate system x c Substitute the formula for the moment of inertia of the axis and the formula for the section moment of inertia of the y-axis in the section coordinate system into the original stiffness calculation formula of the squirrel cage bar to obtain the improved stiffness calculation formula of the squirrel cage bar; Introducing a correction coefficient into the improved stiffness calculation formula of the squirrel cage bar to obtain a corrected stiffness calculation formula of the squirrel cage bar; The cage stiffness is calculated according to the modified cage bar stiffness calculation formula.

2. The data-driven squirrel cage elastic support structure stiffness calculation method according to claim 1, characterized in that: The method for establishing the cross-section coordinate system of the squirrel cage bar is as follows: the cross-section shape of the squirrel cage bar is regarded as the difference between two concentric sectors with different radii, the centers of the two sectors are used as the center of the coordinate system, the horizontal line passing through the centers is used as the x-axis, the vertical line passing through the centroid of the cross section of the cage bar is used as the y-axis, and the horizontal line passing through the centroid of the cross section of the cage bar is used as the x-axis. c axis.

3. The data-driven squirrel cage elastic support structure stiffness calculation method according to claim 1, characterized in that: Get the cross section of the cage bar about the centroid coordinate system x c The specific steps of the formula for the moment of inertia of the axis are: According to the squirrel cage bar cross-section coordinate system and the definition of moment of inertia, the formula of the moment of inertia of the sector about the coordinate system passing through the center of the circle is obtained; According to the formula for the moment of inertia of the sector about the coordinate system passing through the center of the circle, the cross section of the squirrel cage bar is regarded as the difference between the two sectors, and the formula for the moment of inertia of the cross section of the squirrel cage bar about the coordinate system passing through the center of the circle is obtained; The moment of inertia formula of the squirrel cage bar section about the center coordinate system is combined with the parallel axis theorem of the moment of inertia c The vertical distance between the axis and the x-axis gives the cross section of the cage bar about the centroid coordinate system x c Formula for the moment of inertia of an axis.

4. The data-driven squirrel-cage elastic support structure stiffness calculation method according to claim 1, characterized in that: The specific steps to obtain the formula for the section moment of inertia of the squirrel cage bar section about the y-axis in the section coordinate system are: According to the cross-sectional shape characteristics of the cage bars, the cross-sectional shape of the cage bars is divided into the first part at both ends, the third part and the second part in the middle, so that the number of sides of the first part and the third part is minimized; Considering the first and third parts as triangles, the calculation formulas for the first and third parts are obtained according to the definition of moment of inertia; According to the definition of moment of inertia, the formula of the second part of the section moment of inertia about the y-axis is obtained; The calculation formula of the first part, the calculation formula of the third part and the formula of the section moment of inertia about the y-axis in the second part are added together to obtain the formula of the section moment of inertia of the cage bar section about the y-axis.

5. The data-driven squirrel-cage elastic support structure stiffness calculation method according to claim 1, characterized in that: The correction coefficient is obtained by three-dimensional fitting stiffness ratio based on a data-driven method.

6. The data-driven squirrel-cage elastic support structure stiffness calculation method according to claim 1, characterized in that: The cross section of the cage bar is about the centroid coordinate system x c The formula for the moment of inertia of an axis is: Among them: I x I represents the moment of inertia of the cage cross section about the x-axis passing through the center of the circle. xc represents the moment of inertia of the cage bar section about the x-axis passing through the centroid, y c Indicates the vertical offset distance between the centroid of the cage cross section and the center of the circle, S A represents the cross-sectional area of ​​the cage bar, R represents the outer diameter of the cage bar, r represents the inner diameter of the cage bar, and θ represents half of the sector arc angle; The formula for the section moment of inertia about the y-axis in the section coordinate system is: The improved squirrel cage stiffness calculation formula is: Among them: K1 represents the stiffness of the improved squirrel cage, E represents the elastic modulus of the material, L represents the length of the cage bar, n represents the number of cage bars, Indicates the angle between the i-th cage bar and the horizontal line starting from the vertical direction 7. The data-driven squirrel-cage elastic support structure stiffness calculation method according to claim 1, characterized in that: The modified stiffness calculation formula of the squirrel cage bar is: Where, K r =p+p1·(Rr)+p2·θ+p3·(Rr) 2 +p4·(Rr)·θ Where: n is the number of cage bars, L is the length of the cage bars, E is the elastic modulus, R is the outer diameter of the cage bars, r is the inner diameter of the cage bars, θ is half of the sector arc angle, Indicates the angle between the i-th cage bar and the horizontal line starting from the vertical direction p, p1, p2, p3, and p4 are fitting parameters to be determined, which are 1.06, -1.93×10-2, -4.2×10-2, -2.9×10-3, and 1.2×10-3, respectively.

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