A method for determining the residual stress control domain of an aero-engine blade

Abstract

The present invention relates to a method for determining the residual stress control domain of an aero-engine blade. First, the equivalent depth set in the feed direction and the cutting width direction of the blade is predicted by the equivalent depth prediction model in the feed direction and the cutting width direction. Then, the surface residual stress state set in the two directions and the predicted equivalent depth set are used as inputs to perform static analysis to obtain the overall induced deformation of the residual stress of the target blade in the feed and cutting width directions. Finally, the surface residual stress in the feed and cutting width directions and the overall induced deformation of the residual stress are respectively subjected to surface fitting to obtain the surface residual stress control domain of the target blade in the feed direction under the contour constraint and the surface residual stress control domain in the cutting width direction under the position constraint. The present invention can directly determine the residual stress control domain of the blade, provide guidance for blade processing, and greatly reduce the processing cycle and cost.

Description

Technical Field

[0001] The present invention relates to the technical field of computer-aided machining of engine blades, and in particular to a method for determining a residual stress control domain of an aero-engine blade. Background Art

[0002] Aircraft engine compressor blades are typical thin-walled components with low rigidity, with thicknesses at the leading and trailing edges potentially less than 0.15 mm. For these thin-walled components, deformation control is a primary goal in selecting and optimizing blade machining parameters. Blade deformation is caused by residual stresses within the material, which can be categorized into two types: The first type of residual stress is caused by material preparation processes such as rolling and quenching during blank manufacturing; the second type of residual stress is caused by machining residual stresses introduced during part forming processes such as milling and strengthening.

[0003] Research has shown that when part thickness is less than 3 mm, the influence of type II residual stress on deformation is more significant. Therefore, for aeroengine compressor blades, residual stresses inevitably introduced during machining are a key factor in blade deformation. Once blade deformation occurs under the influence of residual stresses, the blade's aerodynamic performance changes. When the deformation exceeds a certain threshold, not only will the aeroengine's operating performance decline significantly, but the blade will also be susceptible to premature fatigue fracture, seriously threatening flight safety. Therefore, defining the permissible range of residual stresses introduced during machining, known as the residual stress control domain (RSD), based on deformation constraints, is a key indicator for machining control of aeroengine compressor blades. The RSD can be used to plan and determine the appropriate range of process parameters for blade machining. As long as the blade machining parameters fall within this range, the machined blade will meet the standard. For example, in milling, all residual stresses within the RSD can be substituted into the correlation model between milling process parameters and residual stresses to calculate the range of milling process parameters, such as feed per tooth, feed rate, and depth of cut, thus providing guidance for selecting blade machining process parameters.

[0004] However, the existing technology lacks a method for determining the residual stress control domain. In the processing of aircraft engine compressor blades, trial cutting method, empirical method and stress repair method are mainly used to achieve processing deformation control of the blades. Among them, the empirical method and trial cutting method require continuous trial and error to determine more reasonable processing parameters before processing the blades on the blade disk. The stress repair method is to measure and repair the deformation of each blade after processing. The processing cycle of the trial cutting method, empirical method and stress repair method is long and increases the processing cost. Summary of the Invention

[0005] Based on this, it is necessary to provide a method for determining the residual stress control domain of aero-engine blades to address the above technical problems. This method can directly calculate the residual stress control domain of the blades, provide guidance for blade processing, and significantly reduce processing cycle and cost.

[0006] The present invention provides a method for determining a residual stress control region of an aero-engine blade, comprising the following steps:

[0007] Construct the surface residual stress state set in the feed direction and the surface residual stress state set in the cut width direction of the blade base and blade back of the target blade;

[0008] Inputting the surface residual stress state set in the feed direction into the feed direction equivalent depth prediction model to obtain the feed direction equivalent depth set, and inputting the surface residual stress state set in the cutting width direction into the cutting width direction equivalent depth prediction model to obtain the cutting width direction equivalent depth set;

[0009] Static analysis is performed on the surface residual stress state set in the feed direction, the equivalent depth set in the feed direction, and the surface residual stress state set and the equivalent depth set in the cut width direction, respectively, to obtain the overall induced deformation of the residual stress of the target blade in the feed direction and the overall induced deformation of the residual stress of the target blade in the cut width direction.

[0010] A first correlation model diagram is obtained by performing surface fitting on the surface residual stress state set in the feed direction and the overall induced deformation of the residual stress of the target blade in the feed direction, and a second correlation model diagram is obtained by performing surface fitting on the surface residual stress state set in the cut width direction and the overall induced deformation of the residual stress of the target blade in the cut width direction;

[0011] The first correlation model diagram and the second correlation model diagram are projected on the same plane respectively to obtain the surface residual stress control domain in the feed direction under the contour constraint and the surface residual stress control domain in the cut width direction under the position constraint of the target blade.

[0012] In one embodiment, the first correlation model diagram is a correlation model diagram of the residual stress on the surface of the target blade in the feed direction and the contour, and the second correlation model diagram is a correlation model diagram of the residual stress on the surface of the target blade in the cut width direction and the position.

[0013] In one embodiment, constructing a surface residual stress state set in the feed direction and a surface residual stress state set in the cut width direction of the blade base and blade back of the target blade includes the following steps:

[0014] A 3D model of the target blade is established in UG software, and the blade base and blade back of the 3D model are divided into multiple regions;

[0015] Import the 3D model of the target blade into ANSYS Workbench software to extract the node coordinates of the blade basin and blade back regions of the 3D model of the target blade. Based on the node coordinates of all regions, the surface residual stress assignment tables of the target blade in the feed direction and the cut width direction are created respectively.

[0016] The surface residual stress assignment tables in the feed direction and the cut width direction were respectively imported into the first statics analysis module of ANSYS Workbench software, and the scaling factor was adjusted to obtain the surface residual stress state set in the feed direction and the surface residual stress state set in the cut width direction of the blade basin and blade back of the target blade.

[0017] In one embodiment, the feed direction equivalent depth prediction model is:

[0018] ,

[0019] Where, h eq-MD Indicates the equivalent depth of the blade feed direction, h Indicates the thickness of the leaf, z Indicates the depth of a point inside the blade from the milling surface. represents the residual stress field in the depth section of the blade feed direction, Indicates the surface residual stress state of the blade in the feed direction, v represents the Poisson's ratio of the blade material, E represents the Young's modulus of the blade material, A MD represents the coefficient describing the residual stress distribution area in the blade feed direction, h s-MD represents the depth coefficient of the residual stress field in the blade feed direction, z d-MD Indicates the depth corresponding to the minimum residual stress in the blade feed direction.

[0020] In one embodiment, the prediction model of equivalent depth in the cutting width direction is:

[0021] ,

[0022] Where, h Indicates the thickness of the leaf, z Indicates the depth of a point inside the blade from the milling surface. h eq-CWD Indicates the equivalent depth of the blade in the cutting width direction, represents the residual stress field in the depth section of the blade in the direction of the cut width, Indicates the surface residual stress state of the blade in the cutting width direction, E represents the Young's modulus of the blade material, ACWD It represents the coefficient describing the residual stress distribution area along the blade width. h s-CWD The depth coefficient of the residual stress field in the blade width direction is represented by z d-CWD Indicates the depth corresponding to the maximum residual stress in the blade width direction.

[0023] In one embodiment, importing the 3D model of the target blade into ANSYS Workbench software to extract the node coordinates of the blade base and blade back regions of the 3D model of the target blade includes the following steps:

[0024] Export the 3D model of the target blade in UG into STEP format and import it into the DesignModal module of ANSYS Workbench software;

[0025] Select the Surface command, create new sheets on the divided area and number the sheets, and use the From New Part command to bind all the sheets and entities into a multi-body part.

[0026] Establish a second statics analysis module and import the data of the Design Modal module into the second statics analysis module;

[0027] In the second static analysis module, any external load is applied to the multi-body parts to perform stress calculation;

[0028] Based on the stress calculation results, the node data of all regional slices are extracted to obtain a node information table, where the node data includes node ID and node coordinates.

[0029] In one embodiment, creating a surface residual stress assignment table for a target blade in feed and cut width directions based on the node coordinates of all regions includes the following steps:

[0030] Add columns xx, yy, zz, xy, yz, and xz to the right of the node information table, where xx is the normal stress in the x-direction, yy is the normal stress in the y-direction, zz is the normal stress in the z-direction, xy is the shear stress in the x-direction, yz is the shear stress in the y-direction, and xz is the shear stress in the z-direction.

[0031] Assign all values ​​of the xx column of the node information table after adding the column to -100 MPa to obtain the surface residual stress assignment table of the target blade in the feed direction; assign all values ​​of the yy column of the node information table after adding the column to -100 MPa to obtain the surface residual stress assignment table of the target blade in the cutting width direction.

[0032] In one embodiment, the surface residual stress state set in the feed direction and the surface residual stress state set in the cutting width direction both includen The residual stress state of the group surface, n ≥100.

[0033] The beneficial effects of the present invention are as follows: the present invention first predicts the equivalent depths of all blades in the feed and cut width directions through an equivalent depth prediction model in the feed direction and the cut width direction, then performs static analysis and finite element calculations based on ANSYS Workbench software using the surface residual stress state set and the predicted equivalent depth set in the two directions as input to obtain the target blade residual stress overall induced deformation in the feed direction and the cut width direction, and finally performs surface fitting on the surface residual stress set and the residual stress overall induced deformation in the feed and cut width directions to obtain the target blade surface residual stress control domain in the feed direction under the contour constraint and the surface residual stress control domain in the cut width direction under the position constraint. The present invention can directly determine the blade residual stress control domain, provide guidance for blade processing, and significantly reduce the processing cycle and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram of a first association model diagram provided in an embodiment of the present invention;

[0035] Figure 2 for Figure 1 Contour plot of residual stress versus profile obtained after projection on the XY plane;

[0036] Figure 3 A schematic diagram of a second association model diagram provided in an embodiment of the present invention;

[0037] Figure 4 for Figure 3 Contour plot of residual stress versus profile obtained after projection on the XY plane. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] In one embodiment, a method for determining a residual stress control region of an aerospace engine blade includes the following steps:

[0040] S101. Constructing a surface residual stress state set in the feed direction and a surface residual stress state set in the cut width direction of the blade base and blade back of the target blade.

[0041] Specifically, the surface residual stress state set in the feed direction and the surface residual stress state set in the cutting width direction both include n The residual stress state of the group surface, n≥100.

[0042] The blade basin of the target blade is the concave side of the blade curvature, the blade back is the convex side of the blade curvature, the feed direction is the direction from the trailing edge to the leading edge of the blade, and the cutting width direction is the direction perpendicular to the feed direction and pointing to the blade tip.

[0043] S102, inputting the surface residual stress state set in the feed direction into the feed direction equivalent depth prediction model to obtain the feed direction equivalent depth set, and inputting the surface residual stress state set in the cutting width direction into the cutting width direction equivalent depth prediction model to obtain the cutting width direction equivalent depth set.

[0044] Among them, the feed direction equivalent depth prediction model is:

[0045] ,

[0046] Where, h eq-MD Indicates the equivalent depth of the blade feed direction, h Indicates the thickness of the leaf, z Indicates the depth of a point inside the blade from the milling surface. represents the residual stress field in the depth section of the blade feed direction, Indicates the surface residual stress state of the blade in the feed direction, v represents the Poisson's ratio of the blade material, E represents the Young's modulus of the blade material, A MD represents the coefficient describing the residual stress distribution area in the blade feed direction, h s-MD represents the depth coefficient of the residual stress field in the blade feed direction, z d-MD Indicates the depth corresponding to the minimum residual stress in the blade feed direction.

[0047] The prediction model of equivalent depth in cutting width direction is:

[0048] ,

[0049] Where, h Indicates the thickness of the leaf, z Indicates the depth of a point inside the blade from the milling surface. h eq-CWD Indicates the equivalent depth of the blade in the cutting width direction, represents the residual stress field in the depth section of the blade in the direction of the cut width, Indicates the surface residual stress state of the blade in the cutting width direction, E represents the Young's modulus of the blade material, A CWDIt represents the coefficient describing the residual stress distribution area along the blade width. h s-CWD The depth coefficient of the residual stress field in the blade width direction is represented by z d-CWD Indicates the depth corresponding to the maximum residual stress in the blade width direction.

[0050] It should be noted that the feed direction surface residual stress state set is input into the feed direction equivalent depth prediction model to obtain the feed direction equivalent depth set. Specifically, each feed direction surface residual stress state is input into the feed direction equivalent depth prediction model to obtain a feed direction equivalent depth, and all the feed direction equivalent depths finally obtained are combined to form the feed direction equivalent depth set.

[0051] Similarly, the surface residual stress state set in the cutting width direction is input into the cutting width direction equivalent depth prediction model to obtain the cutting width direction equivalent depth set. Specifically, each surface residual stress state in the cutting width direction is input into the cutting width direction equivalent depth prediction model to obtain an equivalent depth in the cutting width direction, and all the equivalent depths in the cutting width direction finally obtained are combined to form the cutting width direction equivalent depth set.

[0052] In this embodiment, the equivalent depth prediction model calculates the residual stress field in the depth profile by directly measuring the surface residual stress state. This can then be used to further predict the equivalent depths in the feed and cut width directions. Compared to current residual stress field measurement methods that require gradual layer peeling, this method eliminates the need for blade peeling, thus avoiding damage to the research object.

[0053] S103. Perform static analysis on the surface residual stress state set in the feed direction, the equivalent depth set in the feed direction, and the surface residual stress state set in the cut width direction, and the equivalent depth set in the cut width direction, respectively, to obtain the overall induced deformation of the residual stress of the target blade in the feed direction and the overall induced deformation of the residual stress of the target blade in the cut width direction.

[0054] When performing static analysis on the surface residual stress state set in the feed direction, the equivalent depth set in the feed direction, and the surface residual stress state set in the cutting width direction and the equivalent depth set in the cutting width direction, respectively, the surface residual stress state set in the feed direction and the equivalent depth set in the feed direction are subjected to static analysis, while the surface residual stress state set in the cutting width direction and the equivalent depth set in the cutting width direction are subjected to static analysis.

[0055] Specifically, when performing static analysis, a hexahedral mesh is used to mesh the blade, with the length and width of the mesh aligned with the feed and cut width directions, respectively. In the data to be analyzed, select the initial stress and the unit coordinate system. Click Import Load to verify that the stress mapping direction is consistent with the actual value. If not, change the coordinate system.

[0056] This embodiment performs static analysis on the residual stress state set and the equivalent depth set, and uses finite element software to achieve stress mapping of the surface residual stress state in the unit coordinate system. This can ensure that the direction of the residual stress is consistent with the actual residual stress direction caused by processing when dealing with the blade surface.

[0057] S104, performing surface fitting on the feed direction surface residual stress state set and the overall induced deformation of the residual stress of the target blade in the feed direction to obtain a first correlation model diagram, and performing surface fitting on the cut width direction surface residual stress state set and the overall induced deformation of the residual stress of the target blade in the cut width direction to obtain a second correlation model diagram.

[0058] Specifically, the first correlation model diagram is a correlation model diagram of the residual stress on the surface of the target blade in the feed direction and the contour, and the second correlation model diagram is a correlation model diagram of the residual stress on the surface of the target blade in the cut width direction and the position.

[0059] It is worth noting that the residual stress in the blade feed direction primarily affects the profile, while the residual stress in the cut width direction primarily affects the position. Therefore, to meet the target blade machining profile requirement, this embodiment performs surface fitting by combining the surface residual stress state set in the feed direction with the overall induced deformation of the target blade residual stress in the feed direction. To meet the target blade machining position requirement, this embodiment performs surface fitting by combining the surface residual stress state set in the cut width direction with the overall induced deformation of the target blade residual stress in the cut width direction.

[0060] S105 , projecting the first associated model graph and the second associated model graph onto the same plane respectively, to obtain the surface residual stress control domain in the feed direction under the contour constraint and the surface residual stress control domain in the cut width direction under the position constraint of the target blade.

[0061] It should be noted that the residual stress control domain of the target blade surface in the feed direction under the contour constraint is associated with the residual stress control domain of the target blade surface in the cut width direction under the position constraint to form the residual stress control domain of the target blade.

[0062] The method for determining the residual stress control domain of an aero-engine blade in this embodiment can directly determine the residual stress control domain of the blade, provide guidance for blade processing, and significantly reduce processing cycle and cost.

[0063] In one embodiment, based on the above embodiment, constructing the surface residual stress state set in the feed direction and the surface residual stress state set in the cut width direction of the blade base and blade back of the target blade includes the following steps:

[0064] S201: Create a three-dimensional model of the target blade in UG software and divide the blade base and blade back of the three-dimensional model into multiple regions.

[0065] S202: Importing the three-dimensional model of the target blade into ANSYS Workbench software to extract the node coordinates of each area of ​​the blade base and blade back of the three-dimensional model of the target blade, and creating surface residual stress assignment tables in the feed direction and the cutting width direction of the target blade based on the node coordinates of all areas.

[0066] S203: Importing the surface residual stress assignment tables in the feed direction and the cut width direction into the first statics analysis module of the ANSYS Workbench software, respectively, and adjusting the scaling factor to obtain the feed direction surface residual stress state set and the cut width direction surface residual stress state set of the blade base and blade back of the target blade.

[0067] The scaling factor is adjusted to achieve the assignment of the actual surface residual stress. For example, if the actual surface residual stress is -432 MPa, the scaling factor is 4.32.

[0068] In one embodiment, based on the above embodiment, the three-dimensional model of the target blade is imported into ANSYS Workbench software to extract the node coordinates of the blade base and blade back regions of the three-dimensional model of the target blade, including the following steps:

[0069] S301: Export the 3D model of the target blade in UG into STEP format and import it into the Design Modal module of ANSYS Workbench software.

[0070] S302: Select the surface command, create new sheets on the divided area and number the sheets, and use the From new part command to bind all the sheets and entities into a multi-entity part.

[0071] It is worth noting that in this embodiment, only one new slice needs to be created on the segmented area, and one residual stress layer is used instead of the residual stress stratification, which greatly simplifies the calculation complexity.

[0072] S303: Establish a second statics analysis module, and import the data of the Design Modal module into the second statics analysis module.

[0073] It should be noted that the material parameters used in the second statics analysis module are determined according to the specific aerospace engine blade.

[0074] S304: In the second statics analysis module, any external load is applied to the multi-body part to perform stress calculation.

[0075] S305: Extracting node data of all regional slices based on the stress calculation results to obtain a node information table, wherein the node data includes node IDs and node coordinates.

[0076] In one embodiment, creating surface residual stress assignment tables for the target blade in the feed direction and the cut width direction based on the node coordinates of all regions includes the following steps:

[0077] Add columns xx, yy, zz, xy, yz, and xz to the right of the node information table, where xx is the normal stress in the x-direction, yy is the normal stress in the y-direction, zz is the normal stress in the z-direction, xy is the shear stress in the x-direction, yz is the shear stress in the y-direction, and xz is the shear stress in the z-direction.

[0078] In order to avoid repeatedly creating an assignment table, in this embodiment, all the xx columns of the node information table after the column is added are assigned to -100 MPa to obtain the surface residual stress assignment table in the feed direction of the target blade, and all the yy columns of the node information table after the column is added are assigned to -100 MPa to obtain the surface residual stress assignment table in the cutting width direction of the target blade.

[0079] In a specific embodiment, residual stress control domains are determined for a GH4169D seven-stage compressor blade. In this embodiment, both the blade basin and blade back of the three-dimensional model of the GH4169D seven-stage compressor blade are segmented into 18 regions, with 9 regions corresponding to each of the blade basin and blade back.

[0080] Based on the node coordinates of 18 regions, the surface residual stress assignment tables for the feed direction and the cut width direction of the GH4169D seven-stage disk compressor blade were created. The data volume is relatively large, so only a portion is extracted for illustration in this embodiment. The feed direction surface residual stress assignment table is shown in Table 1, and the cut width surface residual stress assignment table is shown in Table 2.

[0081] Table 1 Excerpt of the surface residual stress assignment table in the feed direction

[0082]

[0083] Table 2 Excerpt of the surface residual stress assignment table in the feed direction

[0084]

[0085] The first correlation model diagram finally obtained is as follows Figure 1 As shown, the contour map of residual stress versus contour obtained after the first correlation model is projected on the XY plane is shown in Figure 2 As shown, from Figure 2 It can be seen from the figure that the residual stress control domain of the target blade surface in the feed direction under the contour constraint is the area sandwiched by the contour lines from -40um to +40um.

[0086] The final second correlation model diagram is as follows Figure 3 As shown, the contour map of residual stress versus position obtained after the second correlation model is projected on the XY plane is shown in Figure 4 As shown, from Figure 4 It can be seen from the figure that the target blade's surface residual stress control domain in the cutting width direction under the position constraint is the area sandwiched by the contour lines from -75um to +75um.

[0087] The above-described embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for determining the residual stress control region of an aero-engine blade, characterized in that: The following steps are involved: Constructing the surface residual stress state set in the feed direction and the surface residual stress state set in the cut width direction of the blade base and blade back of the target blade; Input the surface residual stress state set in the feed direction into the feed direction equivalent depth prediction model to obtain the feed direction equivalent depth set, and input the surface residual stress state set in the cutting width direction into the cutting width direction equivalent depth prediction model to obtain the cutting width direction equivalent depth set; Static analysis is performed on the surface residual stress state set in the feed direction, the equivalent depth set in the feed direction, the surface residual stress state set in the cutting width direction, and the equivalent depth set in the cutting width direction, respectively, to obtain the overall induced deformation of the residual stress of the target blade in the feed direction and the overall induced deformation of the residual stress of the target blade in the cutting width direction; The surface residual stress state set in the feed direction is surface fitted with the residual stress overall induced deformation of the target blade in the feed direction to obtain a first correlation model diagram, and the surface residual stress state set in the cutting width direction is surface fitted with the residual stress overall induced deformation of the target blade in the cutting width direction to obtain a second correlation model diagram; The first correlation model diagram and the second correlation model diagram are projected on the same plane respectively to obtain the surface residual stress control domain in the feed direction under the contour constraint and the surface residual stress control domain in the cut width direction under the position constraint of the target blade.

2. The method for determining the residual stress control region of an aero-engine blade according to claim 1, characterized in that: The first correlation model diagram is a correlation model diagram of the residual stress on the surface of the target blade in the feed direction and the contour, and the second correlation model diagram is a correlation model diagram of the residual stress on the surface of the target blade in the cut width direction and the position.

3. The method for determining the residual stress control region of an aero-engine blade according to claim 2, characterized in that: The construction of the surface residual stress state set in the feed direction and the surface residual stress state set in the cut width direction of the blade basin and the blade back of the target blade comprises the following steps: A three-dimensional model of a target blade is established in UG software, and the blade base and the blade back of the three-dimensional model are divided into multiple regions; The 3D model of the target blade is imported into ANSYS Workbench software to extract the node coordinates of the blade basin and blade back regions of the 3D model of the target blade, and the surface residual stress assignment tables of the target blade in the feed direction and the cutting width direction are created based on the node coordinates of all regions; The surface residual stress assignment tables in the feed direction and the cutting width direction are respectively imported into the first statics analysis module of ANSYS Workbench software, and the scaling factor is adjusted to obtain the surface residual stress state set in the feed direction and the surface residual stress state set in the cutting width direction of the blade basin and blade back of the target blade.

4. The method for determining the residual stress control region of an aero-engine blade according to claim 3, characterized in that: The feed direction equivalent depth prediction model is: ， In the formula, h eq-MD represents the equivalent depth of the blade feed direction, h represents the thickness of the leaf, z Indicates the depth of a point inside the blade from the milling surface. represents the residual stress field in the depth profile of the blade feed direction, Indicates the surface residual stress state of the blade in the feed direction, v represents the Poisson's ratio of the blade material, E represents the Young's modulus of the blade material, A MD represents the coefficient describing the residual stress distribution area in the blade feed direction, h s-MD represents the depth coefficient of the residual stress field in the blade feed direction, z d-MD Indicates the depth corresponding to the minimum residual stress in the blade feeding direction.

5. The method for determining the residual stress control region of an aero-engine blade according to claim 3, characterized in that: The prediction model of equivalent depth in cutting width direction is: ， In the formula, h represents the thickness of the leaf, z Indicates the depth of a point inside the blade from the milling surface. h eq-CWD It represents the equivalent depth of the blade in the cutting width direction. represents the residual stress field of the blade in the depth section along the cutting width, Indicates the surface residual stress state of the blade in the cutting width direction, E represents the Young's modulus of the blade material, A CWD It represents the coefficient describing the residual stress distribution area in the blade cutting width direction, h s-CWD represents the depth coefficient of the residual stress field in the blade width direction, z d-CWD Indicates the depth corresponding to the maximum residual stress in the blade width direction.

6. The method for determining the residual stress control region of an aero-engine blade according to claim 4 or 5, characterized in that: The step of importing the three-dimensional model of the target blade into the ANSYS Workbench software to extract the node coordinates of the blade basin and blade back regions of the three-dimensional model of the target blade comprises the following steps: Export the 3D model of the target blade in UG into STEP format and import it into the DesignModal module of ANSYS Workbench software; Select the Surface command, create new sheets on the divided area and number the sheets, and use the From newpart command to bind all sheets and entities into a multi-entity part; Establish a second statics analysis module, and import the data of the Design Modal module into the second statics analysis module; In the second static analysis module, any external load is applied to the multi-solid part to perform stress calculation; Based on the stress calculation results, the node data of all regional slices are extracted to obtain a node information table, wherein the node data includes a node ID and a node coordinate.

7. The method for determining the residual stress control region of an aero-engine blade according to claim 6, characterized in that: The method of creating a surface residual stress assignment table in the feed direction and the cutting width direction of the target blade based on the node coordinates of all regions comprises the following steps: Add xx column, yy column, zz column, xy column, yz column and xz column to the right of the node information table, where xx is the normal stress in the x direction, yy is the normal stress in the y direction, zz is the normal stress in the z direction, xy is the shear stress in the x direction, yz is the shear stress in the y direction, and xz is the shear stress in the z direction; Assign all values ​​of the xx column of the node information table after adding the column to -100 MPa to obtain the surface residual stress assignment table of the target blade in the feed direction; assign all values ​​of the yy column of the node information table after adding the column to -100 MPa to obtain the surface residual stress assignment table of the target blade in the cutting width direction.

8. The method for determining the residual stress control region of an aero-engine blade according to claim 7, characterized in that: The surface residual stress state set in the feed direction and the surface residual stress state set in the cutting width direction both include n The residual stress state of the group surface, n ≥100.

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