Method and system for generating geometric shape of spinning pre-forming generatrix of curved surface component

Abstract

The invention provides a method and system for generating a geometric shape of a spinning pre-forming bus of a curved surface component, and the method comprises the steps: S1, selecting a wall thickness reduction rate psi t and a standard equivalent strain epsilonangle according to a task target; s2, determining the three-dimensional strain of a material unit according to the wall thickness reduction rate psi t and the standard equivalent strain epsilongnorm by taking the geometric shape of the bus of the final forming die as a reference; the three-direction strain comprises strain epsilon 1 in the thickness direction, strain epsilon 2 in the bus direction and strain epsilon 3 in the loop direction; s3, on the basis of the three-dimensional strain of the material unit, the shape and position of the corresponding preform material unit are obtained through calculation; and S4, based on the shape and the position of the preformed piece material unit, generating the geometric shape of the spinning preformed generatrix of the curved surface component. The shape and the position of the material unit of the corresponding preform are calculated according to the three-dimensional strain of the material unit, and a reference basis is provided for the geometric shape design of the preform mold.

Description

Technical Field

[0001] This invention belongs to the field of sheet metal plastic processing technology, specifically relating to a method and system for generating the geometry of the generatrix of spun preformed curved components. More specifically, it is a method for designing the geometry of the generatrix of spun preformed spherical and ellipsoidal components. Background Technology

[0002] Spin forming technology is evolving towards greater complexity and intelligence, with target parts expanding from simple cylindrical and conical bodies of revolution to complex curved surface components. Because curved components require significant deformation during spin forming, direct forming can easily lead to defects such as wrinkles and cracks near the large end, affecting product quality. Introducing preforming technology allows for pre-deformation of the workpiece, making the subsequent forming process smoother and effectively reducing local stress concentration, thus lowering the difficulty of deformation. On the other hand, direct forming can introduce significant forming errors, while preforming technology allows the initial shape of the blank to more closely resemble the final product shape, reducing subsequent correction processing. This not only improves dimensional and shape accuracy but also significantly enhances overall forming efficiency.

[0003] Therefore, introducing preforming technology into the spinning process of curved components has become an important means to optimize the forming effect and improve the forming quality.

[0004] Although some research has been conducted on the design of preformed mold generatrix geometry, the design methodology is not yet fully mature. Due to the varying forming requirements and shape complexities of different curved components, the design methods for mold generatrix geometry are still being continuously optimized and improved. In practical applications of complex shaped components, mold design often still relies on experience and trial-and-error methods, resulting in a time-consuming design process and placing high demands on the designer's experience and technical skills.

[0005] Patent document CN114029396A discloses a method for forming a complex curved busbar integral ring-shaped component. The method includes: cutting sheet metal into circular blanks; placing the circular blanks in a spinning die and spinning them into a conical blank with a bottom; placing the conical blank in a forming die; applying a force along the central axis of the forming die, causing the die to radially deform the conical blank; and when the blank's radial deformation reaches a certain extent, coupling pressure is applied to the peripheral wall of the conical blank from both the inner and outer sides of the forming die, ultimately forming a complex curved busbar integral ring-shaped component. This method fully utilizes the technical advantages of both spinning and bulging processes, providing a possibility for forming complex titanium alloy busbar integral ring-shaped components with bending structures. However, this method cannot achieve quantitative design of the busbar geometry in the pre-forming die. This problem urgently needs to be solved.

[0006] In other words, existing literature on spinning preforming processes largely focuses on the influence of existing preforming dies on the spinning performance of curved components, but experimental descriptions rarely address specific design methods for the generatrix geometry of the preforming die. Literature review reveals no publicly available reports on parametric design methods for the generatrix geometry of preforming curved components during spinning. In particular, research on the trajectory design of the spinning preforming process for curved components, especially the quantitative design of the generatrix geometry of the preforming die, is lacking. This deficiency limits the application of digital planning for the generatrix geometry of the preforming die, indicating that there is still room for further exploration and development in this field. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and system for generating the geometry of preformed busbars for spun curved components.

[0008] A method for generating the geometry of a preformed generatrix of a curved component according to the present invention includes:

[0009] Step S1: Select the wall thickness reduction rate ψ according to the task objective. t and standard equivalent strain ε e_norm ;

[0010] Step S2: Based on the final forming mold generatrix geometry, and according to the wall thickness reduction rate ψ t and standard equivalent strain ε e_norm The triaxial strain of the material unit is confirmed; the triaxial strain includes: thickness direction strain ε1, generatrix direction strain ε2 and toroidal direction strain ε3.

[0011] Step S3: Based on the triaxial strain of the material unit, calculate the shape and position of the corresponding preform material unit;

[0012] Step S4: Based on the shape and position of the preform material unit, generate the geometry of the spun preform generatrix of the curved component.

[0013] Preferably, in step S1, the wall thickness reduction rate ψ t ≤10%, standard equivalent strain ε e_norm It ranges from 10% to 20%.

[0014] Preferably, step S2 includes:

[0015] Step S2.1: Set the value of the thickness direction strain ε1 to be equal to the negative wall thickness reduction rate ψ. t The value of ε2(θ) is obtained, and then the first critical strain function ε3(θ) and the second critical strain function ε3(θ) of the generatrix geometry of the preform are obtained; where θ is the inclination angle of the material element, that is, the angle between the tangent direction of the material element and the x-axis;

[0016] Step S2.2: Based on the standard equivalent strain ε e_norm Confirm the strain ε in the standard busbar direction. 2_norm And the limiting tilt angle θ was calculated. max ;

[0017] Step S2.3: Determine if θ is less than the limiting tilt angle θ max If the result is yes, then let the strain ε2 in the generatrix direction be equal to the first critical strain function ε2(θ), and let the strain ε3 in the toroidal direction be equal to the second critical strain function ε3(θ); if the result is no, then let the strain ε2 in the generatrix direction be equal to the strain ε in the standard generatrix direction. 2_norm Let the strain ε3 in the loop direction be equal to the strain in the standard loop direction, and the equivalent strain ε e Equal to standard equivalent strain ε e_norm .

[0018] Preferably, in step S2.2, the simultaneous mathematical expression of the first critical strain function ε2(θ) and the second critical strain function ε3(θ) is as follows:

[0019]

[0020] (1+ε1)(1+ε2)(1+ε3)=1

[0021] Where r is the radial distance of the material element from the rotation axis; ε1 is the strain in the thickness direction; ε2 is the strain in the generatrix direction; ε3 is the strain in the circumferential direction; ε represents the differential symbol; r(θ) represents the radial distance r of the point on the final forming die from the rotation axis as a function of the tilt angle θ;

[0022] In step S2.3, the strain ε in the standard generatrix direction 2_norm The mathematical expression is:

[0023]

[0024] Where, ε 2_norm ε1 represents strain in the standard generatrix direction; ε2 represents strain in the thickness direction.

[0025] The mathematical expression for 'a' is:

[0026]

[0027] Where, ε e_norm For standard equivalent strain;

[0028] The mathematical expression for b is:

[0029]

[0030] The limiting tilt angle θ max The mathematical expression is:

[0031]

[0032] Where, θ max This is the limiting angle of inclination;

[0033] In step S2.3, the mathematical expression for the strain ε3 in the loop direction is:

[0034]

[0035] Where ε3 is the strain in the loop direction; ε2 is the strain in the generatrix direction;

[0036] The equivalent strain ε e The mathematical expression is:

[0037]

[0038] Step S3 includes:

[0039] Step S3.1: Confirm the division accuracy of the pre-forming mold generatrix, and then obtain the integration points A of the uniformly distributed generatrix of the final forming mold. i i is a positive integer;

[0040] Step S3.2: Based on the triaxial strain of the material element, calculate the position B of the integration point on the generatrix of the final forming die before spinning, corresponding to the generatrix of the pre-forming die. i ;

[0041] In step S4, based on the pre-spinning position B i Generate the geometry of the preformed generatrix of the spun surface component.

[0042] Preferably, in step S3.1, the division precision is k, k≥1; the number of integration points is N, N=10 k ;

[0043] In step S3.2, the position B before spinning i The mathematical expression is:

[0044]

[0045] Among them, B i (x i ,y i (x) represents the position of the point on the preformed generatrix before spinning. i ,y i Point B on the preformed generatrix i The x and y coordinates, (X i,Y i (A) is the integration point on the final forming die generatrix. i The x and y coordinates; θ i Point A on the final forming generatrix i The angle between the tangential direction and the x-axis; ε3(θ1) represents the circumferential strain experienced by point A1 on the final forming generatrix during the spinning process; θ1 represents the angle between the tangential direction and the x-axis of point A1 on the final forming generatrix; Y1 represents the ordinate of the integration point A1 on the final forming die generatrix; X1 represents the abscissa of the integration point A1 on the final forming die generatrix; ε3(θ1) represents the circumferential strain experienced by point A1 on the final forming die generatrix; ε3(θ1) represents the circumferential strain experienced by point A1 on the final forming die generatrix; θ1 represents the tangential direction of ...θ1 represents i () represents point A on the final forming generatrix. i The circumferential strain experienced during the spinning process;

[0046] The ΔY i-1 The mathematical expression is:

[0047]

[0048] A system for generating the geometry of a preformed generatrix of a curved component by spinning, according to the present invention, comprises:

[0049] Module M1: Select the wall thickness reduction rate ψ based on the task objective. t and standard equivalent strain ε e_norm ;

[0050] Module M2: Based on the final forming mold generatrix geometry, and according to the wall thickness reduction rate ψ t and standard equivalent strain ε e_norm The triaxial strain of the material unit is confirmed; the triaxial strain includes: thickness direction strain ε1, generatrix direction strain ε2 and toroidal direction strain ε3.

[0051] Module M3: Based on the triaxial strain of the material unit, calculate the shape and position of the corresponding preform material unit;

[0052] Module M4: Based on the shape and position of the preform material unit, generate the geometry of the spun preform generatrix of the curved component.

[0053] Preferably, in the module M1, the wall thickness reduction rate ψ t ≤10%, standard equivalent strain ε e_norm It ranges from 10% to 20%.

[0054] Preferably, module M2 includes:

[0055] Module M2.1: Set the value of the thickness direction strain ε1 to a negative wall thickness reduction rate ψ. tThe value of ε2(θ) is obtained, and then the first critical strain function ε3(θ) and the second critical strain function ε3(θ) of the generatrix geometry of the preform are obtained; where θ is the inclination angle of the material element, that is, the angle between the tangent direction of the material element and the x-axis;

[0056] Module M2.2: Based on standard equivalent strain ε e_norm Confirm the strain ε in the standard busbar direction. 2_norm And the limiting tilt angle θ was calculated. max ;

[0057] Module M2.3: Determine if θ is less than the limiting tilt angle θ max If the result is yes, then let the strain ε2 in the generatrix direction be equal to the first critical strain function ε2(θ), and let the strain ε3 in the toroidal direction be equal to the second critical strain function ε3(θ); if the result is no, then let the strain ε2 in the generatrix direction be equal to the strain ε in the standard generatrix direction. 2_norm Let the strain ε3 in the loop direction be equal to the strain in the standard loop direction, and the equivalent strain ε e Equal to standard equivalent strain ε e_norm .

[0058] Preferably, in module M2.2, the simultaneous mathematical expression of the first critical strain function ε2(θ) and the second critical strain function ε3(θ) is as follows:

[0059]

[0060] (1+ε1)(1+ε2)(1+ε3)=1

[0061] Where r is the radial distance of the material element from the rotation axis; ε1 is the strain in the thickness direction; ε2 is the strain in the generatrix direction; ε3 is the strain in the circumferential direction; d represents the differential symbol; r(θ) represents the radial distance r from the point on the final forming die to the rotation axis as a function of the tilt angle θ;

[0062] In module M2.3, the strain ε in the standard busbar direction 2_norm The mathematical expression is:

[0063]

[0064] Where, ε 2_norm ε1 represents strain in the standard generatrix direction; ε2 represents strain in the thickness direction.

[0065] The mathematical expression for 'a' is:

[0066]

[0067] Where, ε e_norm For standard equivalent strain;

[0068] The mathematical expression for b is:

[0069]

[0070] The limiting tilt angle θ max The mathematical expression is:

[0071]

[0072] Where, θ max This is the limiting angle of inclination;

[0073] In module M2.3, the mathematical expression for the strain ε3 in the loop direction is:

[0074]

[0075] Where ε3 is the strain in the loop direction; ε2 is the strain in the generatrix direction;

[0076] The equivalent strain ε e The mathematical expression is:

[0077]

[0078] The module M3 includes:

[0079] Module M3.1: Confirm the division accuracy of the pre-forming mold generatrix, and then obtain the integration point A where the final forming mold generatrix is ​​uniformly distributed. i i is a positive integer;

[0080] Module M3.2: Based on the triaxial strain of the material element, calculate the position B of the integration point on the generatrix of the final forming die before spinning, corresponding to the generatrix of the pre-forming die. i ;

[0081] In module M4, based on the pre-spinning position B i Generate the geometry of the preformed generatrix of the spun surface component.

[0082] Preferably, in module M3.1, the division precision is k, k≥1; the number of integration points is N, N=10 k ;

[0083] In module M3.2, the position B before spinning i The mathematical expression is:

[0084]

[0085] Among them, B i (x i ,y i(x) represents the position of the point on the preformed generatrix before spinning. i ,y i Point B on the preformed generatrix i The x and y coordinates, (X i ,Y i (A) is the integration point on the final forming die generatrix. i The x and y coordinates; θ i Point A on the final forming generatrix i The angle between the tangential direction and the x-axis; ε3(θ1) represents the circumferential strain experienced by point A1 on the final forming generatrix during the spinning process; θ1 represents the angle between the tangential direction and the x-axis of point A1 on the final forming generatrix; Y1 represents the ordinate of the integration point A1 on the final forming die generatrix; X1 represents the abscissa of the integration point A1 on the final forming die generatrix; ε3(θ1) represents the circumferential strain experienced by point A1 on the final forming die generatrix; ε3(θ1) represents the circumferential strain experienced by point A1 on the final forming die generatrix; θ1 represents the tangential direction of ...θ1 represents i () represents point A on the final forming generatrix. i The circumferential strain experienced during the spinning process;

[0086] The ΔY i-1 The mathematical expression is:

[0087]

[0088] Compared with the prior art, the present invention has the following beneficial effects:

[0089] 1. This invention calculates the shape and position of the corresponding preform material unit based on the triaxial strain of the material unit, providing a reference for the geometric design of the preform mold.

[0090] 2. The method for designing the geometry of the preformed generatrix of the curved component spinning provided by the present invention can effectively control the wall thickness reduction rate and equivalent strain during the final spinning process, thereby achieving high-quality spinning.

[0091] 3. This invention can effectively control the wall thickness reduction rate and equivalent strain of the slab during the spinning process, achieve high-quality spinning forming, reduce the difficulty of final forming deformation and reduce the finishing time, and effectively improve the material utilization rate by about 5% while improving the dimensional accuracy by 5% to 15%. Attached Figure Description

[0092] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0093] Figure 1 This invention provides a schematic diagram of the method flow.

[0094] Figure 2The diagram shows the triaxial strain of the final forming material unit provided by the present invention; wherein, 1 represents the thickness direction of the material unit, 2 represents the generatrix direction of the material unit, 3 represents the loop direction of the material unit, r represents the radial distance from the material unit to the rotation axis, l represents the generatrix distance from the material unit to the vertex, t represents the thickness distance from the material unit to the corresponding point of the mold, dl represents the length of the material unit, dc represents the width of the material unit, and dt represents the thickness of the material unit.

[0095] Figure 3 A schematic diagram of the generatrix geometry of the elliptical final forming mold provided by the present invention; wherein, d0 represents the diameter of the small end of the mold; a represents the semi-major axis of the elliptical mold; V represents the length of the large end of the mold; and b represents the semi-minor axis of the elliptical mold.

[0096] Figure 4 This is a schematic diagram of the geometry of the preformed mold busbar provided by the present invention. Detailed Implementation

[0097] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0098] A method for generating the geometry of a preformed generatrix of a curved component according to the present invention includes:

[0099] Step S1: Select the wall thickness reduction rate ψ according to the spinning process requirements and the shape of the final forming die. t and standard equivalent strain ε e_norm ;

[0100] Step S2: Based on the geometry of the generatrix of the final forming mold, determine the triaxial strains ε1, ε2 and ε3 experienced by the material unit in the thickness direction, generatrix direction and loop direction during the final forming process.

[0101] Step S3: Calculate the shape and position of the corresponding preform material unit based on the triaxial strain of the material unit;

[0102] Step S4: Design and draw the geometry of the preformed generatrix of the spun surface component.

[0103] Specifically, in step S1, the wall thickness reduction rate is taken as ψ. t ≤10%, standard equivalent effect variable is ε e_norm =10%~20%.

[0104] In step S1, the wall thickness reduction rate ψ varies for different materials. t and standard equivalent strain εe_norm The following conditions must be met when selecting:

[0105] For the wall thickness reduction rate ψ t Aluminum alloys account for 70%–75%, and steel accounts for 60%–75%. However, in high-quality spinning of curved parts, when the pre-formed component is spun to the final shape, in order to ensure high-quality forming, the wall thickness reduction rate is generally taken as ψ. t ≤10%;

[0106] For the standard equivalent strain ε e_norm Take |ε e_norm |≈(2~4)|ψ t In high-quality spinning of curved parts, when the preformed component is spun to the final shape, in order to ensure high-quality forming, the standard equivalent strain is generally taken as ε. e_norm =10%~20%.

[0107] Specifically, step S2 includes the following steps:

[0108] Step S2.1: To ensure uniform thickness throughout the pre-formed and final-formed components, the strain in the thickness direction of each material element on the generatrix of the final-formed mold is taken as a constant ε1 = -ψ. t ;

[0109] Step S2.2: Determine the critical strain functions ε2(θ) and ε3(θ) that ensure the geometry of the preformed busbar has a real solution;

[0110] Step S2.3: Adjust ε from standard equivalent effect e_norm Determine the strain ε in the standard busbar direction 2_norm And calculate the limiting inclination angle θ max ;

[0111] Step S2.4: Material element tilt angle θ < θ max At that time, the strain in the direction of the generatrix is ​​ε2=ε2(θ), the strain in the direction of the loop is ε3=ε3(θ), and the equivalent strain is ε e =ε e (θ), the tilt angle of the material element θ≥θ max At that time, the strain in the direction of the generatrix is ​​ε2=ε 2_norm The strain in the circumferential direction is ε3=ε 3_norm Equivalent effect ε e =ε e_norm .

[0112] Specifically, the critical strain functions ε2(θ) and ε3(θ) in step S2.2 are given by the following equations:

[0113]

[0114] (1+ε1)(1+ε2)(1+ε3)=1

[0115] In the formula, θ is the angle between the tangent direction of the material element and the x-axis; r is the radial distance of the material element from the axis of rotation.

[0116] Specifically, in step S2.3, the strain ε in the standard generatrix direction... 2_norm It is given by the following formula:

[0117]

[0118] In the formula, a and b are both intermediate variables.

[0119] Specifically, in step S2.3, the limiting tilt angle θ max It is given by the following formula:

[0120]

[0121] Specifically, in step S2.4, the strain ε3 in the loop direction and the equivalent strain ε e It is given by the following formula:

[0122]

[0123] Specifically, step S3 includes:

[0124] Step S3.1: Determine the numerical solution resolution accuracy k (k≥1) of the geometry of the preforming mold generatrix S1K1;

[0125] Step S3.2: Distribute N (N = 10) evenly on the final forming die generatrix S2K2. k There are ) integration points A1, A2, ..., A N ;

[0126] Step S3.3: Based on the triaxial strain calculation obtained in step S2, N integration points A1, A2, ..., A are uniformly distributed on the generatrix S2K2 of the final forming mold. N Before spinning, positions B1, B2, ..., B corresponding to the preforming die generatrix S1K1 are: N .

[0127] Specifically, in step S3.3, each integration point A i Position B before spinning i (where i is a positive integer) is:

[0128]

[0129] In the formula, (X i ,Y i Point A on the final forming mold generatrix is ​​the final forming mold generatrix. i The x and y coordinates; (x i ,y iPoint B on the preformed generatrix i The x and y coordinates; θ i Point A on the final forming generatrix i The angle between the tangential direction and the x-axis is called the tilt angle.

[0130] Specifically, in step S4, B obtained in step S3 is sequentially connected. i Numerical solutions for the geometry of the preformed generatrix of the spun surface component can then be plotted.

[0131] Preferred Implementation: In this preferred embodiment, the following is adopted: Figure 3 An ellipsoidal final forming mold with a semi-major axis of 160mm and a semi-minor axis of 100mm;

[0132] according to Figure 4 Generate a pre-formed busbar geometry; specifically, Figure 3 This is the actual proportion. Figure 4 The proportions are different from reality; it is a sketch intended for easy viewing.

[0133] Generating the preformed busbar geometry includes the following steps:

[0134] Step 1: Based on the cold deformation characteristics of aluminum alloys after solution treatment, select the wall thickness reduction rate ψ. t =3%, standard equivalent strain ε e_norm =10%.

[0135] Step 2: According to step S2 of the present invention, the numerical solutions of the critical strain functions ε2(θ) and ε3(θ) are calculated using the Matlab program, and the limiting inclination angle θ is obtained. max =25.31°, the critical strain functions ε2(θ) and ε3(θ) can guarantee that when θ < 25.31°, the generatrix of the preforming mold is specifically a horizontal line parallel to the x-axis:

[0136] ε1=-ψ t =-0.03

[0137]

[0138] Step 3: In this preferred example, the partitioning precision k = 2.7 is selected, and a total of 500 integration points A1, A2, ..., A are divided. 500 A script function was written using Matlab to calculate the positions B1, B2, ..., B on the generatrix of the final forming die before spinning, corresponding to 500 integration points. 500 .

[0139] Step 4: Connect B1, B2, ..., B obtained in Step 3 in sequence. 500 The numerical solution for the geometry of the generatrix of the ellipsoidal part can then be plotted.

[0140] Using this preformed busbar geometry design method, this example demonstrates the wall thickness reduction rate ψ. t =3%, standard equivalent strain ε e_norm =10%, drawing the geometry of the preformed busbar with a division accuracy of k=2.7, such as Figure 4 As shown.

[0141] The present invention also provides a system for generating the geometry of a preformed busbar of a spun surface component. The system for generating the geometry of a preformed busbar of a spun surface component can be implemented by executing the process steps of the method for generating the geometry of a preformed busbar of a spun surface component. That is, those skilled in the art can understand the method for generating the geometry of a preformed busbar of a spun surface component as a preferred embodiment of the system for generating the geometry of a preformed busbar of a spun surface component.

[0142] Those skilled in the art will understand that, besides implementing the system and its various devices, modules, and units provided by this invention in the form of purely computer-readable program code, the same functions can be achieved entirely through logical programming of the method steps, making the system and its various devices, modules, and units of this invention function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers. Therefore, the system and its various devices, modules, and units provided by this invention can be considered as a hardware component, and the devices, modules, and units included therein for implementing various functions can also be considered as structures within the hardware component; alternatively, the devices, modules, and units for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0143] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for generating the geometry of a preformed generatrix for spinning curved components, characterized in that, include: Step S1: Select the wall thickness reduction rate ψ according to the task objective. t and standard equivalent strain ε e_norm ; Step S2: Based on the final forming mold generatrix geometry, and according to the wall thickness reduction rate ψ t and standard equivalent strain ε e_norm The triaxial strain of the material unit is confirmed; the triaxial strain includes: thickness direction strain ε1, generatrix direction strain ε2 and toroidal direction strain ε3. Step S3: Based on the triaxial strain of the material unit, calculate the shape and position of the corresponding preform material unit; Step S4: Based on the shape and position of the preform material unit, generate the geometry of the spun preform generatrix of the curved component.

2. The method for generating the geometry of the preformed generatrix of a curved component by spinning according to claim 1, characterized in that, In step S1, the wall thickness reduction rate ψ t ≤10%, standard equivalent strain ε e_norm It ranges from 10% to 20%.

3. The method for generating the geometry of the preformed generatrix of a curved component by spinning according to claim 1, characterized in that, Step S2 includes: Step S2.1: Set the value of the thickness direction strain ε1 to be equal to the negative wall thickness reduction rate ψ. t The value of ε2(θ) is obtained, and then the first critical strain function ε3(θ) and the second critical strain function ε3(θ) of the generatrix geometry of the preform are obtained; where θ is the inclination angle of the material element, that is, the angle between the tangent direction of the material element and the x-axis; Step S2.2: Based on the standard equivalent strain ε e_norm Confirm the strain ε in the standard busbar direction 2_norm And the limiting tilt angle θ was calculated. max ; Step S2.3: Determine if θ is less than the limiting tilt angle θ max If the result is yes, then let the strain ε2 in the generatrix direction be equal to the first critical strain function ε2(θ), and let the strain ε3 in the toroidal direction be equal to the second critical strain function ε3(θ); if the result is no, then let the strain ε2 in the generatrix direction be equal to the strain ε in the standard generatrix direction. 2_norm Let the strain ε3 in the loop direction be equal to the strain in the standard loop direction, and the equivalent strain ε e Equal to standard equivalent strain ε e_norm .

4. The method for generating the geometry of the preformed generatrix of a curved component by spinning according to claim 3, characterized in that, In step S2.2, the simultaneous mathematical expressions for the first critical strain function ε2(θ) and the second critical strain function ε3(θ) are as follows: (1+ε1)(1+ε2)(1+ε3)=1 Where r is the radial distance of the material element from the rotation axis; ε1 is the strain in the thickness direction; ε2 is the strain in the generatrix direction; ε3 is the strain in the circumferential direction; d represents the differential symbol; r(θ) represents the radial distance r from the point on the final forming die to the rotation axis as a function of the tilt angle θ; In step S2.3, the strain ε in the standard generatrix direction 2_norm The mathematical expression is: Where, ε 2_norm ε1 represents strain in the standard generatrix direction; ε2 represents strain in the thickness direction. The mathematical expression for 'a' is: Where, ε e_norm For standard equivalent strain; The mathematical expression for b is: The limiting tilt angle θ max The mathematical expression is: Where, θ max This is the limiting angle of inclination; In step S2.3, the mathematical expression for the strain ε3 in the loop direction is: Where ε3 is the strain in the loop direction; ε2 is the strain in the generatrix direction; The equivalent strain ε e The mathematical expression is: Step S3 includes: Step S3.1: Confirm the division accuracy of the pre-forming mold generatrix, and then obtain the integration points A of the uniformly distributed generatrix of the final forming mold. i i is a positive integer; Step S3.2: Based on the triaxial strain of the material element, calculate the position B of the integration point on the generatrix of the final forming die before spinning, corresponding to the generatrix of the pre-forming die. i ; In step S4, based on the pre-spinning position B i Generate the geometry of the preformed generatrix of the spun surface component.

5. The method for generating the geometry of the preformed generatrix of a curved component by spinning according to claim 4, characterized in that, In step S3.1, the division precision is k, k≥1; the number of integration points is N, N=10 k ; In step S3.2, the position B before spinning i The mathematical expression is: Among them, B i (x i ,y i (x) represents the position of the point on the preformed generatrix before spinning. i ,y i Point B on the preformed generatrix i x and y coordinates, (X i ,Y i (A) is the integration point on the final forming die generatrix. i The x and y coordinates; θ i Point A on the final forming generatrix i The angle between the tangential direction and the x-axis; ε3(θ1) represents the circumferential strain experienced by point A1 on the final forming generatrix during the spinning process; θ1 represents the angle between the tangential direction and the x-axis of point A1 on the final forming generatrix; Y1 represents the ordinate of the integration point A1 on the final forming die generatrix; X1 represents the abscissa of the integration point A1 on the final forming die generatrix; ε3(θ1) represents the circumferential strain experienced by point A1 on the final forming die generatrix; ε3(θ1) represents the circumferential strain experienced by point A1 on the final forming die generatrix; θ1 represents the tangential direction of ...θ1 represents i () represents point A on the final forming generatrix. i The circumferential strain experienced during the spinning process; The ΔY i-1 The mathematical expression is:

6. A system for generating the geometry of a preformed generatrix for spinning curved components, characterized in that, include: Module M1: Select the wall thickness reduction rate ψ based on the task objective. t and standard equivalent strain ε e_norm ; Module M2: Based on the final forming mold generatrix geometry, and according to the wall thickness reduction rate ψ t and standard equivalent strain ε e_norm The triaxial strain of the material unit is confirmed; the triaxial strain includes: thickness direction strain ε1, generatrix direction strain ε2 and toroidal direction strain ε3. Module M3: Based on the triaxial strain of the material unit, calculate the shape and position of the corresponding preform material unit; Module M4: Based on the shape and position of the preform material unit, generate the geometry of the spun preform generatrix of the curved component.

7. The system for generating the geometry of the preformed generatrix of a curved component by spinning according to claim 6, characterized in that, In module M1, the wall thickness reduction rate ψ t ≤10%, standard equivalent strain ε e_norm It ranges from 10% to 20%.

8. The system for generating the geometry of a preformed generatrix of a curved component by spinning according to claim 6, characterized in that, The module M2 includes: Module M2.1: Set the value of the thickness direction strain ε1 to a negative wall thickness reduction rate ψ. t The value of ε2(θ) is obtained, and then the first critical strain function ε3(θ) and the second critical strain function ε3(θ) of the generatrix geometry of the preform are obtained; where θ is the inclination angle of the material element, that is, the angle between the tangent direction of the material element and the x-axis; Module M2.2: Based on standard equivalent strain ε e_norm Confirm the strain ε in the standard busbar direction 2_norm And the limiting tilt angle θ was calculated. max ; Module M2.3: Determine if θ is less than the limiting tilt angle θ max If the result is yes, then let the strain ε2 in the generatrix direction be equal to the first critical strain function ε2(θ), and let the strain ε3 in the toroidal direction be equal to the second critical strain function ε3(θ); if the result is no, then let the strain ε2 in the generatrix direction be equal to the strain ε in the standard generatrix direction. 2_norm Let the strain ε3 in the loop direction be equal to the strain in the standard loop direction, and the equivalent strain ε e Equal to standard equivalent strain ε e_norm .

9. The system for generating the geometry of the preformed generatrix of a curved component by spinning according to claim 8, characterized in that, In module M2.2, the simultaneous mathematical expressions for the first critical strain function ε2(θ) and the second critical strain function ε3(θ) are as follows: (1+ε1)(1+ε2)(1+ε3)=1 Where ε is the radial distance of the material element from the rotation axis; ε1 is the strain in the thickness direction; ε2 is the strain in the generatrix direction; ε3 is the strain in the circumferential direction; d represents the differential symbol; r(θ) represents the radial distance r of the point on the final forming die from the rotation axis as a function of the tilt angle θ; In module M2.3, the strain ε in the standard busbar direction 2_norm The mathematical expression is: Where, ε 2_norm ε1 represents strain in the standard generatrix direction; ε2 represents strain in the thickness direction. The mathematical expression for 'a' is: Where, ε e_norm For standard equivalent strain; The mathematical expression for b is: The limiting tilt angle θ max The mathematical expression is: Where, θ max This is the limiting angle of inclination; In module M2.3, the mathematical expression for the strain ε3 in the loop direction is: Where ε3 is the strain in the loop direction; ε2 is the strain in the generatrix direction; The equivalent strain ε e The mathematical expression is: The module M3 includes: Module M3.1: Confirm the division accuracy of the pre-forming mold generatrix, and then obtain the integration point A where the final forming mold generatrix is ​​uniformly distributed. i i is a positive integer; Module M3.2: Based on the triaxial strain of the material element, calculate the position B of the integration point on the generatrix of the final forming die before spinning, corresponding to the generatrix of the pre-forming die. i ; In module M4, based on the pre-spinning position B i Generate the geometry of the preformed generatrix of the spun surface component.

10. The system for generating the geometry of the preformed generatrix of a curved component by spinning according to claim 9, characterized in that, In module M3.1, the division precision is k, k≥1; the number of integration points is N, N=10 k ; In module M3.2, the position B before spinning i The mathematical expression is: Among them, B i (x i ,y i (x) represents the position of the point on the preformed generatrix before spinning. i ,y i Point B on the preformed generatrix i x and y coordinates, (X i ,Y i (A) is the integration point on the final forming die generatrix. i The x and y coordinates; θ i Point A on the final forming generatrix i The angle between the tangential direction and the x-axis; ε3(θ1) represents the circumferential strain experienced by point A1 on the final forming generatrix during the spinning process; θ1 represents the angle between the tangential direction and the x-axis of point A1 on the final forming generatrix; Y1 represents the ordinate of the integration point A1 on the final forming die generatrix; X1 represents the abscissa of the integration point A1 on the final forming die generatrix; ε3(θ1) represents the circumferential strain experienced by point A1 on the final forming die generatrix; ε3(θ1) represents the circumferential strain experienced by point A1 on the final forming die generatrix; θ1 represents the tangential direction of ...θ1 represents i () represents point A on the final forming generatrix. i The circumferential strain experienced during the spinning process; The ΔY i-1 The mathematical expression is:

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