Methods, systems, and media for establishing a heat source model for spot ring laser welding.

Abstract

This invention discloses a method, system, and medium for establishing a heat source model for point-ring laser welding, belonging to the field of laser welding. The point-ring laser consists of a point beam from a central laser heat source and a ring beam from a ring-shaped laser surface heat source. The former is used to achieve a high aspect ratio weld on the material being welded, while the latter is used for auxiliary heating and slow cooling of the material. The method for establishing the point-ring laser welding heat source model provided by this invention allows for arbitrary adjustment of the laser power ratio between the point beam and the ring beam, and the defocusing amount of the point beam and the ring beam can be controlled independently. Spot parameters such as the spot diameter of the point beam and the spot diameter of the ring beam can be used to effectively express the heat flux density distribution. This heat source model establishment method provides a strong reference for accurately simulating the temperature field, stress field, and deformation field of point-ring laser welding. Combined with the control of the welding path, this invention can be widely applied to the finite element simulation of point-ring laser linear welding and oscillating welding.

Description

Technical Field

[0001] This invention relates to the field of laser welding, specifically to the field of finite element simulation of laser welding, and particularly to a method, system, and medium for establishing a heat source model for spot ring laser welding. Background Technology

[0002] Laser welding technology is widely used in new energy, aerospace, and electronic equipment fields, boasting advantages such as high precision, high efficiency, and high automation, making it an advanced welding technology. With the development of automation technology, oscillating welding technology has gradually been introduced into the laser welding field. By controlling the oscillation motion of the laser beam through an oscillating head and oscillating lens, this automated oscillating laser welding can improve the stability, consistency, and precision of the welding process, reducing human error. Oscillating laser welding effectively solves the problem of excessively high assembly precision requirements in traditional narrow-gap laser welding. In recent years, laser systems have been continuously upgraded and improved, and ring-core tunable laser welding technology has been introduced into the laser welding market. The most representative example is the ring-core tunable laser produced by Trumpf. Ring-core tunable lasers, also known as point-ring beams, represent a completely new laser beam mode. Conventional laser fibers output only a single point light source, while ring-core tunable lasers add a ring light source to the conventional point light source, forming a point-ring beam mode. During the welding process, the leading edge of the ring light in the welding direction preheats the metal material, while the trailing edge cools it slowly. Previous reports have indicated that spot ring laser welding significantly reduces spatter compared to conventional laser welding. However, the welding characteristics of spot ring light, its energy ratio, process parameter matching, and the mechanism for suppressing spatter remain unclear. The energy distribution of spot ring light differs from that of conventional lasers, and welding spatter is related to the dynamic behavior of the keyhole during welding. Analyzing this relationship from an energy distribution perspective can be done through finite element simulation to model the flow behavior and heat transfer characteristics of the molten pool during welding. Establishing a welding heat source model is the first step in conducting finite element simulation of laser welding, as it provides the energy distribution form of the welding heat source. Currently, there is no good model to characterize the heat source of spot ring laser welding, especially the heat source of spot ring laser oscillating welding. Therefore, it is necessary to provide a heat source model for spot ring laser welding. Summary of the Invention

[0003] 1. Technical problems to be solved

[0004] The purpose of this invention is to solve the problem of difficulty in establishing a heat source model for point ring laser welding of a ring-core tunable laser, and to provide a method, system and medium for establishing a heat source model for point ring laser welding.

[0005] 2. Technical Solution

[0006] The objective of this invention is achieved through the following technical solutions.

[0007] In a first aspect, the present invention provides a method for establishing a heat source model for spot ring laser welding, comprising the following steps:

[0008] Establish a point ring laser welding heat source model: The point ring laser consists of the point light from the central laser body heat source and the ring light from the ring laser surface heat source. The control equations of the point ring laser welding heat source are shown in formulas (1) and (2):

[0009]

[0010] In equations (1) and (2), q Total (x,y,z) represents the total heat flux density function of the point ring laser welding heat source, (x,y,z) represents the coordinates of the global coordinate system, α represents the laser power distribution coefficient, which refers to the power proportion of the point light in the point ring laser. The laser power distribution coefficient α takes values ​​in the range [0,1], where α=0 represents the laser heat source as a ring light, 0<α<1 represents the laser heat source as a point ring light, and α=1.0 represents the laser heat source as a point light. Q represents the total input laser power, β represents the heat flux concentration coefficient of the central laser, γ represents the heat flux concentration coefficient of the ring laser, H represents the effective heating depth of the volume heat source, and the heat source heating effect exists within the heat source depth in the range [-H,0]. The spot parameters include r v r s r1 and r2, r v The effective heating radius of the central laser body heat source is represented by the subscript v, indicating the body heat source; r s This represents the location with the highest heat flux density of the ring laser surface heat source, with the subscript 's' indicating the surface heat source; the effective heating range of the ring laser surface heat source is [r]. 1, r2].

[0011] Establish welding path equations: The welding path equations are one or more of the following: straight welding control equations, circular oscillating welding control equations, sinusoidal oscillating welding control equations, and straight oscillating welding control equations;

[0012] The moving equations of the spot ring laser welding heat source model are obtained: Select the desired welding path form, substitute the welding control equation corresponding to the welding path form into the control equation (1) of the welding heat source, and obtain the moving equations of the spot ring laser welding heat source model.

[0013] In some embodiments, a language code program for the point ring laser welding heat source model in formulas (1) and (2) is written using language compilation software to generate welding heat source data and images for later optimization. The images will generate a peak heat flux density of the heat source, with the peak value ranging from 10. 6 -10 7 W / cm 2 .

[0014] Specifically, in the step of establishing the welding path equation:

[0015] The control equation for straight-line welding is established as shown in equation (3):

[0016]

[0017] In equation (3), (x,y,z) represents the coordinates of the global coordinate system, (x0,y0,z0) represents the coordinates of the welding start position, v represents the welding speed, and t represents the welding time; the welding trajectory is a straight line.

[0018] The control equation for circular oscillation welding is established as shown in equation (4):

[0019]

[0020] In equation (4), (x, y, z) represent the coordinates of the global coordinate system, (x0, y0, z0) represent the coordinates of the welding start position, v represents the welding speed, t represents the welding time, r represents the radius of the oscillation circle, and T period The oscillation period represents the oscillation of the oscillating circle; the welding trajectory is a spiral.

[0021] The sinusoidal oscillation welding control equation is established as shown in equation (5):

[0022]

[0023] In equation (5), (x, y, z) represent the coordinates of the global coordinate system, (x0, y0, z0) represent the coordinates of the welding start position, v represents the welding speed, t represents the welding time, r represents the amplitude of the sinusoidal oscillation, and T period The oscillation period represents the sinusoidal oscillation; the welding trajectory is a sine curve.

[0024] The control equations for linear oscillation welding are established as shown in equations (6)-(8):

[0025]

[0026] In equations (6)-(8), (x,y,z) represent the coordinates of the global coordinate system, (x0,y0,z0) represent the coordinates of the welding start position, v represents the welding speed, t represents the welding time, and r represents the amplitude of the linear oscillation in one oscillation cycle. The reciprocating speeds within the arc are v1 and v2, respectively. When v1 = -v2, the welding trajectory is an isosceles triangular waveform.

[0027] The global coordinate system of formulas (3) to (8) should match the coordinate system of the three-dimensional finite element mesh model. That is, the coordinates (x0, y0, z0) in the movement equation of the point ring laser welding heat source model are the starting welding position of the three-dimensional finite element mesh model, and the relative displacement of z0 and the workpiece surface in formulas (3)-(6) represents the defocusing amount.

[0028] Furthermore, select the desired welding path form, and substitute formulas (3), (4), (5) or (6)-(8) into formula (1) to obtain the moving equation of the spot ring laser welding heat source model.

[0029] In some embodiments, language code programs for the point ring laser welding moving heat source model are written based on language compilation software, which facilitates the subsequent calling of subroutines by simulation software.

[0030] Furthermore, the method for establishing the heat source model of spot ring laser welding requires establishing a three-dimensional solid thermal conductivity partial differential equation with heat source and transient temperature field, and solving it in finite element calculation software to perform thermo-mechanical coupling calculations. The three-dimensional solid thermal conductivity partial differential equation with heat source and transient temperature field is shown in equation (9):

[0031]

[0032] In equation (9), T represents the transient temperature of the material, t Total The values ​​represent welding and cooling time, k represents the thermal conductivity of the material, ρ represents the material density, and c represents the welding and cooling time. p q represents the specific heat of the material. Total (x,y,z) represents the total heat flux density function of the point ring laser welding heat source shown in formula (1), and (x,y,z) are the coordinates of the global coordinate system.

[0033] The method for establishing the spot ring laser welding heat source model in this invention is applicable to weldable thin sheet metal materials, including but not limited to common metal materials such as aluminum alloys, stainless steel, titanium alloys, and copper alloys.

[0034] A second aspect of the present invention provides a spot ring laser welding system, comprising a spot ring laser, a spot ring laser fiber, a welding head, and a computing unit, wherein:

[0035] A dot ring laser is used to generate a dot ring laser, and the dot ring laser is directed into the welding head through a dot ring laser fiber.

[0036] The welding head is equipped with a motor and a control unit. The control unit controls the motor to swing according to a set swing trajectory.

[0037] The computing unit includes a memory, a processor, and a communication bus; the communication bus enables communication between the processor and the memory, and the processor executes one or more programs stored in the memory; the computing unit is used for finite element simulation calculation and process optimization, and feeds back the simulation results to the control unit for setting the swing trajectory and swing parameters, so as to run the method for establishing the point ring laser welding heat source model of the first aspect of the present invention.

[0038] A third aspect of the present invention provides a computer-readable storage medium storing one or more programs, which can be executed by one or more processors to run the method for establishing a spot ring laser welding heat source model according to the first aspect of the present invention.

[0039] 3. Beneficial effects

[0040] Compared to existing technologies, the advantages of this invention are as follows: This invention establishes a novel heat source model for point-ring laser welding, which can accurately simulate the energy distribution of the point-ring beam pattern. By adjusting the laser power ratio parameters, the input power of the point beam and the ring beam can be arbitrarily controlled. By changing the initial welding position (x0, y0, z0), the defocusing amount of the point beam and the ring beam can be controlled independently. By combining spot parameters such as the effective heating radius of the central laser heat source and the effective heating range of the ring laser surface heat source, the heat flux density distribution of the point-ring laser can be effectively expressed. The method for establishing this heat source model provides a strong reference for accurately simulating the temperature field, stress field, and deformation field of point-ring laser welding. Combined with the control of the welding path, this invention can be widely applied in the finite element simulation field of point-ring laser linear welding and oscillating welding. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the heat source model for spot ring laser welding established in this invention;

[0042] Figure 2 This is a ring-light welding heat source model compiled using MATLAB language in an embodiment of the present invention;

[0043] Figure 3 This is a point ring optical welding heat source model compiled using MATLAB language in an embodiment of the present invention;

[0044] Figure 4 This is a point light welding heat source model compiled using MATLAB language in an embodiment of the present invention;

[0045] Figure 5 This is the longitudinal section morphology of the welding temperature field obtained from the ring-light welding heat source model in this embodiment of the invention;

[0046] Figure 6 This is the longitudinal section morphology of the welding temperature field obtained from the point ring optical welding heat source model in this embodiment of the invention;

[0047] Figure 7 This is the longitudinal section morphology of the welding temperature field obtained from the spot welding heat source model in this embodiment of the invention;

[0048] Figure 8 This is the cross-sectional morphology of the welding temperature field obtained from the ring-light welding heat source model in this embodiment of the invention;

[0049] Figure 9 This is the cross-sectional morphology of the welding temperature field obtained from the point ring optical welding heat source model in this embodiment of the invention;

[0050] Figure 10 This is the cross-sectional morphology of the welding temperature field obtained from the spot welding heat source model in this embodiment of the invention;

[0051] Figure 11 The welding temperature field and weld surface morphology obtained by the circular oscillating point photothermal source model in this embodiment of the invention;

[0052] Figure 12 The welding temperature field weld surface morphology obtained by the sinusoidal oscillating point photothermal source model in this embodiment of the invention;

[0053] Figure 13 The welding temperature field and weld surface morphology obtained by the linear oscillating point photothermal source model in this embodiment of the invention are shown. Detailed Implementation

[0054] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0055] Example 1

[0056] The technical solutions in the embodiments of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments proposed by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] The present invention provides a method for establishing a heat source model for spot ring laser welding, comprising the following steps:

[0058] A heat source model for spot ring laser welding was established.

[0059] The point-ring laser consists of the point light from the central laser body heat source and the ring light from the ring laser surface heat source. The control equations for the point-ring laser welding heat source are shown in formulas (1) and (2):

[0060]

[0061] In equations (1) and (2), q Total(x,y,z) represents the total heat flux density function of the point ring laser welding heat source, (x,y,z) represents the coordinates of the global coordinate system, α represents the laser power distribution coefficient, which refers to the power proportion of the point light in the point ring laser, Q represents the total input laser power, β represents the heat flux concentration coefficient of the central laser, γ represents the heat flux concentration coefficient of the ring laser, H represents the effective heating depth of the volume heat source, and the heat source heating effect exists within the heat source depth in the interval [-H,0]. The spot parameters include r v r s r1 and r2, r v r represents the effective heating radius of the central laser heat source. s This represents the location with the highest heat flux density of the annular laser surface heat source. The effective heating range of the annular laser surface heat source is [r1, r2].

[0062] Based on the MATLAB language compiler, a MATLAB language code program was written for the point ring laser welding heat source model described in formulas (1) and (2), generating welding heat source data and images for later optimization. Other languages ​​can also be used to achieve the same function, and MATLAB is not the only option.

[0063] Establish the welding path equation.

[0064] The control equation for straight-line welding is established as shown in equation (3):

[0065]

[0066] In equation (3), (x,y,z) represents the coordinates of the global coordinate system, (x0,y0,z0) represents the coordinates of the welding start position, v represents the welding speed, and t represents the welding time; the welding trajectory is a straight line.

[0067] The control equation for circular oscillation welding is established as shown in equation (4):

[0068]

[0069] In equation (4), (x, y, z) represent the coordinates of the global coordinate system, (x0, y0, z0) represent the coordinates of the welding start position, v represents the welding speed, t represents the welding time, r represents the radius of the oscillation circle, and T period The oscillation period represents the oscillation of the oscillating circle; the welding trajectory is a spiral.

[0070] The sinusoidal oscillation welding control equation is established as shown in equation (5):

[0071]

[0072] In equation (5), (x, y, z) represent the coordinates of the global coordinate system, (x0, y0, z0) represent the coordinates of the welding start position, v represents the welding speed, t represents the welding time, r represents the amplitude of the sinusoidal oscillation, and T period The oscillation period represents the sinusoidal oscillation; the welding trajectory is a sine curve.

[0073] The control equations for linear oscillation welding are established as shown in equations (6)-(8):

[0074]

[0075] In equations (6)-(8), (x,y,z) represent the coordinates of the global coordinate system, (x0,y0,z0) represent the coordinates of the welding start position, v represents the welding speed, t represents the welding time, and r represents the amplitude of the linear oscillation in one oscillation cycle. The reciprocating speeds within the arc are v1 and v2, respectively. When v1 = -v2, the welding trajectory is an isosceles triangular waveform.

[0076] Select the desired welding path form, and substitute formulas (3), (4), (5) or (6)-(8) into formula (1) to obtain the moving equation of the spot ring laser welding heat source model. In this embodiment, the FORTRAN language code program of the spot ring laser welding moving heat source model is written based on FORTRAN language compilation software, which facilitates the subsequent simulation software to call the subroutine. Similarly, it is not limited to which language is used to write and call the relevant program.

[0077] The global coordinate system of formulas (3) to (8) should match the coordinate system of the three-dimensional finite element mesh model. That is, the coordinates (x0, y0, z0) in the movement equation of the point ring laser welding heat source model are the starting welding position of the three-dimensional finite element mesh model. The relative displacement between z0 in formulas (3)-(6) and the z-axis coordinate of the three-dimensional finite element mesh model represents the defocusing amount.

[0078] The method requires establishing a three-dimensional partial differential equation for solid heat conduction with a heat source and a transient temperature field, and solving it in finite element software to perform thermo-mechanical coupling calculations. The three-dimensional partial differential equation for solid heat conduction with a heat source and a transient temperature field is shown in equation (9):

[0079]

[0080] In equation (9), T represents the transient temperature of the material, t Total The values ​​represent welding and cooling time, k represents the thermal conductivity of the material, ρ represents the material density, and c represents the welding and cooling time. p q represents the specific heat of the material. Total(x,y,z) represents the total heat flux density function of the point ring laser welding heat source shown in formula (1), and (x,y,z) are the coordinates of the global coordinate system.

[0081] The method for establishing the heat source model for spot ring laser welding of the present invention is applicable to weldable thin sheet metal materials, including but not limited to common metal materials such as aluminum alloys, stainless steel, titanium alloys, and copper alloys.

[0082] The process will be described in detail below with specific examples.

[0083] Figure 1 This is a schematic diagram of the heat source model for spot ring laser welding established in this invention, according to... Figure 1 Formulas (1) and (2) are used, with the following variable parameters: effective heating radius r of the central laser heat source. v =0.3mm, the effective heating range of the annular laser surface heat source is r1=0.4mm and r2=0.8mm, and the position of maximum heat flux density of the annular laser surface heat source is r s =0.6mm, total laser power Q=2000W;

[0084] Figures 2-4 These are, respectively, the ring light, point ring light, and point light welding heat source models compiled based on MATLAB language in the embodiments of the present invention. The laser power allocation coefficients α are 0, 0.6, and 1.0, respectively. α = 0 represents a ring light laser heat source, α = 0.6 represents a point ring light laser heat source, and α = 1.0 represents a point light laser heat source. Based on the MATLAB language compilation software, the MATLAB language code program of the point ring laser welding heat source model described in formulas (1) and (2) is written, and the welding heat source image is generated as shown below. Figures 2-4 As shown;

[0085] To establish the welding path equation, the linear welding control equation shown in formula (3) is selected first. Based on the FORTRAN language compilation software, the FORTRAN language code program for the moving heat source model of point ring laser welding is written, where the laser power distribution coefficients α are 0, 0.6 and 1.0 respectively. α = 0 represents that the laser heat source is a ring light, α = 0.6 represents that the laser heat source is a point ring light, and α = 1.0 represents that the laser heat source is a point light; the initial welding position is (0,2,0), and the welding speed is 200mm / s;

[0086] A three-dimensional geometric model was established using ABAQUS finite element simulation software. The aluminum alloy workpiece has geometric dimensions of 20mm × 10mm × 2mm. Mesh generation was performed with a minimum mesh size of 0.2mm and a maximum of 1.0mm, a total of 20,000 meshes, and 230,001 nodes. Eight-node thermally coupled hexahedral elements were selected as the mesh type, suitable for thermo-mechanical coupling calculations. Material properties and boundary conditions were established, with both the initial workpiece temperature and the ambient temperature set to 20℃. The simulation was then submitted to the finite element software for calculation, and the analysis results were obtained. Figures 5-7 These are the longitudinal section morphologies of the welding temperature field obtained from the ring light, point ring light, and point light welding heat source models according to embodiments of the present invention. Figures 8-10 These are the cross-sectional morphologies of the welding temperature field obtained from the ring light, point ring light, and point light welding heat source models of this invention. The portion above 2300℃ represents the keyhole during the welding process; the portion above 660℃ represents the molten pool, which becomes the weld after cooling. Similarly, there is no limitation on which finite element software is used for modeling, meshing, and simulation calculation.

[0087] By selecting the circular, sinusoidal, and linear oscillation welding control equations shown in formulas (4), (5), and (6)-(8) respectively, the weld surface morphology under different oscillation modes was finally obtained. Figure 11 The welding temperature field and weld surface morphology obtained by the circular oscillating point photothermal source model in this embodiment of the invention are shown, wherein the laser power distribution coefficient α = 1.0, the oscillation circle radius r = 2 mm, and the oscillation period T = 0.01 s. Figure 12 The welding temperature field and weld surface morphology obtained by the sinusoidal oscillating point photothermal source model in this embodiment of the invention are shown, wherein the laser power distribution coefficient α = 1.0, the oscillation amplitude r = 2 mm, and the oscillation period T = 0.02 s. Figure 13 This image shows the weld surface morphology of the welding temperature field obtained from the linear oscillating point light heat source model of this invention. The laser power distribution coefficient α = 1.0, the swing amplitude r = 2 mm, and the reciprocating speeds v1 = 400 mm / s and v2 = -400 mm / s. It can be understood that although the oscillating welding model of this invention does not use point ring light (0 < α < 1), this is because point light has a smaller weld width, allowing for a more direct view of the welding trajectory. Point ring light has a larger weld width, which would cover the welding trajectory and make it difficult to distinguish visually. However, this does not affect the use of point ring light in circular, sinusoidal, and linear oscillating welding heat source models. The different colored icons in the image correspond to temperature values ​​in degrees Celsius.

[0088] This invention establishes a heat source model for point-ring laser welding, which can effectively simulate the energy distribution of the point-ring beam pattern. The laser power ratio of the point beam and the ring beam can be adjusted in any proportion, and the defocusing amount of the point beam and the ring beam can be controlled separately. Beam parameters such as the spot diameter of the point beam and the spot diameter of the ring beam can be used to effectively express the heat flux density distribution. This heat source model establishment method provides a strong reference for accurately simulating the temperature field, stress field, and deformation field of point-ring laser welding. Combined with the control of the welding path, this invention can be widely applied in the finite element simulation field of point-ring laser linear welding and oscillating welding.

[0089] Example 2

[0090] In a second aspect, the present invention provides a spot ring laser welding system, comprising a spot ring laser, a spot ring laser fiber, a welding head, and a computing unit. The spot ring laser generates spot ring laser light and projects it into the welding head via the spot ring laser fiber. The welding head is equipped with a motor and a control unit. The control unit controls the motor to oscillate according to a set oscillation trajectory. The computing unit includes a memory, a processor, and a communication bus. The communication bus enables communication between the processor and the memory. The processor executes one or more programs stored in the memory. The computing unit is used for finite element simulation calculations and process optimization, and feeds back the simulation results to the control unit for setting the oscillation trajectory and oscillation parameters, thereby implementing the steps of the spot ring laser welding heat source model establishment method in Embodiment 1 above.

[0091] Example 3

[0092] In a third aspect, embodiments of this application also provide a computer-readable storage medium storing one or more programs that can be executed by one or more processors to perform any step of the method for establishing the spot ring laser welding heat source model as described in Embodiment 1 above.

[0093] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. The accompanying drawings are only one embodiment of the present invention, and the actual structure is not limited thereto. No reference numerals in the claims should limit the scope of the claims. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the scope of protection of the present invention. Furthermore, the word "comprising" does not exclude other elements or steps, and the word "a" preceding an element does not exclude the inclusion of "a plurality" of that element. Multiple elements stated in the product claims may also be implemented by a single element through software or hardware. The terms "first," "second," etc., are used to indicate names and do not indicate any specific order.

Claims

1. A method for establishing a heat source model for spot ring laser welding, characterized in that, The steps include: Establish a point ring laser welding heat source model: The point ring laser consists of the point light of the central laser body heat source and the ring light of the ring laser surface heat source. The control equations of the point ring laser welding heat source are shown in formulas (1) and (2). In equations (1) and (2), q Total (x,y,z) represents the total heat flux density function of the point ring laser welding heat source, (x,y,z) represents the coordinates of the global coordinate system, α represents the laser power distribution coefficient, which refers to the power proportion of the point light in the point ring laser, Q represents the total input laser power, β represents the heat flux concentration coefficient of the central laser, γ represents the heat flux concentration coefficient of the ring laser, H represents the effective heating depth of the volume heat source, and the heat source heating effect exists within the heat source depth in the interval [-H,0]. The spot parameters include r v r s r1 and r2, r v The effective heating radius of the central laser body heat source is represented by the subscript v, indicating the body heat source; r s This represents the location with the highest heat flux density of the ring laser surface heat source, with the subscript 's' indicating the surface heat source; the effective heating range of the ring laser surface heat source is [r]. 1, r2]; Establish the welding path equation, select the required welding path form, substitute the welding control equation corresponding to the welding path form into the control equation (1) of the welding heat source, and obtain the movement equation of the point ring laser welding heat source model. Based on the moving equations of the spot ring laser welding heat source model, a code program for the spot ring laser welding moving heat source model was written to generate welding heat source data and images.

2. The method for establishing a heat source model for spot ring laser welding according to claim 1, characterized in that, The welding path equation is one or more of the following: straight welding control equation, circular oscillating welding control equation, sinusoidal oscillating welding control equation, and straight oscillating welding control equation.

3. The method for establishing a heat source model for spot ring laser welding according to claim 2, characterized in that, The image includes the peak heat flux density of the heat source.

4. The method for establishing a heat source model for spot ring laser welding according to claim 3, characterized in that, The peak heat flux density of the heat source is in the range of 10. 6 -10 7 W / cm 2 .

5. The method for establishing a heat source model for spot ring laser welding according to claim 4, characterized in that, The control equation for straight-line welding is established as shown in equation (3): In equation (3), (x,y,z) represents the coordinates of the global coordinate system, (x0,y0,z0) represents the coordinates of the welding start position, v represents the welding speed, and t represents the welding time; the welding trajectory is a straight line.

6. The method for establishing a heat source model for spot ring laser welding according to claim 4, characterized in that, The control equation for circular oscillation welding is established as shown in equation (4): In equation (4), (x, y, z) represent the coordinates of the global coordinate system, (x0, y0, z0) represent the coordinates of the welding start position, v represents the welding speed, t represents the welding time, r represents the radius of the oscillation circle, and T period The oscillation period represents the oscillation of the oscillating circle; the welding trajectory is a spiral.

7. The method for establishing a heat source model for spot ring laser welding according to claim 4, characterized in that, The sinusoidal oscillation welding control equation is established as shown in equation (5): In equation (5), (x, y, z) represent the coordinates of the global coordinate system, (x0, y0, z0) represent the coordinates of the welding start position, v represents the welding speed, t represents the welding time, r represents the amplitude of the sinusoidal oscillation, and T period The oscillation period represents the sinusoidal oscillation; the welding trajectory is a sine curve.

8. The method for establishing a heat source model for spot ring laser welding according to claim 4, characterized in that, The control equations for linear oscillation welding are established as shown in equations (6)-(8): In equations (6)-(8), (x,y,z) represent the coordinates of the global coordinate system, (x0,y0,z0) represent the coordinates of the welding start position, v represents the welding speed, t represents the welding time, and r represents the amplitude of the linear oscillation in one oscillation cycle. The reciprocating speeds within the arc are v1 and v2, respectively. When v1 = v2, the welding trajectory is an isosceles triangular waveform.

9. The method for establishing a spot ring laser welding heat source model according to any one of claims 1-8, characterized in that, Furthermore, a three-dimensional partial differential equation for solid heat conduction with heat source and transient temperature field is established, and thermo-mechanical coupling calculations are performed. The three-dimensional partial differential equation for solid heat conduction with heat source and transient temperature field is shown in Equation (9): In equation (9), T represents the transient temperature of the material, t Total The values ​​represent welding and cooling time, k represents the thermal conductivity of the material, ρ represents the material density, and c represents the welding and cooling time. p Specific heat of the material.

10. A spot ring laser welding system, comprising a spot ring laser, a spot ring laser fiber, a welding head, and a computing unit; characterized in that, in: A dot ring laser is used to generate a dot ring laser, and the dot ring laser is directed into the welding head through a dot ring laser fiber. The welding head is equipped with a motor and a control unit. The control unit controls the motor to swing according to a set swing trajectory. The computing unit includes memory, processor, and communication bus; The communication bus enables communication between the processor and memory, allowing the processor to execute one or more programs stored in memory. The computing unit is used for finite element simulation calculation and process optimization, and feeds back the simulation results to the control unit for setting the swing trajectory and swing parameters, so as to run the method for establishing the point ring laser welding heat source model according to any one of claims 1-9.

11. A computer-readable storage medium storing one or more programs, characterized in that, The one or more programs may be executed by one or more processors to run the method for establishing the point ring laser welding heat source model according to any one of claims 1-9.

Images