Laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method and system

Abstract

The invention belongs to the technical field of laser welding, and discloses a laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method, which adopts a diffusion interface theory, considers macro heat flow information to revise micro phase field and solute field evolution equations, considers micro phase quality information to revise macro temperature field and flow field evolution equations, and considers micro heat flow information to revise micro phase field and solute field evolution equations. A macroscopic heat flow-microcosmic phase and mass multi-physics field bidirectional coupling model is innovatively constructed, and macroscopic and microcosmic bidirectional coupling calculation in the same computational domain is achieved. The model can overcome the limitation that a traditional sharp interface is difficult to couple, and a theoretical model basis is provided for precise prediction of macroscopic forming and microstructure evolution in the laser welding process. According to the method, a macroscopic temperature field / flow field-microscopic phase field / solute field bidirectional coupling mechanism is established, a cross-scale data bidirectional collaborative interaction method is provided, and therefore a laser welding macro-microscopic multi-physical field / cross-scale bidirectional coupling modeling method is provided, and precise simulation of macro-microscopic forming in the laser welding process is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser welding, and in particular relates to a laser welding macro-micro multi-physical field cross-scale bidirectional coupling modeling method and system. Background Art

[0002] Laser welding has the advantages of high energy density, fast welding speed, and good processing flexibility. It provides an effective means for high-quality and efficient manufacturing of high-performance components of major equipment in the fields of rail transportation, aerospace, etc. Its high temperature, transient, and multi-scale characteristics lead to complex macroscopic heat transfer / flow and microstructural evolution behaviors in the welding process, which directly affect the formation and performance of the welded joint. Existing experimental methods are difficult to accurately characterize the macroscopic heat transfer / flow and microstructural evolution behaviors of the welding process. With the development of computational fluid dynamics / materials science and the improvement of computer performance, numerical simulation technology provides an effective method for studying the macro-micro dynamic evolution process of laser welding.

[0003] During laser welding, the heat / flow oscillation in the mushy zone drives the dynamic nucleation and growth of micro dendrites, while the micro dendrite network and local solute enrichment at the solidification front reversely affect the heat transfer and convection behavior in the mushy zone. Clarifying the interaction law of the macroscopic temperature field-flow field and the microscopic phase field-solute field multi-physics field, and the time-space asynchronous / heterogeneous data interaction transmission method are the basis for establishing a macro-micro bidirectional coupling model for laser welding.

[0004] The coupling behavior of the macroscopic temperature field-flow field and the microscopic phase field-solute field in the laser welding process is extremely complex. At present, the macroscopic and microscopic multi-physics field modeling methods for laser welding are mostly "one-way input" of macroscopic information to microscopic simulation, using macroscopic heat flow information as input to unidirectionally drive the evolution of microscopic phase field / solute field, without considering the complex interaction behavior between macroscopic and microscopic multi-physics fields, and the simulation accuracy is insufficient. In addition, cross-scale spatiotemporal asynchronous / heterogeneous data interaction is mostly a one-way computing architecture of "macroscopic input-microscopic output", and the reverse information interaction of "microscopic input-macroscopic output" is still to be carried out.

[0005] Technical problems caused by existing technologies in industrial applications.

[0006] 1. Insufficient simulation accuracy

[0007] The current macro-micro multi-physics modeling method for laser welding mainly relies on the "one-way input" of macro information to micro simulation, that is, using macro heat flow information as input to unidirectionally drive the evolution of micro phase field and solute field. This method ignores the complex interaction between the macro temperature field and flow field and the micro phase field and solute field, resulting in significant deviations between the simulation results and the actual welding process, and cannot accurately reflect the real physical phenomena.

[0008] 2. Process optimization is limited

[0009] Due to the lack of a macro-micro bidirectional coupling modeling method, existing technologies are limited in the optimization of laser welding process parameters. It is impossible to accurately predict the combined impact of different process parameter combinations on welding quality and energy consumption through simulation, resulting in the process optimization process relying on a large amount of experiments and experience, which is inefficient and costly.

[0010] 3. Difficulty in equipment design and control

[0011] The existing one-way modeling method is difficult to provide accurate data support for the design and real-time control of laser welding equipment. The lack of a comprehensive understanding of the dynamic interaction between macroscopic and microscopic physical fields makes it difficult for the equipment to achieve optimal performance in actual operation, affecting the stability and consistency of the welding process.

[0012] 4. Extended R&D cycle

[0013] Due to the limitations of simulation models, the research and development of new processes and new materials needs to rely on a large number of experimental verifications, which increases the cost and cycle of research and development. The lack of high-precision, two-way coupled modeling tools has hindered the rapid iteration and application promotion of new technologies and reduced the efficiency of industrial innovation.

[0014] 5. Not adaptable to changes in complex working conditions

[0015] In actual production, the laser welding process often faces complex changes in working conditions, such as dynamic changes in welding speed, laser power and environmental conditions. The existing one-way modeling method is difficult to adapt to and accurately simulate these changes in real time, resulting in a lack of effective early warning and adjustment measures when dealing with emergencies, affecting production stability and product consistency.

[0016] 6. Low resource utilization efficiency

[0017] Due to the lack of simulation accuracy, existing technologies waste energy and materials. For example, the inability to accurately predict and control heat input leads to excessive energy consumption or excessive melting of materials, reducing the resource utilization efficiency of the overall production process and increasing operating costs.

[0018] The existing macro-micro multi-physics modeling methods for laser welding have significant deficiencies in simulation accuracy, process optimization, equipment design and control, R&D efficiency, coping with complex working conditions, and resource utilization efficiency. These technical problems limit the widespread application of laser welding technology in the fields of high precision, high efficiency, and high reliability, and they urgently need to be solved by establishing a more comprehensive and accurate macro-micro bidirectional coupling model to improve overall production efficiency and economic benefits. Summary of the invention

[0019] In view of the problems existing in the prior art, the present invention provides a cross-scale bidirectional coupling modeling method for macro-micro multi-physical fields in laser welding.

[0020] The present invention is implemented as follows: a laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method includes:

[0021] Step 1: Based on the principles of nonlinear thermodynamics and fluid dynamics, considering the influence of macroscopic temperature field and flow field on phase field, derive a mathematical model describing the evolution of microscopic phase field driven by macroscopic temperature field and flow field;

[0022] The optimized microscopic phase field governing equation is as follows:

[0023]

[0024] In the formula, τ 0 represents the relaxation time, k Cu represents the solute equilibrium distribution coefficient of copper element, u Cu represents the dimensionless concentration of copper element, M Cu represents the interpolation function related to the concentration of copper solute, D 1,Cu represents the diffusion coefficient of copper, D l,Li represents the diffusion coefficient of lithium, k Li represents the solute equilibrium distribution coefficient of lithium, u Li represents the dimensionless concentration of lithium element, represents the anisotropy factor, φ represents the phase field, W 0 represents the phase field interface thickness, and represents the interpolation function related to the double-well potential and volume free energy, λ represents the coupling coefficient related to the thermodynamic driving force, Δf(T,t) represents the spatiotemporal distribution data of the temperature field obtained by the macro model, f(u,t) represents the spatiotemporal distribution data of the flow field obtained by the macro model, and t represents time;

[0025] Step 2: Based on the momentum conservation equation, considering the effect of fluid flow on solute transport, a mathematical model describing the evolution of macroscopic flow field and microscopic phase solute field is established;

[0026] Step 3, extracting the spatiotemporal distribution data of key parameters such as macro-scale temperature field and flow field;

[0027] Step 4, describing the free energy density function of the multiphase system in the welding process based on the conservative phase field and gradient flow theory;

[0028] Step 5, based on the substitutional solution model, real-time acquisition of the thermodynamic driving force of various phases at the microscopic scale;

[0029] Step 6, based on the macroscopic model and microscopic simulation established above, combined with the physical scale relationship of the macro-micro model time step, determine the real-time sequential solution method of the model, and construct a macro-micro bidirectional coupling model of laser welding considering macroscopic heat / flow-microscopic phase / quality.

[0030] Furthermore, based on the momentum conservation equation, the influence of fluid flow on solute transport is considered, and a mathematical model describing the evolution of macroscopic flow field and microscopic phase solute field is established:

[0031] The optimized microscopic solute field evolution equation is as follows:

[0032]

[0033] In the formula, α m represents the material phase fraction, ρ m Indicates the material density, C l represents the concentration of liquid solute, C represents the total solute concentration, and D l represents the diffusion coefficient, represents the corrected liquid phase solute concentration, k v is the solute equilibrium distribution coefficient, C s represents the solid solute concentration, f l represents the liquid fraction, u represents the velocity, and f s represents the solid phase fraction;

[0034] Considering the influence of microscopic phase field on macroscopic temperature field, the energy conservation equation is established under the microscopic phase field distribution-mushy zone solid phase fraction-solid-liquid phase change latent heat mapping model;

[0035] The optimized macroscopic temperature field control equation is as follows:

[0036]

[0037] In the formula, ρ(f s ,c,t) represents the spatial density under different solid fractions, solute concentrations and time steps, h represents the thermal enthalpy, λ T represents the thermal diffusion coefficient, T represents the temperature, and q laser represents the laser heat source, q vap represents evaporation heat dissipation, L represents latent heat of fusion, q rad Indicates radiative heat dissipation.

[0038] Furthermore, considering the influence of microscopic phase field and solute distribution on the macroscopic flow field equation, the macroscopic momentum conservation equation driven by the evolution of the solid fraction and solute distribution in the mushy zone and the thermophysical parameters in the mushy zone is established.

[0039] The optimized macroscopic momentum conservation equation is as follows:

[0040]

[0041] In the formula, p represents pressure, F s represents the surface tension, F b represents gravity, S represents the mushy zone constant, Precoil Indicates steam recoil pressure.

[0042] Furthermore, the temporal and spatial distribution data of key parameters such as macro-scale temperature field and flow field are extracted:

[0043] Based on the interlayer interpolation technology of generative adversarial neural network, the machine learning model is trained to generate double interpolation results from macroscopic heat / flow (mm / ms level) to microscopic temperature gradient-growth rate (um / us level);

[0044] Realize the mapping interaction from macroscopic low spatiotemporal resolution to microscopic high spatiotemporal resolution asynchronous (ms~us) / heterogeneous (mm~um) data;

[0045] Extract the spatiotemporal distribution data of key parameters such as phase field and solute field of microscopic nonlinear thermodynamic multiphase field model;

[0046] Based on the representative volume unit to describe the macroscopic scale effect, the homogenization method is used to calculate the corresponding macroscopic thermophysical parameters;

[0047] Realize the mapping interaction from small-scale micro data to large-scale macro data.

[0048] Furthermore, the free energy density function of the multiphase system in the welding process is described based on the conservative phase field and gradient flow theory;

[0049] Consider the nonlinear effects of phase field distribution and solute field distribution on macroscopic solid-liquid phase density, specific heat capacity and other thermophysical parameters;

[0050] The phase field method and lattice Boltzmann method are used to construct a unified diffusion interface model of laser welding macroscopic lattice Boltzmann multiphase flow considering the microscopic phase / mass distribution. Among them, the phase field method is used to track the gas-liquid free surface, and the lattice Boltzmann method is used to solve the temperature field and flow field equations.

[0051] Furthermore, the thermodynamic driving force of various phases at the microscopic scale is obtained in real time based on the Substitutional solution model:

[0052] The lattice Boltzmann method is used to obtain the dissipative resistance of dendrite growth induced by macroscopic melt flow;

[0053] Combined with the non-isothermal extrapolation method, a multiphase field model of microstructure evolution of laser welding with nonlinear thermodynamic coupling under the influence of macroscopic heat / flux distribution is constructed.

[0054] Another object of the present invention is to provide a laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling system comprising:

[0055] The derivation module is used to consider the influence of the macroscopic temperature field and flow field on the phase field based on the principles of nonlinear thermodynamics and fluid dynamics, and to derive a mathematical model describing the evolution of the microscopic phase field driven by the macroscopic temperature field and flow field;

[0056] Establish a module to consider the influence of fluid flow on solute transport based on the momentum conservation equation and establish a mathematical model to describe the evolution of macroscopic flow field and microscopic phase solute field;

[0057] Extraction module, used to extract the spatiotemporal distribution data of key parameters such as macro-scale temperature field and flow field;

[0058] Description module, used to describe the free energy density function of multiphase system in welding process based on conservative phase field and gradient flow theory;

[0059] The acquisition module is used to obtain the thermodynamic driving force of various phases at the microscopic scale in real time based on the substitutional solution model;

[0060] The construction module is used to determine the real-time sequential solution method of the model based on the macroscopic model and microscopic simulation established above, combined with the physical scale relationship of the macroscopic and microscopic model time steps, and to construct a macroscopic and microscopic bidirectional coupling model of laser welding that considers macroscopic heat / flow-microscopic phase / quality.

[0061] Another object of the present invention is to provide a computer device, which includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method.

[0062] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, enables the processor to execute the steps of the laser welding macro-micro multi-physical field cross-scale bidirectional coupling modeling method.

[0063] Another object of the present invention is to provide an information data processing terminal, which is used to implement the laser welding macro-micro multi-physical field cross-scale bidirectional coupling modeling system.

[0064] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0065] First, the present invention establishes a bidirectional coupling mechanism of macroscopic temperature field / flow field-microscopic phase field / solute field, proposes a bidirectional collaborative interaction method of cross-scale data, and thus proposes a laser welding macro-micro multi-physics field / cross-scale bidirectional coupling modeling method to achieve accurate simulation of macro-micro forming in the laser welding process.

[0066] This project adopts the diffusion interface theory, considers the macroscopic heat flow information to revise the microscopic phase field and solute field evolution equations, considers the microscopic phase and material information to revise the macroscopic temperature field and flow field evolution equations, and innovatively constructs a macroscopic heat flow-microscopic phase and material multi-physics field bidirectional coupling model to realize macro-micro bidirectional coupling calculations within the same computational domain.

[0067] This model can overcome the limitations of traditional sharp interface coupling and provide a theoretical model basis for the accurate prediction of macroscopic forming and microstructural evolution in the laser welding process.

[0068] Second, the present invention solves the technical problems of the prior art in industrial applications and achieves significant technical progress.

[0069] 1. Existing technical problems solved

[0070] 1. Insufficient simulation accuracy

[0071] The current macro-micro multi-physics modeling method for laser welding mainly relies on the "one-way input" of macro information to micro simulation, that is, using macro heat flow information as input to unidirectionally drive the evolution of micro phase field and solute field. This method ignores the complex interaction between the macro temperature field and flow field and the micro phase field and solute field, resulting in significant deviations between the simulation results and the actual welding process, and cannot accurately reflect the real physical phenomena.

[0072] 2. Process optimization is limited

[0073] Due to the lack of a macro-micro bidirectional coupling modeling method, existing technologies are limited in the optimization of laser welding process parameters. It is impossible to accurately predict the combined impact of different process parameter combinations on welding quality and energy consumption through simulation, resulting in the process optimization process relying on a large amount of experiments and experience, which is inefficient and costly.

[0074] 3. Difficulty in equipment design and control

[0075] The existing one-way modeling method is difficult to provide accurate data support for the design and real-time control of laser welding equipment. The lack of a comprehensive understanding of the dynamic interaction between macroscopic and microscopic physical fields makes it difficult for the equipment to achieve optimal performance in actual operation, affecting the stability and consistency of the welding process.

[0076] 4. Extended R&D cycle

[0077] Due to the limitations of simulation models, the research and development of new processes and new materials needs to rely on a large number of experimental verifications, which increases the cost and cycle of research and development. The lack of high-precision, two-way coupled modeling tools has hindered the rapid iteration and application promotion of new technologies and reduced the efficiency of industrial innovation.

[0078] 5. Not adaptable to changes in complex working conditions

[0079] In actual production, the laser welding process often faces complex changes in working conditions, such as dynamic changes in welding speed, laser power and environmental conditions. The existing one-way modeling method is difficult to adapt to and accurately simulate these changes in real time, resulting in a lack of effective early warning and adjustment measures when dealing with emergencies, affecting production stability and product consistency.

[0080] 6. Low resource utilization efficiency

[0081] Due to the lack of simulation accuracy, existing technologies waste energy and materials. For example, the inability to accurately predict and control heat input leads to excessive energy consumption or excessive melting of materials, reducing the resource utilization efficiency of the overall production process and increasing operating costs.

[0082] The existing macro-micro multi-physics modeling methods for laser welding have significant deficiencies in simulation accuracy, process optimization, equipment design and control, R&D efficiency, coping with complex working conditions, and resource utilization efficiency. These technical problems limit the widespread application of laser welding technology in the fields of high precision, high efficiency, and high reliability, and they urgently need to be solved by establishing a more comprehensive and accurate macro-micro bidirectional coupling model to improve overall production efficiency and economic benefits.

[0083] 2. Significant Technological Advances

[0084] 1. Bidirectional coupling modeling methods and systems significantly improve simulation accuracy:

[0085] The present invention is based on the principles of nonlinear thermodynamics and fluid dynamics, considers the influence of macroscopic temperature field and flow field on phase field, and derives a mathematical model describing the evolution of microscopic phase field driven by macroscopic temperature field and flow field; based on the momentum conservation equation, considers the influence of fluid flow on solute transport, and establishes a mathematical model describing the evolution of macroscopic flow field and microscopic phase solute field; considers the influence of microscopic phase field on macroscopic temperature field, and establishes an energy conservation equation considering the microscopic phase field distribution-mushy zone solid phase fraction-solid-liquid phase change latent heat mapping model; considers the influence of microscopic phase field and solute distribution on macroscopic flow field equation, and establishes a macroscopic momentum conservation equation driven by the evolution of mushy zone solid phase fraction and solute distribution-mushy zone thermophysical property parameters, thereby establishing a complete multi-physical field bidirectional coupling mechanism at the physical level to achieve precise simulation.

[0086] 2. Effectively support process optimization:

[0087] Based on the above-mentioned laser welding bidirectional coupling method, the spatiotemporal evolution law of the three-dimensional microstructure of the weld under different combinations of process parameters such as laser welding power, welding speed, defocus, laser beam inclination, etc. can be accurately simulated; the welding process range with beautiful weld formation, excellent mechanical properties and low comprehensive energy consumption can be obtained; thereby reducing the blindness of process optimization and experimental costs.

[0088] 3.Limited reduction in equipment design and control difficulty

[0089] The bidirectional coupling modeling method can clarify the evolution mechanism of laser welding macro and micro forming, reveal the influence mechanism of laser welding process parameters on welding quality, and provide accurate data support for the design and real-time control of laser welding equipment. Based on a comprehensive understanding of the dynamic interaction between macro and micro physical fields, it can effectively support the control method of laser welding equipment process parameters, optimize equipment energy consumption, and thus ensure the stability and consistency of the welding process.

[0090] 4. Shorten the research and development cycle of new laser welding processes

[0091] The bidirectional coupling method and system proposed in the present invention get rid of the dependence of traditional modeling methods on equipment process parameters and material thermal physical properties parameters. It can quickly carry out process simulation experiments according to the process requirements of new materials, and realize rapid principle exploration of new processes and new materials, thereby greatly improving the research and development speed and accelerating the rapid iteration and promotion and application of new technologies.

[0092] 5. Realize adaptive adaptation to complex working conditions

[0093] Based on the massive simulation results under the bidirectional coupling method, the laser welding process knowledge base can be further constructed to quantitatively analyze the changes in weld quality under different laser welding parameters from a mechanism level. When the laser welding process parameters change, the weld formation results can be quickly and accurately predicted, thereby ensuring the quality inspection of the welding process.

[0094] 6. Improve resource utilization efficiency

[0095] Based on accurate simulation results, the laser welding process parameter range can be obtained, in which the energy consumption and material loss under different process parameter combinations can be further evaluated. Then, by adjusting the process parameters, energy consumption optimization or material saving can be achieved, which improves the resource utilization efficiency of the overall production process and reduces operating costs.

[0096] The laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method and system established by the present invention significantly improves the accurate simulation of laser welding macro weld formation and microstructure evolution through innovative bidirectional coupling mechanism, cross-scale data interaction method and simulation model, and solves the shortcomings of existing unidirectional coupling models in simulation accuracy, process optimization support, equipment control stability, etc. At the same time, the method and system of the present invention are universal for new materials and new processes for laser welding, further improve the efficiency of R&D iteration, reduce the market promotion and application cycle of new technologies, and improve overall production efficiency and economic benefits.

[0097] Third, as auxiliary evidence of the inventiveness of the claims of the present invention, it is also reflected in the following important aspects:

[0098] (1) The expected benefits and commercial value of the technical solution of the present invention after transformation are:

[0099] The present invention can significantly improve welding quality and efficiency and reduce production costs by providing a cross-scale bidirectional coupling modeling method and system for macro-micro multi-physical fields in laser welding. Specific expected benefits include: improving the quality and consistency of welding products and reducing scrap rates; optimizing welding process parameters and improving production efficiency; reducing energy consumption and material waste; and enhancing product market competitiveness. The commercial value includes: promoting the application scope of laser welding technology in aerospace, marine ships, automobiles and other fields, with broad market application prospects, and is expected to bring significant economic and social benefits.

[0100] (2) The technical solution of the present invention fills the technical gap in the industry at home and abroad:

[0101] The technical solution of the present invention fills the technical gap in the cross-scale bidirectional coupling modeling of macro-micro multi-physics fields in laser welding at home and abroad. Traditional unidirectional simulation usually only focuses on a single scale or simplified physical field coupling, while the present invention can more accurately simulate the macro-micro physical phenomena in the welding process through cross-scale bidirectional coupling modeling, solving the shortcomings of the existing technology in simulation accuracy and efficiency.

[0102] (3) Whether the technical solution of the present invention solves the technical problems that people have been eager to solve but have not been able to solve successfully:

[0103] The technical solution of the present invention solves a technical problem that has not been effectively solved for a long time. Traditional welding simulation technology has limitations in dealing with complex multi-physics field coupling and cross-scale problems, resulting in a large deviation between the simulation results and the actual welding process. The present invention achieves accurate simulation and prediction of the welding process through an innovative multi-physics field cross-scale bidirectional coupling modeling method, solving this problem that has long plagued the development of the industry.

[0104] (4) Whether the technical solution of the present invention overcomes technical prejudice:

[0105] The technical solution of the present invention overcomes the traditional technical prejudice to a certain extent. The traditional concept is that it is difficult to effectively couple the macro and micro physical fields in the welding process, which leads to many research and technology development being limited by this concept. The present invention breaks this technical prejudice through an innovative modeling method, proves the feasibility and effectiveness of multi-physical field cross-scale bidirectional coupling modeling, and provides a new technical path and solution for the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0106] Figure 1It is a flow chart of the laser welding macro-micro multi-physical field cross-scale bidirectional coupling modeling method provided by an embodiment of the present invention.

[0107] Figure 2 It is a structural block diagram of the laser welding macro-micro multi-physical field cross-scale bidirectional coupling modeling system provided by an embodiment of the present invention.

[0108] Figure 3 It is a diagram of the macro-micro multi-physics field / cross-scale bidirectional coupling mechanism of laser welding provided in an embodiment of the present invention.

[0109] Figure 4 It is a diagram of an interactive method for mapping macro-scale data to micro-scale provided by an embodiment of the present invention.

[0110] Figure 5 It is a diagram of an interactive method for mapping micro-scale data to macro-scale provided by an embodiment of the present invention.

[0111] Figure 6 This is a simulation effect diagram of macro-micro bidirectional coupling of laser welding provided by an embodiment of the present invention;

[0112] Figure 7 This is a simulation result diagram of the macro-micro bidirectional coupling experiment of laser welding provided by an embodiment of the present invention, (a) is the macro-scale molten pool-keyhole simulation effect under macro-micro coupling, and (b) is the micro-scale dendrite growth process under macro-micro coupling. DETAILED DESCRIPTION

[0113] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0114] like Figure 1 As shown, a laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method provided by an embodiment of the present invention includes the following steps:

[0115] S101, based on the principles of nonlinear thermodynamics and fluid dynamics, considering the influence of macroscopic temperature field and flow field on phase field, derive the mathematical model describing the evolution of microscopic phase field driven by macroscopic temperature field and flow field;

[0116] The optimized microscopic phase field governing equation is as follows:

[0117]

[0118] In the formula, τ 0 represents the relaxation time, k Cu represents the solute equilibrium distribution coefficient of copper element, u Cu represents the dimensionless concentration of copper element, MCu represents the interpolation function related to the concentration of copper solute, D 1,Cu represents the diffusion coefficient of copper, D l,Li represents the diffusion coefficient of lithium, k Li represents the solute equilibrium distribution coefficient of lithium, u Li represents the dimensionless concentration of lithium element, represents the anisotropy factor, φ represents the phase field, W 0 represents the phase field interface thickness, and represents the interpolation function related to the double-well potential and volume free energy, λ represents the coupling coefficient related to the thermodynamic driving force, Δf(T,t) represents the spatiotemporal distribution data of the temperature field obtained by the macro model, f(u,t) represents the spatiotemporal distribution data of the flow field obtained by the macro model, and t represents time;

[0119] S102, based on the momentum conservation equation, considering the effect of fluid flow on solute transport, a mathematical model describing the evolution of macroscopic flow field and microscopic phase solute field is established;

[0120] S103, extracting the spatiotemporal distribution data of key parameters such as macro-scale temperature field and flow field;

[0121] S104, describing the free energy density function of multiphase system in welding process based on conservative phase field and gradient flow theory;

[0122] S105, real-time acquisition of thermodynamic driving forces of various phases at microscopic scale based on substitutional solution model;

[0123] S106, based on the macroscopic model and microscopic simulation established above, combined with the physical scale relationship of the macroscopic and microscopic model time steps, determine the real-time sequential solution method of the model, and construct a macroscopic and microscopic bidirectional coupling model of laser welding considering macroscopic heat / flow-microscopic phase / quality.

[0124] The present invention provides a laser welding macro-micro multi-physical field cross-scale bidirectional coupling modeling method, which aims to achieve accurate simulation and optimization of the laser welding process by combining macro- and micro-scale physical phenomena. The method is first based on the principles of nonlinear thermodynamics and fluid dynamics, considers the influence of macroscopic temperature field and flow field on microscopic phase field, and derives a mathematical model that describes the evolution of microscopic phase field driven by macroscopic temperature field and flow field. In step 1, the temperature field spatiotemporal distribution data Δf(T, t) and flow field spatiotemporal distribution data f(u, t) obtained by the macroscopic model are introduced into the description of phase field evolution through the optimized microscopic phase field control equation, ensuring that the microscopic phase change process can accurately reflect the changes in the macroscopic environment.

[0125] In step 2, based on the momentum conservation equation, the method further considers the influence of fluid flow on solute transport and establishes a mathematical model to describe the evolution of macroscopic flow field and microscopic solute field. This model can not only simulate the movement and heat conduction of fluid on a macroscopic scale, but also accurately describe the diffusion and reaction process of solute in the microscopic phase, thereby achieving a comprehensive understanding and prediction of the multiphase system in the welding process.

[0126] Steps 3 to 5 are performed sequentially. First, the spatiotemporal distribution data of key parameters such as the macroscopic temperature field and flow field are extracted to ensure that the data input of the macroscopic model is accurate and reliable. Then, based on the theory of conservative phase field and gradient flow, the free energy density function of the multiphase system in the welding process is described, and the thermodynamic basis of the system is constructed. Then, the substitutional solution model is used to obtain the thermodynamic driving force of various phases at the microscopic scale in real time, providing a dynamic basis for the evolution of the phase field. These steps ensure that the microscopic phase change process can dynamically respond to changes in the macroscopic environment, enhancing the authenticity and applicability of the model.

[0127] Finally, in step 6, based on the macroscopic model and microscopic simulation established above, combined with the physical scale relationship of the macro-micro model time step, the real-time sequential solution method of the model was determined, and a macro-micro bidirectional coupling model of laser welding considering the interaction between macroscopic heat / flow and microscopic phase / mass was constructed. This coupling model realizes information exchange and dynamic adjustment between macroscopic and microscopic scales through a bidirectional feedback mechanism, making the simulation of the entire welding process more accurate and efficient. Ultimately, this method not only improves the simulation accuracy of the laser welding process, but also provides strong technical support for optimizing welding process parameters, improving welding quality, and reducing energy consumption.

[0128] The laser welding macro-micro multi-physical field cross-scale bidirectional coupling modeling method of the present invention successfully realizes the comprehensive simulation and control of complex physical phenomena in the laser welding process through systematic steps and scientific mathematical models, significantly improves the understanding and optimization capabilities of the welding process, and has broad application prospects and significant technical advantages.

[0129] The embodiment of the present invention provides a mathematical model based on the momentum conservation equation, taking into account the influence of fluid flow on solute transport, to describe the evolution of the macroscopic flow field and the microscopic phase solute field:

[0130] The optimized microscopic solute field evolution equation is as follows:

[0131]

[0132] In the formula, α m represents the material phase fraction, ρ m Indicates the material density, C l represents the concentration of liquid solute, C represents the total solute concentration, and Dl represents the diffusion coefficient, represents the corrected liquid phase solute concentration, k v is the solute equilibrium distribution coefficient, C s represents the solid solute concentration, f l represents the liquid fraction, u represents the velocity, and f s represents the solid phase fraction;

[0133] Considering the influence of microscopic phase field on macroscopic temperature field, the energy conservation equation is established under the microscopic phase field distribution-mushy zone solid phase fraction-solid-liquid phase change latent heat mapping model;

[0134] The optimized macroscopic temperature field control equation is as follows:

[0135]

[0136] In the formula, ρ(f s ,c,t) represents the spatial density under different solid fractions, solute concentrations and time steps, h represents the thermal enthalpy, λ T represents the thermal diffusion coefficient, T represents the temperature, and q laser represents the laser heat source, q vap represents evaporation heat dissipation, L represents latent heat of fusion, q rad Indicates radiative heat dissipation.

[0137] The embodiment of the present invention provides a macroscopic momentum conservation equation driven by the evolution of the solid phase fraction and solute distribution in the mushy zone-the thermophysical property parameters in the mushy zone, taking into account the influence of the microscopic phase field and the solute distribution on the macroscopic flow field equation;

[0138] The optimized macroscopic momentum conservation equation is as follows:

[0139]

[0140] In the formula, p represents pressure, F s represents the surface tension, F b represents gravity, S represents the mushy zone constant, P recoil Indicates steam recoil pressure.

[0141] The spatiotemporal distribution data of key parameters such as macro-scale temperature field and flow field provided by the embodiment of the present invention are:

[0142] Based on the interlayer interpolation technology of generative adversarial neural network, the machine learning model is trained to generate double interpolation results from macroscopic heat / flow (mm / ms level) to microscopic temperature gradient-growth rate (um / us level);

[0143] Realize the mapping interaction from macroscopic low spatiotemporal resolution to microscopic high spatiotemporal resolution asynchronous (ms~us) / heterogeneous (mm~um) data;

[0144] Extract the spatiotemporal distribution data of key parameters such as phase field and solute field of microscopic nonlinear thermodynamic multiphase field model;

[0145] Based on the representative volume unit to describe the macroscopic scale effect, the homogenization method is used to calculate the corresponding macroscopic thermophysical parameters;

[0146] Realize the mapping interaction from small-scale micro data to large-scale macro data.

[0147] The embodiment of the present invention provides a free energy density function for describing a multiphase system in a welding process based on the conservative phase field and gradient flow theory;

[0148] Consider the nonlinear effects of phase field distribution and solute field distribution on macroscopic solid-liquid phase density, specific heat capacity and other thermophysical parameters;

[0149] The phase field method and lattice Boltzmann method are used to construct a unified diffusion interface model of laser welding macroscopic lattice Boltzmann multiphase flow considering the microscopic phase / mass distribution. Among them, the phase field method is used to track the gas-liquid free surface, and the lattice Boltzmann method is used to solve the temperature field and flow field equations.

[0150] The embodiment of the present invention provides a substitutional solution model for obtaining the thermodynamic driving force of various phases at the microscopic scale in real time:

[0151] The lattice Boltzmann method is used to obtain the dissipative resistance of dendrite growth induced by macroscopic melt flow;

[0152] Combined with the non-isothermal extrapolation method, a multiphase field model of microstructure evolution of laser welding with nonlinear thermodynamic coupling under the influence of macroscopic heat / flux distribution is constructed.

[0153] like Figure 2 As shown, a laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling system provided by an embodiment of the present invention includes:

[0154] The derivation module is used to consider the influence of the macroscopic temperature field and flow field on the phase field based on the principles of nonlinear thermodynamics and fluid dynamics, and to derive a mathematical model describing the evolution of the microscopic phase field driven by the macroscopic temperature field and flow field;

[0155] Establish a module to consider the influence of fluid flow on solute transport based on the momentum conservation equation and establish a mathematical model to describe the evolution of macroscopic flow field and microscopic phase solute field;

[0156] Extraction module, used to extract the spatiotemporal distribution data of key parameters such as macro-scale temperature field and flow field;

[0157] Description module, used to describe the free energy density function of multiphase system in welding process based on conservative phase field and gradient flow theory;

[0158] The acquisition module is used to obtain the thermodynamic driving force of various phases at the microscopic scale in real time based on the substitutional solution model;

[0159] The construction module is used to determine the real-time sequential solution method of the model based on the macroscopic model and microscopic simulation established above, combined with the physical scale relationship of the macroscopic and microscopic model time steps, and to construct a macroscopic and microscopic bidirectional coupling model of laser welding that considers macroscopic heat / flow-microscopic phase / quality.

[0160] Another object of the present invention is to provide a computer device, which includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method.

[0161] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, enables the processor to execute the steps of the laser welding macro-micro multi-physical field cross-scale bidirectional coupling modeling method.

[0162] Another object of the present invention is to provide an information data processing terminal, which is used to implement the laser welding macro-micro multi-physical field cross-scale bidirectional coupling modeling system.

[0163] The present invention is specifically implemented:

[0164] The first aspect of the present invention establishes a bidirectional coupling mechanism of macroscopic temperature field / flow field-microscopic phase field / solute field, such as Figure 3 As shown, the main contents include:

[0165] Based on the principles of nonlinear thermodynamics and fluid dynamics, the influence of macroscopic temperature field and flow field on phase field is considered, and a mathematical model describing the evolution of microscopic phase field driven by macroscopic temperature field and flow field is derived.

[0166] The optimized microscopic phase field governing equation is as follows:

[0167]

[0168] In the formula, τ 0 represents the relaxation time, k Cu represents the solute equilibrium distribution coefficient of copper element, u Cu represents the dimensionless concentration of copper element, M Cu represents the interpolation function related to the concentration of copper solute, D l,Cu represents the diffusion coefficient of copper, D l,Li represents the diffusion coefficient of lithium, k Lirepresents the solute equilibrium distribution coefficient of lithium, u Li represents the dimensionless concentration of lithium element, represents the anisotropy factor, φ represents the phase field, W 0 represents the phase field interface thickness, and represents the interpolation function related to the double-well potential and volume free energy, λ represents the coupling coefficient related to the thermodynamic driving force, Δf(T,t) represents the spatiotemporal distribution data of the temperature field obtained by the macro model, f(u,t) represents the spatiotemporal distribution data of the flow field obtained by the macro model, and t represents time;

[0169] The embodiment of the present invention provides a mathematical model based on the momentum conservation equation, taking into account the influence of fluid flow on solute transport, to describe the evolution of macroscopic flow field and microscopic phase solute field;

[0170] The optimized microscopic solute field evolution equation is as follows:

[0171]

[0172] In the formula, α m represents the material phase fraction, ρ m Indicates the material density, C l represents the concentration of liquid solute, C represents the total solute concentration, and D l represents the diffusion coefficient, represents the corrected liquid phase solute concentration, k v is the solute equilibrium distribution coefficient, C s represents the solid solute concentration, f l represents the liquid fraction, u represents the velocity, and f s represents the solid phase fraction;

[0173] The embodiment of the present invention provides an energy conservation equation considering the influence of the microscopic phase field on the macroscopic temperature field, and establishing a mapping model of microscopic phase field distribution-solid phase fraction in the mushy zone-solid-liquid phase change latent heat;

[0174] The optimized macroscopic temperature field control equation is as follows:

[0175]

[0176] In the formula, ρ(f s ,c,t) represents the spatial density under different solid fractions, solute concentrations and time steps, h represents the thermal enthalpy, λ T represents the thermal diffusion coefficient, T represents the temperature, and q laser represents the laser heat source, q vap represents evaporation heat dissipation, L represents latent heat of fusion, q rad Indicates radiative heat dissipation.

[0177] The embodiment of the present invention provides a macroscopic momentum conservation equation driven by the evolution of the solid phase fraction and solute distribution in the mushy zone-the thermophysical property parameters in the mushy zone, taking into account the influence of the microscopic phase field and the solute distribution on the macroscopic flow field equation;

[0178] The optimized macroscopic momentum conservation equation is as follows:

[0179]

[0180] In the formula, p represents pressure, F s represents the surface tension, F b represents gravity, S represents the mushy zone constant, P recoil Indicates steam recoil pressure.

[0181] The second aspect of the present invention proposes a macro / micro-temporal-spatial asynchronous / heterogeneous data cross-scale bidirectional collaborative interaction method, comprising:

[0182] Extract spatiotemporal distribution data of key parameters such as macro-scale temperature field and flow field;

[0183] The interlayer interpolation technology based on generative adversarial neural network provided in the embodiment of the present invention trains the machine learning model to generate double interpolation results from macroscopic heat / flow (mm / ms level) to microscopic temperature gradient-growth rate (um / us level);

[0184] The embodiment of the present invention provides a method for realizing the mapping interaction of macroscopic low spatiotemporal resolution to microscopic high spatiotemporal resolution asynchronous (ms~us) / heterogeneous (mm~um) data, such as Figure 4 As shown;

[0185] Extract the spatiotemporal distribution data of key parameters such as phase field and solute field of microscopic nonlinear thermodynamic multiphase field model;

[0186] The embodiment of the present invention provides a method for describing macroscopic scale effects based on representative volume units and calculating corresponding macroscopic thermophysical property parameters using a homogenization method;

[0187] The embodiment of the present invention provides an implementation for constructing a mapping interaction from small-scale microscopic data to large-scale macroscopic data, such as Figure 5 shown.

[0188] The third aspect of the present invention constructs a macro-micro bidirectional coupling model of laser welding considering heat / flux distribution-phase / mass distribution, including:

[0189] Based on the conservative phase field and gradient flow theory, the free energy density function of the multiphase system in the welding process is described;

[0190] The embodiment of the present invention provides a method for considering the nonlinear effects of phase field distribution and solute field distribution on macroscopic solid-liquid phase density, specific heat capacity and other thermophysical parameters;

[0191] The embodiment of the present invention provides a laser welding macroscopic lattice Boltzmann multiphase flow unified diffusion interface model that considers microscopic phase / mass distribution by using phase field method and lattice Boltzmann method. The phase field method is used to track the gas-liquid free surface, and the lattice Boltzmann method is used to solve the temperature field and flow field equations.

[0192] Obtain the thermodynamic driving force of various phases at the microscopic scale in real time based on the Substitutional solution model;

[0193] The embodiment of the present invention provides a method for obtaining the dendrite growth dissipation resistance induced by macroscopic melt flow by using a lattice Boltzmann method;

[0194] The embodiment of the present invention provides a non-isothermal extrapolation method to construct a multiphase field model of microstructure evolution of laser welding with nonlinear thermodynamic coupling under the influence of macroscopic heat / flow distribution;

[0195] Based on the macroscopic model and microscopic simulation established above, combined with the physical scale relationship between the time steps of the macroscopic and microscopic models, the real-time sequential solution method of the model is determined, and a macroscopic and microscopic bidirectional coupling model of laser welding considering macroscopic heat / flow and microscopic phase / quality is constructed.

[0196] Example 1: Periodic Fluctuation Behavior of Titanium Alloy Keyhole

[0197] 1. Background and Requirements

[0198] Titanium alloys have high specific strength and good corrosion resistance. They are suitable for use in fields such as aerospace and automobiles that have stringent requirements on weight and strength. Welding is an important manufacturing process. Laser welding, as an advanced optomechanical and electrical welding technology, has been widely used in the manufacture of titanium alloy components. The keyhole fluctuation behavior directly affects the stability of the welding process and needs to be studied urgently.

[0199] 2. Material properties

[0200] Based on the bidirectional coupling method and system of the present invention, a numerical simulation experiment of titanium alloy laser welding was carried out, and the material parameters are as follows:

[0201] Density 4378.48kg / m 3 , laser absorption rate 0.0158mPa·s, solid phase temperature 1878K, liquid phase temperature 2023K, surface tension 1.588N / m, Fresnel absorption coefficient 0.2, latent heat of melting 3×10 5 J / kg, latent heat of evaporation 0.65×10 -7 J / kg.

[0202] 3. Experimental simulation effect

[0203] The simulation experiment was carried out with the welding parameters of laser power 200W, welding speed 800mm / s and 0 defocus. The simulation results are as follows Figure 6 As shown in (a), the integrated simulation of molten pool and keyhole is realized.

[0204] 4. Conclusion and application prospects

[0205] like Figure 6 (b) shows that the embodiment of the present invention has statistically analyzed the opening length of the keyhole cross section at Z = -24 microns. The statistical results are as follows: Figure 6 As shown in (c), it can be found from the figure that the keyhole opening length has obvious periodic fluctuation behavior, which provides effective support for the later research on the stability mechanism of laser welding keyhole and the regulation of process parameters.

[0206] Example 2: Numerical simulation of macro-micro bidirectional coupling of aluminum alloy

[0207] 1. Background and Requirements

[0208] Aluminum alloy laser welding is an advanced manufacturing technology that uses laser energy to melt and combine aluminum alloy materials. Due to the characteristics of aluminum alloy such as light weight, high strength and good thermal conductivity, the application of laser welding technology on this material is particularly important. The microstructure of aluminum alloy welds determines the mechanical properties, so we continue to carry out macro-micro integrated simulation to achieve weld microstructure prediction.

[0209] 2. Material properties

[0210] Based on the above model, the aluminum alloy laser welding process was numerically simulated, and its thermophysical parameters were as follows: liquid metal density 2350kg m -3 , solid metal density 2670kg m -3 , viscosity 1.3×10 -3 kg m -1 s -1 、Liquid relative heat 1170J kg -1 K -1 、Solid specific heat 1040J kg -1 K -1 、Liquid phase thermal conductivity 90W m -1 K -1 、Solid phase thermal conductivity 150W m -1 K -1 , liquidus temperature 913.15K, solidus temperature 813.15K, heat transfer coefficient 20W m -2 K -1 Surface tension: 0.907N m -1 , latent heat of fusion 3.62×105J kg -1 , Latent heat of vaporization 1.08×107J kg -1, surface tension gradient -0.271×10-3N m -1 K -1 .

[0211] 3. Experimental simulation effect

[0212] The experimental simulation results are as follows Figure 7 shown. Figure 7 (a) shows the simulation effect of the macroscopic melt pool-keyhole under macro-micro coupling. Thanks to the diffusion interface method proposed in the present invention, the keyhole interface is accurately tracked. Figure 7 (b) is a micro-scale dendrite growth simulation under macro-micro coupling, showing the dendrite growth process under the influence of macroscopic temperature field and flow field.

[0213] 4. Conclusion and application prospects

[0214] This embodiment shows that it is feasible to realize macro-micro integrated synchronous simulation based on the macro-micro bidirectional coupling method and system for laser welding proposed in the present invention. Based on more accurate numerical simulation results, it can provide strong theoretical support for the control of laser welding process parameters.

[0215] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. It can be understood by a person of ordinary skill in the art that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0216] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method, characterized in that: The following steps are involved: Step 1: Based on the principles of nonlinear thermodynamics and fluid dynamics, considering the influence of macroscopic temperature field and flow field on phase field, derive a mathematical model describing the evolution of microscopic phase field driven by macroscopic temperature field and flow field; The optimized microscopic phase field governing equation is as follows: In the formula, τ0 represents the relaxation time, k Cu represents the solute equilibrium distribution coefficient of copper element, u Cu represents the dimensionless concentration of copper element, M Cu represents the interpolation function related to the concentration of copper solute, D 1，Cu represents the diffusion coefficient of copper, D l，Li represents the diffusion coefficient of lithium, k Li represents the solute equilibrium distribution coefficient of lithium, u Li represents the dimensionless concentration of lithium, represents the anisotropy factor, φ represents the phase field, W0 represents the phase field interface thickness, and represents the interpolation function related to the double-well potential and volume free energy, λ represents the coupling coefficient related to the thermodynamic driving force, Δf(T, t) represents the spatiotemporal distribution data of the temperature field obtained by the macro model, f(u, t) represents the spatiotemporal distribution data of the flow field obtained by the macro model, and t represents time; Step 2: Based on the momentum conservation equation, considering the effect of fluid flow on solute transport, a mathematical model describing the evolution of macroscopic flow field and microscopic phase solute field is established; Step 3, extracting the spatiotemporal distribution data of key parameters such as macro-scale temperature field and flow field; Step 4, describing the free energy density function of the multiphase system in the welding process based on the conservative phase field and gradient flow theory; Step 5, based on Substitutional so lution model obtains the thermodynamic driving force of various phases at the microscopic scale in real time; Step 6, based on the macroscopic model and microscopic simulation established above, combined with the physical scale relationship of the macro-micro model time step, determine the real-time sequential solution method of the model, and construct a macro-micro bidirectional coupling model of laser welding considering macroscopic heat / flow-microscopic phase / quality.

2. The laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method according to claim 1, characterized in that: Based on the momentum conservation equation, the influence of fluid flow on solute transport is considered, and a mathematical model describing the evolution of macroscopic flow field and microscopic phase solute field is established: The optimized microscopic solute field evolution equation is as follows: In the formula, α m represents the material phase fraction, ρ m Indicates the material density, C l represents the concentration of liquid solute, C represents the total solute concentration, and D l represents the diffusion coefficient, represents the corrected liquid phase solute concentration, k v is the solute equilibrium distribution coefficient, C s represents the solid solute concentration, f l represents the liquid fraction, u represents the velocity, and f s represents the solid phase fraction; Considering the influence of microscopic phase field on macroscopic temperature field, the energy conservation equation is established under the microscopic phase field distribution-mushy zone solid phase fraction-solid-liquid phase change latent heat mapping model; The optimized macroscopic temperature field control equation is as follows: In the formula, ρ(f s , c, t) represents the spatial density under different solid fractions, solute concentrations and time steps, h represents the thermal enthalpy, λ T represents the thermal diffusion coefficient, T represents the temperature, and q laser represents the laser heat source, q vap represents evaporation heat dissipation, L represents latent heat of fusion, q rad Indicates radiative heat dissipation.

3. The laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method according to claim 1, characterized in that: Considering the influence of microscopic phase field and solute distribution on macroscopic flow field equation, the macroscopic momentum conservation equation driven by the evolution of solid fraction and solute distribution in mushy zone and thermophysical parameters in mushy zone is established. The optimized macroscopic momentum conservation equation is as follows: In the formula, p represents pressure, F s represents the surface tension, F b represents gravity, S represents the mushy zone constant, P recoil Indicates steam recoil pressure.

4. The laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method according to claim 1, characterized in that: The temporal and spatial distribution data of key parameters such as macro-scale temperature field and flow field are extracted: Based on the interlayer interpolation technology of generative adversarial neural network, the machine learning model is trained to generate double interpolation results from macroscopic heat / flow (mm / ms level) to microscopic temperature gradient-growth rate (um / us level); Realize the mapping interaction from macroscopic low spatiotemporal resolution to microscopic high spatiotemporal resolution asynchronous (ms~us) / heterogeneous (mm~um) data; Extract the spatiotemporal distribution data of key parameters such as phase field and solute field of microscopic nonlinear thermodynamic multiphase field model; Based on the representative volume unit to describe the macroscopic scale effect, the homogenization method is used to calculate the corresponding macroscopic thermophysical parameters; Realize the mapping interaction from small-scale micro data to large-scale macro data.

5. The laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method according to claim 1, characterized in that: The free energy density function of the multiphase system in the welding process is described based on the conservative phase field and gradient flow theory; Consider the nonlinear effects of phase field distribution and solute field distribution on macroscopic solid-liquid phase density, specific heat capacity and other thermophysical parameters; The phase field method and lattice Boltzmann method are used to construct a unified diffusion interface model of laser welding macroscopic lattice Boltzmann multiphase flow considering the microscopic phase / mass distribution. Among them, the phase field method is used to track the gas-liquid free surface, and the lattice Boltzmann method is used to solve the temperature field and flow field equations.

6. The laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method according to claim 1, characterized in that: The thermodynamic driving force of various phases at the microscopic scale is obtained in real time based on the Substitutional solution model: The lattice Boltzmann method is used to obtain the dissipative resistance of dendrite growth induced by macroscopic melt flow; Combined with the non-isothermal extrapolation method, a multiphase field model of microstructure evolution of laser welding with nonlinear thermodynamic coupling under the influence of macroscopic heat / flux distribution is constructed.

7. A laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling system implementing the laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method according to any one of claims 1 to 6, characterized in that: The laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling system comprises: The derivation module is used to consider the influence of the macroscopic temperature field and flow field on the phase field based on the principles of nonlinear thermodynamics and fluid dynamics, and to derive a mathematical model describing the evolution of the microscopic phase field driven by the macroscopic temperature field and flow field; Establish a module to consider the influence of fluid flow on solute transport based on the momentum conservation equation and establish a mathematical model to describe the evolution of macroscopic flow field and microscopic phase solute field; Extraction module, used to extract the spatiotemporal distribution data of key parameters such as macro-scale temperature field and flow field; Description module, used to describe the free energy density function of multiphase system in welding process based on conservative phase field and gradient flow theory; The acquisition module is used to obtain the thermodynamic driving force of various phases at the microscopic scale in real time based on the substitutional solution model; The construction module is used to determine the real-time sequential solution method of the model based on the macroscopic model and microscopic simulation established above, combined with the physical scale relationship of the macroscopic and microscopic model time steps, and to construct a macroscopic and microscopic bidirectional coupling model of laser welding that considers macroscopic heat / flow-microscopic phase / quality.

8. A computer device, characterized in that: The computer device includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method as claimed in any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the laser welding macro-micro multi-physics field cross-scale bidirectional coupling modeling method as described in any one of claims 1 to 6.

10. An information data processing terminal, characterized in that: The information data processing terminal is used to implement the laser welding macro-micro multi-physical field cross-scale bidirectional coupling modeling system as described in claim 7.

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