Finite element simulation method for enhancing metal and composite material interface bonding performance through micron protrusion structure

Abstract

The invention provides a finite element simulation method for enhancing metal and composite material interface bonding performance through a micron protrusion structure, and relates to the field of metal and composite material interface toughening, and the method specifically comprises the steps that the micron protrusion structure is constructed on the metal surface, and different metal layers and adhesive film materials are selected to form a complementary structure; aBAQUS software is used for establishing an initial finite element model and a simplified single-row micron convex interface unit strip model; according to the method, under the same constraint and boundary conditions, single-lap tensile shear simulation is carried out, the interface energy density, the equivalent elastic modulus and the interface shear strength are calculated, and finally, the three performance indexes are fused to generate a comprehensive evaluation index so as to evaluate and optimize the interface bonding performance. According to the method, the mechanical locking effect and the interface bonding strength of the interface are improved by introducing the micron bulge structure, in addition, the calculation process is simplified by establishing the equivalent single-row micron bulge interface unit strip model, and the simulation efficiency and precision are improved.

Description

Technical Field

[0001] The invention relates to the technical field of metal and composite material interface toughening, and in particular to a finite element simulation method for enhancing the interface bonding performance of metal and composite materials through a micron protrusion structure. Background Art

[0002] In modern engineering applications, the combination of metals and composites is the key to achieving high-performance structures. However, the traditional smooth interface design has significant deficiencies in interface bonding performance, especially under high loads and complex environments, where debonding and interface damage are prone to occur. Traditional methods mainly rely on chemical bonding and mechanical interlocking to improve interface bonding performance, but these methods often have limited effects in practical applications. Chemical bonding is susceptible to environmental influences, such as moisture and corrosion, while mechanical interlocking is prone to failure under high stress. In addition, existing interface enhancement technologies, such as surface treatment and coating, although they improve interface bonding performance to a certain extent, these technologies are usually complex, costly, and unstable in long-term use. Therefore, finding an efficient, stable and feasible interface enhancement method has become a research focus.

[0003] In recent years, the design of micron- and nanoscale interface structures has gradually attracted the attention of researchers. By introducing micron-scale protrusions or pits at the interface, the mechanical locking effect of the interface can be significantly improved, thereby enhancing the interface bonding performance. However, most of the existing studies focus on verification in laboratory environments, and lack a systematic finite element simulation method to guide the design and optimization of micron structures. At the same time, existing studies usually only focus on a single mechanical performance index, such as shear strength or fracture toughness, and fail to comprehensively evaluate the comprehensive interface performance under different material combinations. In addition, due to the complexity of micron structure design, how to achieve efficient and feasible structural design in actual engineering remains a huge challenge. Therefore, it is particularly necessary to develop a systematic finite element simulation method to comprehensively evaluate multiple performance indicators such as interface energy density, equivalent elastic modulus, and interface shear strength. Such a method can not only predict and optimize interface performance in the design stage, but also provide scientific basis and technical support for practical engineering applications.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute the prior art that is already known to one of ordinary skill in the art. Summary of the invention

[0005] The purpose of the present invention is to provide a finite element simulation method for enhancing the interface bonding performance between metal and composite materials by a micron protrusion structure, so as to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A finite element simulation method for enhancing the interface bonding performance between metal and composite materials by a micron protrusion structure, the specific steps comprising:

[0008] Step 1: construct a micron-protrusion structure on the metal surface, which is designed as circular protrusions and arranged in a linear array. The structure is characterized by three parameters: protrusion height, protrusion diameter, and protrusion spacing.

[0009] Step 2: Select different metal layer materials and film materials. In the single lap tensile shear model, the upper and lower sides are metal layers with micron-protruding structures, and the middle is a film layer with a pit structure complementary to the micron-protruding structure of the metal layer;

[0010] Step 3: Use ABAQUS software to establish an initial finite element model through the component and assembly module, which includes a metal layer with a micron-protrusion structure and a film layer with a complementary pit structure. Under the same constraints and boundary conditions, an equivalent single-row micron-protrusion interface unit strip model is established. The simplified model is the same as the actual model in terms of length scale, but the width scale is reduced to include only one row of micron-protrusion structure arrangement;

[0011] Step 4: Perform single lap tensile shear simulation based on ABAQUS, and calculate the interface energy density, equivalent elastic modulus and interface shear strength of different material combinations based on the collected parameters;

[0012] Step 5: Integrate the interface energy density, equivalent elastic modulus and interface shear strength to generate a comprehensive evaluation index. Evaluate the interface bonding performance of each material combination based on the comprehensive evaluation index, and use the comprehensive evaluation index to optimize the structural design and improve the interface bonding performance.

[0013] Furthermore, the micron protrusion structure is in the shape of a circular protrusion and is arranged in a linear array, and the protrusion structure is represented as: (R, A, B), where R is the protrusion height, A is the protrusion diameter, and B is the protrusion spacing.

[0014] Furthermore, the metal layer includes a titanium alloy plate, an aluminum alloy plate and a magnesium alloy plate, and the adhesive film layer includes an epoxy resin adhesive film, a polyetheretherketone adhesive film and a polystyrene adhesive film.

[0015] Furthermore, the initial finite element model established using ABAQUS software, compared to the size of an ordinary single lap tensile shear specimen, establishes an equivalent single-row micron-protrusion interface unit strip model under the same constraints and boundary conditions, which has the same length scale and only one row of micron-protrusion structures arranged on the width scale.

[0016] Furthermore, the initial model is established through the component and assembly module of ABAQUS, and the detailed modeling method is as follows:

[0017] When establishing a metal layer with a micron-protruding structure, first calculate the radius of curvature of the micron-protruding structure through its diameter and height, model a sphere with the radius of curvature, and based on the height of the micron-protruding structure, cut off the excess part of the sphere to obtain the required micron-protruding structure, and then establish a minimum rectangular component with the thickness of the metal layer according to the spacing and diameter parameters of the micron-protruding structure, and assemble and merge it with the established micron-protruding structure model to obtain the minimum unit body of the micron-protruding structure metal layer joint, and use the linear array function to obtain the required joint part model of the metal layer with the micron-protruding structure array, and then use the stretching function of the component module to obtain the metal layer model of the single lap tensile shear specimen;

[0018] When establishing a film layer with a micron-pit structure complementary to the micron-protrusion structure on the metal layer, based on the shear component function, the micron-protrusion structure established above is used to cut out the pit structure on the minimum rectangular component with the thickness of the film layer, so as to obtain a unit body with a micron-pit structure, and the required film layer model with a micron-pit structure array is obtained through the linear array function.

[0019] Furthermore, the specific logic for calculating the interface energy density is:

[0020] A geometric model was established in ABAQUS. The model was a metal layer with a micron-protrusion structure and a film layer with a complementary pit structure. The elastic modulus and Poisson's ratio of the metal layer and the film layer were defined. A tensile load was applied to simulate the interface fracture process. By extracting simulation data, the energy absorbed by the interface during the fracture process, i.e., the interface fracture energy, was calculated, denoted as W. interface , and measure the actual area of ​​the interface fracture in the model, that is, the interfacial area, recorded as S, and calculate the interface energy density according to the following formula:

[0021]

[0022] Where γ is the interface energy density, W interface represents the interfacial fracture energy, S is the interfacial area;

[0023] The specific logic for calculating the equivalent elastic modulus is:

[0024] A geometric model was established in ABAQUS. The model was a metal layer with a micron-protrusion structure and a film layer with a complementary pit structure. The elastic modulus and Poisson's ratio of the metal layer and the film layer were defined. A tensile load was applied to the model to simulate the stress-strain relationship in different directions. The simulation data was extracted and the equivalent elastic modulus was calculated:

[0025]

[0026] Among them, E eff is the equivalent elastic modulus, Δσ is the stress change, and Δ∈ is the strain change;

[0027] The specific logic for calculating the interface shear strength is:

[0028] A geometric model was established in ABAQUS. The model was a metal layer with a micron-protrusion structure and a film layer with a complementary pit structure. The elastic modulus and Poisson's ratio of the metal layer and the film layer were defined. A tensile load was applied to the metal layer. The shear behavior of the film layer at the interface was simulated. The stress-strain relationship in different directions was simulated. The simulation data was extracted. The interface shear strength was calculated according to the following formula:

[0029]

[0030] Among them, τ interface is the interface shear strength, F max is the maximum shear force recorded during the simulation, S interface It is the actual area that is subjected to shear force at the interface between the metal layer and the film layer of the composite material.

[0031] Furthermore, the formula for generating the comprehensive evaluation index is as follows:

[0032] IBPI=α*lnγ+β*lnE eff +μ*lnτ interface +C

[0033] Among them, IBPI is the comprehensive evaluation index, γ is the interface energy density, α is the proportional coefficient preset by lnγ, and E eff is the equivalent elastic modulus, β is lnE eff Preset scaling factor, τ interface is the interface shear strength, μ is lnτ interface The preset proportional coefficient, and μ>β>γ>0, C is the constant correction index;

[0034] The interface bonding performance of each material combination was evaluated based on the comparison of the obtained comprehensive evaluation index IBPI for each material combination.

[0035] Furthermore, the single lap tensile shear finite element model based on ABAQUS is established by the following method:

[0036] Set material property parameters. The material parameters of the metal layer and the film layer are determined according to the supplier and literature, and the interface is created. The metal layer is a homogeneous solid section, and the film layer is a viscous section and uses the traction separation criterion;

[0037] The metal layer, the adhesive film, and the metal layer are assembled from bottom to top in sequence, and the dynamic display analysis method is used to perform finite element simulation calculations, and binding constraints are given between the connection interfaces of the metal layer and the adhesive film layer;

[0038] Couple the surfaces at the ends of the two metal layers of the single lap tensile shear specimen with one point on the surface to give them displacement constraints and check the support reaction force. Give displacement constraints at the two coupling points. One coupling point restricts all its degrees of freedom, and the other coupling point restricts the translational degrees of freedom and all rotational degrees of freedom in other directions except for the displacement in the length direction.

[0039] The metal layer adopts C3D8R three-dimensional stress unit, and the film layer adopts COH3D8 three-dimensional viscosity unit. The grid of the film layer needs to be set to have its plying direction the same as the normal direction of the interface between the metal layer and the film layer.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention successfully solves the problem that the traditional smooth interface is easy to debond and damage under high load by constructing a micron-protrusion structure on the metal surface and combining it with ABAQUS finite element software for system simulation. Specifically, the introduction of the micron-protrusion structure significantly improves the mechanical locking effect and interface bonding strength of the interface. The experimental results show that this structure can significantly improve the interface shear strength, equivalent elastic modulus and interface energy density. In addition, by establishing an equivalent single-row micron-protrusion interface unit bar model, the calculation process is simplified and the simulation efficiency and accuracy are improved. The present invention also integrates three key mechanical performance indicators to generate a comprehensive evaluation index, which provides a scientific evaluation basis for material combination and structural design. Finally, the present invention not only significantly improves the interface bonding performance, but also provides an efficient and feasible optimization method for the design of metal and composite interface, which has important engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the overall method flow of the present invention;

[0043] Figure 2 It is a schematic diagram of the shape of the micron protrusion structure;

[0044] Figure 3 Schematic diagram of the metal layer structure of the constructed micron-raised structure;

[0045] Figure 4 It is a schematic diagram of the structure of a single lap tensile shear test specimen, wherein 1 is a metal layer, 2 is an adhesive film layer, and 3 is a metal layer. DETAILED DESCRIPTION

[0046] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0047] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0048] Example:

[0049] See also Figure 1-4 , the present invention provides a technical solution:

[0050] A finite element simulation method for enhancing the interface bonding performance between metal and composite materials by a micron protrusion structure, the specific steps comprising:

[0051] Step 1: construct a micron-protrusion structure on the metal surface, which is designed as circular protrusions and arranged in a linear array. The structure is characterized by three parameters: protrusion height, protrusion diameter, and protrusion spacing.

[0052] In this embodiment, the micron protrusion structure is in the shape of a circular protrusion and is arranged in a linear array, and the protrusion structure is represented as: (R, A, B), where R is the protrusion height, A is the protrusion diameter, and B is the protrusion spacing;

[0053] The micron-protrusion structure can significantly increase the mechanical locking effect of the interface, thereby improving the interface bonding strength. The circular protrusion structure can optimize the stress distribution at the interface, reduce stress concentration, and reduce the risk of interface damage. By adjusting the three parameters of protrusion height, protrusion diameter, and protrusion spacing, the interface bonding performance can be finely controlled to meet the needs of different application scenarios.

[0054] Traditional smooth interfaces are prone to debonding and interface damage under high loads, while micron-raised structures can significantly improve interface strength and reduce the risk of damage. Traditional chemical bonding and surface treatment methods are easily affected by the environment, while micron-raised structures have higher stability and can maintain good interface bonding performance under different environmental conditions. By adjusting the micron-structure parameters, the design can be optimized for different materials and application requirements, while the traditional methods have poor adjustability and cannot achieve fine control. The design and construction of the micron-raised structure provides an accurate and controllable interface model for subsequent finite element simulations, ensuring the accuracy and feasibility of the simulation results. By increasing the mechanical locking effect and optimizing the stress distribution, the bonding performance of the interface is significantly improved, laying the foundation for performance evaluation and optimization in subsequent steps.

[0055] Step 2: Select different metal layer materials and film materials. In the single lap tensile shear model, the upper and lower sides are metal layers with micron-protruding structures, and the middle is a film layer with a pit structure complementary to the micron-protruding structure of the metal layer;

[0056] In this embodiment, the metal layer includes a titanium alloy plate, an aluminum alloy plate and a magnesium alloy plate, and the adhesive film layer includes an epoxy resin adhesive film, a polyetheretherketone adhesive film and a polystyrene adhesive film. The complementary pit structure allows the adhesive film material to be tightly combined with the micron protrusion structure of the metal layer, further improving the mechanical locking effect of the interface and enhancing the bonding strength. The combination of different materials can optimize the physical and chemical properties at the interface and improve the compatibility and stability of the overall structure.

[0057] Step 3: Using ABAQUS software, an initial finite element model is established through the component and assembly modules, which includes a metal layer with a micron-protrusion structure and a film layer with a complementary pit structure; under the same constraints and boundary conditions, an equivalent single-row micron-protrusion interface unit strip model is established. The simplified model is the same as the actual model in length scale, but the width scale is reduced to only include one row of micron-protrusion structure arrangement;

[0058] In this embodiment, the initial finite element model established using ABAQUS software, compared to the size of an ordinary single lap tensile shear specimen, establishes an equivalent single-row micron-protrusion interface unit strip model under the same constraints and boundary conditions, which has the same length scale and only one row of micron-protrusion structures arranged in the width scale.

[0059] The initial model is established through the component and assembly module of ABAQUS, and the detailed modeling method is as follows:

[0060] When establishing a metal layer with a micron-protruding structure, first calculate the radius of curvature of the micron-protruding structure through its diameter and height, model a sphere with the radius of curvature, and based on the height of the micron-protruding structure, cut off the excess part of the sphere to obtain the required micron-protruding structure, and then establish a minimum rectangular component with the thickness of the metal layer according to the spacing and diameter parameters of the micron-protruding structure, and assemble and merge it with the established micron-protruding structure model to obtain the minimum unit body of the micron-protruding structure metal layer joint, and use the linear array function to obtain the required joint part model of the metal layer with the micron-protruding structure array, and then use the stretching function of the component module to obtain the metal layer model of the single lap tensile shear specimen;

[0061] When establishing a film layer with a micron-pit structure complementary to the micron-protrusion structure on the metal layer, based on the shear component function, the micron-protrusion structure established above is used to cut out the pit structure on the minimum rectangular component with the thickness of the film layer, so as to obtain a unit body with a micron-pit structure, and the required film layer model with a micron-pit structure array is obtained through the linear array function.

[0062] Through ABAQUS software, a detailed model of the metal layer with micron-protrusion structure and the film layer with complementary pit structure can be accurately established to ensure the accuracy of the simulation results. By simplifying the establishment of the model, the width is reduced to only one column of micron-protrusion structure arrangement, which significantly reduces the calculation complexity and improves the calculation efficiency. Modeling is performed under the same constraints and boundary conditions to ensure the comparability and consistency of the results.

[0063] Step 4: Perform single lap tensile shear simulation based on ABAQUS, and calculate the interface energy density, equivalent elastic modulus and interface shear strength of different material combinations based on the collected parameters;

[0064] In this embodiment, the specific logic for calculating the interface energy density is:

[0065] A geometric model was established in ABAQUS. The model was a metal layer with a micron-protrusion structure and a film layer with a complementary pit structure. The elastic modulus and Poisson's ratio of the metal layer and the film layer were defined. A tensile load was applied to simulate the interface fracture process. By extracting simulation data, the energy absorbed by the interface during the fracture process, i.e., the interface fracture energy, was calculated, denoted as W. interface , and measure the actual area of ​​the interface fracture in the model, that is, the interfacial area, recorded as S, and calculate the interface energy density according to the following formula:

[0066]

[0067] Where γ is the interface energy density, W interface represents the interfacial fracture energy, S is the interfacial area;

[0068] The specific logic for calculating the equivalent elastic modulus is:

[0069] A geometric model was established in ABAQUS. The model was a metal layer with a micron-protrusion structure and a film layer with a complementary pit structure. The elastic modulus and Poisson's ratio of the metal layer and the film layer were defined. A tensile load was applied to the model to simulate the stress-strain relationship in different directions. The simulation data was extracted and the equivalent elastic modulus was calculated:

[0070]

[0071] Among them, E eff is the equivalent elastic modulus, Δσ is the stress change, and Δ∈ is the strain change;

[0072] The specific logic for calculating the interface shear strength is:

[0073] A geometric model was established in ABAQUS. The model was a metal layer with a micron-protrusion structure and a film layer with a complementary pit structure. The elastic modulus and Poisson's ratio of the metal layer and the film layer were defined. A tensile load was applied to the metal layer. The shear behavior of the film layer at the interface was simulated. The stress-strain relationship in different directions was simulated. The simulation data was extracted. The interface shear strength was calculated according to the following formula:

[0074]

[0075] Among them, τ interface is the interface shear strength, F max is the maximum shear force recorded during the simulation, S interface It is the actual area at the interface between the metal layer and the film layer of the composite material that is subjected to shear force.

[0076] The single lap tensile shear finite element model based on ABAQUS is established by the following method:

[0077] Set material property parameters. The material parameters of the metal layer and the film layer are determined according to the supplier and literature, and the interface is created. The metal layer is a homogeneous solid section, and the film layer is a viscous section and uses the traction separation criterion;

[0078] The metal layer, the adhesive film, and the metal layer are assembled from bottom to top in sequence, and the dynamic display analysis method is used to perform finite element simulation calculations, and binding constraints are given between the connection interfaces of the metal layer and the adhesive film layer;

[0079] Couple the surfaces at the ends of the two metal layers of the single lap tensile shear specimen with one point on the surface to give them displacement constraints and check the support reaction force. Give displacement constraints at the two coupling points. One coupling point restricts all its degrees of freedom, and the other coupling point restricts the translational degrees of freedom and all rotational degrees of freedom in other directions except for the displacement in the length direction.

[0080] The metal layer adopts C3D8R three-dimensional stress unit, and the film layer adopts COH3D8 three-dimensional viscosity unit. The grid of the film layer needs to be set to have its plying direction the same as the normal direction of the interface between the metal layer and the film layer.

[0081] Step 5: Integrate the interface energy density, equivalent elastic modulus and interface shear strength to generate a comprehensive evaluation index, evaluate the interface bonding performance of each material combination based on the comprehensive evaluation index, and use the comprehensive evaluation index to optimize the structural design and improve the interface bonding performance;

[0082] In this embodiment, the formula for generating the comprehensive evaluation index is as follows:

[0083] IBPI=α*lnγ+β*lnE eff +μ*lnτ interface +C

[0084] Among them, IBPI is the comprehensive evaluation index, γ is the interface energy density, α is the proportional coefficient preset by lnγ, and E eff is the equivalent elastic modulus, β is lnE eff The preset scaling factor, v interface is the interface shear strength, μ is lnτ interface The preset proportionality coefficient is μ>β>γ>0, because the structural material must be able to withstand and transmit large shear forces; C is a constant correction index; high interface energy density means that the interface can absorb more energy before rupture, which is beneficial to resist dynamic loads. Therefore, when the interface energy density γ increases, the comprehensive evaluation index IBPI increases; high equivalent elastic modulus means that the interface area exhibits higher stiffness when load is applied, which is beneficial to maintain the stability of the interface under high load conditions and reduce the deformation of the interface. Therefore, when the equivalent elastic modulus E eff When the interface shear strength τ increases, the comprehensive evaluation index IBPI increases; high interface shear strength indicates that the interface has a higher bearing capacity and stronger interface bonding performance under shear load, so when the interface shear strength τ interface When it increases, the comprehensive evaluation index IBPI increases; that is, γ, E eff , τ interface It is positively correlated with the comprehensive evaluation index IBPI.

[0085] The interface bonding performance of each material combination was evaluated based on the comparison of the obtained comprehensive evaluation index IBPI for each material combination.

[0086] By integrating multiple key performance indicators, the generated comprehensive evaluation index can comprehensively reflect the interface bonding performance. The comprehensive evaluation index provides a quantitative method to more accurately compare and evaluate the performance of different material combinations. Traditional methods may only focus on a single performance indicator, while the comprehensive evaluation index integrates multiple key performance indicators, providing a more comprehensive and scientific evaluation result, and providing a unified evaluation standard to facilitate the comparison and selection between different material combinations and design schemes. Traditional methods may find it difficult to achieve such comparability.

[0087] The specific implementation of the present invention is further described below in conjunction with the drawings and examples.

[0088] like Figure 1-4 As shown;

[0089] The present invention provides a method for enhancing interface bonding performance by constructing a micron protrusion structure on a metal surface, and simulates the interface enhancement effect through a single lap tensile shear model based on ABAQUS, wherein the model includes a metal layer and an adhesive film layer. Figure 3 Schematic diagram of the structure of the single lap tensile shear test specimen, 1 and 3 are metal layers, and 2 is the film layer.

[0090] In the present invention, unless otherwise specified, the materials used for simulation are all commercially available products well known to those skilled in the art.

[0091] In the present invention, the metal layer preferably includes a titanium alloy plate, an aluminum alloy plate or a magnesium alloy plate, and the thickness of the metal layer is preferably set to 1.6 mm. The film layer includes an epoxy resin film, a polyetheretherketone film and polystyrene, and the thickness of the film is preferably set to 0.1-0.3 mm.

[0092] The present invention also provides a modeling method for the above solution, comprising the following steps:

[0093] The component module and the assembly module are used to model the metal layer and the film layer respectively. The metal layer and the film layer are three-dimensional deformable solid units.

[0094] Set material property parameters. The material parameters of the metal layer and the film layer are determined by the supplier. Create cross sections for them. The metal layer is a homogeneous solid cross section, and the film is a viscous cross section.

[0095] Assemble in order from bottom to top according to the metal layer, film layer, and metal layer;

[0096] The dynamic display analysis method is adopted. After the initial analysis step, an analysis step 1 is set to simulate the stretching process of the single lap tensile shear model, and mass scaling is turned on to speed up the calculation efficiency. The mass scaling factor is set to 5. According to the results, the ratio of kinetic internal energy is less than 5%, ensuring that the analysis process meets the quasi-static response.

[0097] Because there is no relative sliding between the metal layer and the film layer, a binding constraint is given to the contact surface;

[0098] To simulate the single lap tensile shear test, the rotational freedom and translational freedom of the metal layer at one end are restricted to 0 in all analysis steps, making it completely fixed. The metal layer at the other end controls the tensile length of the test through the translational freedom in analysis step 1, and makes the tensile direction along the length direction, while limiting its rotational freedom to 0.

[0099] The metal layer uses C3D8R three-dimensional stress unit, and the film layer uses COH3D8 three-dimensional viscosity unit. The mesh of the film layer needs to be set to have the same ply direction as the normal direction of the interface between the metal layer and the film layer. The mesh unit corresponds to the section type used, and the advanced algorithm is selected to refine the mesh at the contact surface between the metal layer and the film layer, and coarsen the edge mesh to reduce the number of meshes and increase the solution efficiency.

[0100] The following will take a single-lap stretching model of a micron-protruding structure with a diameter of A=400μm, a spacing of B=400μm, and a height of R=50μm as an example to clearly and completely describe the technical solution of the present invention. The following implementation is only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the scope of protection of the present invention.

[0101] Embodiment 1:

[0102] Step 1: When establishing a metal layer with a micron-protruding structure, first calculate the radius of curvature of the micron-protruding structure to be 425μm through the diameter and height of the micron-protruding structure, establish a sphere with a radius of 425μm, and use the shear component function to shear the sphere so that a 50μm end of the sphere remains, which is the required micron-protruding structure. Then establish a unit cuboid with a size of 800μm*800μm*1600μm, place the established micron-protruding structure at the center of its surface, and combine the two to obtain a new component through model assembly. Use the linear array function to obtain a 1×15 micron-protruding array structure of the new component, which is the joint part of the metal layer, and then use the stretching function of the component module to obtain the metal layer of the single lap tensile shear specimen.

[0103] Step 2: When establishing a film layer with a micron-pit structure that is complementary to the micron-protrusion structure on the metal layer, a unit rectangular block with a size of 800μm*800μm*200μm is established. Based on the shear component function, the pit structure is cut out on the rectangular block using the micron-protrusion structure established above to obtain a unit body with a micron-pit structure, and a 1×15 micron-pit array structure film layer is obtained through the linear array function.

[0104] Step 3: Assemble the aluminum alloy metal layer 1, the epoxy resin film, and the aluminum alloy metal layer 2 from bottom to top.

[0105] Step 4: Using the dynamic display analysis method, set an analysis step 1 after the initial analysis step to simulate the stretching process of the single lap tensile shear model, and turn on mass scaling to speed up the calculation efficiency. The mass scaling factor is set to 5. According to the results, the ratio of kinetic internal energy is less than 5%, which can ensure that the analysis process meets the quasi-static response.

[0106] Step 5: Because there is no relative sliding between the aluminum alloy metal layer and the epoxy resin film layer at the contact surface, a binding constraint is given to the contact surface;

[0107] Step 6: To simulate the single lap tensile shear test, the rotational and translational degrees of freedom at the end of the aluminum alloy metal layer 1 are restricted to 0 in all analysis steps to make it completely fixed. The end of the aluminum alloy metal layer 2 is coupled to the reference point, and a displacement load of 20 mm is applied in the length direction of the specimen through the reference point.

[0108] Step 7: Mesh the components. The metal layer uses C3D8R three-dimensional stress units, and the film layer uses COH3D8 three-dimensional viscosity units. The mesh of the film layer needs to be set to have the same ply direction as the normal direction of the interface between the metal layer and the film layer. The mesh unit corresponds to the section type used, and the advanced algorithm is selected. A fine mesh is required at the contact surface between the metal layer and the film layer, so the mesh seed size is 0.2mm. The end of the metal layer does not involve complex stress changes, so only a coarse mesh is required, and the mesh seed size is 0.4mm, in order to reduce the number of meshes and increase the solution efficiency.

[0109] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

[0110] The specific values ​​of α, β and μ in the formula are generally determined by technical personnel in this field according to actual conditions. The technical personnel in this field collect multiple groups of sample data, and set corresponding preset proportional coefficients for each group of sample data. The preset proportional coefficients and the collected sample data are substituted into the formula. Through repeated experiments and parameter adjustments, the accuracy of the model output and the rationality of the results are observed, and these factor coefficients are gradually adjusted. The performance and effect of the model under different parameter settings are compared to find the optimal coefficient combination, and the calculated factor coefficients are screened and averaged to obtain the values ​​of α, β and μ.

[0111] In addition, the size of the preset factor coefficient is to quantify each parameter to obtain a specific value. In order to facilitate subsequent comparison, the size of the coefficient depends on the amount of sample data and the preset proportional coefficient initially set by technical personnel in this field for each set of sample data. It is not unique as long as it does not affect the proportional relationship between the parameter and the quantized value.

[0112] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0113] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product. Those skilled in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software methods depends on the specific application and design constraints of the technical solution.

[0114] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0115] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A finite element simulation method for enhancing the interface bonding performance between metal and composite materials by micron protrusion structure, characterized in that: The specific steps include: Step 1: construct a micron protrusion structure on the metal surface, which is designed as circular protrusions and arranged in a linear array. The structure is characterized by three parameters: protrusion height, protrusion diameter, and protrusion spacing. Step 2: Select different metal layer materials and film materials. In the single lap tensile shear model, the upper and lower sides are metal layers with micron-protruding structures, and the middle is a film layer with a pit structure complementary to the micron-protruding structure of the metal layer; Step 3: Use ABAQUS software to establish an initial finite element model through the component and assembly module, which includes a metal layer with a micron-protrusion structure and a film layer with a complementary pit structure. Under the same constraints and boundary conditions, an equivalent single-row micron-protrusion interface unit strip model is established. The simplified model is the same as the actual model in terms of length scale, but the width scale is reduced to include only one row of micron-protrusion structure arrangement; Step 4: Perform single lap tensile shear simulation based on ABAQUS, and calculate the interface energy density, equivalent elastic modulus and interface shear strength of different material combinations based on the collected parameters; Step 5: Integrate the interface energy density, equivalent elastic modulus and interface shear strength to generate a comprehensive evaluation index. Evaluate the interface bonding performance of each material combination based on the comprehensive evaluation index, and use the comprehensive evaluation index to optimize the structural design and improve the interface bonding performance.

2. The finite element simulation method for enhancing the interface bonding performance between metal and composite materials by using a micron protrusion structure according to claim 1, characterized in that: The micron protrusion structure is in the shape of a circular protrusion and is arranged in a linear array, and the protrusion structure is represented as: (R, A, B), where R is the protrusion height, A is the protrusion diameter, and B is the protrusion spacing.

3. The finite element simulation method for enhancing the interface bonding performance between metal and composite material by using a micron protrusion structure according to claim 1, characterized in that: The metal layer includes a titanium alloy plate, an aluminum alloy plate and a magnesium alloy plate, and the adhesive film layer includes an epoxy resin adhesive film, a polyetheretherketone adhesive film and a polystyrene adhesive film.

4. The finite element simulation method for enhancing the interface bonding performance between metal and composite materials by using a micron protrusion structure according to claim 1, characterized in that: The initial finite element model established using ABAQUS software, compared to the size of an ordinary single lap tensile shear specimen, establishes an equivalent single-row micron-protrusion interface unit strip model under the same constraints and boundary conditions, which has the same length scale and only one row of micron-protrusion structures arranged on the width scale.

5. The finite element simulation method for enhancing the interface bonding performance between metal and composite material by using a micron protrusion structure according to claim 4, characterized in that: The initial model is established through the component and assembly module of ABAQUS, and the detailed modeling method is as follows: When establishing a metal layer with a micron-protruding structure, first calculate the radius of curvature of the micron-protruding structure through its diameter and height, model a sphere with the radius of curvature, and based on the height of the micron-protruding structure, cut off the excess part of the sphere to obtain the required micron-protruding structure, and then establish a minimum rectangular component with the thickness of the metal layer according to the spacing and diameter parameters of the micron-protruding structure, and assemble and merge it with the established micron-protruding structure model to obtain the minimum unit body of the micron-protruding structure metal layer joint, and use the linear array function to obtain the required joint part model of the metal layer with the micron-protruding structure array, and then use the stretching function of the component module to obtain the metal layer model of the single lap tensile shear specimen; When establishing a film layer with a micron-pit structure complementary to the micron-protrusion structure on the metal layer, based on the shear component function, the micron-protrusion structure established above is used to cut out the pit structure on the minimum rectangular component with the thickness of the film layer, so as to obtain a unit body with a micron-pit structure, and the required film layer model with a micron-pit structure array is obtained through the linear array function.

6. The finite element simulation method for enhancing the interface bonding performance between metal and composite materials by using a micron protrusion structure according to claim 1, characterized in that: The specific logic for calculating the interface energy density is: A geometric model was established in ABAQUS. The model was a metal layer with a micron-protrusion structure and a film layer with a complementary pit structure. The elastic modulus and Poisson's ratio of the metal layer and the film layer were defined. A tensile load was applied to simulate the interface fracture process. By extracting simulation data, the energy absorbed by the interface during the fracture process, i.e., the interface fracture energy, was calculated, denoted as W. interface , and measure the actual area of ​​the interface fracture in the model, that is, the interfacial area, recorded as S, and calculate the interface energy density according to the following formula: Where γ is the interface energy density, W interface represents the interfacial fracture energy, S is the interfacial area; The specific logic for calculating the equivalent elastic modulus is: A geometric model was established in ABAQUS. The model was a metal layer with a micron-protrusion structure and a film layer with a complementary pit structure. The elastic modulus and Poisson's ratio of the metal layer and the film layer were defined. A tensile load was applied to the model to simulate the stress-strain relationship in different directions. The simulation data was extracted and the equivalent elastic modulus was calculated: Among them, E eff is the equivalent elastic modulus, Δσ is the stress change, and Δ∈ is the strain change; The specific logic for calculating the interface shear strength is: A geometric model was established in ABAQUS. The model was a metal layer with a micron-protrusion structure and a film layer with a complementary pit structure. The elastic modulus and Poisson's ratio of the metal layer and the film layer were defined. A tensile load was applied to the metal layer. The shear behavior of the film layer at the interface was simulated. The stress-strain relationship in different directions was simulated. The simulation data was extracted. The interface shear strength was calculated according to the following formula: Among them, τ interface is the interface shear strength, F max is the maximum shear force recorded during the simulation, S interface It is the actual area at the interface between the metal layer and the film layer of the composite material that is subjected to shear force.

7. The finite element simulation method for enhancing the interface bonding performance between metal and composite material by using a micron protrusion structure according to claim 6, characterized in that: The formula for generating the comprehensive evaluation index is as follows: IBPI=α*lnβ+β*ln E eff +μ*lnτ interface +C Among them, IBPI is the comprehensive evaluation index, γ is the interface energy density, α is the proportional coefficient preset by lnγ, and E eff is the equivalent elastic modulus, β is ln E eff Preset scaling factor, τ interface is the interface shear strength, μ is lnτ interface The preset proportional coefficient, and μ>β>γ>0, C is the constant correction index; The interface bonding performance of each material combination was evaluated based on the comparison of the obtained comprehensive evaluation index IBPI for each material combination.

8. The finite element simulation method for enhancing the interface bonding performance between metal and composite materials by using a micron protrusion structure according to claim 1, characterized in that: The single lap tensile shear finite element model based on ABAQUS is established by the following method: Set material property parameters. The material parameters of the metal layer and the film layer are determined according to the supplier and literature, and the interface is created. The metal layer is a homogeneous solid section, and the film layer is a viscous section and uses the traction separation criterion; The metal layer, the adhesive film, and the metal layer are assembled from bottom to top in sequence, and the dynamic display analysis method is used to perform finite element simulation calculations, and binding constraints are given between the connection interfaces of the metal layer and the adhesive film layer; Couple the surfaces at the ends of the two metal layers of the single lap tensile shear specimen with one point on the surface to give them displacement constraints and check the support reaction force. Give displacement constraints at the two coupling points. One coupling point restricts all its degrees of freedom, and the other coupling point restricts the translational degrees of freedom and all rotational degrees of freedom in other directions except for the displacement in the length direction. The metal layer adopts C3D8R three-dimensional stress unit, and the film layer adopts COH3D8 three-dimensional viscosity unit. The grid of the film layer needs to be set to have its plying direction the same as the normal direction of the interface between the metal layer and the film layer.

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