Large-tow carbon fiber surface modification method, device, equipment, medium and product

Abstract

The invention provides a large-tow carbon fiber surface modification method, device, equipment, medium and product, and the method comprises the following steps: establishing a graphene oxide-sizing agent-modifier-matrix resin microscopic model, and determining a target modifier with better interface performance under the microscopic scale; obtaining a mechanical property test result of the composite material sample modified by the target modifier under a macroscale; establishing a composite material mesoscopic model, applying mechanical property test conditions, and adjusting interface unit material parameters until the interface unit material parameters correspond to the interface properties under the microscale, so as to obtain a mechanical property simulation result under the microscale; and comparing a mechanical property test result under the macro scale with a mechanical property simulation result under the micro scale, and verifying the accuracy of regulating and controlling the modified interface performance of the large-tow carbon fiber composite material by the micro-scale simulation. The large-tow carbon fiber surface modification research method based on microcosmic-microcosmic-macroscopic multi-scale simulation is achieved, logic is clear, the steps are simple, and operation is easy.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material modification interface research, and in particular to a large-tow carbon fiber surface modification method, device, equipment, medium and product. Background Art

[0002] At present, large-tow carbon fiber is mainly used in the industrial field, especially in wind turbine blades and pressure vessels (on-board hydrogen storage cylinders). The large-scale and lightweight development of wind turbines has promoted the demand for carbon fiber and its composite materials. The relevant research on large-tow carbon fiber started late, and there is relatively little research on the interface properties of large-tow carbon fiber composites. In the production process of carbon fiber, sizing treatment is an indispensable link. The sizing agent directly acts on the surface of carbon fiber and can change its key properties such as surface state, surface functional groups and surface wettability. The selection of appropriate sizing agent can significantly improve the surface activity of carbon fiber, enhance its affinity and wettability with the resin matrix, and solve the problem of hair fibers that may occur during processing, thereby effectively improving the overall quality and performance of carbon fiber.

[0003] In actual production, in order to ensure that the fibers will not disperse, carbon fibers need to be coated with sizing agents before leaving the factory. Currently, the interface properties can be adjusted by replacing the sizing agent. This method requires that the existing sizing agent on the surface be removed first, otherwise the interface properties of the carbon fiber surface may be greatly reduced. However, this method is complicated to operate and may damage the original properties of the carbon fiber. There may also be problems with the original sizing agent not being removed cleanly, thus affecting the interface properties. It is not practical in actual production applications.

[0004] Therefore, how to modify the surface of large-tow carbon fibers and achieve the regulation of the interfacial properties of large-tow carbon fiber composites, thereby improving the practicality and ease of operation of interfacial properties regulation of large-tow carbon fiber composites in actual production applications, is a problem that needs to be solved urgently. Summary of the invention

[0005] The present invention provides a large-tow carbon fiber surface modification method, device, equipment, medium and product, which are used to solve the problem that the surface modification of large-tow carbon fibers in the prior art is difficult to control, and realize the control of the interface performance of large-tow carbon fiber composite materials based on micro-meso-macro multi-scale simulation.

[0006] The present invention provides a large-tow carbon fiber surface modification method, comprising: Establish a composite microscopic model of graphene oxide-sizing agent-modifier-matrix resin on the surface of large-tow carbon fiber, and calculate the interface properties of the composite microscopic model with different modifiers at the microscopic scale; Determine a target modifier used in a composite material micromodel whose interface performance meets preset requirements, and obtain mechanical property test results of a composite material sample modified by the target modifier at a macroscopic scale; Establishing a composite material mesoscopic model, applying mechanical property test conditions to the composite material mesoscopic model, adjusting interface unit material parameters until the interface unit material parameters correspond to the interface properties of the composite material microscopic model using the target modifier at the microscale, and obtaining mechanical property simulation results of the composite material mesoscopic model at the mesoscale; The mechanical property test results at the macro scale are compared with the mechanical property simulation results at the micro scale to verify the accuracy of the micro simulation in regulating the modified interface properties of large-tow carbon fiber composites.

[0007] According to a large tow carbon fiber surface modification method provided by the present invention, the graphene oxide-sizing agent-modifier-matrix resin composite micromodel of the large tow carbon fiber surface is established, and the interface performance of the composite micromodel using different modifiers at the microscale is calculated, including: The graphene unit cell is periodically expanded, and oxygen-containing functional groups are added to the surface of the graphene based on a predetermined carbon-oxygen ratio to obtain graphene oxide; Establishing a cross-linked structure of the sizing agent, and allowing the sizing agent to be tightly combined with the surface of the graphene oxide through relaxation; Establishing a thin layer structure of modifier molecules and placing it above the sizing agent, and allowing the thin layer of modifier molecules to fully react with the sizing agent through relaxation; Establishing a cross-linked structure of a base resin placed above the modifier, and allowing the base resin to fully react with a thin layer of modifier molecules through relaxation; The interface properties at the microscopic scale are calculated based on the established microscopic model of composite materials using different modifiers.

[0008] According to a large-tow carbon fiber surface modification method provided by the present invention, the intermolecular spacing in the modifier molecular thin layer structure is within a preset spacing range, the difference ratio of the number of molecules in different modifier molecular thin layers is less than or equal to a preset ratio; the distance between the established new molecular layer and the original structure is greater than or equal to the preset distance.

[0009] According to a large-tow carbon fiber surface modification method provided by the present invention, the interface performance at the microscopic scale is characterized by the unit atomic binding energy and stress-strain curve of the interface; The unit atomic binding energy of the interface is calculated based on the binding energy of the interface of the composite material microscopic model output by molecular dynamics software and the number of atoms in the modifier molecular thin layer; Wherein, the stress-strain curve is obtained by drawing: Calculating a strain value based on a displacement value of the composite material micromodel along a loading direction and a length of the composite material micromodel in the loading direction; Calculating stress values ​​based on the stress values ​​output by the molecular dynamics software and the lengths of the composite material micromodel along the horizontal axis, the longitudinal axis and the vertical axis; Based on the strain value and the stress value, the stress-strain curve is drawn.

[0010] According to a large-tow carbon fiber surface modification method provided by the present invention, the mechanical property test results at a macro scale include tensile strength, bending strength and shear strength; the mechanical property test results at a macro scale of the composite material sample modified by the target modifier are obtained, including: Calculating the tensile strength based on the maximum load of the composite material sample modified by the target modifier when the sample is damaged during a tensile test, and the width and thickness of the composite material sample; Calculating the bending strength based on the maximum load, span, width and thickness of the composite material sample when the composite material sample is damaged during the bending test; The shear strength is calculated based on the maximum load of the composite material sample when the sample fails during the shear test, the width and thickness of the composite material sample.

[0011] According to a large-tow carbon fiber surface modification method provided by the present invention, the establishment of a composite material microscopic model comprises: Based on the size of the composite material sample, a large-tow carbon fiber model and a matrix resin model are established; Splicing the large-tow carbon fiber model and the matrix resin model, and determining the spliced ​​model as a volume unit; An interface unit is added at the interface between the large-tow carbon fiber model and the matrix resin model to obtain a composite material microscopic model.

[0012] The present invention also provides a large-tow carbon fiber surface modification device, comprising: Microscopic simulation module, used to establish a microscopic model of the composite material of graphene oxide-sizing agent-modifier-matrix resin on the surface of large-tow carbon fiber, and calculate the interface performance of the composite material microscopic model with different modifiers at the microscopic scale; A macro test module is used to determine the target modifier used in the composite micro model whose interface performance meets the preset requirements, and to obtain the mechanical property test results of the composite sample modified by the target modifier at the macro scale; A mesoscopic simulation module is used to establish a mesoscopic model of a composite material, apply mechanical property test conditions to the mesoscopic model of the composite material, adjust interface unit material parameters until the interface unit material parameters correspond to the interface properties of the microscopic model of the composite material using the target modifier at the microscopic scale, and obtain mechanical property simulation results of the mesoscopic model of the composite material at the mesoscopic scale; The verification module is used to compare the mechanical property test results at the macro scale with the mechanical property simulation results at the micro scale to verify the accuracy of the micro simulation in regulating the modified interface performance of large-tow carbon fiber composite materials.

[0013] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the surface modification method of large-tow carbon fiber as described above is implemented.

[0014] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the surface modification method of large-tow carbon fiber as described above is implemented.

[0015] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the method for surface modification of large-tow carbon fiber as described above is implemented.

[0016] The surface modification method, device, equipment, medium and product of large-tow carbon fiber provided by the present invention modify the sizing agent on the surface of large-tow carbon fiber by using a modifier, take the modified interface of large-tow carbon fiber composite material as the research object, analyze the mechanical properties of different modified interfaces from the microscopic, mesoscopic and macroscopic levels, and then design and control the modified interface of large-tow carbon fiber composite material. The interface performance and mechanical properties of large-tow carbon fiber composite material can be optimized and improved at the microscopic, mesoscopic and macroscopic scales, and better support can be provided for the application of large-tow carbon fiber composite material. The present invention realizes the optimization of the interface performance and mechanical properties of large-tow carbon fiber composite material based on micro-mesoscopic and macroscopic scales. The study on the surface modification of large-tow carbon fibers by macroscopic multi-scale simulation can verify the modification effects of different modifiers on the sizing agent on the surface of large-tow carbon fibers obtained by simulation or experiment at various scales. The research has clear logic, simple steps and is easy to operate. It can improve the practicality and ease of operation of the research on the regulation of modified interface properties of large-tow carbon fiber composites in actual production applications. The simulation results can be compared with the macroscopic test data, which has obvious application advantages and broad prospects in the research on surface modification of large-tow carbon fibers. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic flow chart of a large-tow carbon fiber surface modification method provided in an embodiment of the present invention.

[0019] Figure 2 It is a schematic diagram of a microscopic model of a composite material provided in an embodiment of the present invention.

[0020] Figure 3 This is a damage cloud diagram of shear simulation of a large-tow carbon fiber composite material provided by an embodiment of the present invention.

[0021] Figure 4 It is a schematic structural diagram of a large-tow carbon fiber surface modification device provided in an embodiment of the present invention.

[0022] Figure 5 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In the description of the embodiments of the present invention, the terms "include", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] In actual production, in order to ensure that the fibers will not disperse, carbon fibers need to be coated with sizing agents before leaving the factory. Currently, the interface properties can be adjusted by replacing the sizing agent. However, this method requires that the existing sizing agent on the surface be removed first, otherwise the interface properties of the carbon fiber surface may be greatly reduced. In contrast, if the sizing agent on the carbon fiber surface is directly modified, the interface bonding properties can be adjusted without destroying the original properties of the carbon fiber.

[0026] Modifiers play an important "hub" role in composite materials, which can tightly connect the sized carbon fibers with the resin. Good interfacial interactions help ensure that the load can be transferred evenly and efficiently between the carbon fibers and the resin matrix, thereby reducing the risk of stress concentration. Therefore, the performance of the interface is directly related to the overall mechanical properties of the carbon fiber reinforced resin matrix composite. However, due to the late start of related research on large-tow carbon fibers, there are relatively few studies on the interfacial properties of large-tow carbon fiber composites. Although there have been some research works, the reaction time is long and the process is complicated, so it is not very practical in actual production applications.

[0027] In view of the above problems, in order to fully understand and recognize the interfacial mechanical properties of large-tow carbon fiber composites, the embodiments of the present invention modify the sizing agent on the surface of large-tow carbon fibers by using a modifier, thereby realizing the regulation of the interfacial properties of large-tow carbon fiber composites at micro, meso and macro scales. Considering the diversity of modifiers, the effects of various modifiers on the interfacial bonding properties are studied in depth, and preliminary screening is carried out; then, the effects on the interfacial properties are verified through micro interface simulation and macro interface tests, and the interfacial properties are optimized by multiple parameters; finally, the interfacial properties are regulated by meso simulation technology, so as to optimize the interfacial properties of large-tow carbon fiber composites at the micro, meso and macro scales.

[0028] It should be noted that in the relevant standards, the test method for tensile strength of carbon fiber only includes 24K carbon fiber. Due to the different number of monofilaments contained in large tow carbon fiber, there will be certain errors in the results in terms of fiber dipping, reinforcement sheet and fixture, tensile rate and testing instrument. At the same time, large tow carbon fiber lacks fixed test methods and standards for wear resistance, and cannot provide effective data for the production process of carbon fiber and its composite materials. In addition, compared with small tow carbon fiber, large tow carbon fiber involves more difficult manufacturing processes. During the production process, problems such as unstable tow uniformity, high proportion of hair, and hair during carbonization will be encountered. The possibility of microscopic distortion and knotting in the tow increases, and it is difficult for the resin to penetrate into the tow to form holes, resulting in aggregation and separation of the fiber phase and the resin phase. Therefore, in order to accurately characterize the interface performance of large tow carbon fiber composites and explain the changes in the material interface performance from a mechanistic point of view, the research method of small tow carbon fiber composites cannot be simply applied, and multi-scale research on large tow carbon fiber composites is required. The embodiment of the present invention provides the necessary microscopic perspective for the meso scale through atomic scale simulation, and then verifies the macro model using meso scale simulation, thereby establishing a micro-meso-macro multi-scale mechanical model of large-tow carbon fiber materials, so as to realize the design and regulation research of the modified interface of large-tow carbon fiber composite materials.

[0029] Figure 1 Schematic diagram of the process of surface modification of large tow carbon fiber provided by an embodiment of the present invention. Figure 1 The embodiment of the present invention provides a method for surface modification of large tow carbon fiber, and the method may specifically include the following steps: Step 101, establishing a composite microscopic model of graphene oxide-sizing agent-modifier-matrix resin on the surface of large-tow carbon fiber, and calculating the interface properties of the composite microscopic model using different modifiers at the microscopic scale.

[0030] It should be noted that the execution subject of the surface modification method of large tow carbon fiber provided in the embodiment of the present invention can be an electronic device, a component in an electronic device, an integrated circuit or a chip. The electronic device can be a mobile electronic device or a non-mobile electronic device. For example, the mobile electronic device can be a mobile phone, a tablet computer, a laptop computer, a PDA, a wearable device, an ultra-mobile personal computer (UMPC), a netbook or a personal digital assistant (PDA), etc., and the non-mobile electronic device can be a server, a network attached storage (NAS), a personal computer (PC), a television (TV), a teller machine or a self-service machine, etc., and the embodiment of the present invention does not specifically limit this.

[0031] In an embodiment of the present invention, microscopic interface simulation can be performed based on a molecular dynamics simulation method. Specifically, a microstructure of graphene oxide-sizing agent-modifying agent-matrix resin on the surface of a large-tow carbon fiber can be established, and a microscopic model of a large-tow carbon fiber composite material in which the sizing agent is modified by a modifier can be obtained, and the microscopic model can be relaxed and stretched by molecular dynamics software to evaluate the interface performance of the established microscopic model.

[0032] For different types of modifiers, microscopic models of composite materials using different modifiers can be established, so as to calculate the interface properties of the microscopic models of composite materials using different modifiers at the microscopic scale. The interface properties may include interface binding energy and interface tensile properties.

[0033] Optionally, the modifier may include a polymer material, such as polyamide-imide (PAI), or an organic silicon compound, such as octadecyltrimethoxysilane (OTE), carbon black, and the like.

[0034] Optionally, the matrix resin may be an epoxy resin, and the sizing agent may be an epoxy sizing agent.

[0035] In some embodiments, after constructing a microscopic model of carbon fiber-modifier, by comparing and analyzing the interface properties between different modifiers and large-tow carbon fibers sized with sizing agents, the interface bonding properties between different types of modifiers and large-tow carbon fibers after sizing can be studied.

[0036] In some embodiments, after constructing a microscopic model of large-tow carbon fiber-modifier-matrix resin after sizing with a sizing agent, the interface properties between the sizing agent modified by the modifier and the matrix resin are compared and analyzed with the interface properties between the unmodified sizing agent and the matrix resin, thereby studying the interface bonding effects of different modifiers on the sizing agent and the matrix resin.

[0037] In some embodiments, a composite microscopic model of graphene (without functional groups on the surface)-sizing agent-modifier-matrix resin (hereinafter referred to as a microscopic model without functional groups) can also be constructed. By comparing and analyzing the interface properties of the microscopic model without functional groups and the microscopic model with functional groups using the same modifier at the microscopic scale, the interface bonding effect of the composite material with or without the same modifier with functional groups can be studied.

[0038] In some embodiments, by comparing and analyzing the interface properties at the microscopic scale of composite material microscopic models that respectively adopt a modifier thin layer structure and a modifier monomer molecular structure, it is possible to study the interface bonding effect of the composite material when the same modifier is modified using a modifier thin layer structure or a modifier monomer molecular structure.

[0039] The embodiments of the present invention take into account the diversity of modifiers. By studying the interface properties of large-tow carbon fiber composites modified with various modifiers on a sizing agent at a microscopic scale, better modifiers can be further screened out for macroscopic interface tests, and a microscopic perspective can be provided for the study of interface properties at a mesoscopic scale.

[0040] Step 102, determining a target modifier used in a composite material micro-model whose interface performance meets preset requirements, and obtaining a mechanical property test result of a composite material sample modified by the target modifier at a macro scale.

[0041] The better the modification effect of the modifier on the sizing agent, the higher the interfacial performance of the modified interface of the composite material, and the better the mechanical properties of the composite material. The preset requirement may refer to the interface performance being higher than the preset performance value. In an embodiment of the present invention, based on the interface performance of the composite material micromodel using different modifiers at the microscale, the target modifier used by the composite material micromodel whose interface performance meets the preset requirements can be screened out for macroscopic interface testing. Among them, the target modifier can be at least one modifier.

[0042] The mechanical properties test results may include tensile strength, bending strength and shear strength. Specifically, in the macro interface test, large-tow carbon fiber composite samples modified with the target modifier with different concentration gradients can be prepared, and the tensile strength, bending strength and shear strength of the large-tow carbon fiber composite samples modified with the target modifier can be obtained through composite tensile test, bending test and shear test. The multi-parameter characterization, and then the influence of each modifier and its concentration on the modified interface performance of the large-tow carbon fiber composite material is analyzed to achieve multi-parameter optimization of the interface performance of the large-tow carbon fiber composite material.

[0043] Step 103, establish a composite material meso model, apply mechanical property test conditions to the composite material meso model, adjust the interface unit material parameters until the interface unit material parameters correspond to the interface properties of the composite material micro model using the target modifier at the micro scale, and obtain the mechanical property simulation results of the composite material meso model at the meso scale.

[0044] In an embodiment of the present invention, a microscopic interface simulation can be performed based on a finite element simulation method. Specifically, a large-tow carbon fiber composite microscopic model having the same size as the large-tow carbon fiber composite sample used in the macroscopic test can be imported into the simulation analysis optimization software.

[0045] The mechanical properties test conditions may refer to the same tensile load, bending load and shear load as the macro test process. The same tensile load, bending load and shear load as the macro test can be applied to the established composite meso model, and the material parameters of the interface unit can be adjusted until the interface unit material parameters correspond to the interface properties of the composite micro model using the target modifier at the micro scale, and the mechanical properties simulation results of the large tow carbon fiber composite meso model at the meso scale are obtained.

[0046] The mechanical property simulation results may include simulated tensile strength, simulated bending strength and simulated shear strength.

[0047] By studying the interface properties of large-tow carbon fiber composites at the meso scale in which the sizing agent is modified by the screened target modifier, the embodiment of the present invention can verify the macro model, thereby verifying the accuracy of the meso simulation in regulating the modified interface properties of large-tow carbon fiber composites.

[0048] Step 104, comparing the mechanical property test results at the macro scale with the mechanical property simulation results at the micro scale, to verify the accuracy of the micro simulation in regulating the modified interface performance of the large-tow carbon fiber composite material.

[0049] After the meso-scale interface simulation is completed, the mechanical properties test results at the macro-scale can be compared with the mechanical properties simulation results at the meso-scale, and the accuracy of the meso-scale simulation in regulating the modified interface properties of large-tow carbon fiber composites can be verified based on the comparison results.

[0050] Taking carbon black, PAI and OTE as examples of target modifiers, if the mechanical properties test results at the macroscopic scale and the mechanical properties simulation results at the microscopic scale both show that PAI has a higher improvement effect on interface performance than OTE and carbon black, it can be explained that more and more stable chemical bonds are formed between PAI and epoxy resin, and its interface bonding performance has been greatly improved. As for the carbon black system, the carbon black structure is a sheet structure similar to graphene. When subjected to shear, it is easy for molecules to slide, thereby reducing its interface bonding performance.

[0051] The embodiment of the present invention performs multi-parameter optimization of the interface from two aspects of different modifiers and different concentrations of modifiers through macroscopic experiments and microscopic simulations, which helps to screen out modifiers that can improve the interface properties and mechanical properties of large-tow carbon fiber composites; and by studying large-tow carbon fiber reinforced composites at macroscopic and microscopic scales, the influence of each modifier on the mechanical properties of the composite is evaluated, thereby achieving multi-performance evaluation and verification of large-tow carbon fiber composites at the specimen level, thereby providing guidance for the production and application of large-tow carbon fiber composites, and can improve the practicality and ease of operation of interface performance regulation of large-tow carbon fiber composites in actual production applications.

[0052] The embodiment of the present invention uses a modifier to modify the sizing agent on the surface of large-tow carbon fiber, takes the modified interface of large-tow carbon fiber composite material as the research object, analyzes the mechanical properties of different modified interfaces from three levels of micro, meso and macro, and then designs and regulates the modified interface of large-tow carbon fiber composite material, which can optimize and improve the interface performance and mechanical properties of large-tow carbon fiber composite material at micro, meso and macro scales, and better provide support for the application of large-tow carbon fiber composite material; the present invention realizes the research on surface modification of large-tow carbon fiber based on micro-meso-macro multi-scale simulation. During the whole simulation process, the modification effects of different modifiers on the sizing agent on the surface of large-tow carbon fiber obtained by simulation or experiment at each scale can be mutually verified, the research logic is clear, the steps are simple and easy to operate, and the practicality and ease of operation of the regulation research on the modified interface performance of large-tow carbon fiber composite material in actual production application can be improved. The actual situation is fit to the utmost in the whole simulation process, and the simulation results can be compared with the macro test data. It has obvious application advantages and broad prospects in the research on surface modification of large-tow carbon fiber.

[0053] Based on any of the above embodiments, the establishment of a composite microscopic model of graphene oxide-sizing agent-modifier-matrix resin on the surface of large tow carbon fiber, and the calculation of the interface properties of the composite microscopic model using different modifiers at the microscopic scale include: The graphene unit cell is periodically expanded, and oxygen-containing functional groups are added to the surface of the graphene based on a predetermined carbon-oxygen ratio to obtain graphene oxide; Establishing a cross-linked structure of the sizing agent, and allowing the sizing agent to be tightly combined with the surface of the graphene oxide through relaxation; Establishing a thin layer structure of modifier molecules and placing it above the sizing agent, and allowing the thin layer of modifier molecules to fully react with the sizing agent through relaxation; Establishing a cross-linked structure of a base resin placed above the modifier, and allowing the base resin to fully react with a thin layer of modifier molecules through relaxation; The interface properties at the microscopic scale are calculated based on the established microscopic model of composite materials using different modifiers.

[0054] Specifically, the graphene unit cell (i.e., the basic unit of graphene) can be expanded to form a periodic structure along the x and y directions, and oxygen-containing functional groups can be added to the surface of the graphene according to the actual carbon-oxygen ratio to obtain oxidized graphene, thereby simulating the oxidation of surface graphene during processing in actual working conditions.

[0055] The x-direction and the y-direction refer to two spatial coordinate directions in a two-dimensional lattice (horizontal and vertical directions on a plane). For example, assuming that the cell is expanded n times in the x-direction and m times in the y-direction, a two-dimensional lattice of size n×m can be obtained.

[0056] Alternatively, the oxygen-containing functional group may include a carboxyl group, a hydroxyl group, an epoxy group, an aldehyde group, and the like.

[0057] Figure 2 Schematic diagram of a composite material microscopic model provided by an embodiment of the present invention. Figure 2 In the embodiment of the present invention, graphene oxide can be chemically bonded or physically adsorbed on the surface of large-tow carbon fiber, and the cross-linked structure of the sizing agent can be established through the polymer modeling program, and the sizing agent can be tightly combined with the surface of graphene oxide through relaxation; the thin layer structure of the modifier molecule to be screened can be established, placed above the sizing agent, and the thin layer of the modifier molecule can be fully reacted with the sizing agent through relaxation; the cross-linked structure of the matrix resin can be established through the polymer modeling program, placed above the modifier, and the matrix resin can be fully reacted with the thin layer of the modifier molecule through relaxation. For the established large-tow carbon fiber composite microscopic model, the interface binding energy can be calculated, and the tensile properties of the interface can be calculated at the same time to obtain the interface properties at the microscopic scale.

[0058] Specifically, a large-tow carbon fiber surface model can be constructed based on graphene and oxidized functional groups; an epoxy sizing agent with cross-linking properties is constructed, and its size in the x and y directions is made similar to that of the large-tow carbon fiber by cell expansion, while the periodicity in the z direction is removed and the chain structure of the epoxy sizing agent is retained; the cross-linked structure of the epoxy sizing agent is placed on a large-tow carbon fiber layer with oxygen-containing functional groups, and the sizing agent is tightly combined with the surface of graphene oxide through relaxation, and the model is gradually turned into a uniform layer during the relaxation process. The rectangular parallelepiped structure is convenient for subsequent faster and more complete reaction with the modifier or the matrix resin; the modifier thin layer structure is placed on the upper layer of the epoxy sizing agent, and the modifier molecules are allowed to fully react with the sizing agent through relaxation, thereby avoiding the influence of the functional group position on the binding energy of the modifier monomer through the modifier thin layer structure, and ensuring that the modifier thin layer can completely interact with all functional groups; a cross-linked structure of the matrix resin is established and placed above the modifier, and the matrix resin is allowed to fully react with the thin layer of modifier molecules through relaxation.

[0059] In some embodiments, the microscopic model of the large-tow carbon fiber composite material can be subjected to NPT (number of particles, pressure, and temperature) relaxation to make the distribution of molecules in the overall structure of the microscopic model of the composite material uniform and the molecules at the interface more tightly bound; then the microscopic model of the composite material is subjected to NVT (number of particles, volume, and temperature) relaxation to maintain the molecules at the interface in a stable state, thereby being closer to the interface morphology of the real large-tow carbon fiber composite material.

[0060] Take the example of allowing the modifier molecules to fully react with the sizing agent through relaxation. First, the microstructure can be NPT relaxed for 2ps to release the initially compressed internal pressure of the structure, while allowing the modifier and the sizing agent on the surface of the large-tow carbon fiber to begin to diffuse and form new chemical bonds. Next, the system can be NVT relaxed for 1ps to allow the system to enter a stable state and maintain the current structural state. Subsequently, the large-tow carbon fiber can be constrained to push the modifier molecules downward every 1ps to accelerate the downward diffusion rate of the modifier molecules. At this time, due to the shortening of the distance between a large number of molecules, the energy in the system continues to rise. After each push to move the modifier molecules, the sizing agent and the modifier can be NVT relaxed to allow the sizing agent molecules and the modifier molecules to fully react and reduce the energy to the current minimum, thereby obtaining a stable state at the current stage. As the distance between the modifier molecules and the sizing agent molecules becomes smaller and smaller, more and more chemical bonds are gradually formed between the two, and the modifier molecules gradually become a thin layer tightly attached to the surface of the sizing agent. After the final relaxation, the expected microstructure of the large-tow carbon fiber composite material modified by the modifier can be obtained.

[0061] The embodiment of the present invention can realize the research on the surface modification of large tow carbon fibers based on the micro scale by establishing a composite material microscopic model of graphene oxide-sizing agent-modifier-matrix resin on the surface of large tow carbon fibers, which is conducive to further verifying the modification effects of different modifiers on the sizing agent on the surface of large tow carbon fibers obtained by simulation or experiment at the micro-meso-macro multi-scales.

[0062] Based on any of the above embodiments, the intermolecular spacing in the modifier molecular thin layer structure is within a preset spacing range, the difference ratio of the number of molecules in different modifier molecular thin layers is less than or equal to a preset ratio; the distance between the newly established molecular layer and the original structure is greater than or equal to the preset distance.

[0063] In the embodiment of the present invention, by controlling the intermolecular spacing in the thin layer structure of the modifier molecules within a preset spacing range, it is possible to better approximate a real large-tow carbon fiber composite material.

[0064] Optionally, the preset spacing range may be 0.2 times the size of the molecular monomer, specifically 0.3 nm to 0.8 nm.

[0065] In an embodiment of the present invention, when it is necessary to compare the effects of different modifiers on the interface, by controlling the difference ratio of the number of molecules in each modifier molecular layer to be less than or equal to a preset ratio, interference from other factors can be eliminated, thereby improving the reliability of subsequent mutual verification of the modification effects of different modifiers on the sizing agent on the surface of large-tow carbon fiber obtained by simulation or experiment at micro-meso-macro multi-scales.

[0066] Optionally, the preset ratio may be 5%.

[0067] In the embodiment of the present invention, each time a new molecular layer is added, the distance between the new molecular layer and the original structure can be controlled to be greater than or equal to a preset distance, which is conducive to ensuring the stability and uniformity of the interface and avoiding the stacking and aggregation of the molecular layers, thereby ensuring the mechanical properties and stability of the material. Optionally, the preset distance can be 0.3 nm.

[0068] Exemplarily, when adding a sizing agent, the distance between the sizing agent molecular layer and the graphene oxide can be controlled to be at least 0.3 nm, thereby preventing the initial configuration from being too poor; when adding a modifier, the distance between the modifier molecular layer and the graphene oxide-sizing agent microstructure can be controlled to be at least 0.3 nm; when adding a matrix resin, the distance between the matrix resin molecular layer and the graphene oxide-sizing agent-modifier microstructure can be controlled to be at least 0.3 nm.

[0069] Based on any of the above embodiments, the interface performance at the microscopic scale is characterized by unit atomic binding energy and stress-strain curve of the interface; The unit atomic binding energy of the interface is calculated based on the binding energy of the interface of the composite material microscopic model output by molecular dynamics software and the number of atoms in the modifier molecular thin layer; Wherein, the stress-strain curve is obtained by drawing: Calculating a strain value based on a displacement value of the composite material micromodel along a loading direction and a length of the composite material micromodel in the loading direction; Calculating stress values ​​based on the stress values ​​output by the molecular dynamics software and the lengths of the composite material micromodel along the horizontal axis, the longitudinal axis and the vertical axis; Based on the strain value and the stress value, the stress-strain curve is drawn.

[0070] In the embodiment of the present invention, the microstructure is relaxed by molecular dynamics software, and each stage is relaxed for about 20ps to reach the stable state of the microstructure under the molecular dynamics simulation time scale. During the relaxation process, the coordinates of each atom in the output evolution region, the total energy (i.e., the binding energy of the interface), and the stress value and other parameters can be set, so as to facilitate the subsequent calculation of the interface binding energy and the drawing of the stress-strain curve.

[0071] Optionally, the molecular dynamics software may employ QuantumATK software to assist in understanding the microscopic behavior of the large-tow carbon fiber composite micromodel.

[0072] Specifically, the molecular dynamics module is called in the molecular dynamics software to relax the microstructure of the composite material. After calculating the interface binding energy, the unit atomic binding energy of the interface can be calculated, thereby avoiding the influence of different atomic numbers on the interface binding energy of large tow carbon fiber composite materials. The unit atomic binding energy can be calculated as follows: ; in, is the binding energy of the interface (kcal / mol), is the number of atoms in the modifier molecular layer, is the unit atomic binding energy of the interface (kcal / mol).

[0073] Specifically, after the molecular dynamics software calculates the tensile properties, the atomic stress values ​​can be further processed to draw the stress-strain curve of the microscopic system, so as to determine the tensile strength and other mechanical properties of the composite micromodel through the stress-strain curve, and determine the fracture position and fracture diffusion direction of the composite material during the simulated tensile process. In the real unit system of the molecular dynamics module, the calculation method of stress and strain can be as follows: ; in, is the stress value (GPa), The stress values ​​(atmospheres) output by the program, l x , l y , l z are the lengths of the composite micromodel in the xyz direction (Å); is the strain value, is the displacement along the loading direction (Å), l i is the loading direction.

[0074] Based on any of the above embodiments, the mechanical properties test results at the macro scale include tensile strength, bending strength and shear strength; the obtaining of the mechanical properties test results at the macro scale of the composite material sample modified by the target modifier includes: Calculating the tensile strength based on the maximum load of the composite material sample modified by the target modifier when the sample is damaged during a tensile test, and the width and thickness of the composite material sample; Calculating the bending strength based on the maximum load, span, width and thickness of the composite material sample when the composite material sample is damaged during the bending test; The shear strength is calculated based on the maximum load of the composite material sample when the sample fails during the shear test, the width and thickness of the composite material sample.

[0075] In an embodiment of the present invention, a tensile test, a bending test and a shear test can be performed on a large-tow carbon fiber composite material sample modified with a target modifier, so as to obtain the tensile strength, bending strength and shear strength of the large-tow carbon fiber composite material sample modified with the modifier.

[0076] The calculation formula for tensile strength can be: ; Wherein, σ1 is the tensile strength (MPa), F is the maximum load when the specimen fails in the tensile test (N), b is the specimen width (mm), and d is the specimen thickness (mm).

[0077] The calculation formula for bending strength can be: ; Among them, σ2 is the bending strength (MPa), P is the maximum load when the specimen fails in the bending test (N), l is the span (mm), h is the specimen thickness (mm), and b is the specimen width (mm).

[0078] Interlaminar shear strength S 12 The calculation method can be as follows: ; Among them, S 12 is the interlaminar shear strength (MPa), P is the maximum load when the specimen is damaged in the shear test (N), b is the specimen width (mm), and h is the specimen thickness (mm).

[0079] Figure 3 This is a damage cloud diagram of a large tow carbon fiber composite material shear simulation provided by an embodiment of the present invention. Figure 3In the shear simulation test of large-tow carbon fiber composites, as external force is applied, damage will occur inside the large-tow carbon fiber composite, which manifests as microcracks, changes in microstructure or degradation of material strength. The shear damage evolution gradient (SDEG) can be used to understand how the damage changes in space and time inside the material.

[0080] The embodiments of the present invention can solve the problem that it is difficult to simultaneously measure the microscopic interface properties and macroscopic mechanical properties of large-tow carbon fiber composites under a single scale by establishing a micro-macro multi-scale test method, thereby achieving accurate measurement of the large-tow carbon fiber / matrix resin interface properties and the overall mechanical properties of large-tow carbon fiber composites.

[0081] Based on any of the above embodiments, the step of establishing a composite material microscopic model includes: Based on the size of the composite material sample, a large-tow carbon fiber model and a matrix resin model are established; Splicing the large-tow carbon fiber model and the matrix resin model, and determining the spliced ​​model as a volume unit; An interface unit is added at the interface between the large-tow carbon fiber model and the matrix resin model to obtain a composite material microscopic model.

[0082] Specifically, a large-tow carbon fiber model with transversely isotropic material properties and a matrix resin model with isotropic material properties can be established, and the model is consistent with the actual size of the composite material specimen in the macroscopic test at the mesoscale.

[0083] Specifically, after the large-tow carbon fiber model and the matrix resin model are spliced, they can be divided into deletable volume units, and deletable interface units are added at the interface between the large-tow carbon fiber model and the matrix resin model, thereby obtaining a microscopic model of the large-tow carbon fiber composite material modified by the target modifier. The secondary development of the cohesive unit material properties can be achieved based on the Fortran language, so that the material properties of the cohesive unit correspond to the interface properties obtained in the microscopic simulation.

[0084] The volume unit may refer to a C3D8R unit, which may be used to simulate the stress, strain, deformation, etc. of the volume of a microscopic model of a large-tow carbon fiber composite material.

[0085] The interface unit may refer to a COH3D8 interface unit, which may be used for interface simulation in a large-tow carbon fiber composite microscopic model, and describes the bonding, separation, and crack propagation between the large-tow carbon fiber model and the matrix resin model.

[0086] The embodiment of the present invention establishes a finite element model with an adjustable interface based on mesomechanics, gives the material properties of large-tow carbon fiber, matrix resin, and interface, and uses the finite element method to realize the simulation of the meso model of multi-component large-tow carbon fiber composite materials. This can solve the problem that the damage process of the interface is difficult to accurately describe at the macro scale, and realize the micro-meso-macro cross-scale simulation of domestic large-tow composite materials.

[0087] The embodiment of the present invention can solve the problem that the surface modification of large-tow carbon fiber is difficult to control at the micro, meso and macro multi-scale interfaces. On the basis of molecular dynamics simulation and finite element simulation, combined with macro interface test, the research on the surface modification of large-tow carbon fiber based on micro-meso-macro multi-scale is realized. The calculation method has clear logic, simple steps and easy operation. The method is extremely consistent with the actual situation throughout the simulation process, and the simulation results can be compared with the test data. In the research on the surface modification of domestic large-tow carbon fiber, it has obvious advantages and broad prospects.

[0088] The large-tow carbon fiber surface modification device provided by the present invention is described below. The large-tow carbon fiber surface modification device described below and the large-tow carbon fiber surface modification method described above can correspond to each other.

[0089] Figure 4 Schematic diagram of the structure of a large-tow carbon fiber surface modification device provided by an embodiment of the present invention. Figure 4 The embodiment of the present invention provides a large-tow carbon fiber surface modification device, which may specifically include the following modules: The microscopic simulation module 410 is used to establish a composite microscopic model of graphene oxide-sizing agent-modifier-matrix resin on the surface of large-tow carbon fiber, and calculate the interface performance of the composite microscopic model using different modifiers at the microscopic scale; The macro test module 420 is used to determine the target modifier used in the composite material micro model whose interface performance meets the preset requirements, and obtain the mechanical property test results of the composite material sample modified by the target modifier at the macro scale; A mesoscopic simulation module 430 is used to establish a composite material mesoscopic model, apply mechanical property test conditions to the composite material mesoscopic model, adjust interface unit material parameters until the interface unit material parameters correspond to the interface properties of the composite material microscopic model using the target modifier at the microscopic scale, and obtain mechanical property simulation results of the composite material mesoscopic model at the mesoscopic scale; The verification module 440 is used to compare the mechanical property test results at the macro scale with the mechanical property simulation results at the micro scale to verify the accuracy of the micro simulation in regulating the modified interface performance of the large-tow carbon fiber composite material.

[0090] The embodiment of the present invention uses a modifier to modify the sizing agent on the surface of large-tow carbon fiber, takes the modified interface of large-tow carbon fiber composite material as the research object, analyzes the mechanical properties of different modified interfaces from three levels of micro, meso and macro, and then designs and regulates the modified interface of large-tow carbon fiber composite material, which can optimize and improve the interface performance and mechanical properties of large-tow carbon fiber composite material at micro, meso and macro scales, and better provide support for the application of large-tow carbon fiber composite material; the present invention realizes the research on surface modification of large-tow carbon fiber based on micro-meso-macro multi-scale simulation. During the whole simulation process, the modification effects of different modifiers on the sizing agent on the surface of large-tow carbon fiber obtained by simulation or experiment at each scale can be mutually verified, the research logic is clear, the steps are simple and easy to operate, and the practicality and ease of operation of the regulation research on the modified interface performance of large-tow carbon fiber composite material in actual production application can be improved. The actual situation is fit to the utmost in the whole simulation process, and the simulation results can be compared with the macro test data. It has obvious application advantages and broad prospects in the research on surface modification of large-tow carbon fiber.

[0091] Figure 5 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 5 As shown, the electronic device may include: a processor (processor) 510, a communication interface (Communications Interface) 520, a memory (memory) 530 and a communication bus 540, wherein the processor 510, the communication interface 520, and the memory 530 communicate with each other through the communication bus 540. The processor 510 can call the logic instructions in the memory 530 to execute the surface modification method of large-tow carbon fiber, which includes: establishing a composite microscopic model of graphene oxide-sizing agent-modifier-matrix resin on the surface of large-tow carbon fiber, and calculating the interface performance of the composite microscopic model using different modifiers at the microscale; determining the target modifier used by the composite microscopic model whose interface performance meets the preset requirements, and obtaining the mechanical property test results of the composite sample modified by the target modifier at the macroscale; establishing a composite microscopic model, and applying mechanical property test conditions to the composite microscopic model, adjusting the interface unit material parameters until the interface unit material parameters correspond to the interface performance of the composite microscopic model using the target modifier at the microscale, and obtaining the mechanical property simulation results of the composite microscopic model at the mesoscale; comparing the mechanical property test results at the macroscale with the mechanical property simulation results at the mesoscale to verify the accuracy of the mesoscopic simulation in regulating the modified interface performance of large-tow carbon fiber composite materials.

[0092] In addition, the logic instructions in the above-mentioned memory 530 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0093] On the other hand, the present invention also provides a computer program product, which includes a computer program, which can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the large-tow carbon fiber surface modification method provided by the above methods, the method comprising: establishing a composite micromodel of graphene oxide-sizing agent-modifier-matrix resin on the surface of large-tow carbon fiber, calculating the interface properties of the composite micromodel using different modifiers at the microscale; determining the target modifier used by the composite micromodel whose interface properties meet the preset requirements, and obtaining the target modifier used by the composite micromodel; Mechanical property test results of composite material specimens modified by modifiers at a macro scale; establishing a composite material meso model, applying mechanical property test conditions to the composite material meso model, adjusting interface unit material parameters until the interface unit material parameters correspond to the interface properties of the composite material micro model using the target modifier at a micro scale, and obtaining mechanical property simulation results of the composite material meso model at a meso scale; comparing the mechanical property test results at a macro scale with the mechanical property simulation results at a meso scale to verify the accuracy of meso simulation in regulating the modified interface properties of large-tow carbon fiber composites.

[0094] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented when the computer program is executed by a processor to perform the large-tow carbon fiber surface modification method provided by the above methods, the method comprising: establishing a composite microscopic model of graphene oxide-sizing agent-modifier-matrix resin on the surface of large-tow carbon fiber, calculating the interface properties of the composite microscopic model using different modifiers at the microscopic scale; determining the target modifier used in the composite microscopic model whose interface properties meet the preset requirements, and obtaining the composite sample modified by the target modifier at the macroscopic scale; Mechanical property test results at macro scale; establishing a composite material meso model, applying mechanical property test conditions to the composite material meso model, adjusting interface unit material parameters until the interface unit material parameters correspond to the interface properties of the composite material micro model using the target modifier at the micro scale, and obtaining mechanical property simulation results of the composite material meso model at the meso scale; comparing the mechanical property test results at the macro scale with the mechanical property simulation results at the meso scale to verify the accuracy of the meso simulation in regulating the modified interface performance of large-tow carbon fiber composites.

[0095] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0096] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for surface modification of large tow carbon fiber, characterized in that: include: Establish a composite microscopic model of graphene oxide-sizing agent-modifier-matrix resin on the surface of large-tow carbon fiber, and calculate the interface properties of the composite microscopic model with different modifiers at the microscopic scale; Determine a target modifier used in a composite material micromodel whose interface performance meets preset requirements, and obtain mechanical property test results of a composite material sample modified by the target modifier at a macroscopic scale; Establishing a composite material mesoscopic model, applying mechanical property test conditions to the composite material mesoscopic model, adjusting interface unit material parameters until the interface unit material parameters correspond to the interface properties of the composite material microscopic model using the target modifier at the microscale, and obtaining mechanical property simulation results of the composite material mesoscopic model at the mesoscale; The mechanical property test results at the macro scale are compared with the mechanical property simulation results at the micro scale to verify the accuracy of the micro simulation in regulating the modified interface properties of large-tow carbon fiber composites.

2. The method according to claim 1, characterized in that The method of establishing a composite microscopic model of graphene oxide-sizing agent-modifier-matrix resin on the surface of large-tow carbon fiber and calculating the interface properties of the composite microscopic model using different modifiers at a microscopic scale includes: The graphene unit cell is periodically expanded, and oxygen-containing functional groups are added to the surface of the graphene based on a predetermined carbon-oxygen ratio to obtain graphene oxide; Establishing a cross-linked structure of the sizing agent, and allowing the sizing agent to be tightly combined with the surface of the graphene oxide through relaxation; Establishing a thin layer structure of modifier molecules and placing it above the sizing agent, and allowing the thin layer of modifier molecules to fully react with the sizing agent through relaxation; Establishing a cross-linked structure of a base resin placed above the modifier, and allowing the base resin to fully react with a thin layer of modifier molecules through relaxation; The interface properties at the microscopic scale are calculated based on the established microscopic model of composite materials using different modifiers.

3. The method according to claim 2, characterized in that The intermolecular spacing in the modifier molecular thin layer structure is within a preset spacing range, the molecular number difference ratio in different modifier molecular thin layers is less than or equal to a preset ratio; and the distance between the newly established molecular layer and the original structure is greater than or equal to a preset distance.

4. The method according to claim 2, characterized in that: The interface performance at the microscopic scale is characterized by unit atomic binding energy and stress-strain curve of the interface; The unit atomic binding energy of the interface is calculated based on the binding energy of the interface of the composite material microscopic model output by molecular dynamics software and the number of atoms in the modifier molecular thin layer; Wherein, the stress-strain curve is obtained by drawing: Calculating a strain value based on a displacement value of the composite material micromodel along a loading direction and a length of the composite material micromodel in the loading direction; Calculating stress values ​​based on the stress values ​​output by the molecular dynamics software and the lengths of the composite material micromodel along the horizontal axis, the longitudinal axis and the vertical axis; Based on the strain value and the stress value, the stress-strain curve is drawn.

5. The method according to claim 1, characterized in that The mechanical properties test results at the macro scale include tensile strength, bending strength and shear strength; the mechanical properties test results at the macro scale of the composite material sample modified by the target modifier are obtained, including: Calculating the tensile strength based on the maximum load of the composite material sample modified by the target modifier when the sample is damaged during a tensile test, and the width and thickness of the composite material sample; Calculating the bending strength based on the maximum load, span, width and thickness of the composite material sample when the composite material sample is damaged during the bending test; The shear strength is calculated based on the maximum load of the composite material sample when the sample fails during the shear test, the width and thickness of the composite material sample.

6. The method according to claim 1, characterized in that The method of establishing a composite material microscopic model comprises: Based on the size of the composite material sample, a large-tow carbon fiber model and a matrix resin model are established; Splicing the large-tow carbon fiber model and the matrix resin model, and determining the spliced ​​model as a volume unit; An interface unit is added at the interface between the large-tow carbon fiber model and the matrix resin model to obtain a composite material microscopic model.

7. A large-tow carbon fiber surface modification device, characterized in that: include: Microscopic simulation module, used to establish a microscopic model of the composite material of graphene oxide-sizing agent-modifier-matrix resin on the surface of large-tow carbon fiber, and calculate the interface performance of the composite material microscopic model with different modifiers at the microscopic scale; A macro test module is used to determine the target modifier used in the composite micro model whose interface performance meets the preset requirements, and to obtain the mechanical property test results of the composite sample modified by the target modifier at the macro scale; A mesoscopic simulation module is used to establish a mesoscopic model of a composite material, apply mechanical property test conditions to the mesoscopic model of the composite material, adjust interface unit material parameters until the interface unit material parameters correspond to the interface properties of the microscopic model of the composite material using the target modifier at the microscopic scale, and obtain mechanical property simulation results of the mesoscopic model of the composite material at the mesoscopic scale; The verification module is used to compare the mechanical property test results at the macro scale with the mechanical property simulation results at the micro scale to verify the accuracy of the micro simulation in regulating the modified interface performance of large-tow carbon fiber composite materials.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the large-tow carbon fiber surface modification method according to any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for surface modification of large-tow carbon fiber according to any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for surface modification of large-tow carbon fiber according to any one of claims 1 to 6 is implemented.

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