Method for studying mechanical properties of multi-component road marking material

Abstract

The application provides a kind of mechanical property research method of multi-component road marking material, it is related to road marking material analysis technical field, marking line material includes: acrylic resin 18-24%, pigment is polyisoprene modified titanium dioxide 3-8%, filler is 600 mesh double fly ash 35-50%, 40-80 mesh quartz sand 10-18%, glass bead is 20-80 mesh reflective glass bead 15-25%, organic bentonite 0.1-0.5%, accelerator 0.05-0.2%.The application provides a kind of multiscale synergistic method of molecular dynamics-finite element-experimental verification, realizes the through characterization and parameter inversion from nanoscale to macroscopic mechanical response, can quantitatively guide formula design and reveal micro stress mechanism, significantly reduces the development trial and error cost and cycle, improves the controllability of quality.Meanwhile it can also realize the balanced optimization and on-demand customization of material mechanical index, effectively improve the overall durability, crack resistance, wear resistance and service reliability of road marking, and reduce the life cycle cost.

Description

Technical Field

[0001] This invention relates to the field of road marking material analysis technology, and in particular to a method for studying the mechanical properties of multi-component road marking materials. Background Technology

[0002] In recent years, against the backdrop of green construction concepts and the promotion of achieving "dual carbon" goals, acrylic resin composites have found wide applications in aerospace, military, and civilian fields (especially in road marking materials) due to their significant advantages such as environmental friendliness, safety, and ease of construction. Research on improving the mechanical properties of acrylic resins has also been conducted. However, acrylic resins used alone have poor mechanical and physical properties, which significantly limits their applications in other areas. Therefore, enhancing the performance of acrylic composites by adding various fillers has become a research hotspot and important direction in this field.

[0003] Currently, existing research methods have the following limitations:

[0004] Limitations of traditional experimental methods: Conventional methods for measuring the content of specific components in composite materials are complex to operate, time-consuming and labor-intensive, and cannot achieve precise control at the nanoscale.

[0005] Insufficient research on specific systems: There is relatively little research on the mechanical properties of acrylic resin composites reinforced by the synergistic use of glass beads, quartz sand, and heavy calcium carbonate fillers.

[0006] Lack of multi-scale correlation analysis: While molecular dynamics simulations and finite element simulations are two effective computational methods that can reveal material properties at different scales, current research rarely combines them with experimental data. Specifically, there is a lack of a multi-scale collaborative simulation method that can span atomic, mesoscopic, and macroscopic scales to analyze and predict the impact of the content and distribution of reinforcements on the overall properties of such multi-component composite materials.

[0007] Therefore, developing a multi-scale collaborative research method that combines molecular dynamics, finite element simulation, and experimental verification for the mechanical property analysis and optimization design of multi-component road marking materials is of great significance for guiding the preparation of composite materials, improving material properties, and expanding their applications. Summary of the Invention

[0008] The purpose of this invention is to provide a method for studying the mechanical properties of multi-component road marking materials, which solves the problems of traditional experimental methods being complex, time-consuming, unable to achieve nanoscale precision control, having limited research on composite materials synergistically reinforced by glass beads / quartz sand / heavy calcium carbonate, and lacking effective multi-scale simulation methods for analyzing and optimizing material formulations.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a method for studying the mechanical properties of multi-component road marking materials, taking the aforementioned multi-component road marking materials as the research object, including the following steps:

[0010] S1: Establish a molecular dynamics model with titanium dioxide as the nanofiller phase and polyisoprene as the polymer phase, and generate polyisoprene polymer chains with different repeating unit numbers by changing the number of monomers in the polymer phase, and further construct molecular dynamics models of titanium dioxide / polyisoprene composite materials with different degrees of polymerization.

[0011] S2: Perform molecular dynamics uniaxial tensile simulation on the titanium dioxide / polyisoprene composite material described in step S1 to obtain stress-strain curves and extract elastic modulus and yield strength to determine the target titanium dioxide volume fraction and polyisoprene chain length parameters.

[0012] S3: Prepare the multi-component road marking material according to the parameters determined in step S2. Treat all materials in the road marking except glass beads as the matrix and glass beads as the reinforcement. Prepare ordinary road marking specimen Y containing glass beads and road marking specimen W without glass beads. Prepare multiple specimens Y and W for uniaxial tensile test to reduce error.

[0013] S4: Perform digital image correlation (DIC) post-processing on the tensile test, analyze the strain cloud map of specimen Y and specimen W in the frame before fracture, and determine the effect of glass bead addition on the vertical displacement of multi-component road marking materials and the difference in fracture cross sections.

[0014] S5: Substitute the matrix material parameters extracted from the experiment into the finite element simulation, establish a specimen model, apply loads and boundary conditions, perform static simulation and calculation, and compare the force-displacement curves obtained in the numerical simulation with the force-displacement curves obtained in the experiment.

[0015] S6: Substitute the mechanical parameters of the matrix material obtained above into the microscopic model, randomly distribute glass beads in the microscopic model, fix the size and density of the glass beads, and randomly distribute their positions to establish a microscopic road marking model, and further explain the degree of influence of glass beads on the matrix.

[0016] S7: The tensile properties of specimens Y and W were tested using a universal testing machine; the bending properties were tested using the unconstrained support three-point bending method; and the compressive properties were tested along the vertical direction of specimens Y and W using uniform loading. The effects of glass beads, quartz sand, and fly powder content on road markings were analyzed through experiments.

[0017] Preferably, in step S1, titanium dioxide in the form of brookite is used as a nanofiller phase, and polyisoprene with different degrees of polymerization is selected as a polymer phase. Homopolymer chains are formed by polymerization of isoprene as a single monomer, with the number of repeating units ranging from 10 to 50, thereby forming polyisoprene chains of different lengths. Subsequently, these polymer chains and titanium dioxide molecules are used together to construct a molecular dynamics model of the titanium dioxide / polyisoprene composite material. The titanium dioxide / polyisoprene composite material is used as polyisoprene-modified titanium dioxide and is soluble or compatible with an acrylic resin matrix.

[0018] Preferably, in step S2, the mechanical properties of the composite material at the atomic scale are simulated using molecular dynamics software. The ReaxFF force field is configured, the time step and periodic boundary conditions are set, the energy minimization method is applied, the NVE ensemble and NPT ensemble are selected for relaxation, the corresponding relaxation time is set, and the strain rate parameters of uniaxial tension are determined.

[0019] Preferably, when constructing the molecular dynamics model of the titanium dioxide / polyisoprene composite material, an initial time step is set, and periodic boundary conditions are adopted. During the energy minimization process, the conjugate gradient method is selected, and the relaxation ensemble, time setting, and uniaxial stretching steps include:

[0020] S2.1: In the relaxation phase, the model is first relaxed for a first predetermined time under the microcanonical ensemble (NVE) while maintaining the temperature at 250-350K. Then, the model is switched to the isobaric isothermal (NPT) ensemble and further relaxed for a second predetermined time at 250-350K.

[0021] S2.2: In molecular dynamics simulation, a microcanonical ensemble (NVE) is used, and a tensile force is applied in at least one axis. The rate of change of the box size is preset using an affine deformation method. After each stretching step, the system is relaxed for a third predetermined time to restore it to equilibrium before the next stretching is performed.

[0022] S2.3: During the tensile simulation, data processing software is used to analyze the simulation data, generate stress-strain curves, and extract mechanical property parameters from them. Through curve fitting and data processing, Young's modulus and yield strength mechanical properties are calculated.

[0023] Preferably, in step S3, the preparation process of specimen Y and specimen W is as follows: First, weigh the corresponding weight of acrylic resin, add polyisoprene modified titanium dioxide, double-flying powder, organic bentonite and accelerator to the resin in sequence, and stir with an electric stirrer at 500-1000 r / min. Then, add glass beads and quartz sand, stir for 3-5 minutes, add curing agent, and finally pour into a mold and let it stand for curing. Place the specimen in a ventilated environment to cure for at least 48 hours until it is completely cured.

[0024] Preferably, the surfaces of specimens Y and W are cleaned, then painted, with the paint size controlled to form a uniform surface speckle pattern. The specimens are then vertically clamped in the grips of a tensile testing machine, which includes an illumination, image acquisition, and optical imaging unit. The working distance between the specimen and the camera is adjusted to meet the requirements of field of view and resolution, ensuring that the specimen surface is flat and parallel to the camera sensor and that the camera is parallel to the ground. Strain analysis is performed after image acquisition.

[0025] Preferably, in step S5, in order to verify the accuracy and effectiveness of the numerical simulation, the relevant parameters of the matrix material extracted from the experiment are substituted into the finite element simulation, and a specimen model is established. Loads and boundary conditions are applied, and static simulation and calculation are performed. The stress-strain curves obtained in the numerical simulation are compared with the stress-strain curves obtained in the experiment.

[0026] Preferably, in step S7, the tensile properties of the specimen are tested using a universal testing machine with a tensile loading rate of 1 mm / min; the bending properties of the specimen are tested using the unconstrained three-point bending method with a specimen size of 70-90 mm × 10-20 mm and a thickness of 3-5 mm, and a bending loading rate of 1 mm / min; the compressive properties are tested using a uniform loading method along the vertical direction of the specimen with a cube having a side length of 15-25 mm and a compressive loading rate of 30 mm / min.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] I. This invention utilizes a multi-scale synergistic method combining molecular dynamics, finite element method, and experimental verification to achieve comprehensive characterization and parameter inversion from nanoscale filler phase behavior to macroscopic component mechanical response. It can quantitatively guide the selection of titanium dioxide volume fraction and polyisoprene chain length, and based on a mesoscopic model, reveals the stress transfer path and stress concentration mechanism of glass beads in the matrix. Furthermore, by optimizing the synergistic ratio of glass beads, quartz sand, and double-flying powder, the material achieves more balanced tensile, bending, and compressive properties while maintaining high brightness and reflectivity. This reduces the risk of interface-induced brittle fracture and crack initiation probability, improving the overall durability and service reliability of road markings.

[0029] Second, this invention significantly reduces the trial-and-error costs and R&D cycle of material design and improves the controllability of formulation scale-up and quality by standardizing the preparation process window (a set of parameters for stirring speed, stirring time, and curing agent dosage) and using a DIC-driven mechanical parameter identification and model calibration process. The established micro-random distribution model and macro-simulation evaluation system can quickly evaluate the coupling effect of different particle size distributions and content variations on mechanical-functional properties, enabling on-demand customization for different application scenarios, thereby improving the crack resistance, wear resistance, and service life of road markings, and reducing maintenance frequency and total life cycle costs. Attached Figure Description

[0030] Figure 1 This is a molecular dynamics model diagram of the titanium dioxide / polyisoprene composite material;

[0031] Figure 2 These are stress-strain curves of isoprene composed of different numbers of monomers.

[0032] Figure 3 These are tensile fracture diagrams and atomic stress cloud diagrams of titanium dioxide / polyisoprene composite materials;

[0033] Figure 4 It is a standard test specimen drawing of two-component road markings;

[0034] Figure 5 These are the force-displacement curves of specimens W and Y;

[0035] Figure 6 This is a strain contour plot of a glass bead-free specimen during tensile testing;

[0036] Figure 7 This is a strain contour map of a glass bead specimen during tensile testing.

[0037] Figure 8 It is a comparison chart of force-displacement curves between experimental calculations and finite element simulations;

[0038] Figure 9 This is a comparison diagram of the fracture locations calculated experimentally and simulated using finite element methods;

[0039] Figure 10 It is a detailed model drawing of road markings;

[0040] Figure 11 This is a diagram showing the dimensions of the specimen for the tensile properties test;

[0041] Figure 12 This is a diagram showing the dimensions of the specimen used in the bending performance test.

[0042] Figure 13 This is a diagram from a compression performance test. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Example 1

[0045] like Figures 1 to 13 As shown, this embodiment provides a multi-component road marking material, which is composed of the following components by mass percentage: 21% acrylic resin, 5% polyisoprene modified titanium dioxide pigment, 39.7% 600-mesh double-flying powder filler, 12% 40-80 mesh quartz sand, 22% 20-80 mesh reflective glass beads, 0.2% organic bentonite, and 0.1% accelerator.

[0046] This embodiment also provides a method for preparing a multi-component road marking material. The preparation method includes the following steps: weighing acrylic resin and accelerator, and stirring at a mixer speed of 700 r / min; after complete mixing, adding polyisoprene-modified titanium dioxide and continuing stirring; after the polyisoprene-modified titanium dioxide dissolves, adding double-flying powder, accelerator and organic bentonite and continuing stirring; after mixing evenly, adding glass beads and quartz sand, and continuing stirring for 5 minutes; then adding 1% of the total mass of the marking paint as curing agent, pouring into a mold and letting it stand to cure.

[0047] This embodiment also provides a method for studying the mechanical properties of multi-component road marking materials, including the following steps:

[0048] S1: Establish a molecular dynamics model with titanium dioxide as the nanofiller phase and polyisoprene as the polymer phase, and generate polyisoprene polymer chains with different repeating unit numbers by changing the number of monomers in the polymer phase, and further construct molecular dynamics models of titanium dioxide / polyisoprene composite materials with different degrees of polymerization.

[0049] S2: Molecular dynamics uniaxial tensile simulation was performed on the titanium dioxide / polyisoprene composite material from step S1 to obtain stress-strain curves and extract elastic modulus and yield strength, so as to determine the target titanium dioxide volume fraction and polyisoprene chain length parameters.

[0050] S3: Prepare two-component road markings according to the parameters determined in step S2. Treat all materials in the road markings except for glass beads as the matrix and glass beads as the reinforcement. Prepare ordinary road marking specimen Y containing glass beads and road marking specimen W without glass beads. Prepare multiple specimens Y and W for uniaxial tensile tests to reduce errors.

[0051] S4: Perform digital image correlation (DIC) post-processing on the tensile test, analyze the strain cloud map of specimen Y and specimen W in the frame before fracture, and determine the effect of glass bead addition on the vertical displacement of the two-component road marking and the difference in fracture cross section.

[0052] S5: Substitute the matrix material parameters extracted from the experiment into the finite element simulation, establish a specimen model, apply loads and boundary conditions, perform static simulation and calculation, and compare the force-displacement curves obtained in the numerical simulation with the force-displacement curves obtained in the experiment.

[0053] S6: Substitute the mechanical parameters of the matrix material obtained above into the microscopic model, randomly distribute glass beads in the microscopic model, fix the size and density of the glass beads, and randomly distribute their positions to establish a microscopic road marking model, and further explain the degree of influence of glass beads on the matrix.

[0054] S7: The tensile properties of the specimens were tested using a universal testing machine; the bending properties were tested using the unconstrained three-point bending method; and the compressive properties were tested using uniform loading along the vertical direction of the specimen. The effects of glass beads, quartz sand, and fly powder content on road markings were analyzed through experiments.

[0055] like Figure 2 As shown, further, in step S1, titanium dioxide in the form of brookite is used as a nanofiller phase, and polyisoprene with different degrees of polymerization is selected as a polymer phase. Homopolymer chains are formed by polymerization of isoprene as a single monomer, with repeating unit numbers ranging from 10, 20, 30, 40, and 50, thereby forming polyisoprene chains of different lengths. Subsequently, these polymer chains and titanium dioxide molecules are used together to construct a molecular dynamics model of the titanium dioxide / polyisoprene composite material for stress-strain testing. The titanium dioxide / polyisoprene composite material is used as polyisoprene-modified titanium dioxide and is soluble or compatible with an acrylic resin matrix.

[0056] Furthermore, in step S2, the mechanical properties of the composite material at the atomic scale are simulated using LAMMPS software. The ReaxFF force field is configured, the time step and periodic boundary conditions are set, the energy minimization method is applied, the NVE ensemble and NPT ensemble are selected for relaxation, the corresponding relaxation time is set, and the strain rate parameters of uniaxial tension are determined.

[0057] Furthermore, in constructing the molecular dynamics model of the titanium dioxide / polyisoprene composite material, the initial time step was set to 0.05 fs, and periodic boundary conditions were adopted. During the energy minimization process, the conjugate gradient method was selected. The relaxation ensemble, time setting, and uniaxial stretching steps included:

[0058] S2.1: In the relaxation phase, the model is first relaxed for a first predetermined time of 250 fs under the microcanonical ensemble (NVE) while maintaining the temperature at 300 K. Then, the model is switched to the isobaric isothermal (NPT) ensemble and further relaxed for a second predetermined time of 1250 fs at 300 K.

[0059] S2.2: In the molecular dynamics simulation, a microcanonical ensemble (NVE) was used, and a tensile force was applied along the x-axis. The deform command was used to set the rate of change of the box size to 5 × 10⁻⁻⁻⁶. 5 ps⁻¹ After each stretching step, the system is relaxed for a third predetermined time, i.e., 10fs, to restore it to equilibrium before the next stretching is performed.

[0060] S2.3: During the tensile simulation, MATLAB is used to analyze the simulation data, generate stress-strain curves, and extract mechanical property parameters from them. Through curve fitting and data processing, the Young's modulus and yield strength mechanical properties are calculated.

[0061] LAMMPS can calculate the stress of each atom, and can also obtain the stress during uniaxial tension of the model through pressure equivalence, i.e.:

[0062]

[0063] In the formula: and Indicates atomic index; and These represent the mass and velocity of the atom, respectively. and Indices in Cartesian coordinates; for and The distance between atoms; for and Interatomic forces; This represents the volume of an atom.

[0064] like Figure 4 As shown, further, in step S3, the preparation process of specimens Y and W is as follows: First, weigh the corresponding weight of acrylic resin, add polyisoprene modified titanium dioxide, double-flying powder, organic bentonite and accelerator to the resin in sequence, and stir with an electric stirrer at 700 r / min. Then add glass beads and quartz sand, stir for 5 minutes, add curing agent, and finally pour into the mold and let it stand for curing. Place the specimen in a ventilated environment to cure for at least 48 hours, and wait for it to be completely cured.

[0065] Furthermore, the surfaces of specimens Y and W are cleaned and then painted. The size of the paint spray is controlled to form a uniform surface speckle pattern. The specimens are then vertically clamped in the grips of the tensile testing machine, which includes lighting, image acquisition, and optical imaging units. The working distance between the specimen and the camera is adjusted to meet the requirements of field of view and resolution, ensuring that the specimen surface is flat and parallel to the camera sensor and that the camera is parallel to the ground. Strain analysis is performed after image acquisition.

[0066] Furthermore, in step S5, to verify the accuracy and effectiveness of the numerical simulation, the relevant parameters of the matrix material extracted from the experiment are substituted into the finite element simulation, and a specimen model is established. Loads and boundary conditions are applied, and static simulation and calculation are performed. The stress-strain curves obtained in the numerical simulation are compared with the stress-strain curves obtained in the experiment.

[0067] Furthermore, in step S7, referring to the GB / T2567—2021 standard for test methods of performance of resin castings, the tensile properties of the specimen are tested using a universal testing machine with a tensile loading rate of 1 mm / min; referring to the GB / T2567—2021 standard for test methods of performance of resin castings, the bending properties of the specimen are tested using the unconstrained support three-point bending method, with the specimen size being 80 mm × 15 mm and the thickness being 4 mm, and the bending loading rate being 1 mm / min; the compressive properties are tested using a uniform loading method along the vertical direction of the specimen, with the specimen being a 20 mm × 20 mm × 20 mm cube and the compression loading rate being 30 mm / min.

[0068] Example 2

[0069] Compared with Example 1, as another embodiment of the present invention, the following components are composed by mass percentage: 21% acrylic resin, 5% polyisoprene modified titanium dioxide as pigment, 48.85% 600-mesh double-flying powder as filler, 10% 40-80 mesh quartz sand, 15% 20-80 mesh reflective glass beads, 0.1% organic bentonite, and 0.05% accelerator.

[0070] The preparation method of this embodiment includes the following steps: weighing acrylic resin and accelerator, and stirring at a mixer speed of 500 r / min; after complete mixing, adding polyisoprene-modified titanium dioxide and continuing stirring; after the polyisoprene-modified titanium dioxide dissolves, adding double-flying powder and organic bentonite and continuing stirring; after mixing evenly, adding glass beads and quartz sand, and continuing stirring for 3 minutes; then adding 0.5% of the total mass of the marking paint as curing agent, pouring into a mold and letting it stand to cure.

[0071] In the mechanical property research method of this embodiment, steps S1-S6 are the same as in Embodiment 1. The test parameters for step S7 are as follows: the tensile properties of the specimen are tested using a universal testing machine at a tensile loading rate of 1 mm / min; the bending properties of the specimen are tested using the unconstrained three-point bending method, with the specimen dimensions being 70 mm × 10 mm and a thickness of 3 mm, and the bending loading rate being 1 mm / min; the compressive properties are tested using a uniform loading method along the vertical direction of the specimen, with the specimen being a 20 mm × 20 mm × 20 mm cube and the compressive loading rate being 30 mm / min.

[0072] Example 3

[0073] Compared with Example 1, as another embodiment of the present invention, the following components are composed by mass percentage: 18% acrylic resin, 3% polyisoprene modified titanium dioxide as pigment, 35.3% 600-mesh double-flying powder as filler, 18% 40-80 mesh quartz sand, 25% 20-80 mesh reflective glass beads, 0.5% organic bentonite, and 0.2% accelerator.

[0074] The preparation method of this embodiment includes the following steps: weighing acrylic resin and accelerator, stirring at a speed of 1000 r / min; after complete mixing, adding polyisoprene-modified titanium dioxide and continuing stirring; after the polyisoprene-modified titanium dioxide dissolves, adding double-flying powder and organic bentonite and continuing stirring; after mixing evenly, adding glass beads and quartz sand, and continuing stirring for 8 minutes; then adding 2% of the total mass of the marking paint as curing agent, pouring into a mold and letting it stand to cure.

[0075] In the mechanical property research method of this embodiment, steps S1-S6 are the same as in Embodiment 1. The test parameters for step S7 are as follows: the tensile properties of the specimen are tested using a universal testing machine at a tensile loading rate of 1 mm / min; the bending properties of the specimen are tested using the unconstrained three-point bending method, with the specimen dimensions being 90 mm × 20 mm and a thickness of 5 mm, and the bending loading rate being 1 mm / min; the compressive properties are tested using a uniform loading method along the vertical direction of the specimen, with the specimen being a 25 mm × 25 mm × 25 mm cube and the compressive loading rate being 30 mm / min.

[0076] like Figure 5 As shown, under the test specimens and loading conditions used in this embodiment, the effect of glass beads on the strain response is not significant in the elastic stage. For the ultimate strength, there is a difference between samples containing and without glass beads, the specific magnitude of which is related to factors such as the volume fraction, particle size distribution, spatial distribution, and interface state between the glass beads and the matrix. In this batch of samples, the effect of glass beads on the latter part of the stress-strain curve is more sensitive; the specific manifestation can be seen in the curve comparison in the figure.

[0077] like Figure 7 As shown in step 4, the fracture cross-section of the glass bead-containing specimen reveals localized separation of the glass beads from the matrix or near-interface cracking. Cracks primarily propagate along or near the interface. The interfacial bonding condition is related to the surface condition of the glass beads, the pretreatment method, the curing conditions, and the bonding performance with the matrix, and may vary between different samples.

[0078] like Figure 8 and Figure 9 As shown, the stress-strain curves obtained from the numerical simulation generally agree well with the experimental results, the main characteristics can be captured by the simulation, and the fracture location shows a high degree of consistency with experimental observations. This result indicates that the parameter identification and model setting used are effective to a certain extent.

[0079] like Figure 10 As shown, randomly distributed glass beads in the mesoscopic model alter the stress transfer path in the matrix, potentially leading to localized stress concentrations around the glass beads and in areas where they are close to each other. The extent of these concentrations depends on factors such as the size, content, spatial distribution, and interfacial interactions of the glass beads.

[0080] like Figures 10 to 13 As shown, within the implementation conditions and sample ratio range, adjusting the relative contents of glass beads, quartz sand, and double-flying powder resulted in different sensitivities and optimal ranges for various mechanical properties. For example, appropriately adjusting the glass bead content improved tensile and compressive properties within a certain range; bending properties showed an optimal range for changes in quartz sand content; increasing the double-flying powder content had a positive impact on tensile and compressive properties, while bending properties might reach a better value near a certain range. These phenomena are closely related to particle size, distribution morphology, and interface state. Specific ratios can be weighed and optimized based on the target performance, as detailed in the curve comparison in the figure.

[0081] In molecular dynamics comparisons, the mechanical response of the model showed certain differences with the number of repeating units in the polyisoprene chain, exhibiting a trend of higher elastic modulus near the medium chain length. The introduction of nano-titanium dioxide improved the elastic modulus of the model, and the extent of the improvement was related to the model configuration, interaction parameters, and simulation conditions.

[0082] Through comparative analysis of experiments and finite element numerical simulations, it was found that the matrix material bore the main load in this sample under the loading conditions. The influence of glass beads on the elastic stage was relatively limited, while the influence on the strength index was closely related to factors such as the volume fraction, particle size distribution, distribution state, and interfacial bonding of the glass beads, exhibiting a certain degree of sensitivity.

[0083] Based on these tensile, bending, and compression experiments, the effects of glass beads, quartz sand, and double-flying powder content on different mechanical properties varied within the investigated formulation range and process conditions, and a trade-off relationship existed between the different properties. The optimal formulation can be determined based on the comprehensive requirements of the target application for tensile, bending, and compression properties; relevant trends and typical results are shown in the corresponding figures.

[0084] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for studying the mechanical properties of a multi-component road marking material, characterized in that, Includes the following steps: S1: Establish a molecular dynamics model with titanium dioxide as the nanofiller phase and polyisoprene as the polymer phase, and generate polyisoprene polymer chains with different repeating unit numbers by changing the number of monomers in the polymer phase, and further construct molecular dynamics models of titanium dioxide / polyisoprene composite materials with different degrees of polymerization. S2: Perform molecular dynamics uniaxial tensile simulation on the titanium dioxide / polyisoprene composite material described in step S1 to obtain stress-strain curves and extract elastic modulus and yield strength to determine the target titanium dioxide volume fraction and polyisoprene chain length parameters. S3: Prepare the multi-component road marking material according to the parameters determined in step S2. Treat all materials in the road marking except glass beads as the matrix and glass beads as the reinforcement. Prepare ordinary road marking specimen Y containing glass beads and road marking specimen W without glass beads. Prepare multiple specimens Y and W for uniaxial tensile tests to reduce errors. S4: Perform digital image correlation post-processing on the tensile test, analyze the strain cloud map of specimen Y and specimen W in the frame before fracture, and determine the effect of glass bead addition on the vertical displacement of multi-component road marking materials and the difference in fracture cross sections. S5: Substitute the matrix material parameters extracted from the experiment into the finite element simulation, establish a specimen model, apply loads and boundary conditions, perform static simulation and calculation, and compare the force-displacement curves obtained in the numerical simulation with the force-displacement curves obtained in the experiment. S6: Substitute the mechanical parameters of the matrix material obtained above into the microscopic model, randomly distribute glass beads in the microscopic model, fix the size and density of the glass beads, and randomly distribute their positions to establish a microscopic road marking model, and further explain the degree of influence of glass beads on the matrix. S7: The tensile properties of specimens Y and W were tested using a universal testing machine; the bending properties were tested using the unconstrained three-point bending method; and the compressive properties were tested along the vertical direction of specimens Y and W using uniform loading. The effects of glass beads, quartz sand, and fly powder content on road markings were analyzed through experiments.

2. The method for studying the mechanical properties of a multi-component road marking material according to claim 1, characterized in that: In step S1, titanium dioxide in the form of brookite is used as a nanofiller phase, and polyisoprene with different degrees of polymerization is selected as a polymer phase. Homopolymer chains are formed by polymerization of isoprene as a single monomer, with the number of repeating units ranging from 10 to 50, thereby forming polyisoprene chains of different lengths. Subsequently, these polymer chains and titanium dioxide molecules are used together to construct a molecular dynamics model of the titanium dioxide / polyisoprene composite material. The titanium dioxide / polyisoprene composite material is used as polyisoprene-modified titanium dioxide and is soluble or compatible with acrylic resin matrix.

3. The method for studying the mechanical properties of a multi-component road marking material according to claim 2, characterized in that: In step S2, the mechanical properties of the composite material at the atomic scale are simulated using molecular dynamics software. The ReaxFF force field is configured, the time step and periodic boundary conditions are set, the energy minimization method is applied, the NVE ensemble and NPT ensemble are selected for relaxation, the corresponding relaxation time is set, and the strain rate parameters of uniaxial tension are determined.

4. The method for studying the mechanical properties of a multi-component road marking material according to claim 3, characterized in that: When constructing the molecular dynamics model of the titanium dioxide / polyisoprene composite material, an initial time step was set, and periodic boundary conditions were adopted. During the energy minimization process, the conjugate gradient method was selected. The relaxation ensemble, time setting, and uniaxial stretching steps included: S2.1: In the relaxation phase, the model is first relaxed for a first predetermined time under the microcanonical ensemble, while maintaining the temperature at 250-350K. Then, the model is switched to the isobaric isothermal ensemble and further relaxed for a second predetermined time at 250-350K. S2.2: In molecular dynamics simulation, a microcanonical ensemble is used, and a tensile force is applied in at least one axis. The rate of change of the box size is preset using an affine deformation method. After each stretching step, the system is relaxed for a third predetermined time to restore it to equilibrium before the next stretching is performed. S2.3: During the tensile simulation, data processing software is used to analyze the simulation data, generate stress-strain curves, and extract mechanical property parameters from them. Through curve fitting and data processing, Young's modulus and yield strength mechanical properties are calculated.

5. The method for studying the mechanical properties of a multi-component road marking material according to claim 1, characterized in that: In step S3, the preparation process of specimens Y and W is as follows: First, weigh the corresponding weight of acrylic resin, add polyisoprene modified titanium dioxide, double-flying powder, organic bentonite and accelerator to the resin in sequence, and stir with an electric stirrer at 500-1000 r / min. Then add glass beads and quartz sand, stir for 3-5 minutes, add curing agent, and finally pour into the mold and let it stand for curing. Place the specimen in a ventilated environment to cure for at least 48 hours and wait for it to be completely cured.

6. The method for studying the mechanical properties of a multi-component road marking material according to claim 5, characterized in that: The surfaces of specimens Y and W are cleaned and then painted. The size of the paint spray is controlled to form a uniform surface speckle pattern. The specimens are then vertically clamped in the grips of the tensile testing machine, which includes lighting, image acquisition, and optical imaging units. The working distance between the specimen and the camera is adjusted to meet the requirements of field of view and resolution, the specimen surface is flat and parallel to the camera sensor, and the camera is parallel to the ground. Strain analysis is performed after image acquisition.

7. The method for studying the mechanical properties of a multi-component road marking material according to claim 1, characterized in that: In step S5, to verify the accuracy and effectiveness of the numerical simulation, the relevant parameters of the matrix material extracted from the experiment are substituted into the finite element simulation, and a specimen model is established. Loads and boundary conditions are applied, and static simulation and calculation are performed. The stress-strain curves obtained in the numerical simulation are compared with the stress-strain curves obtained in the experiment.

8. The method for studying the mechanical properties of a multi-component road marking material according to claim 1, characterized in that: In step S7, the tensile properties of the specimen are tested using a universal testing machine with a tensile loading rate of 1 mm / min. The bending properties of the specimen are tested using the unconstrained three-point bending method. The specimen has dimensions of 70-90 mm × 10-20 mm and a thickness of 3-5 mm, with a bending loading rate of 1 mm / min. The compressive properties are tested using a uniform loading method along the vertical direction of the specimen. The specimen is a cube with a side length of 15-25 mm, and the compressive loading rate is 30 mm / min.

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