Cross-scale analysis method and system for asphalt mixture based on macro-micro feature coupling

Abstract

The present invention provides a cross-scale analysis method and system for asphalt mixture based on macro- and micro-feature coupling, which relates to the technical field of finite element analysis. The method includes: obtaining the cracking characteristics and mechanical properties of asphalt mixture, and the relationship between the cracks and the time and load state; constructing a micro-scale cracking model of asphalt mixture, and establishing the cracking criterion of asphalt mixture; simulating the stress distribution in asphalt mixture by extended finite element, reconstructing the evolution behavior of meso-cracks in asphalt mixture, and obtaining the meso-scale stress distribution law of asphalt mixture; fitting to obtain a macro- and micro-scale cross-scale coupling model of asphalt mixture cracking damage, and analyzing the cracking behavior of asphalt mixture at different scales based on the macro- and micro-scale cross-scale coupling model of asphalt mixture cracking damage. The present invention can realize the macro- and micro-scale cross-scale analysis of the cracking behavior of asphalt mixture.

Description

Technical Field

[0001] The present invention relates to the technical field of finite element analysis, and in particular to a cross-scale analysis method and system for asphalt mixture based on macroscopic and microscopic feature coupling. Background Art

[0002] Asphalt mixture is a general term for a mixture of mineral aggregate and asphalt binder, which is commonly used for asphalt pavement paving. In order to guide pavement maintenance strategies and optimize the service performance of pavement structures over their life cycle, it is necessary to study and predict the cracking behavior of asphalt pavements.

[0003] At present, in response to the problems that it is difficult to accurately detect the multi-mode cracking distribution of asphalt pavements and to accurately predict the crack evolution, existing research mainly focuses on the performance evaluation of asphalt materials. However, there is still a lack of relevant research on the mesoscopic cracking failure mechanism and macro- and micro-scale cross-scale characterization of asphalt mixtures considering multiple cracking modes. As a result, it is difficult to provide an accurate and systematic explanation of the macroscopic performance decay behavior of asphalt mixtures based on mesoscopic cracking and crack evolution behavior, or to give a direct and clear answer to the decay law of the service performance of asphalt pavements. Summary of the invention

[0004] In order to address the deficiencies of the prior art, the purpose of the present invention is to provide a cross-scale analysis method and system for asphalt mixture based on macro- and micro-feature coupling, so as to realize macro- and micro-scale cross-scale analysis of the cracking behavior of asphalt mixture.

[0005] In order to achieve the above object, according to some embodiments, a first aspect of the present invention provides a cross-scale analysis method for asphalt mixture based on macro-micro feature coupling, comprising:

[0006] Based on asphalt mixture cracking experiments and asphalt mixture viscoelastic mechanics experiments, the cracking characteristics and mechanical properties of asphalt mixtures, as well as the relationship between cracks and time and load conditions, are obtained;

[0007] Based on the cracking characteristics and mechanical properties of asphalt mixture, a mesoscale cracking model of asphalt mixture is constructed. By simulating the cracking behavior of asphalt mixture by extended finite element method, a mesoscale cracking criterion of asphalt mixture is established.

[0008] Based on the relationship between crack changes over time and load conditions, the mesoscale cracking criterion of asphalt mixture is modified.

[0009] Based on the revised meso-scale cracking criterion of asphalt mixture, the stress distribution in asphalt mixture is simulated by extended finite element method, the evolution behavior of meso-scale cracks in asphalt mixture is reconstructed, and the meso-scale stress distribution law of asphalt mixture is obtained.

[0010] Based on the obtained meso-scale stress distribution law of asphalt mixture, a macro- and micro-scale cross-scale coupling model of asphalt mixture cracking damage is fitted. Based on the macro- and micro-scale coupling model of asphalt mixture cracking damage, the cracking behavior of asphalt mixture at different scales is analyzed.

[0011] The second aspect of the present invention provides an asphalt mixture cross-scale analysis system based on macro-micro feature coupling, comprising:

[0012] The experimental module is configured to obtain the cracking characteristics and mechanical properties of asphalt mixtures, as well as the relationship between cracks and time and load conditions based on asphalt mixture cracking experiments and asphalt mixture viscoelastic mechanics experiments;

[0013] The asphalt mixture mesoscale cracking criterion acquisition module is configured to construct a mesoscale cracking model of asphalt mixture based on the cracking characteristics and mechanical properties of asphalt mixture, simulate the cracking behavior of asphalt mixture by extended finite element method, and establish the mesoscale cracking criterion of asphalt mixture;

[0014] A correction module is configured to correct the asphalt mixture mesoscale cracking criterion based on the relationship between the crack and the time and load state;

[0015] The simulation and reconstruction module is configured to simulate the stress distribution in the asphalt mixture based on the modified meso-scale cracking criterion of the asphalt mixture by extending the finite element method, reconstruct the evolution behavior of the meso-scale cracks in the asphalt mixture, and obtain the meso-scale stress distribution law of the asphalt mixture;

[0016] The cross-scale coupling module is configured to fit the macro- and micro-scale cross-scale coupling model of asphalt mixture cracking damage based on the obtained meso-scale stress distribution law of asphalt mixture, and analyze the cracking behavior of asphalt mixture at different scales based on the macro- and micro-scale cross-scale coupling model of asphalt mixture cracking damage.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention provides a cross-scale analysis method and system for asphalt mixture based on macro-micro feature coupling, which couples the cracking behavior of asphalt mixture at macro and micro scales by using stress distribution characteristics as a medium, thereby realizing macro-micro cross-scale analysis of the cracking behavior of asphalt mixture. At the micro scale, the extended finite element (XFEM) method is used to reconstruct the crack evolution and expansion behavior of asphalt mixture. At the same time, the geometric information and expansion process of cracks in the multi-cracking mode of asphalt mixture collected by high-speed industrial cameras are combined to analyze the spatiotemporal variation law of stress distribution in asphalt mixture with crack expansion; at the macro scale, the macro-mechanical evolution behavior in the multi-mode cracking experiment of asphalt mixture is studied based on damage mechanics theory to obtain a macro-mechanical model; finally, the macro-mechanical model and the meso-scale stress distribution law are combined to construct a macro-micro cross-scale coupling model of crack damage in the multi-cracking mode of asphalt mixture, thereby realizing effective analysis of the cracking behavior of asphalt mixture at different scales.

[0019] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0021] Figure 1 Schematic diagram of the process of the method in Embodiment 1 of the present invention. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0023] Embodiment 1

[0024] Embodiment 1 of the present invention provides a cross-scale analysis method for asphalt mixture based on macro-micro feature coupling, such as Figure 1 As shown, including:

[0025] S100, based on asphalt mixture cracking test and asphalt mixture viscoelastic mechanics test, obtain the cracking characteristics and mechanical properties of asphalt mixture, as well as the relationship between cracks and time and load state;

[0026] S200. Based on the cracking characteristics and mechanical properties of asphalt mixture, a mesoscale cracking model of asphalt mixture is constructed. By simulating the cracking behavior of asphalt mixture by extended finite element method, a mesoscale cracking criterion of asphalt mixture is established.

[0027] S300, based on the relationship between cracks and time and load conditions, the mesoscale cracking criterion of asphalt mixture is modified;

[0028] S400, based on the revised asphalt mixture meso-scale cracking criterion, the stress distribution in the asphalt mixture is simulated by extending the finite element method, the evolution behavior of the meso-scale cracks in the asphalt mixture is reconstructed, and the meso-scale stress distribution law of the asphalt mixture is obtained;

[0029] S500. Based on the obtained meso-scale stress distribution law of asphalt mixture, a macro-micro cross-scale coupling model of asphalt mixture cracking damage is fitted, and the cracking behavior of asphalt mixture at different scales is analyzed based on the macro-micro cross-scale coupling model of asphalt mixture cracking damage.

[0030] In step S100, an asphalt mixture cracking experiment and an asphalt mixture viscoelastic mechanics experiment are carried out respectively. The asphalt mixture cracking experiment is used to obtain the crack distribution and geometric characteristics of the asphalt mixture at a macroscopic scale, and the asphalt mixture viscoelastic mechanics experiment is used to obtain the mechanical performance parameters of the asphalt mixture, including the stress-strain state. At the same time, during the asphalt mixture cracking experiment, a high-speed industrial camera is used to capture the geometric characteristics and evolution path of the cracks during the experiment, and the expansion path of the cracks with time and load state is obtained.

[0031] In the asphalt mixture cracking experiment, the cracking characteristics of type I cracking, as well as the coupling behavior of type I and type II, type I and type III cracking are studied experimentally, including:

[0032] S111. The four-point bending test is used to characterize the opening type (Type I) cracking characteristics of asphalt mortar. In the four-point bending test, under the combined action of two supporting points and a load point, the middle part of the bottom of the specimen is only subjected to tensile stress, and Type I cracking will occur.

[0033] S112, sliding type (Type II) and tearing type (Type III) cracking modes are generally difficult to characterize separately through experiments. In actual engineering, they often occur in coupling with Type I cracking. The two coupled cracking behaviors are characterized by three-point bending test and edge notch disk bending test respectively.

[0034] S1121. A three-point bending test is used to study the type I and type II coupled cracking behaviors of asphalt mixtures. During the experiment, there is only one load point in the middle part of the specimen. Therefore, in addition to the bending and tensile loads, the specimen is also subjected to shear loads, resulting in type I and type II coupled cracking behaviors of the asphalt mixture.

[0035] S1122. The Edge Notched Disc Bend Test is used to characterize the coupling behavior of mode I and mode III cracking by adjusting the angle between the indenter and the initial crack.

[0036] S113. Use a high-speed industrial camera to capture the crack propagation path of asphalt mixture during micro-cracking process with time and load conditions.

[0037] The viscoelastic mechanics experiment of asphalt mixture specifically includes:

[0038] S121. Dynamic mechanical analyzer (DMA) and dynamic shear rheometer (DSR) were used to test the viscoelastic mechanical properties of asphalt mixture.

[0039] S122. Scanning electron microscopy and atomic force microscopy were used to observe the microstructure of the asphalt-aggregate interface and the thickness of the asphalt film, and the Derjaguin-Muller-Toporov (DMT) model was used to fit the effective modulus of the asphalt-aggregate interface.

[0040] S123. The asphalt-aggregate pull-out test was used to characterize the type I cracking behavior of the interface, and the dynamic shear rheometer was used to apply shear stress to test the type II and type III cracking behaviors of the asphalt-aggregate interface.

[0041] In step S200, the multi-mode cracking behavior of asphalt mixture is numerically simulated and reconstructed using the extended finite element (XFEM) method to simulate the cracking behavior of asphalt mixture, establish a unified mesoscale cracking criterion for asphalt mixture and its control parameter form, and provide a parameter basis for the macro-micro joint characterization of the cracking behavior of asphalt mixture. The mesoscale cracking criterion for asphalt mixture and its control parameter form indicate under what parameter conditions the asphalt mixture will crack, such as fracture toughness, fracture energy, and crack limit opening width.

[0042] Step S200 specifically includes:

[0043] S210, based on the crack propagation path of the asphalt mixture during the microscopic cracking process collected in step S113 with time and load conditions, combined with the mechanical mechanism and the mechanical property parameters of the asphalt mixture obtained from the viscoelastic mechanics experiment of the asphalt mixture, analyze and determine the stress distribution law near the crack tip area at a unit scale.

[0044] S220. Compare the three-stage behaviors of asphalt mixture cracking process, namely uncracked, cracking evolution and failure, fit the cracking behaviors under different loading modes, load levels, loading speeds and ambient temperatures, and establish a unified mesoscale cracking criterion for asphalt mixture and its control parameter form.

[0045] S230. Based on the stress distribution law obtained in step S210, a meso-scale cracking model of asphalt mixture is created by extended finite element method (XFEM), and the simulation of multi-mode cracking behavior of asphalt mixture is realized in the XFEM framework. The model simulation parameters are determined according to the asphalt mixture cracking experiment in step S100, and the loading method, load level, loading speed and ambient temperature are the same as those in the asphalt mixture cracking experiment. The cracking characteristics of the asphalt mixture are determined based on the established meso-scale cracking criterion and its control parameter form, and the mechanical properties of the asphalt mixture are determined based on the results of the asphalt mixture viscoelasticity experiment.

[0046] S240. Initial cracks are set in the mesoscale cracking model of asphalt mixture to study the cracking evolution behavior of type I, II, and III cracking modes and their coupling effects.

[0047] In step S300, based on the grading characteristics of the asphalt mixture, the simulation results of the meso-scale cracking model are calibrated using the expansion paths of the cracks over time and load states collected in step S100, and the simulation results of the cracks in the cracking process of the asphalt mixture by the meso-scale cracking model are compared with the collected results of the crack changes during the experiment. The parameters and boundary conditions of the meso-scale cracking model, including the loading method, load level, loading speed and ambient temperature, are modified so that the simulation results of the model correspond to the experimental change results, thereby correcting the meso-scale cracking criterion.

[0048] In step S400, based on the crack modeling method of the phase field model, the mesoscopic crack evolution behavior of the multi-cracking mode of the asphalt mixture is reconstructed in the finite element, the interaction relationship between the stress distribution change and the crack propagation evolution is clarified, and the mesoscopic scale stress distribution law of the asphalt mixture considering the multi-mode crack path is established.

[0049] Step S400 specifically includes:

[0050] S410, constructing a phase field model and defining phase field variables to indicate the presence or absence of cracks. The phase field model is based on an evolution equation of an unbounded parameter field and mathematically describes the morphology and evolution process of cracks.

[0051] S420, discretize the model, discretize the phase field model into a finite element grid with a grid size of 1, so as to perform calculations in a finite element simulation. This is achieved by dividing the physical domain into units and defining the values ​​of the phase field variables at the nodes.

[0052] S430. According to the mechanical properties of the asphalt mixture, the mesoscale cracking model obtained after the parameter modification in step S300 is selected to simulate the mesoscale crack evolution behavior of the asphalt mixture, which involves simulating the elasticity, plasticity, viscoelasticity and other mechanical properties of the asphalt mixture, and applying the modified boundary conditions to simulate the actual stress environment in detail.

[0053] S440, setting the crack evolution rules to drive the generation, expansion and branching of cracks based on the values ​​of phase field variables, including determining the evolution equation of the phase field variables, the crack growth rate equation, and the mechanical and thermal effects related to the crack evolution.

[0054] S450, conduct finite element simulation, observe the evolution process of cracks, and analyze the morphology, expansion rate and distribution characteristics of cracks. By analyzing the simulation results, the microscopic crack evolution behavior characteristics of the multi-cracking mode of asphalt mixture can be obtained, and the stress distribution of asphalt mixture cracks in the whole process of evolution can be obtained.

[0055] Step S450 specifically includes:

[0056] S451: The established asphalt mixture mesoscale cracking model is used to simulate the process of the asphalt mixture cracking experiment in step S100, wherein the asphalt mixture uses solid units. According to the characteristics of the asphalt mixture cracking experiment, 2.36 mm is used as the dividing line between coarse and fine aggregates. For the convenience of calculation, a regular octagon is used to simulate the shape of the aggregate.

[0057] S452: Cracks are introduced into the mesoscale cracking model by using the extended finite element method (XFEM), and the model parameters and boundary conditions are the parameters and boundary conditions modified in step S300, including loading mode, load level, loading speed and ambient temperature.

[0058] S453: Use the established asphalt mixture finite element model to simulate the stress distribution in the asphalt mixture, and dynamically simulate the changes in the stress field during the crack propagation process to consider the impact of crack propagation on the stress distribution.

[0059] S454: By simulating the process of crack propagation, observing the crack evolution behavior and analyzing the multi-mode characteristics of the crack path, including observing the direction, rate and morphological changes of crack propagation, as well as the mutual influence between cracks.

[0060] S455: Analyze the interaction between stress distribution changes and crack expansion evolution, observe the changes in stress field with crack expansion, and the impact of crack expansion on the surrounding stress field, so as to obtain the mutual influence relationship between crack expansion and stress distribution.

[0061] S456: Based on the simulation results of crack evolution behavior in step S454 and the analysis of the interaction between stress distribution changes and crack propagation evolution in step S455, a mesoscale stress distribution law of asphalt mixture considering multi-mode crack paths is established, that is, the stress distribution law on the crack evolution path of asphalt mixture.

[0062] In step S500, it is assumed that after meso-scale cracking and crack evolution occur in the asphalt mixture, the macroscopic stress-strain response can be equivalent to the effective stress-strain response in the lossless state. Based on this, a damage variable is introduced to represent the degree of decay of the effective stress-strain in the structure, thereby characterizing the degree of crack evolution inside the asphalt material; based on the meso-scale stress distribution law of the asphalt mixture obtained in step S450, the damage variable function of the entire structure at the macro-scale is fitted, thereby realizing the coupling of the meso-scale crack evolution characteristics and the macro-scale damage evolution behavior.

[0063] Step S500 specifically includes:

[0064] S510. Determine the scale range covered by the multi-scale simulation. In this patent, the scale range includes macroscopic scale and microscopic scale.

[0065] S520. Based on the macroscopic structural geometric characteristics of the asphalt mixture obtained in step S100 (such as pore structure, aggregate distribution, etc.), combined with the homogenization theory, a macro-microscopic cross-scale coupling mechanism of asphalt mixture cracking damage mediated by stress distribution characteristics is proposed to describe the relationship between macroscopic damage variables and microscopic crack characteristics, and explain how macroscopic damage is driven by microscopic crack evolution behavior.

[0066] Step S520 specifically includes:

[0067] S521: Establish a nondestructive model and a cracking model of asphalt mixture with the same scale and boundary conditions in abaqus software.

[0068] S522: Mark a point in the cracking model as P, and collect macroscopic structural geometric feature data of point P during the finite element simulation of the cracking model in step S400, including crack location, boundary conditions and mechanical response.

[0069] S523: Calibrate point P1 in the non-destructive model corresponding to point P in the cracking model, and analyze the stress distribution state of the non-destructive model and the crack extension under the same external force load, including the crack position, boundary conditions and mechanical response.

[0070] S524: Repeat the above process, select points different from P and P1 in the two models for calibration and repeat the above analysis process.

[0071] S525: Using statistical principles, establish a functional relationship between the stress state of each point in the model and the crack geometry information (including crack length, crack width, vertical distance to the crack, distance to the crack tip, and angle with the crack tip).

[0072] The functional relationship between the stress state at any point P and the crack geometry information satisfies the following equation:

[0073] ;

[0074] in, represents the stress state at any point in the cracking model; Characterize the stress state of non-destructive models of the same size under the same external load; To establish the functional relationship, is the crack length, is the crack width, is the vertical distance from point P to the crack, is the distance from point P to the crack tip, is the angle between point P and the crack tip.

[0075] S526: The collected data are sorted, and the relationship between the crack geometric characteristics of the calibrated points in the cracking model and the stress distribution state of the corresponding points in the non-destructive model is analyzed by statistical methods, so as to characterize the crack geometric characteristics through the stress state, establish a macro-micro cross-scale coupling model of asphalt mixture cracking damage, and obtain the functional relationship between the macro damage variable based on stress distribution and the crack micro characteristics. The macro-micro cross-scale coupling model of asphalt mixture cracking damage, that is, the damage variable function of the entire structure at the macro scale, is as follows:

[0076] ;

[0077] Among them, φ is the damage variable, which increases as the effective load-bearing area in the structure decreases; and Respectively represent the effective load-bearing area and nominal load-bearing area in the structure; and represents the volume of the structure in the cracked and intact states; g is the functional relationship between the damage variable and the stress state defined based on continuum damage mechanics.

[0078] S527: Use independent experimental data or field monitoring data to verify the established macro-micro cross-scale coupling model of asphalt mixture cracking damage, compare the model prediction results with the actual stress distribution data, and evaluate the accuracy and reliability of the model.

[0079] Embodiment 2

[0080] This embodiment provides an asphalt mixture cross-scale analysis system based on macro-micro feature coupling, including:

[0081] The experimental module is configured to obtain the cracking characteristics and mechanical properties of asphalt mixtures, as well as the relationship between cracks and time and load conditions based on asphalt mixture cracking experiments and asphalt mixture viscoelastic mechanics experiments;

[0082] The asphalt mixture mesoscale cracking criterion acquisition module is configured to construct a mesoscale cracking model of asphalt mixture based on the cracking characteristics and mechanical properties of asphalt mixture, simulate the cracking behavior of asphalt mixture by extended finite element method, and establish the mesoscale cracking criterion of asphalt mixture;

[0083] A correction module is configured to correct the asphalt mixture mesoscale cracking criterion based on the relationship between the crack and the time and load state;

[0084] The simulation and reconstruction module is configured to simulate the stress distribution in the asphalt mixture based on the modified meso-scale cracking criterion of the asphalt mixture by extending the finite element method, reconstruct the evolution behavior of the meso-scale cracks in the asphalt mixture, and obtain the meso-scale stress distribution law of the asphalt mixture;

[0085] The cross-scale coupling module is configured to fit the macro- and micro-scale cross-scale coupling model of asphalt mixture cracking damage based on the obtained meso-scale stress distribution law of asphalt mixture, and analyze the cracking behavior of asphalt mixture at different scales based on the macro- and micro-scale cross-scale coupling model of asphalt mixture cracking damage.

[0086] It should be noted here that the various modules in this embodiment correspond one-to-one to the steps of the method in Example 1, and the specific implementation process is the same, which will not be repeated here.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A cross-scale analysis method for asphalt mixture based on macro-micro feature coupling, characterized by: include: Based on asphalt mixture cracking experiments and asphalt mixture viscoelastic mechanics experiments, the cracking characteristics and mechanical properties of asphalt mixtures, as well as the relationship between cracks and time and load conditions, are obtained; Based on the cracking characteristics and mechanical properties of asphalt mixture, a mesoscale cracking model of asphalt mixture is constructed, and the cracking behavior of asphalt mixture is simulated by extended finite element method to establish the cracking criterion of asphalt mixture. The specific process is as follows: based on the cracking experiment of asphalt mixture, the cracking characteristics of asphalt mixture are obtained; according to the cracking characteristics of asphalt mixture, the stress distribution law near the crack tip area at unit scale is determined; the mesoscale cracking model of asphalt mixture is constructed, and the functional relationship between the stress state of each point in the mesoscale cracking model of asphalt mixture and the crack geometric information is established; the mesoscale cracking model is simulated by extended finite element method, and the cracking behavior of asphalt mixture under different loading modes, load levels, loading speeds and ambient temperatures in the process of non-cracking, cracking evolution and failure is simulated for the established mesoscale cracking model, and the mesoscale cracking criterion of asphalt mixture and its control parameter form are obtained; based on the relationship between the crack change with time and load state, the asphalt mixture cracking criterion is modified; Based on the revised asphalt mixture cracking criterion, the stress distribution in asphalt mixture is simulated by extended finite element method, the evolution behavior of mesoscopic cracks in asphalt mixture is reconstructed, and the mesoscopic stress distribution law of asphalt mixture is obtained. Based on the obtained meso-scale stress distribution law of asphalt mixture, a macro-micro cross-scale coupling model of asphalt mixture cracking damage is fitted, and the cracking behavior of asphalt mixture at different scales is analyzed based on the macro-micro cross-scale coupling model of asphalt mixture cracking damage; wherein, based on the obtained meso-scale stress distribution law of asphalt mixture, a macro-micro cross-scale coupling model of asphalt mixture cracking damage is fitted, including: establishing a non-destructive model and a cracking model of asphalt mixture with the same scale and the same boundary conditions, determining the relationship between the stress distribution states at corresponding points in the non-destructive model and the cracking model, and obtaining a macro-micro cross-scale coupling model of asphalt mixture cracking damage; the macro-micro cross-scale coupling model of asphalt mixture cracking damage is formulated as follows: ； Among them, φ is the damage variable, which increases as the effective load-bearing area in the structure decreases; and Respectively represent the effective load-bearing area and nominal load-bearing area in the structure; and represents the volume of the structure in the cracked and intact states; g is the functional relationship between the damage variable and the stress state defined based on the continuum damage mechanics; f is the functional relationship between the stress state and the crack geometry information, is the crack length, is the crack width, is the vertical distance from any point P to the crack in the mesoscale cracking model, is the distance from any point P to the crack tip in the mesoscale cracking model, is the angle between any point P in the mesoscale cracking model and the crack tip, is the stress state of the point corresponding to the position of any point P in the lossless model corresponding to the mesoscale cracking model.

2. The cross-scale analysis method for asphalt mixture based on macro-micro feature coupling according to claim 1 is characterized in that: The relationship between the crack changes with time and load state is obtained by capturing the geometric characteristics and evolution path of the cracks during the asphalt mixture cracking experiment using a high-speed industrial camera.

3. The cross-scale analysis method for asphalt mixture based on macro-micro feature coupling according to claim 1 is characterized in that: The asphalt mixture micro-scale cracking criterion indicates under what parameter conditions the asphalt mixture will undergo cracking behavior, and the parameters include fracture toughness, fracture energy, and crack limit opening width.

4. The cross-scale analysis method for asphalt mixture based on macro-micro feature coupling according to claim 1 is characterized in that: The correction of the asphalt mixture cracking criterion includes comparing the simulation results of the meso-scale cracking model on the cracks in the asphalt mixture cracking process and the change results of the cracks during the experiment, and modifying the parameters of the meso-scale cracking model so that the simulation results of the model correspond to the change results of the experiment.

5. The cross-scale analysis method for asphalt mixture based on macro-micro feature coupling according to claim 1 is characterized in that: The method simulates the stress distribution in the asphalt mixture by extended finite element method, reconstructs the evolution behavior of the micro-cracks in the asphalt mixture, and obtains the meso-scale stress distribution law of the asphalt mixture, including establishing a finite element model of the asphalt mixture, introducing cracks into the asphalt mixture finite element model by extended finite element method, simulating the crack propagation process, and obtaining the meso-scale stress distribution law of the asphalt mixture.

6. Asphalt mixture cross-scale analysis system based on macro-micro feature coupling, characterized by: include: The experimental module is configured to obtain the cracking characteristics and mechanical properties of asphalt mixtures, as well as the relationship between cracks and time and load conditions based on asphalt mixture cracking experiments and asphalt mixture viscoelastic mechanics experiments; The asphalt mixture cracking criterion acquisition module is configured to construct a mesoscale cracking model of asphalt mixture based on the cracking characteristics and mechanical properties of asphalt mixture, simulate the cracking behavior of asphalt mixture by extended finite element, and establish the asphalt mixture cracking criterion. The specific process is: based on the asphalt mixture cracking experiment, the cracking characteristics of asphalt mixture are obtained; according to the cracking characteristics of asphalt mixture, the stress distribution law near the crack tip area under the unit scale is determined; the mesoscale cracking model of asphalt mixture is constructed, and the functional relationship between the stress state of each point in the mesoscale cracking model of asphalt mixture and the crack geometric information is established; the mesoscale cracking model is simulated by extended finite element, and the cracking behavior of asphalt mixture under different loading modes, load levels, loading speeds and ambient temperatures in the process of non-cracking, cracking evolution and failure is simulated for the established mesoscale cracking model, so as to obtain the asphalt mixture mesoscale cracking criterion and its control parameter form; A correction module is configured to correct the asphalt mixture cracking criterion based on the relationship between the crack and the time and load state; The simulation and reconstruction module is configured to simulate the stress distribution in the asphalt mixture based on the revised asphalt mixture cracking criterion by extending the finite element method, reconstruct the evolution behavior of the mesoscopic cracks in the asphalt mixture, and obtain the mesoscopic stress distribution law of the asphalt mixture; The cross-scale coupling module is configured to fit a macro-micro cross-scale coupling model of asphalt mixture cracking damage based on the obtained meso-scale stress distribution law of asphalt mixture, and analyze the cracking behavior of asphalt mixture at different scales based on the macro-micro cross-scale coupling model of asphalt mixture cracking damage; wherein, the macro-micro cross-scale coupling model of asphalt mixture cracking damage is fitted based on the obtained meso-scale stress distribution law of asphalt mixture, including: establishing a non-destructive model and a cracking model of asphalt mixture with the same scale and the same boundary conditions, determining the relationship between the stress distribution states at corresponding points in the non-destructive model and the cracking model, and obtaining a macro-micro cross-scale coupling model of asphalt mixture cracking damage; the macro-micro cross-scale coupling model of asphalt mixture cracking damage is formulated as follows: ； Among them, φ is the damage variable, which increases as the effective load-bearing area in the structure decreases; and Respectively represent the effective load-bearing area and nominal load-bearing area in the structure; and represents the volume of the structure in the cracked and intact states; g is the functional relationship between the damage variable and the stress state defined based on the continuum damage mechanics; f is the functional relationship between the stress state and the crack geometry information, is the crack length, is the crack width, is the vertical distance from any point P to the crack in the mesoscale cracking model, is the distance from any point P to the crack tip in the mesoscale cracking model, is the angle between any point P in the mesoscale cracking model and the crack tip, is the stress state of the point corresponding to the position of any point P in the lossless model corresponding to the mesoscale cracking model.

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