High-pressure roller mill wear prediction and service life evaluation method based on DEM-FEM coupling simulation

Abstract

The invention discloses a high-pressure roller mill wear prediction and service life evaluation method based on DEM-FEM coupling simulation. The method comprises the following steps: constructing a roller mill simplified model through modeling software; the method comprises the following steps: simulating crushing and contact behaviors of grinding material particles based on a discrete element method (DEM), and quantifying interaction between the particles and interaction between the particles and a roller surface by adopting a Hertz-Mindlin contact model and a Tavaries crushing model; analyzing stress and deformation characteristics of a roll shaft structure based on a finite element method (FEM), mapping particle contact force output by discrete elements into a distributed load of a finite element model by utilizing a mechanical equilibrium equation, and solving roll shaft contact stress, strain and plastic deformation distribution; and calculating the instantaneous wear loss based on an Archard wear model, converting the instantaneous wear loss under multiple working conditions into a damage index in combination with a linear cumulative damage theory, and judging the service life of the roller surface when the total damage index reaches a threshold value. According to the invention, accurate prediction of roller surface wear and scientific evaluation of service life under the action of multiple working conditions are realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mining machinery, in particular to a high-pressure roller mill wear prediction and life evaluation method based on DEM-FEM coupling simulation. BACKGROUND

[0002] As a high-efficiency and energy-saving crushing device, the high-pressure roller mill has been widely used in the fields of mining, building materials, chemical industry and metallurgy, etc. due to its high crushing efficiency, low energy consumption and fine product size advantage brought by the principle of "laminated crushing".

[0003] However, the roller surface wear is always the core bottleneck restricting the efficient and stable operation of the high-pressure roller mill. Due to the continuous contact between the roller surface and high-hardness materials (such as iron ore, granite, etc.) under the conditions of high pressure (usually up to 10-30 MPa) and low-speed relative motion during the working process, the roller surface material will be severely worn due to particle impact, extrusion, sliding friction, etc. According to industry statistics, the downtime maintenance time caused by roller surface wear accounts for 20%-30% of the total running time in the mining scene, the cost of replacing the roller surface is expensive, and the production line capacity loss caused by downtime is difficult to estimate. In addition, the worn roller surface morphology will change the material crushing trajectory, leading to uneven product size distribution, further affecting the subsequent separation efficiency, and forming a vicious cycle of "wear-production capacity decline-energy consumption rise".

[0004] The traditional single simulation method (such as pure discrete element or pure finite element analysis) cannot accurately simulate the wear mechanism under complex working conditions. This traditional single simulation mode leads to a large deviation between the wear prediction result and the actual working condition. At the same time, the existing life prediction method relies on empirical formula and does not consider the influence of working condition fluctuation on wear accumulation, resulting in low life prediction accuracy and greatly increased operation and maintenance cost.

[0005] The wear analysis and life prediction method based on discrete element and finite element coupling simulation can effectively solve the above problems. This method simulates the particle crushing and dynamic contact force in real time through discrete element, provides accurate dynamic load input for finite element, and calculates the roller shaft structure deformation and stress distribution through finite element. Combined with the Archard wear model and linear cumulative damage theory, the life prediction accuracy is improved, effectively solving the defects of not considering working condition changes and the problem of rough life prediction in traditional research. SUMMARY

[0006] The purpose of the present application is to provide a high-pressure roller mill wear prediction and life evaluation method based on DEM-FEM coupling simulation, which aims to solve the analysis fragmentation problem of traditional single simulation method and the prediction deviation problem caused by not considering working condition fluctuation, and realize accurate life warning under the action of multiple working conditions.

[0007] To achieve the above object, the application provides the following scheme: A high-pressure roller mill wear prediction and life evaluation method based on DEM-FEM coupling simulation, comprising the following steps: S1, constructing a simplified model of the roller mill through modeling software, including a roller shaft, roller pegs, and a box body closely combined with the side surface of the roller shaft; S2, simulating the crushing and contact behavior of the grinding material particles based on the discrete element method, adopting a Hertz-Mindlin contact model and a Tavares crushing model to quantify the interaction between the grinding material particles and between the grinding material particles and the roller surface, matching the actual stress-strain curve through a virtual compression test, and generating particle sizes using a normal distribution; S3, processing the dynamic interaction between the particles and the structure using a two-way coupling simulation of the discrete element and the finite element, calculating the roller surface wear using an Archard wear model, and solving the roller shaft structure stress, strain, and particle and structure contact mechanics related equations; S4, updating the load boundary of the finite element model through a force and displacement exchange mechanism, outputting the particle position and the contact force between the particles and the roller surface from the discrete element simulation to update the particle motion trajectory and the contact interface morphology in the discrete element, and forming a closed-loop feedback; S5, calculating the instantaneous wear amount based on the Archard wear model and the output of the closed-loop feedback, converting the instantaneous wear amount under multiple working conditions into a damage index using a linear cumulative damage theory, and determining the roller surface life when the total damage index reaches a threshold value.

[0008] Preferably, in S1, the construction of the simplified model of the roller mill through the modeling software further comprises setting material properties: the roller shaft material is selected as 45 steel, the grinding material is iron ore, and the size of the constructed simplified model of the roller mill is 800*800mm.

[0009] Preferably, in S2, the particle sizes are generated using a normal distribution, and a mass monitoring sensor is set to monitor the material throughput in real time.

[0010] Preferably, in S2, the simulation of the crushing and contact behavior of the grinding material particles based on the discrete element method specifically comprises: The size distribution of the grinding material particles is set according to a normal distribution, the grinding material particles are generated through a particle generator, the elastic contact between the grinding material particles follows Hooke's law, and the normal contact force calculation formula is:

[0011] wherein, E* is the equivalent elastic modulus, R is the equivalent contact radius, delta n is the normal compression amount. The bond breakage criterion is that the particle is broken when the normal stress exceeds the maximum bearing capacity of the bond, and the formula for calculating the maximum bearing capacity of the bond is:

[0012] wherein, sigma bond is the bond strength, A bond is the bond contact area.

[0013] Preferably, in S2, the formula for the distribution of the particle breakage energy of the Tavares breakage model is:

[0014] wherein, E ∞ is the breakage energy of an infinite particle, d p is the particle size, d 0 , phi is the fitting parameter.

[0015] Preferably, in S3, the formula for calculating the roller surface wear combining the Archard wear model is as follows:

[0016] wherein, Q is the wear volume, k is the wear coefficient, F n is the normal force, s is the sliding distance, H is the roller surface hardness.

[0017] Preferably, in S3, the roller shaft structural mechanics balance equation to be solved is as follows:

[0018] wherein, wherein sigma is the roller shaft stress tensor divergence, rho is the material density, f is the material volume force vector.

[0019] When the stress on the roller surface sigma eq does not exceed its yield strength ( sigma eq < sigma s ), the stress and strain relationship equation is:

[0020] wherein, epsilon ijis the strain tensor component, sigma kk is the trace of the stress tensor, E is the Young's modulus of the roller shaft material, nu is the Poisson's ratio when i j delta ij =1, i not-equals j delta ij =0 .

[0021] when sigma eq > sigma s , the roller surface enters the plastic deformation stage, and the stress and strain relationship equation is:

[0022] wherein, sigma s is the yield strength, K is the strengthening coefficient, epsilon p is the equivalent plastic strain, n is the hardening index.

[0023] Preferably, in S5, the instantaneous wear amount under multiple working conditions is converted into a damage index by combining the linear cumulative damage theory, and the calculation formula is as follows:

[0024] wherein, D i is the damage index of the nth working condition, i Q i is the instantaneous wear amount of the nth working condition, i Q cr is the critical wear amount; the total damage index calculation formula is:

[0025]

[0026] wherein, L i is the wear depth under the nth working condition, i v i is the sliding speed of the nth working condition, i t i is the running time of the nth working condition, i k i is the nth​​​​​​​​i a wear coefficient of the working condition, F n,i the first i a normal force of the working condition, H a hardness of the roll surface.

[0027] Preferably, in S5, when the total damage index reaches a threshold value, the roll surface life is determined, and the roll surface life determination formula is as follows:

[0028] wherein, T a running time of all working conditions, f i =t i / T the first i a time proportion of the working condition, representing a working condition distribution weight; when D total =1 the corresponding total running time T = sum t i is the roll surface life.

[0029] The application also provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the high-pressure roller mill wear prediction and life evaluation method based on DEM-FEM coupling simulation according to any one of the above.

[0030] According to the embodiments of the application, the following technical effects are achieved: (1) The application synchronizes the particle breakage dynamic contact force and the roller shaft structure mechanical response through discrete element and finite element coupling simulation, solves the problems of disconnection between particle breakage force and structure deformation and neglect of roller surface stress influence in traditional one-way simulation. The discrete element simulation accurately simulates the breakage, bond key fracture and dynamic contact mechanical behavior of iron ore particles and the roll surface through the Tavares dynamic damage model, and outputs key wear parameters such as particle and roll surface contact force and sliding distance in real time. The finite element simulation builds a roller shaft structure mechanical model through elasticity and plasticity, solves the stress distribution, strain and local plastic deformation of the roll surface under the action of the particle contact force transmitted by the discrete element, quantifies the feedback influence of structure deformation on the particle contact interface form, and reveals the direct correlation between the stress concentration area of the roll surface and the wear distribution. Then, the "Archard wear model + linear cumulative model" is used to build a life prediction system, the Archard model is used to calculate the instantaneous wear, and the linear cumulative model is used to dynamically accumulate multi-working condition damage, so as to accurately determine the failure life of the roller shaft. (2) The method solves the technical bottlenecks of traditional single simulation analysis fragmentation and life prediction dependence on experience, realizes accurate prediction of roll surface wear and scientific evaluation of life under multiple working conditions, avoids non-planned shutdown risk, reduces operation and maintenance cost and production capacity loss caused by excessive maintenance and sudden failure, provides a technical paradigm for wear research of similar mine crushing equipment, helps the industry to maintain efficient and energy-saving characteristics of equipment, and realizes green and efficient production. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0032] Figure 1 The flowchart of the high-pressure roller mill wear prediction and life evaluation method based on DEM-FEM coupling simulation provided by the present application. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0034] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0035] As shown in Figure 1 The present application provides a high-pressure roller mill wear prediction and life evaluation method based on DEM-FEM coupling simulation, which comprises the following steps: S1, a high-pressure roller mill wear prediction and life evaluation method based on DEM-FEM coupling simulation, characterized in that it comprises the following steps: S1, a simplified model of the roller mill is constructed by modeling software, including a roller shaft, a roller pin, and a box body closely combined with the side surface of the roller shaft; S2, the crushing and contact behavior of the grinding material particles is simulated based on the discrete element method, the Hertz-Mindlin contact model and the Tavares crushing model are used to quantify the interaction between the grinding material particles and the roll surface, the actual stress-strain curve is matched through a virtual compression test, and the particle size is generated by using normal distribution; S3, the dynamic interaction of particles and structure is processed by discrete element and finite element bidirectional coupling simulation, the roller surface wear is calculated by combining the Archard wear model, the roller structure stress, strain and particle and structure contact mechanics related equations are solved; S4, through the force and displacement exchange mechanism, the discrete element simulation outputs the particle position, the contact force between the particle and the roller surface to update the load boundary of the finite element model, the roller surface node displacement is output by the finite element simulation to correct the motion trajectory and contact interface form of the particle in the discrete element, and a closed loop feedback is formed; S5, the instantaneous wear amount is calculated based on the Archard wear model and the output of the closed loop feedback, the instantaneous wear amount under multiple working conditions is converted into a damage index by combining the linear cumulative damage theory, and the roller surface life is determined when the total damage index reaches a threshold value.

[0036] The method specifically comprises: 1. Three-dimensional model construction: The high-pressure roller mill crushing process is quasi-static crushing, the roller shaft rotates at low speed and the stress is concentrated in the roller shaft-material contact area, and the influence of the secondary structure on the particle crushing and wear distribution can be ignored. In order to avoid that the established roller mill is too complex, resulting in various uncertain influencing factors in the simulation process, the model is simplified into two roller shafts and a shell under the condition of not affecting the simulation results. At the same time, the edge effect of the roller shaft is not analyzed, that is, the roller end sealing structure is ignored. In order to prevent mass loss when the particles are broken and scattered during the simulation process and facilitate the later statistics of the mass of the broken particles, a box body closely combined with the side surface of the roller shaft is established, which effectively avoids the error caused by the edge effect. The model size of the high-pressure roller mill is 800*800mm, and the diameter and height of the roller peg are 55*4mm.

[0037] The material of the high-pressure roller shaft equipment is 45 steel, and the material is iron ore. The specific parameters are as shown in Table 1: Table 1

[0038] 2. Discrete element simulation simulation: Through simulation, data such as particle crushing size, pressure distribution, etc. are obtained, and the actual stress-strain curve is matched through virtual compression test.

[0039] During the grinding process of the high-pressure roller mill, the contact between the iron ore particles and the surface of the roller shaft and the extrusion crushing between the particles all follow the law of contact mechanics. The elastic contact between the interaction force between the particles and the relative displacement of the particles can be described by Hooke's law: (1) Among them, F is the interaction force between the particles, kis the contact stiffness between particles (related to the elastic modulus of the material, etc.), delta x is the relative displacement between particles.

[0040] In material mechanics, the stress and strain are expressed as: (2) (3) where A is the force area, delta L is the change in particle diameter, L 0 is the initial diameter of the particle.

[0041] Normal contact force formula: (4) F n is the normal contact force between particles and particles, particles and roller shaft (in a high-pressure roller mill, this force dominates the material crushing); E* is the equivalent elastic modulus, R is the equivalent contact radius, delta n is the normal compression (the deformation amount of the material being extruded during grinding). The compression delta n is greater, the contact force F n is higher, and the material is easier to crush.

[0042] In a high-pressure roller mill, iron ore material often exists in the form of "agglomerated particles", and the breaking of the bonding bond is the direct cause of material crushing. The bonding bond strength is expressed by the following formula: (5) where, F bond is the maximum force that the bonding bond can withstand, sigma bond is the bonding strength, A bond is related to the bonding contact area and the particle diameter. When the roller shaft normal pressure F n exceeds F bond , the bonding bond breaks, and the large particles disintegrate into small particles.

[0043] In the high-pressure roller milling process, the comminution of the material is an extremely complex energy conversion, and the Tavares breakage model can well simulate the process of particle breakage. When using the Tavares breakage model to simulate the breakage of iron ore in the high-pressure roller mill, the fracture energy of different iron ore particles is different. Let E represent the particle fracture energy distribution, which refers to the maximum stress energy that the particle can withstand in collision, and its formula is expressed as: (6) (7) Wherein, E 50 is the median of the distribution, which is a key reference for particle fracture energy, reflecting the average fracture energy level of the particle population. sigma is the standard deviation, reflecting the dispersion degree of the fracture energy. E ∞ is the fracture energy when the particle size is infinite, reflecting the inherent fracture characteristics of the material itself. d 0 is the reference particle size, phi is the adjustment parameter, adjusting the trend of fracture energy with particle size. d p is the representative particle size contained in the size class.

[0044] Due to the size effect of particles, the E 50 value of large particles is relatively large, and the E 50 value of small particles is relatively small, which means that large particles may break at lower energy, while small particles need higher energy. In the roller milling process, iron ore particles are constantly subjected to extrusion and collision, and each impact that does not lead to breakage will cause damage to the particles. With the accumulation of damage, the fracture energy of the particles gradually decreases, and the subsequent impact at lower energy may also break. Its formula is expressed as follows: (8) Wherein, E f is the fracture energy of the damaged particle, E is the original fracture energy of the particle, D represents the degree of damage. e is the energy ratio involved in the collision, determined by the particle stiffness k p and the surface stiffness k s of the particles in contact. gamma is the damage accumulation coefficient, which characterizes the ability of the material to withstand damage before catastrophic fracture.

[0045] The degree of breakage of particles ground by the high-pressure roller mill is represented by t10 represents, the formula is as follows: (9) wherein, t 10 represents the proportion of fragments smaller than the parent particle size 1 / 10 . A and b is the impact parameter, A corresponding to the maximum value that can be reached when the material is destroyed in a single impact event t 10 .

[0046] After setting the material parameters and the like, a virtual box is established above the roller shafts as a particle generator, particles of which are generated from the inside thereof, and the particle size distribution is normally distributed. The particle size is generated using the normal distribution, and a mass sensor is used to monitor the material throughput in real time. Finally, the imported model is meshed, and the grinding simulation is finally debugged to the appropriate time step.

[0047] 3. Finite element simulation: In the wear research of high-pressure roller mills, finite element simulation can reveal the formation mechanism of wear under different working conditions, locate the vulnerable areas of the roller shafts, and quickly optimize the roller surface structure through parameterized simulation.

[0048] From a mechanical point of view, when the material particles enter the high-pressure roller mill and come into contact with the roller shaft, a force will be exerted on the surface of the roller shaft. This force mainly includes normal force and tangential force. The normal force is generated by the reaction force of the particles being extruded by the roller shaft, and the tangential force is mainly generated by the relative sliding of the particles and the roller shaft surface and the mutual friction between the particles to the roller shaft surface. From an energy point of view, during the collision and sliding of the particles with the roller shaft, part of the kinetic energy will be converted into work on the surface of the roller shaft, which may cause plastic deformation, fatigue damage, or even material removal of the surface of the roller shaft, i.e., wear. Through finite element simulation, the high-pressure roller mill model is discretized into a finite number of non-overlapping elements, and then by solving the mechanical equilibrium equation of the elements, the stress, strain and pressure distribution of the contact interface of the roller shaft are obtained, providing a mechanical basis for wear calculation.

[0049] Based on the theory of continuum mechanics, the roller shaft speed of the high-pressure roller mill is low, and the material falling acceleration can be ignored. The structural mechanics equilibrium equation is: (10) wherein, wherein sigma is the roller stress tensor, rho is the material density, f is the material volume.

[0050] When the stress on the roller surface sigma eqWhen the stress is less than the yield strength of the material sigma eq < sigma s , the stress-strain relationship is: (11) (12) where, epsilon ij is the strain tensor component, sigma kk is the trace of the stress tensor, E is the Young's modulus of the roll material, nu is the Poisson's ratio, when i = j delta ij =1, i not-equals j delta ij =0 .

[0051] When sigma eq > sigma s , the roll surface enters the plastic deformation stage, and the stress-strain relationship is: (13) where, sigma s is the yield strength, K is the strengthening coefficient, epsilon p is the equivalent plastic strain, n is the hardening exponent.

[0052] In the coupling simulation framework, the Archard model converts the continuous interaction force and energy transfer into the wear rate. Its formula is expressed as: (14) where, Q is the wear volume, k is the wear coefficient (related to material properties), F n is the normal force, s is the sliding distance, H is the material hardness.

[0053] 4. Coupling of discrete element and finite element simulation: A closed-loop coupling system is constructed through a force and displacement bidirectional exchange mechanism to realize the real-time linkage of particle dynamic behavior and roll structure mechanical response, and through bidirectional data feedback to accurately restore the coupling mechanism of "particle action and structure deformation and wear evolution".​​

[0054] In the discrete element and finite element coupling simulation, the spatial correspondence between the coupling grid and the particle contact boundary is established through geometric coordinate mapping to ensure the spatial consistency of data transmission. A special coupling module interface is built to clarify the variable type and transmission protocol of data interaction.

[0055] Data and result analysis: Data: Obtain a series of large amounts of data such as the mass proportion of particle fineness from discrete element simulation, and then analyze the reliability of the data.

[0056] Results: Through the post-processing of the wear data of the roller mill, the cumulative wear depth or wear rate, roller surface pressure, material speed, etc. Cloud map can be visualized. Analyze the wear of the roller mill and establish a roller surface life prediction model.

[0057] 5. Life prediction Wear prediction: Calculate the wear amount after each working area grinding through simulation, and then continuously iterate the wear depth of the roller surface to establish a life prediction model for prediction.

[0058] Through the Archard wear model combined with the linear cumulative model for life prediction, calculate the instantaneous wear damage under each working condition, and then superimpose the damage through the linear cumulative model until the failure threshold is reached Q cr .

[0059] The high-pressure roller mill provides a huge pressure for grinding through the hydraulic system, and the pressure difference caused by particle crushing can be ignored. Therefore, it is assumed that the grinding process of the high-pressure roller mill is a stable working condition, and the wear amount increases linearly with time or processing amount.

[0060] Wear damage definition: Convert the wear amount Q into wear damage D , which is the ratio of wear amount at a certain stage to critical wear amount.

[0061] (15) Where, Q i is the wear amount under the i th working condition; Q cr is the critical wear amount, which is the maximum allowable wear amount when the component fails.

[0062] Damage accumulation formula under multiple working conditions: Assume that the component experiences n different working conditions, and the running time under each working condition is t i , then the total damage Dtotal This is the sum of damage at each stage.

[0063] (16) (17) in, L i For the first i Wear depth under sub-condition v i For the first i Sliding speed under the next working condition.

[0064] When total damage D total =1 When the component reaches its failure life. T If the running time is... t i The total time is calculated by summing the results. T = sum t i Then the lifespan prediction formula can be expressed as: (18) in, f i =t i / T For the first i The percentage of time spent in each working condition ( ∑f i =1 ), representing the weight of the working condition distribution.

[0065] A life prediction model combining a linear cumulative model and an Archard wear model provides a precise quantitative tool for the efficient operation and maintenance of high-pressure roller mills. By dynamically accumulating wear damage under different operating conditions, this model can scientifically predict the lifespan of the roller surface when it reaches the failure threshold. Compared to traditional disassembly and measurement, it can provide early warning of wear, avoiding excessive maintenance costs caused by periodic replacement based solely on experience, and reducing unplanned downtime losses due to sudden wear.

[0066] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, it implements a method for predicting wear and life assessment of a high-pressure roller mill based on DEM-FEM coupled simulation as described above.

[0067] Those skilled in the art can clearly understand the implementation of the various embodiments by means of software and necessary general hardware platforms through the description of the above embodiments, and of course, the implementation can also be through hardware. Based on such understanding, the above technical solutions 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 a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the method described in each embodiment or some parts of the embodiment.

[0068] The principles and implementation of the present application are described herein by applying specific examples, and the above description of the embodiments is only for the purpose of helping to understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation and application range. In view of the above, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A method for predicting wear and assessing life of high-pressure roller mills based on DEM-FEM coupled simulation, characterized in that, Includes the following steps: S1. Construct a simplified model of the roller mill using modeling software, including the roller shaft, roller nails, and a box body that is tightly integrated with the side of the roller shaft; S2. Based on the discrete element method, the crushing and contact behavior of grinding material particles is simulated. The Hertz-Mindlin contact model and the Tavares crushing model are used to quantify the interaction between grinding material particles and between grinding material particles and roller surface. The actual stress-strain curve is matched by virtual compression test, and the particle size is generated by normal distribution. S3. The dynamic interaction between particles and structure is handled by two-way coupled simulation of discrete element and finite element methods. The wear of the roller surface is calculated by combining the Archard wear model. The stress, strain and mechanical equilibrium equations of the roller structure and particles and structure are solved. S4. Through the force and displacement exchange mechanism, the discrete element simulation outputs the particle position and the contact force between the particle and the roller surface to update the load boundary of the model, and the finite element simulation outputs the roller surface node displacement to correct the particle motion trajectory and contact interface morphology in the discrete element, forming a closed loop feedback. S5. Based on the Arcard wear model and closed-loop feedback, the instantaneous wear amount is calculated. Combined with the linear cumulative damage theory, the instantaneous wear amount under multiple working conditions is converted into a damage index. When the total damage index reaches the threshold, the roller surface life is determined.

2. The method for predicting wear and assessing life of high-pressure roller mills based on DEM-FEM coupled simulation as described in claim 1, characterized in that, In step S1, constructing a simplified model of the roller mill using modeling software also includes setting material properties: the roller material is selected as 45 steel, the grinding material is iron ore, and the size of the constructed simplified roller mill model is 800×800mm.

3. The method for predicting wear and assessing life of high-pressure roller mills based on DEM-FEM coupled simulation as described in claim 1, characterized in that, In step S2, a normal distribution is used to generate particle size, and a quality monitoring sensor is set up to monitor the material throughput in real time.

4. The method for predicting wear and assessing life of high-pressure roller mills based on DEM-FEM coupled simulation as described in claim 1, characterized in that, In step S2, the simulation of the breakage and contact behavior of abrasive material particles based on the discrete element method specifically includes: The particle size distribution of the abrasive material is set according to a normal distribution. Abrasive material particles are generated by a particle generator. The elastic contact between the abrasive material particles follows Hooke's law. The formula for calculating the normal contact force is: in, E* For the equivalent elastic modulus, R For the equivalent contact radius, δ n Normal compression; The bond fracture criterion is that the particle breaks when the normal stress exceeds the maximum bearing capacity of the bond. The formula for calculating the maximum bearing capacity of the bond is: in, σ bond For bond strength, A bond This represents the bonding contact area.

5. The method for predicting wear and assessing life of high-pressure roller mills based on DEM-FEM coupled simulation according to claim 1, characterized in that, In S2, the particle fracture energy distribution formula of the Tavares fragmentation model is: in, E ∞ For the fracture energy of infinitely large particles, d p Particle size, d 0 , φ These are the fitting parameters.

6. The method for predicting wear and assessing life of high-pressure roller mills based on DEM-FEM coupled simulation according to claim 1, characterized in that, In S3, the formula for calculating roller surface wear using the Archard wear model is as follows: in, Q For wear volume, k The wear coefficient is... F n For normal force, s The sliding distance, H The hardness of the roller surface.

7. The method for predicting wear and assessing life of high-pressure roller mills based on DEM-FEM coupled simulation according to claim 1, characterized in that, In S3, the mechanical equilibrium equations of the roller structure are solved as follows: Among them, σ For the roll stress tensor divergence, ρ For material density, f This is the volumetric force vector of the material. When the stress on the roller surface... σ eq It did not exceed its yield strength ( σ eq < σ s When ), the stress-strain relationship equation is: in, ε ij For the strain tensor components, σ kk The trace of the stress tensor. E The Young's modulus of the roller material. ν For Poisson's ratio, when i = j hour δ ij =1, i≠j hour δ ij =0 .when σ eq > σ s At this point, the roller surface enters the plastic deformation stage, and the stress-strain relationship equation is: in, σ s For yield strength, K For the enhancement coefficient, ε p For equivalent plastic strain, n This is the hardening index.

8. The method for predicting wear and assessing life of high-pressure roller mills based on DEM-FEM coupled simulation according to claim 1, characterized in that, In S5, the instantaneous wear under multiple working conditions is converted into a damage index by combining the linear cumulative damage theory. The calculation formula is as follows: in, D i For the first i Damage index of working conditions Q i For the first i Instantaneous wear under operating conditions Q cr The critical wear level is given; the total damage index is calculated using the following formula: in, L i For the first i Wear depth under sub-condition v i For the first i Sliding speed under operating conditions t i For the first i Operating time under operating conditions k i For the first i Wear coefficient under operating conditions F n,i For the first i Normal force under operating conditions H The hardness of the roller surface.

9. The method for predicting wear and assessing life of high-pressure roller mills based on DEM-FEM coupled simulation according to claim 1, characterized in that, In step S5, the roller surface life is determined when the total damage index reaches a threshold. The roller surface life determination formula is as follows: in, T Runtime for all operating conditions, f i =t i / T For the first i The time percentage of each operating condition represents the weight of the operating condition distribution; when D total =1 At that time, the corresponding total running time T=Σt i This is the roller surface life.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements a method for predicting wear and assessing life of a high-pressure roller mill based on DEM-FEM coupled simulation as described in any one of claims 1 to 9.

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