95 results about "Phase field models" patented technology

The invention discloses a fatigue life simulation evaluation method for a lightweight aluminum alloy material of a new energy automobile, and relates to the technical field of material life evaluation. A microstructure image is collected, coupling features are extracted through machine learning, and heterogeneous data fusion and enhancement are completed; generating a topological optimization structure based on a GAN, introducing a VPSC model to describe anisotropy according to a stress gradient dynamic grid, and constructing a dynamic finite element model; fusing vehicle driving data, predicting a load by using LSTM, performing VMD decomposition and environment correction, and realizing space-time correlation load spectrum reconstruction; a phase field model is used in a microcosmic mode, cracks are tracked in a macroscopic mode through XFEM, damage parameters are transmitted in a bidirectional coupling mode, and multi-physics field coupling simulation is carried out; fusing simulation and test data by adopting Bayesian reasoning, calculating life probability distribution, and correcting parameters when errors exceed the limit; according to the method, the fatigue life prediction error is finally reduced, the time consumption of single simulation is reduced, full-life-cycle evaluation and visual early warning are realized, an efficient scheme is provided for lightweight design, and industrial technology upgrading is promoted.

The invention discloses an online detection method for the sealing performance of a sealing element, particularly relates to the technical field of quality detection of industrial sealing elements, and is used for solving the problems of reference value deviation and misjudgment caused by neglecting the influence of mounting stress in an existing detection method. According to the method, a sealed contact interface phase field model is constructed by collecting installation stress data in real time, and crack network permeability is analyzed to predict a leakage diffusion path; high / low stress sensitive areas are divided according to the spatial correlation between the stress gradient and the leakage density, and differential signal acquisition is implemented; extracting a bar code entropy value through topological data analysis, generating a compensation priority sequence, and dynamically correcting a detection reference; and finally, based on the regional weight fusion compensation signal, outputting a high-precision pressure distribution and leakage flow trend result. Cross-field coupling analysis of installation stress and leakage signals is achieved, and the accuracy and reliability of sealing performance detection under complex working conditions are improved.

The invention provides a multi-scale simulation method for high-fidelity selective laser melting forming and phase field-lattice Boltzmann coupling, and belongs to the technical field of selective laser melting numerical simulation. The method comprises the specific steps that a selective laser melting powder laying process model is constructed based on a discrete element method, and a randomly stacked powder bed model is obtained; a high-fidelity selective laser melting forming thermal fluid dynamic model is established, and macroscopic temperature distribution and flow field distribution of a molten pool are simulated; establishing a phase field model-lattice Boltzmann coupling model; and extracting temperature gradient, solidification velocity and melt flow velocity data of local positions of the boundary of the steady-state molten pool, and simulating solidification structure evolution under flowing of molten metal in the molten pool by taking the data as initial conditions of the phase field-lattice Boltzmann coupling model. According to the method, through high-fidelity multi-scale simulation, the relation between the process parameters and the microstructure is established more comprehensively, and reliable numerical support is provided for selective laser melting process optimization and microstructure prediction.

The invention discloses a fracturing fracture extension simulation method based on a self-adaptive multi-scale phase field model, and relates to the field of oil and gas reservoir renovation, and the method is characterized in that reservoir physical property and rock mechanics parameters are obtained, and a reservoir geologic model is established according to the parameters; dividing the reservoir geometric model into a plurality of finite element grids, and assigning grid attributes of the finite element grids by using the parameters to obtain preset hydraulic fractures in the finite element grids and initial variable values on nodes of the finite element grids; according to a preset position relation between the hydraulic fracture and the finite element mesh, constructing a multi-scale adaptive mesh for dynamic expansion of the hydraulic fracture; establishing a coupling mathematical model of a stress field, a seepage field and a phase field of hydraulic fracturing, and constructing a numerical calculation expression of the coupling mathematical model according to the multi-scale adaptive grid; and based on the numerical calculation expression, solving the coupling mathematical model by taking parameters of reservoir physical properties and rock mechanics and boundary conditions of the multi-scale adaptive grid as constraints to obtain hydraulic fracturing fracture extension simulation results under different reservoir and construction conditions.

The invention discloses a fan blade structure damage analysis method and device based on a sub-model, and is used for solving the technical problem that the existing fan blade structure damage and sub-model analysis efficiency is relatively low. The method comprises the following steps: constructing a fan blade finite element model according to obtained fan blade design parameters; performing stress calculation on the fan blade finite element model, and determining a fluid load and a Mises stress value at the Gaussian integral point of each blade unit in the fan blade finite element model at the current time; according to the fluid load, the comparison result between the Mises stress value at the Gaussian integral point of each blade unit at the current time and a preset stress threshold value and the fan blade finite element model, dynamic construction of a target fine mesh entity unit sub-model is completed; and combining a phase field model and a Lagrange-cohesion model to perform structural damage analysis on the target fine grid entity unit sub-model to generate a structural damage analysis result of the target fan blade.

The invention relates to the technical field of metal solidification numerical simulation and calculation material science, and provides a continuous casting billet solidification process phase field simulation method and system based on dynamic temperature boundary conditions. The method comprises the following steps: S1, collecting physical property parameters and component data of steel, continuous casting machine crystallizer parameters and secondary cooling working condition parameters; s2, selecting a phase field method model, and determining initial parameters; s3, solving a phase field control equation, a solute field control equation and a temperature field control equation to obtain phase field variables evolved along with time, solute distribution data and temperature field data; when the temperature field control equation is solved, continuous casting process parameters are introduced into the phase field model, and the actual boundary heat transfer process is simulated by considering the combination of D, N and R thermal boundary conditions. According to the method, any combination and stable solution of the three types of thermal boundary conditions are realized, the adaptability and calculation efficiency of phase field simulation to the complex thermal boundary conditions in the solidification process are remarkably improved, and the analysis precision, the calculation efficiency and the engineering adaptability are considered.

The invention belongs to the technical field of ductile metal fracture analysis, provides an explicit cohesion phase field material point method, and provides a brand new numerical calculation method for metal dynamic fracture damage research. In the method, aiming at the problems of large deformation and high-speed impact in ductile metal spallation and penetration failure, a cohesion phase field material point method and a marble compliant contact algorithm are innovatively provided. The cohesion phase field model can well describe the damage softening and fracture behaviors of the tough metal. The marble compliant contact algorithm effectively suppresses the problems that the speed of impacting the contact surface is over-oscillated and the normal vector outside the contact surface is difficult to calculate. Then, a control equation of dynamic fracture of the ductile metal is deduced through a Lagrange equation, and the control equation of the coupling displacement and cohesion phase field model is discretized in a material point method framework; and finally, a phase field-displacement field interlaced solution strategy is adopted to stably and efficiently solve the problems of contact, large deformation and other strong nonlinear large-scale ductile fracture damage.

The invention provides a numerical method for immiscible solution drop swallowing behavior in limited shear flow, and relates to the technical field of immiscible solution drop swallowing behavior, a simulation task based on a phase field model and a Navier-Stokes equation is established, a computational domain is discretized through a finite element method, a physical field is initialized, and in each time step, the physical field of the immiscible solution drop swallowing behavior in limited shear flow is calculated. Updated velocity field and phase field data are obtained through coupling solution, the interface curvature change rate and the flow field vorticity intensity are comprehensively calculated, a global index representing the dynamic intensity of the system is generated, the index is compared with a preset threshold value, and the dynamic intensity of the system is calculated. When the index is higher than a threshold value, a smaller step length and a higher grid resolution are adopted, otherwise, a larger step length and a lower resolution are adopted, finally, solver configuration is automatically reconstructed according to the selected parameters, solving is continued under a new adjusting strategy, a self-adaptive numerical simulation cycle is formed, and a new time step is obtained. And completing simulation and outputting complete field data of the liquid drop swallowing process.

The invention discloses a polar diaphragm optimization method based on a high-fidelity electrochemical-phase field model, which comprises the following steps: constructing a high-fidelity electrochemical-phase field model considering a diaphragm substrate and a polar coating to describe the growth behavior of lithium dendrites in the electrodeposition process of a lithium battery; collecting physical property parameters of the diaphragm matrix and the polar coating, substituting the physical property parameters into the model, establishing a computational domain and performing grid division; carrying out numerical solution on the model by utilizing a finite difference method to obtain growth morphology data of the lithium dendrites on the surface of the anode; and performing quantitative characterization on dendritic crystal morphology uniformity based on the growth morphology data to obtain dendritic crystal indexes, adjusting diaphragm physical property parameters according to the indexes, and repeating simulation iteration to optimize the diaphragm structure. By introducing multi-phase field sequence parameters and comprehensively describing the influence of the diaphragm matrix and the polar coating on lithium ion transmission, electrochemical reaction and interface characteristics, the high-precision simulation and optimization of the polar diaphragm design are realized, and the growth of lithium dendrites can be effectively inhibited.

The invention discloses a design method and system for a steel sealing layer of a compressed air energy storage underground artificial reservoir based on an isogeometric phase field method, and the method comprises the steps: building a coupling model of air thermodynamics in the reservoir and heat conduction of a wall medium, and carrying out the simulation calculation of the changes of temperature and pressure in the reservoir in the process of inflation-gas storage-deflation-gas storage; establishing a phase field model for thermal coupling fatigue failure analysis of the steel sealing layer, the concrete lining and the surrounding rock; constructing an isogeometric four-order phase field method calculation model for the fatigue failure analysis of the block type steel sealing layer, and performing numerical simulation based on the influence of a block type layout mode, a welding mode, welding defects and welding residual stress of the steel sealing layer on the fatigue failure of the steel sealing layer; and carrying out statistical analysis on a numerical simulation result, and determining a layout method and a welding mode of the steel sealing layer. According to the method, a new thought is provided for design of the steel sealing layer of the compressed air energy storage underground artificial cave depot, and the method assists in solving the electricity abandoning problem of new energy through the CAES technology.

The invention provides a phase field model mass conservation correction method and system for two-phase channel turbulence, and relates to the technical field of two-phase flow numerical calculation, sequence parameters are adopted to describe a current-carrying phase and a dispersed phase in a flow field, the value of a current-carrying phase sequence parameter is 0, and the value of a dispersed phase sequence parameter is 1; comprising the following steps: (1) setting a sequence parameter target total mass M0 according to a mass conservation requirement, the M0 being a volume fraction of a full-field sequence parameter phi i0 at a simulation initial moment, (2) after simulation is started, calculating and updating a sequence parameter phi i (t) of each grid point of the full field at each time step, and (3) determining the total amount delta M (t) of the sequence parameters needing to be corrected according to the difference value between the real-time volume fraction M (t) and the target total mass M0. The method has the advantages that on the basis that an existing solver structure is kept, only the order parameters are operated, the implementation process is simplified, and a mass conservation algorithm which is efficient and easy to implement is achieved.

The invention discloses a reactor nuclear material cross-scale simulation method coupling microstructure simulation and mechanical-thermal performance calculation. The method comprises the following steps: a, planning a most unit sampling point through a most unit method; b, simulating through a mesoscale phase field model to obtain force thermal parameters; c, the force and heat parameters are input into a finite element model to be simulated to obtain force and heat performance; d, the mechanical and thermal performance is input into the phase field model for simulation to obtain the structure morphology of the target nuclear material; e, obtaining a macroscopic scale-mesoscopic scale coupling model by circulating the step c and the step d; f, obtaining a strong coupling model through physical time axis control; and g, constructing a database of the relationship between the mechanical and thermal parameters and the mechanical and thermal performance through a data-driven neural network algorithm. According to the method, strong coupling is achieved through parameter transmission of the mesoscale phase field model and the macroscale finite element, the macroscale and the mesoscale are connected through the most element method, the parameter transmission precision can be adjusted according to convergence, and novel reactor material mechanical and thermal performance prediction can be achieved.

The invention relates to the technical field of numerical simulation of additive manufacturing nickel-based superalloy, and discloses a temperature field and phase field coupling simulation method of SLM forming nickel-based superalloy, which comprises the following steps: establishing a three-dimensional model of a forming part and a substrate for processing to obtain a temperature field basic model; simulating an SLM forming process on the temperature field basic model according to preset parameters to obtain temperature field data, and importing the temperature field data into a phase field simulation module to serve as predefined temperature field data; coupling the gamma ' / gamma mismatch degree and temperature correlation data to the basic phase field model to obtain a gamma' phase change model, correcting the gamma 'phase change model in combination with predefined temperature field data, and adding a nucleation model based on a Poisson seed method; and based on the gamma'phase change model and the nucleation model, growth and coarsening behaviors of the gamma 'phase in the SLM material increasing process are obtained, and a simulation report is formed. According to the method, the vacancy of gamma'phase structure evolution of the existing nickel-based superalloy with high (Al + Ti) content under the SLM complex thermal history condition is solved, and important help is provided for regulating and controlling the structure to obtain the required mechanical property.

The invention discloses a rock material tension-shear failure simulation method and equipment based on a dynamic dual-phase field model. The method comprises the following steps: establishing a stress tensor physical model corresponding to a rock material constitutive relationship; respectively introducing a tension phase field and a shear phase field, and establishing a dynamic double-phase field model corresponding to the rock tension-shear failure physical process; deducing an energy functional of the dynamic double-phase field model; establishing a crack surface local coordinate system, and judging a crack contact state according to a frictional contact phase field theory; switching a stress tensor decomposition mode according to the contact state, and calculating a phase field evolution driving force; rock material tension-shear failure simulation based on the dynamic two-phase field model is achieved, and rock fracture form evolution data are output and used for evaluating rock slope stability.

The invention belongs to the technical field of fracture mechanics calculation, and particularly relates to a hybrid unit beam structure dynamic fracture phase field calculation method. The method comprises the following steps: determining material parameters required by the dynamic fracture phase field calculation of the hybrid unit beam structure; establishing a hybrid unit beam structure dynamic fracture phase field mathematical model according to the Lagrange action quantity principle, wherein the mathematical model comprises a displacement field control equation and a phase field evolution control equation; numerical discretization is carried out on the mathematical model, and a hybrid unit beam structure discrete model is established; and adopting a Newmark method in combination with an interlacing algorithm to carry out numerical solution on the mathematical model after numerical discretization until the displacement field and the phase field both meet convergence conditions, and obtaining a dynamic fracture phase field evolution result of the hybrid unit beam structure. The problem that an existing fracture phase field model cannot accurately simulate crack evolution of the beam structure on the thickness under the dynamic load is solved, and meanwhile the calculation cost for simulating the dynamic fracture of the beam structure is remarkably reduced.

The invention relates to a universal two-phase flow phase field model mesoscopic design method, device and equipment and a storage medium. The method comprises the steps that a two-phase flow control equation based on a phase field model is established; presetting an equilibrium state of the Boltzmann distribution function, calculating a low-order moment, and associating the low-order moment to a macroscopic quantity; performing analysis by using Chapman-Enskog to obtain an integral constraint condition required by a source item; utilizing a Hermite expansion method to obtain an expression of a source item; and outputting a mesoscopic design result. According to the universal two-phase flow phase field model mesoscopic design method provided by the invention, when the phase field model is used for two-phase flow simulation in the future, a mesoscopic format can be quickly obtained even if a new phase field equation is encountered, so that the mesoscopic method can be directly used for simulating the two-phase flow, and mesoscopic design does not need to be carried out again.

The application discloses a preparation method for regulating and controlling ferroelectric texture ceramic grain size by using a phase field method simulation technology, and comprises the following steps: preparing a series of microcrystalline powders with different size distributions; setting an initial phase field structure meeting the particle size distribution; establishing a phase field model for grain orientation growth; simulating and analoging the grain orientation growth process; preparing a film; preparing a green body with microcrystalline parallel distribution; and preparing ferroelectric texture ceramics with target grain size distribution. The application fully utilizes the computer simulation intelligent prediction guidance technology, does not need repeated trial and error experiments, saves time and effort, has good product reproducibility and stability, easily realizes accurate control of the ferroelectric texture ceramic grain size distribution, and is easy to be industrialized; the application effectively controls the occurrence of grain abnormal growth, maintains high grain orientation, and promotes the densification of the ceramic; and the application can not only prepare high-texture-density ferroelectric ceramics, but also regulate and control the grain size.

The application discloses a microstructure evolution prediction method in a selective laser sintering additive manufacturing process, according to the microstructure evolution characteristics of the selective laser sintering additive manufacturing, starting from the free energy density functional of the system, the time and space evolution expressions of temperature, conservative order parameter and non-conservative order parameter are derived in thermodynamic self-consistency, the Cahn-Hilliard equation containing temperature gradient driven diffusion and the determination method of model parameters are given, and numerical calculation is realized through finite element programming. Combined with powder bed laying and finite element calculation, the non-isothermal phase field model can simulate the sintering neck, grain boundary migration and other microstructure evolution in the selective laser sintering additive manufacturing process, simulate the influence of the huge temperature gradient in the selective laser sintering additive manufacturing, optimize the process parameters of the selective laser sintering additive manufacturing, reveal the influence law of the process parameters of the selective laser sintering additive manufacturing on the microstructure evolution and the final microstructure, and improve the design efficiency of the selective laser sintering additive manufacturing.

The invention discloses an integral transformation fracture phase field model implementation method of a random-order polynomial cohesion law, and belongs to the technical field of phase field model finite element analysis. The method comprises the following steps: inputting a parameter equation of a polynomial cohesion law of any order and a target order into a subprogram; deducing a cohesion eigenfunction of a random-order polynomial cohesion law by using a subprogram to determine an analytical expression of a random-order polynomial energy density eigenfunction, solving a target-order polynomial energy density eigenfunction expression and first two-order derivatives thereof, and determining an expansion expression at a zero point by using Maclaurin series; and inputting the target-order polynomial energy density eigenfunction expression, the first two-order derivatives thereof and the expansion expression at the zero point into a phase field model solver to obtain a calculation result of the target-order polynomial integral transformation fracture phase field model. According to the method, the simulation calculation of the integral transformation fracture phase field model of the target-order polynomial cohesion law can be realized under a universal finite element framework, and the accuracy and the efficiency are improved.

The invention discloses a calculation method of an integral transformation fracture phase field model for conformal interpolation reconstruction, and belongs to the technical field of finite element analysis of phase field models. The method comprises the following steps: inputting an interpolation coefficient obtained by performing segmented cubic Hermite interpolation reconstruction on a complex target curve into a subprogram; solving a general term expression of an interpolation segmentation energy density eigenfunction based on a continuity condition by utilizing a subprogram, and determining an interpolation segmentation energy density eigenfunction expression and first two-order derivatives thereof by combining an interpolation coefficient; and inputting the interpolation segmentation energy density eigenfunction expression, the first two-order derivatives of the interpolation segmentation energy density eigenfunction expression and the expansion at the inflection point into a solver for performing an integral transformation fracture phase field model to obtain a simulation result of the integral transformation fracture phase field model of the complex target curve. According to the method, the simulation calculation of the integral transformation fracture phase field model of the complex curve with the inflection point can be realized under a universal finite element framework, and the accuracy and the calculation efficiency are greatly improved.

The invention discloses a dendritic crystal growth and motion simulation method and system based on an Euler-Lagrangian method.The method comprises the steps that firstly, a phase field model is constructed based on convection flux in a solute field; solving liquid convection on an Euler background grid, and solving solid motion through a Lagrange grid; and updating the moved solid boundary through the conservative phase field model. According to the method, on the basis of simulation of the growth condition of the dendritic crystal, the Lagrange grid is introduced into the discrete interface to simulate the motion behavior of the dendritic crystal, the alloy growth morphology and convection motion are simulated at the same time, the problem that the speed between the grid and the fluid is not matched is solved, and the problem of topological change of a complex interface is solved.

The invention discloses a nuclear fuel particle fracture analogue simulation method based on a fracture phase field method, belongs to the technical field of nuclear fuel particle fracture simulation, and aims to solve the problems that the research efficiency is low and the application range of a numerical model is limited when a traditional method is used for a complex fracture condition. The method comprises the steps of building a phase field model, inputting material attribute parameters, setting boundary conditions of nuclear fuel particles, adding irreversibility constraints into an evolution equation of the phase field model, setting differentiated analogue simulation step lengths and outputting simulation results. Spatial distribution of phase field variables is used as characterization of a damaged area and a crack form, and real-time tracking of a crack tip position and an expansion path is not needed; for scenes such as multi-particle intersection cracks, branch cracks and irregular cracks which are difficult to process by a traditional method, accurate simulation can be realized only through phase field variable evolution without adjusting a grid or a calculation model.

The application belongs to but is not limited to the technical field of electronic core industry, and discloses a polycrystalline NCM electrode particle cracking and pulverization prediction method and system, which comprises the following steps: constructing an anisotropic polycrystalline fracture phase field model, including a grain boundary phase field equation, a solid mechanics equation, a Li + diffusion equation and a fracture phase field equation; constructing a two-dimensional geometry of a polycrystalline NCM electrode particle, setting required parameters of physical fields, carrying out grid division and setting initial conditions and boundary conditions; using a finite element simulation software to perform numerical solution, and obtaining cracking and pulverization distribution of the polycrystalline NCM electrode particle. + The application considers bidirectional coupling of Li diffusion and mechanical stress, cracking and pulverization and mechanical stress, and uses grain boundary phase field calculation to correct the critical energy release rate, so that the application can accurately reflect the mechanism of cracking and pulverization of the polycrystalline NCM electrode particle, and improve the accuracy of cracking and pulverization prediction.

A simulation method of microvoid evolution in electric field induced interconnection wire based on phase field method, including constructing a phase field model of microvoid evolution in electric field induced face-centered cubic metal {110} orientation "bamboo joint" interconnection wire based on coupled Cahn-Hilliard equation and Allen-Cahn equation; constructing phase field variables of microvoid and grain boundary; constructing distribution functions of electric conductivity and atomic migration rate varying with spatial coordinates; constructing system free energy function F , introducing a free energy function of four double potential well function to modify Cahn-Hilliard equation and Allen-Cahn equation, obtaining phase field control equation of the system; determining conservative phase field order parameter, non-conservative phase field order parameter and electrostatic field parameter, obtaining microvoid evolution in transgranular interconnection wire by coupling phase field and electrostatic field. A direct quantitative tool for the reliability of integrated circuit interconnection wire is proposed.

The invention provides a steel rail fatigue crack simulation method and system based on a fracture phase field fatigue model, and relates to the technical field of rail traffic structure safety and computational mechanics, and the method comprises the following steps: obtaining geometry, material and wheel load parameters of a steel rail; a three-dimensional steel rail finite element model is constructed according to the basic data, and local encryption grids are arranged in wheel-rail contact and other key areas; on the basis, establishing a fracture phase field model capable of describing natural initiation and expansion of cracks; a fatigue degradation model is further integrated, crack resistance attenuation caused by fatigue is simulated, and a phase-field fatigue coupling model is formed; and finally, simulating a moving wheel load through envelope loading, and performing efficient calculation by applying a cyclic transition strategy to realize accurate simulation of a fatigue crack initiation position, an expansion path and damage field distribution of the steel rail. According to the method, crack evolution can be naturally predicted, and the high-cycle fatigue analysis efficiency is remarkably improved.

The application discloses a fracturing fracture extension simulation method based on an adaptive multi-scale phase field model and relates to the field of oil and gas reservoir reconstruction. The technical scheme is as follows: parameters of reservoir physical properties and rock mechanics are acquired, and a reservoir geological model is established according to the parameters; the reservoir geometric model is divided into a plurality of finite element grids, and the grid attributes of the finite element grids are valued by using the parameters, so that preset hydraulic fractures in the finite element grids and initial variable values on nodes of the finite element grids are obtained; a multi-scale adaptive grid for dynamic expansion of the hydraulic fractures is constructed according to the position relationship between the preset hydraulic fractures and the finite element grids; a coupling mathematical model of stress field, seepage field and phase field of hydraulic fracturing is established, a numerical calculation expression of the coupling mathematical model is constructed according to the multi-scale adaptive grid; and the coupling mathematical model is solved based on the numerical calculation expression, with the parameters of reservoir physical properties and rock mechanics and the boundary conditions of the multi-scale adaptive grid as constraints, so that the hydraulic fracturing fracture extension simulation results under different reservoirs and construction conditions are obtained.

The invention belongs to the technical field of microwave rock breaking, and provides a phase field simulation method for quasi-static hydrofracture of a thermoelastic porous medium under the condition of high-energy fracturing, which comprises the following steps of: firstly, acquiring parameters of a target reservoir and parameters of fluid in the target reservoir; secondly, microwave parameters are set on the basis of target reservoir parameters and fluid parameters in a target reservoir, and a phase field model of quasi-static hydraulic fracturing of the thermoelastic porous medium under the microwave-assisted fracturing condition is established; then, the target reservoir is irradiated with the microwave parameters, and the phase field model is used for simulating the crack evolution process during hydraulic fracturing; according to the method, the crack initiation difficulty of hydraulic fracturing can be reduced through microwave-assisted heating.

The present invention discloses a three-dimensional fatigue crack growth behavior prediction method that considers the surface strengthening effect. The method comprises the following steps: performing surface strengthening on a metal material specimen, characterizing the residual stress of the strengthened metal material specimen, obtaining the gradient distribution of the residual stress inside the metal material specimen, and obtaining the three-dimensional spatial distribution function of the residual stress inside the specimen through numerical fitting. Based on the performance parameters of the metal material, model parameters for fatigue crack growth calculation are obtained through uniaxial tension calculation and fatigue strength calculation. According to the three-dimensional spatial distribution function of the residual stress, the performance parameters and model parameters of the metal material are combined with the residual stress, and a three-dimensional fatigue fracture phase field calculation model is used to predict the fatigue crack growth behavior of the metal material. Considering the influence of the surface strengthening treatment on the residual stress distribution inside the material, a three-dimensional fatigue fracture phase field model considering the gradient structure is established, which is beneficial for improving the prediction of the effect of surface treatment on the fatigue performance of the material.

A relative permeability curve calculation method based on a phase field model relates to the technical field of oil and gas development, and comprises the following steps: selecting a core sample to establish a pore-scale model, performing a single-phase flow simulation, calculating the absolute permeability of the pore-scale model, performing a gas-water two-phase flow simulation, respectively calculating the gas and water phase fluid distribution volume fractions and the total fluid volume flow rate of the pore-scale model in each time interval, then respectively calculating the total gas and water two-phase fluid flow rates of the pore-scale model in each time interval, respectively calculating the volume flow rates of the gas and water phase fluids in each time interval, further calculating the corresponding relative gas phase permeability and relative water phase permeability in each time interval, and drawing a relative permeability curve in combination with water saturation; the relative permeability curve in the present invention can better characterize the fluid physical properties of the complex porous medium pore model, and thus accurately obtain the seepage characteristics of the fluid in the porous medium model.

The invention provides a rock dynamic shear failure simulation method and equipment considering frictional contact. The method comprises the following steps: calculating a stress tensor and a four-order elastic modulus matrix according to an elastic constitutive relation of a rock material; establishing a crack surface local coordinate system based on a maximum shear stress criterion, and determining normal and tangential unit vectors; introducing a crack density function and a corresponding degradation function of the cohesion phase field model, and configuring to eliminate the influence of the phase field characteristic length; deducing an energy functional of a dynamic shear phase field model, judging a contact state according to normal strain of a crack surface, and deducing strong forms of a displacement field control equation and a phase field control equation; variational processing is conducted on the strong forms of the displacement field control equation and the phase field control equation, corresponding weak forms are obtained, rock dynamic shear failure simulation considering frictional contact is achieved based on the weak forms, and rock mass stability evaluation in geological disaster prevention and control is supported. The model is insensitive to the phase field characteristic length, and the simulation result is more reliable.