63 results about "Material point method" patented technology

The invention belongs to the technical field of geological disaster monitoring and early warning, and particularly relates to a landslide catastrophe risk probability intelligent prediction method based on a two-phase substance point method. A two-phase substance point method is used for achieving rainfall-induced landslide catastrophe whole-process numerical simulation, then probability distribution of response quantities such as the sliding distance, the slump range and the slip mass volume is obtained, and the risk probability is predicted in combination with disaster-bearing body characteristics; according to the prior distribution of each parameter variable, a random sample is extracted as an input data set, a response quantity sample obtained through analog calculation is used as an output data set, an XGBoost model is adopted for training, and an agent model of a two-phase substance point method is constructed; and carrying out parameter inversion on slope monitoring data by utilizing Bayesian probability inversion, dynamically updating probability distribution of response quantity of each model, and predicting risk probability in real time according to the response quantity distribution. The physical significance is clear, and the prediction efficiency and the prediction precision are improved.

The invention belongs to the technical field of weak compressible large deformation of soft materials, provides a dynamic analysis explicit substance point method for large deformation of weak compressible materials, and provides a brand new numerical calculation method for large deformation research of the weak compressible materials. According to the method, a weak-form control equation is discretized in a total Lagrangian substance point method framework, and challenges caused by grid distortion when a traditional method is used for solving a large deformation problem are avoided. Besides, the invention provides a volume self-locking processing technology based on an F-bar method, the problem of volume locking of the weakly compressible substance in numerical simulation can be simply, conveniently and effectively solved, and the volume self-locking processing technology can be conveniently embedded into an existing substance point method program. Meanwhile, a construction method of a smooth kernel interpolation function is developed, and the problem that the solving precision of a traditional substance point method in a boundary region is reduced can be effectively solved. According to the method, the problem of large deformation of the weak compressible material can be solved in a stable and efficient manner, and a new technical path is provided for research and application in related fields.

The invention relates to the technical field of mining data processing, and particularly discloses a coal seam layered fully mechanized caving mining water flowing fractured zone height prediction method, which is used for solving the problem that a traditional material point method is difficult to accurately capture a fracture extension path and height, and the method comprises the following steps: monitoring a P-wave and S-wave arrival time difference of a micro-seismic event in real time through a micro-seismic sensor array; a micro-seismic event processing host is used for calculating a three-dimensional expansion path and an accumulative effect of a fracture based on the first equation set, the second equation set and the third equation set in combination with a stress intensity factor and a fracture expansion speed formula, and finally the final height of a fractured zone is accurately predicted by using a fractured zone height prediction formula and integrating rock stratum physical attributes and stress data. Transmitting to anchor rod adjusting equipment for supporting optimization; according to the method, the fracture extension path, the speed and the cumulative effect are calculated, and the physical attribute and the stress environment of the rock stratum are combined, so that the height prediction precision of the fracture zone is remarkably improved, and the safety and the real-time monitoring effectiveness in the coal mining process are ensured.

The invention discloses a landslide stability evaluation method and system combining a material point method and a transfer coefficient method, and the method comprises the steps: building a three-dimensional material point model for a landslide body based on the material point method, and obtaining the stress field distribution, deformation characteristics and fluid-solid coupling effect of the landslide body; dividing the landslide mass into a plurality of block areas, and determining the block area and the position of each material point; constructing a stress transfer matrix taking the positions and physical information of the material points as elements, calculating normal stress in the vertical direction between the block areas of the landslide mass and tangential stress parallel to the contact surface between the block areas based on the stress transfer matrix, and calculating a real-time stability coefficient; based on the displacement, the pore water pressure and stress and the real-time stability coefficient, the dynamic safety coefficient of the landslide mass is calculated, and stability evaluation is conducted on the landslide mass. Through combination of the material point method and the transfer coefficient method, the mechanical behavior and the material propagation process of the landslide mass are considered, and the evaluation precision of the landslide stability is improved.

The invention discloses a material point method-based open pile soil plug effect numerical model construction method, which comprises the following steps: carrying out an indoor semi-model tank test by adopting standard sandy soil, and recording data of friction resistance of the inner side and the outer side of a pile, soil stress, soil plug height and a displacement field in a pile sinking process; a geometric model is established based on an indoor model test, numerical simulation is performed by adopting a two-dimensional axisymmetric substance point method in combination with a grid encryption strategy, and data of friction resistance of the inner side and the outer side of a pile, a soil stress field, the soil plug height and a displacement field are obtained; performing comparative analysis on the indoor test data and the numerical simulation result, and if an error meets a preset requirement, confirming the validity of the numerical model; and if the comparison result does not meet the requirement, optimizing the numerical model. The soil plug effect in the pile sinking process can be effectively simulated, the response of the open pile to a stress field and a displacement field of a surrounding soil body can be deeply researched, and a more accurate basis can be provided for structural design and bearing capacity calculation of the open pile.

The invention discloses a landslide geological disaster deduction method and system based on an MPM method, and the method comprises the steps: collecting the multi-source data of a disaster scene, and synchronously constructing a digital twinborn model; a qualitative and quantitative two-stage inversion calibration model is adopted; a qualitative layer combines a monitored displacement direction and a deformation mode, and preliminarily inverts key parameters such as slip band cohesive force and an internal friction angle; the quantitative layer comparison model calculates the actual deformation range, collapse position and displacement, and parameters are optimized to match the actual landslide state; in landslide long-term evolution deduction, a rock-soil body aging characteristic model is embedded, an exponential function is used for describing annual scale parameter deterioration, prediction is divided into continuous analysis steps, MPM calculation is carried out based on a material point method, full-cycle simulation from the current year to the future years is completed, and deformation range, displacement and outburst risk results are output. And reliable decision support is provided for disaster prevention and reduction.

The invention relates to the technical field of separation layer micro-crack analysis, and provides a separation layer micro-crack analysis system based on a material point method.The method comprises the steps that firstly, a data acquisition module is used for acquiring data such as stress, strain, displacement and acoustic emission signals from a carbonaceous shale sample; the preprocessing module preprocesses the collected data to ensure the accuracy of subsequent analysis; the material point modeling module constructs a discrete material point model according to the processed data, and simulates the mechanical behavior of the carbonaceous shale sample; the micro-crack identification module is responsible for analyzing crack characteristics in the material point model and identifying geometric morphology and spatial distribution of micro-cracks; the crack evolution analysis module further perfects the crack network model by calculating the crack expansion and convergence process; the bed separation judgment module evaluates whether the sample has bed separation or not by combining the change of damage degree and complexity based on the evolution characteristics of the fracture network; and finally, the result output module summarizes and outputs various analyzed result data. Finally, the method is only the preferred embodiment of the invention and is not used for limiting the method, and any modification, equivalent replacement, improvement and the like made within the spirit and principle of the method should be included in the protection range of the method.

In one embodiment, a technique for numerical integration in material point method (MPM)-based geotechnical analysis and simulation is provided. Input terms for an element of a background mesh are received. The input terms including material points in the element that describe a continuum of soil, rock and / or groundwater. A set of constraints is created that defines an optimization problem. The set of constraints provide that numerical integration of the material points weighted by unknown integration weights equal exact integration for finite element shape functions. The optimization problem defined by the constraints is solved by an optimization algorithm to minimize numerical integration error for polynomials up to a given order to produce a set of integration weights. The set of integration weights is scaled to conserve the mass of the material points to produce optimized integration weights. The optimized integration weights are used in numerical integration performed in MPM-based geotechnical analysis and simulation.

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 discloses a virtual reality level simulation method based on a material point method and gridding surface reconstruction, and belongs to the crossing field of computer graphics, physical simulation and virtual reality technologies. The method comprises the following steps: S1, classifying and storing position coordinates of material points according to material numbers of the material points, and traversing the coordinates to obtain a boundary of a bounding box of the material points; s2, selecting a grid size and a boundary extension distance for reconstructing the surface in a self-defined manner, and generating a grid; s3, selecting a Gaussian function to calculate the contribution of each substance point to the overall substance point density field, and obtaining parameters; s4, calculating the contribution of each substance point to the overall substance point density field, and performing accumulation to obtain the overall substance point density field; and S5, obtaining a contour surface of the overall material point density field, and exporting the contour surface as a rendering engine general three-dimensional model to obtain a simulation visual effect. According to the method, the problems that in the prior art, tens of millions of substance points cannot be processed, reconstruction parameters are difficult to select, and connection with a high-end rendering engine is not smooth can be solved, and the virtual reality level simulation visual effect is achieved.

The invention discloses a topological optimization method, device and equipment for material distribution based on particle flow, and relates to the technical field of material structure optimization. According to the method, isogeometric analysis is introduced into the material point method in topological optimization of material distribution, the isogeometric material point method is provided, consistency between geometric modeling and numerical analysis is achieved through a unified primary function of isogeometric analysis, benefit from high-order continuity of the primary function of isogeometric analysis, and the method has the advantages that the method is simple and convenient to implement. The introduction of isogeometric analysis can effectively eliminate and suppress numerical artifacts in topological optimization and unit cross instability in a traditional substance point method. According to the isogeometric material point method, movable particles of material distribution in a physical domain serve as design variables, a set of particle-grid physical information and sensitivity transmission model is established in combination with Lagrange-Euler mixed description, corresponding accurate geometric topology is output while particle evolution is achieved, and the method has the advantages of being high in accuracy and high in reliability. And the accuracy and the flexibility of topological optimization of the material distribution structure are remarkably improved.

This invention relates to a method for analyzing large deformations of saturated soil and structures based on a semi-implicit material point method, comprising: decoupling pore pressure and motion variables using an incremental step method; introducing a penalty function for an enhanced frictional contact algorithm; introducing an artificial compressibility parameter into the pressure Poisson equation; employing the B-bar technique to reduce volume lock-in effects; using an affine particle cell method; modifying the calculation formula for axisymmetric problems, considering volume integrals and gradient evaluation in cylindrical coordinates; and conducting verification. The beneficial effects of this invention are: by employing an incremental step method, artificial fluid compressibility, and the B-bar technique, this invention avoids numerical instability caused by coupling problems in traditional methods, ensures the convergence of the simulation process, and avoids non-physical stress oscillations.

The application discloses a large deformation whole process simulation method of earthquake landslide based on a grid isolation technology and relates to the technical field of geotechnical engineering.The application constructs a separated background grid and a multi-medium model containing a safety isolation zone based on a second-order convection particle domain interpolation material point method, carries out dynamic analysis on the earthquake landslide by using a strain-driven hardening-softening coupling constitutive mechanism, realizes flexible input of the earthquake wave at the isolation zone and anti-drifting of the base, and can accurately simulate the complete evolution process of the landslide from undrained shear cracking to large deformation friction accumulation.The application effectively eliminates wave reflection interference of the dynamic boundary and numerical drift of long-time integration, realizes real physical reproduction of the whole process of the earthquake landslide from cracking to friction accumulation, makes calculation of large deformation and permanent displacement of the slope under the action of the earthquake more accurate and stable, and lays a foundation for prediction and evaluation of the whole process of the landslide disaster evolution.

The present invention discloses a solid-liquid coupling simulation method with surface tension effect based on the material point method, belonging to the fields of computer graphics and physics-based simulation. The system used in the simulation method includes solid model modeling, fluid model modeling, Level Set implicit surface construction, Marching Cubes display surface construction, surface particle resampling, and collision detection. The system simulates fluids and solids on the basis of the material point method, constructs Level Set to resample fluid surface particles, and adds surface tension to the fluid using the CSF model. Different background grids are used to simulate fluids and solids respectively to solve the inherent adhesion phenomenon during MPM solid-liquid coupling and achieve the slip contact effect during solid-liquid coupling. Finally, the coupling phenomenon of incompressible fluid with surface tension effect and nonlinear elastic solid is realized.

The invention discloses a method for generating a material point method model of a soil-rock mixed slope, which is used for simulating the mechanical behavior of the soil-rock mixed slope. The method comprises the following steps of: firstly, randomly dividing a slope region to generate polygonal units conforming to target area and shape distribution; then, according to the shape contour of the polygon unit, generating a random dimension stone contour through polar coordinate sampling and Fourier series fitting, and adjusting and controlling the dimension of the dimension stone through an area proportion; and finally, mapping the generated contour of the block stone into a substance point array, calibrating substance points belonging to the block stone, and completing pretreatment of substance point method calculation. The dimension, shape and spatial distribution characteristics of the rock blocks in the soil-rock mixed slope can be truly reflected, the rock block putting efficiency is effectively improved, the overlapping problem is avoided, the defects that in the prior art, the shape of the rock blocks is simplified, and the distribution randomness is insufficient are overcome, meanwhile, the method is suitable for numerical simulation of the large deformation problem, and the application prospect is wide. The method has high calculation precision and wide engineering application prospects.

The application provides a cuttable interactive soft body simulation method and system based on a GPU accelerated material point method, and belongs to the field of computer graphics physics simulation, and comprises the following steps: S1: sampling and initializing a three-dimensional soft body model to be simulated and a rigid body model interacting with the three-dimensional soft body model; S2: constructing an initial GPU secondary sparse acceleration structure Ggrid based on a virtual scene to be simulated; S3: extending the Ggrid; S4: updating the state of the rigid body model and constructing a rigid body cutting field of the Ggrid; S5: solving a physical explicit integration of the three-dimensional soft body model to be simulated in parallel based on the Ggrid and the rigid body cutting field, and obtaining the position of a Lagrange particle at the next time; and S6: at the last iteration of each frame, reconstructing a surface triangular mesh mesh of the Lagrange particle cluster in real time based on the Ggrid, and smoothing the surface triangular mesh mesh. The method realizes multi-material soft body deformation, cutting interaction, fragmentation and real-time surface reconstruction.

The invention discloses an earthquake landslide large deformation whole process simulation method based on a grid isolation technology, and relates to the technical field of geotechnical engineering. According to the method, a separated background grid containing a safety isolation belt and a multi-medium model are constructed based on a second-order convective particle domain interpolation material point method, and dynamic analysis is performed on seismic landslide by using a strain-driven soft and hard coupling constitutive mechanism, so that flexible input of seismic waves at the isolation belt and drifting prevention of a substrate are realized; and the complete evolution process of the landslide from undrained shear crack initiation to large-deformation friction accumulation can be accurately simulated. According to the method, wave reflection interference of a dynamic boundary and numerical drift of long-lasting integral are effectively eliminated, and real physical reproduction of the whole process of seismic landslide from crack initiation to friction accumulation is realized; therefore, calculation of large deformation and permanent displacement of the side slope under the earthquake action is more accurate and stable, and a foundation is laid for prediction and evaluation of the whole evolution process of landslide disasters.

The application provides a three-dimensional terrain geological modeling method and device based on material point method simulation, and relates to the technical field of geotechnical engineering numerical simulation, and comprises the following steps: S1, extracting elevation data of a three-dimensional terrain geological region model; S2, converting the elevation data into three different type model component data and processing; S3, based on the generated model component data, discretizing the model into material points to generate a material point model; S4, importing the generated material point model into a material point method calculation program to perform material point method simulation, and obtaining large deformation of the geology according to the material point method simulation; the application effectively solves the problem of large deformation simulation modeling caused by complex and diverse terrain and landform, is efficient, stable, simple and feasible, significantly improves the modeling efficiency of the material point method and the quality of the generated material point model, and effectively promotes the application of the material point method simulation in the field of geotechnological engineering numerical simulation.

The invention relates to the technical field of mining data processing, and specifically discloses a method for predicting the height of a water-conducting fracture zone in coal seam stratified fully mechanized caving mining, which is used to solve the problem that the traditional material point method is difficult to accurately capture the fracture expansion path and height. The method uses a microseismic sensor array to monitor the arrival time difference of P waves and S waves of microseismic events in real time, and uses a microseismic event processing host based on the first, second and third equation groups, combined with a stress intensity factor and a fracture expansion speed formula, to calculate the three-dimensional expansion path and cumulative effect of the fracture, and finally uses a fracture zone height prediction formula to comprehensively consider the physical properties of the rock formation and stress data, accurately predict the final height of the fracture zone, and transmit it to an anchor adjustment device for support optimization; the invention significantly improves the accuracy of fracture zone height prediction by calculating the fracture expansion path, speed and cumulative effect, combined with the physical properties of the rock formation and the stress environment, and ensures the safety and real-time monitoring effectiveness during coal seam mining.

The application provides a step-by-step decomposition-space mapping three-dimensional material point material parameter random field generation method, and belongs to the technical field of water conservancy and hydropower. First, a three-dimensional geometric model of a structure is established according to engineering geological data, high-precision mesh division is carried out, each mesh is converted into a material point carrying mass and volume, and a material point model is obtained. Second, a background mesh element is determined, and a background mesh covering the space occupied by the entire structure is generated. Third, a correlation function reflecting the material parameter properties is selected, a step-by-step decomposition method is used, and a material parameter random field on the background mesh element is generated. Finally, the value of the material parameter of the material point model is determined through a space mapping technology, and a three-dimensional material point material parameter random field is generated. The application is based on the material point method, and realizes the generation of a three-dimensional random field of a geotechnical engineering material parameter through the joint application of a step-by-step decomposition-space mapping technology, thereby providing technical support for the simulation of large deformation of a geotechnical engineering considering spatial variability.

A fluid-structure interaction (FSI) simulation method for submerged boundaries based on the material point method and positional dynamics includes: a) solving for the solid state and calculating the Lagrangian elastic force of the solid; b) transferring the elastic force of the solid Lagrangian mesh vertices to the Eulerian background mesh; c) solving the Navier-Stokes fluid control equations and continuity equations on the Eulerian background mesh, feeding back the updated mesh flow field information to the particles, and updating the particle state synchronously; d) using a mapping matrix to map the positions of solid particles back to the vertices of the solid Lagrangian mesh, saving the vertex position data and fluid particle data for rendering output. This invention, through the above-mentioned hybrid Lagrangian-Eulerian perspective coupling solution, can realistically simulate the bidirectional coupling between solids of different materials and complex fluids, significantly improving the physical realism and visual fidelity of the simulation scene.

A virtual reality level simulation method based on material point method and gridding surface reconstruction belongs to the cross field of computer graphics, physical simulation and virtual reality technology. The steps are as follows: S1, storing the material point position coordinates according to the material point material number, and obtaining the bounding box boundary of the material point by traversing the coordinates; S2, defining and selecting the grid size and boundary extension distance for reconstructing the surface, and generating the grid; S3, selecting a Gaussian function to calculate the contribution of each material point to the overall material point density field, and obtaining the parameters; S4, calculating the contribution of each material point to the overall material point density field, and accumulating to obtain the overall material point density field; S5, obtaining the isosurface of the overall material point density field, and exporting it as a general three-dimensional model of a rendering engine to obtain a simulation visual effect. The method can solve the problems that the prior art cannot process ten million material points, the reconstruction parameter selection is difficult, and the connection with a high-end rendering engine is not smooth, and realizes a virtual reality level simulation visual effect.

The present invention belongs to the technical field of geological disaster monitoring and early warning, specifically relating to an intelligent prediction method for landslide disaster risk probability based on the two-phase material point method. By treating parameters such as rock and soil properties and rainfall intensity as statistically correlated multivariate random variables, the two-phase material point method is used to numerically simulate the entire process of rainfall-induced landslide disasters. The probability distribution of response quantities such as sliding distance, collapse range, and sliding body volume is then obtained, and the risk probability is predicted based on the characteristics of the hazard-bearing body. Random samples are extracted based on the prior distribution of each parameter variable as input data sets, and the response quantity samples obtained by simulation calculations are used as output data sets. The method is trained using an XGBoost model to construct a proxy model for the two-phase material point method. Bayesian probabilistic inversion is used to perform parameter inversion on slope monitoring data, dynamically updating the probability distribution of each model response quantity. Based on the response quantity distribution, the risk probability is predicted in real time. This method not only has clear physical meaning but also improves prediction efficiency and accuracy.

The invention provides a landslide motion simulation method considering terrain reconstruction, and solves the logic contradiction of the traditional method for simulating the initial motion by using the landslide terrain. The method comprises the following steps: acquiring high-precision terrain, volume, geological parameters and rainfall data after landslide; the landslide terrain is used as a starting point, and the landslide terrain is restored through volume conservation, reasonable flow direction and flow and rock-soil body strength adaptive constraint iterative correction; based on a reconstructed terrain, coupling rainfall infiltration, a pore water pressure evolution model and a material point method, a landslide movement process is positively simulated, and information such as speed, acceleration and accumulation depth is inversed. According to the invention, initial condition errors are eliminated from the source, the simulation precision is high, and a scientific tool is provided for landslide mechanism research and disaster prevention and control.

The invention provides a boundary self-adaption and surface reconstruction method and device based on a material point method, and relates to the technical field of computer graphics. The method comprises the following steps: splitting original particles according to user control parameters to obtain subdivided particles, and performing position reconstruction on the subdivided particles; information carried by the original particles and the subdivided particles is transmitted to the grid; stress on the grids is calculated according to the information; and returning a stress calculation result to the original particles, and carrying out particle advection. The multi-scale particle interpolation technology provided by the invention ensures the stable interaction of particles with different scales. Multi-scale grid transmission is provided, it is guaranteed that particles of different scales can be mutually influenced through the grids, and the requirement of a user for simulation precision is met by adjusting the sizes of the grids. According to the provided boundary surface particle reconstruction scheme, the problems of unsmooth surface and the like caused by uneven distribution of subdivided particles can be avoided, and a more accurate simulation effect is achieved.

This invention relates to a method and equipment for probabilistic assessment of highway resilience under rainfall-induced landslide conditions, comprising the following steps: S1, calibrating a random rainfall model and the probability density distribution function of soil and rock parameters; S2, numerically simulating the sliding distance of the slope using a two-stage analysis of the finite element method and the material point method, and constructing a sample library of highway residual functions; S3, constructing a two-stage predictive proxy model for highway residual functions; S4, randomly sampling soil and rock parameters and rainfall events, and predicting highway residual functions based on the two-stage predictive proxy model; S5, constructing a probabilistic ladder recovery model for highway functions based on a decision tree, randomly sampling the recovery patterns of the highway after different landslide events, and calculating the highway resilience index based on the predicted value of the highway residual functions; S6, repeating step S5 multiple times to solve for the mean and standard deviation of the highway resilience index. Compared with existing technologies, this invention can achieve rapid and accurate assessment of the resilience level of slope highways.

The application discloses a fast Gaussian splash physical simulation method and related equipment, and relates to the technical field of physical model simulation generation. The method comprises the following steps: segmenting each object in a static three-dimensional Gaussian scene; constructing an occupancy field, and then dividing corresponding points into the interior of the object according to an occupancy probability; filling the points in the interior of the object by using a Monte Carlo importance probability sampling method; acquiring physical parameters of the object for simulation of a material point method according to a text description by using a large language model; and generating simulation results of each object according to the physical parameters. The application firstly segments an input static three-dimensional Gaussian scene, then obtains a preliminary filling result by using an occupancy field, and then fills a complex structure according to Gaussian importance by using the Monte Carlo importance probability sampling method proposed in the application. The text physical optimization based on the large language model proposed in the application can quickly optimize and determine the physical parameters of the object, and obtain stable simulation results.

The invention relates to the technical field of frozen soil deformation prediction, and particularly discloses a thermal-mechanical coupling frozen soil deformation rapid prediction method based on a material point method, and the method comprises the steps: building an improved Takashi three-dimensional frost heaving model; thermal-mechanical coupling frozen soil deformation calculation: carrying out initialized background grid boundary division on the predicted frozen soil position; calculating the temperature gradient according to the node temperature, calculating the heat flux density of the material point, and updating the node temperature and the temperature of the material point; judging whether the material point reaches a frost heaving condition or not according to the updated material point temperature, and if the material point reaches the frost heaving condition, performing frost heaving strain calculation; calculating the strain rate and the rotation rate of the substance point, updating the volume of the substance point by using the strain rate of the substance point, and updating the stress of the substance point by using the constitutive relation; calculating node force and updating node momentum, applying displacement boundary conditions again, mapping node acceleration and velocity back to the material point, and updating the velocity and position of the material point; and repeating the calculation of the next time step by using the undeformed grid.

The present invention discloses a method for generating a material point method model of a soil-rock mixed slope, which is used to simulate the mechanical behavior of a soil-rock mixed slope. The method comprises the following steps: first, randomly dividing the slope area to generate polygonal units that meet the target area and shape distribution; then, based on the shape contours of the polygonal units, generating random block contours through polar coordinate sampling and Fourier series fitting, and controlling the size of the block by adjusting the area ratio; finally, mapping the generated block contours to a material point array, calibrating the material points belonging to the block, and completing the pre-processing of the material point method calculation. The present invention can truly reflect the size, shape, and spatial distribution characteristics of the blocks in the soil-rock mixed slope, effectively improve the efficiency of block placement, avoid overlapping problems, and overcome the defects of the existing technology in the simplification of block shape and insufficient randomness of distribution. At the same time, it is suitable for the numerical simulation of large deformation problems, has high calculation accuracy and broad engineering application prospects.

The invention discloses a subsurface erosion simulation numerical method based on a semi-implicit two-phase substance point method, and relates to the technical field of geotechnical engineering numerical simulation, and the method comprises the following steps: generalizing unsaturated easily subsurface-eroded accumulated soil into a two-phase multi-component medium based on a mixture theory; establishing a solid-liquid double-phase double-layer grid system; establishing a core control equation of seepage subsurface erosion in the soil body; transferring the material point information of the solid phase and the liquid phase to corresponding background grid nodes in the double-layer grid system; applying a boundary condition on a background grid of the double-layer grid system, and carrying out semi-implicit solution on the core control equation; mapping the obtained node speed to a substance point; judging whether the relative velocity of the solid phase and the liquid phase exceeds a seepage velocity threshold value or not; state variable information carried by the two-phase substance points is updated; correcting permeability and saturation; and judging and calculating whether the specified time is up or whether the soil body reaches the yield limit. The method provided by the invention has important theoretical and engineering practical values for solving the difficulty in simulating the subsurface erosion disaster of the accumulated soil.