135 results about "Tetrahedral meshes" patented technology

The invention discloses a physical attribute inversion and three-dimensional reconstruction method based on Gaussian splashing and micro-rendering, and belongs to the technical field of computer vision, and the method comprises the steps: generating a sparse point cloud based on a multi-view image to initialize a Gaussian ball; determining a Gaussian pivot point based on a Gaussian ball, constructing a self-adaptive tetrahedral mesh in combination with gradient optimization, extracting an explicit surface from the self-adaptive tetrahedral mesh, and sampling to obtain geometric information; predicting the physical attribute of each sampling point through an implicit texture network, and providing ambient light through an HDR ambient light map; geometric information, physical attributes and ambient light are used as input, a differentiable PBR renderer is adopted to generate a physical rendering image, multi-term loss function reverse optimization is constructed, and collaborative optimization and inversion of three-dimensional geometry and surface physical attributes are realized. According to the method, the problems of texture dislocation, thin-wall structure disappearance and high rendering calculation cost under dynamic topology are effectively solved, and a digital model with fine geometry and a realistic material can be efficiently recovered from a multi-view image.

The invention provides a GPU-based parallel tetrahedral mesh optimization method, system and device and a medium, and relates to the technical field of numerical simulation. Comprising the steps of generating a triangular mesh covering a surface for a three-dimensional geometric model; generating an initial tetrahedral mesh based on the triangular mesh; performing a round of point smoothing operation on each tetrahedron by using a plurality of GPU threads; carrying out iterative circulation of the combination optimization operation, and simultaneously carrying out a round of point smoothing, edge deletion and multi-surface deletion operation on a plurality of initial tetrahedrons by utilizing a plurality of GPU threads; and when the edge deletion operation and the multi-surface deletion operation cannot further improve the grid quality, simultaneously performing a round of edge contraction and edge segmentation operation on the plurality of initial tetrahedrons by utilizing the plurality of GPU threads. According to the method, the large-scale grid with reliable quality is quickly generated based on the low-quality input grid, and the grid optimization rate is improved, so that the requirement of large-scale unstructured grid optimization in a three-dimensional space is met.

The invention belongs to the field of electromagnetic field numerical solution, and particularly provides a finite element mesh adaptive method for network parameter analysis of a multi-port microwave device, which comprises the following steps: firstly, establishing a geometric structure of the multi-port microwave device, setting simulation frequency, excitation and boundary conditions, and establishing an electromagnetic simulation model; secondly, performing preliminary division and finite element electromagnetic simulation calculation on a computational domain by adopting a tetrahedral mesh to obtain a numerical solution corresponding to each group of excitation, and synthesizing results based on a posterior error estimation method for posterior error estimation; and finally, according to a posterior error indication grid encryption parameter, carrying out simulation calculation again after encryption, and repeating the process until the solution meets the precision requirement. In conclusion, by combining the characteristics of a finite element algorithm and the characteristics of an error estimation algorithm, in the microwave device network parameter analysis process, multiple sets of excited numerical solutions are comprehensively used for posterior error estimation and grid adaptive encryption indication, so that the analysis precision of network parameters is improved.

The invention provides a well-ground frequency domain electromagnetic detection method and device and electronic equipment, and the method comprises the steps: setting a perfect matching layer based on stretching coordinate transformation at the outer side of a model based on a three-dimensional geologic model, constructing an overall computational domain, facing the overall computational domain, and implementing adaptive mesh generation according to posterior error estimation. And generating an unstructured tetrahedral mesh which is locally refined in a target area, and on the tetrahedral mesh, performing spatial discretization and solution on a frequency domain Maxwell equation by adopting a first-order or second-order vector finite element in an H (curl) space to realize well-ground frequency domain electromagnetic forward modeling calculation. According to the method, through cooperation of the adaptive grids and the vector finite elements under the microframework, both precision and efficiency are considered, forward modeling stability and imaging resolution are improved, and a scientific basis is provided for efficiency improvement and cost saving of mineral resource exploration and development.

The invention discloses an oral cavity finite element simulation calculation method based on collision detection. The method comprises the following steps: 1) acquiring oral scanning data of teeth, generating surface grid data of the invisible appliance according to the oral scanning data, and then generating a tetrahedral grid from the surface grid of the invisible appliance for subsequent simulation calculation; 2) on the basis of collision detection, calculating a pushing vector of teeth to the invisible appliance, and taking the pushing vector as a displacement boundary condition of subsequent calculation; 3) constructing a three-dimensional finite element model taking voxels as units, calculating an element stiffness matrix, assembling an overall stiffness matrix, loading displacement boundary conditions, forming a finite element solution equation set, and obtaining a model node displacement result; and 4) calculating stress and strain of the finite element model according to a displacement result. Aiming at the orthodontic mechanical analysis of the invisible orthodontic appliance, the invention provides a modeling method for the interaction between the teeth and the invisible orthodontic appliance based on a collision detection technology, completes the subsequent simulation solution of a finite element model, and gives consideration to the solution precision and speed.

The invention relates to the technical field of biomedical engineering and microfluidics, in particular to a fluid dynamics topological optimization design method of a circulating tumor cell sorting structure, which comprises the following steps of: establishing a three-dimensional flow field model containing a key separation area in a preset design domain, dispersing by adopting a tetrahedral mesh and setting boundary conditions; the method comprises the following steps: establishing a multi-objective optimization function based on a maximized transverse focusing distance, a minimum shear force peak value and a total pressure drop, dispersing a design domain into units and endowing the units with density variables, and realizing global automatic topological optimization by adopting penalty material interpolation and minimum flow velocity threshold constraint. An optimization result is subjected to structural reconstruction processing to generate a CAD model adaptive to micro-nano machining, closed-loop feedback is formed through secondary verification and experimental verification of computational fluid mechanics, it is ensured that the design meets the requirements for sorting efficiency and cell activity, limitation of a traditional flow channel form is broken through, and the design freedom degree, manufacturability and application value are improved.

The invention relates to the technical field of geophysical electromagnetic data exploration, in particular to a three-dimensional time-frequency domain electromagnetic joint inversion method based on a finite element algorithm. The method comprises the following steps: respectively acquiring time domain and frequency domain electromagnetic observation data of a to-be-measured region; dividing a to-be-measured region to obtain a non-structural tetrahedral mesh to construct a time-frequency domain inversion initial model; performing forward modeling calculation on the time-frequency domain inversion initial model to obtain time domain and frequency domain electromagnetic response data; obtaining a time domain electromagnetic data residual error and a frequency domain electromagnetic data residual error, respectively obtaining corresponding adaptive weights, and establishing a joint inversion objective function; performing iterative solution on the joint inversion target function, and calculating an update vector of the inversion initial model; and iteratively updating the initial inversion model until a set condition is met, and completing the time-frequency domain electromagnetic joint inversion. According to the method, the accuracy of three-dimensional inversion is effectively improved through joint inversion, so that the practical effect of three-dimensional inversion is enhanced.

The invention relates to a simulation analysis-based alkaline electrolytic cell stretching net flow channel optimization method. The method comprises the following steps: 1, establishing a zero-clearance stretching net flow channel alkaline electrolytic cell numerical simulation model; 2, a free tetrahedral mesh is adopted to divide a computational domain, a boundary layer mesh is divided near a flow boundary, and angle refinement is set in a whole flow area to encrypt the density of the mesh; 3, initializing an electric field; 4, calculating a flow field; 5, thermal field calculation; 6, post-processing a result; 7, analyzing the influence of different stretching net structures on the working characteristics of the alkaline water electrolyser through multi-physics field coupling simulation, and optimizing the design scheme on the experimental basis; according to the method, the tensile net alkaline electrolytic cell model is established, the electrochemical field, the flow field and the thermal field are distributed and coupled, the reaction gas production process is simplified through the step function, the simulation calculation amount is reduced, the model convergence is better improved, the method acts on tensile net flow channel structure optimization, and the performance of the tensile net flow channel alkaline electrolytic cell is improved.

The invention discloses an automatic radiation noise simulation method, device and equipment of acoustic finite element software and a storage medium, and relates to the technical field of noise simulation, and the method comprises the steps: obtaining a grid size and a convex hull grid distance according to a geometric model, a material and a frequency input by a user; performing mesh generation on the surface of the geometric model based on the mesh size to obtain a surface mesh; obtaining a convex hull grid based on the convex hull grid distance and the surface grid; generating a tetrahedral mesh in an area between the surface mesh and the convex hull mesh; based on the surface grid, the tetrahedral grid and the convex hull grid, acoustic radiation noise simulation is carried out, full-process autonomous generation from simulation input to grid calculation is realized, and the efficiency problem of grid division and boundary setting depending on artificial experience in the prior art is solved. The calculation precision is guaranteed, meanwhile, the pretreatment workload is reduced to the degree that only basic parameters need to be input, and the operation complexity of radiation noise simulation conducted by acoustic finite element software is reduced.

The invention discloses a spherical domain magnetotelluric non-structural vector finite element inversion method capable of automatically modeling, which comprises the following steps of: automatically establishing a spherical domain initial model through global topographic data, and performing spatial discretization by using a non-structural tetrahedral mesh to realize three-dimensional magnetotelluric non-structural finite element solution of two polarization modes in a spherical domain; constructing a spherical domain magnetotelluric three-dimensional regularization inversion objective function according to the actual observation data and the prediction data; adopting adjoint forward modeling to solve a Jacobian matrix and a product of transpose and a vector of the Jacobian matrix, and utilizing a nonlinear conjugate gradient method to realize iterative inversion of spherical domain magnetotelluric, so as to obtain a final inversion model and complete spherical domain magnetotelluric non-structural vector finite element inversion. According to the method, spherical domain magnetotelluric non-structural vector finite element inversion is realized, errors caused by coordinate projection can be avoided, and a large-scale inversion result is more accurate and more conforms to a real earth model.

The invention discloses an explosive shock wave intelligent mixed numerical simulation method, device and equipment, and relates to the field of numerical simulation, and the method comprises the steps: determining a computational domain range, grid node information and simulation termination time of an explosive shock wave simulation problem, and constructing a tetrahedral grid; initializing a physical flow field based on a computational domain range, and constructing a flow field analysis model based on the tetrahedral mesh; using a mean total variation bounded discontinuous detection method to identify a discontinuous region and a smooth region in a computational domain range; for the discontinuous region, reconstructing physical parameters in the flow field analytical model by adopting a non-structural multi-resolution weighted essential oscillation-free reconstruction method, and for the smooth region, reconstructing physical parameters in the flow field analytical model by adopting a linear windward reconstruction method; and performing spatial discretization on the physical flow field based on the flow field analysis model, then performing time discretization, and obtaining a numerical simulation result until the calculation time exceeds the simulation termination time. According to the invention, optimal balance of precision and efficiency is realized.

The invention provides a tetrahedron classification method and system based on geologic body surface grids, and relates to the technical field of geologic modeling. The method comprises the following steps: acquiring closed surface grid data of a plurality of geologic bodies; performing tetrahedral subdivision on the closed surface grid to obtain a corresponding tetrahedral grid; performing category division on the subdivided tetrahedrons based on a partition strategy and a priority strategy according to the spatial geometric information and the attribute labels of the geologic body to obtain tetrahedron classification information; recognizing contact surfaces in the generated tetrahedral mesh, and generating a contact surface category matrix based on a boundary relationship among the plurality of geologic bodies; and outputting a tetrahedral mesh data structure containing tetrahedral classification information and a contact surface category matrix. The method can significantly reduce manual operation, improves classification precision and simulation efficiency, and is suitable for complex geological numerical simulation tasks.

The invention discloses a sea surface small target detection method and system based on a magnetic KNN and an optimized concave packet, and belongs to the technical field of radar signal processing. Comprising the following steps: extracting high-dimensional features of sea clutters and echoes to be detected, and selecting three-dimensional feature points of the clutters and the echoes to be detected according to a dimension reduction algorithm; processing the three-dimensional feature points of the clutters by adopting a constant false alarm algorithm to obtain clutter feature points after constant false alarm; on the basis of the clutter feature points after the constant false alarm, constructing a concave packet by adopting an optimized concave packet construction algorithm; the clutter feature points in the concave packet serve as vertexes of a tetrahedron, and the concave packet is divided into tetrahedral grids; positioning the points in the tetrahedrons by using a pointLocation function, judging the indexes of the tetrahedrons where the points are located, and if the indexes exist, judging that the points are clutters; and if the index does not exist, judging as a target. According to the detection method, the construction efficiency of the concave packet is also improved while the relatively high detection probability is ensured, and the method has relatively good generalization.

The invention discloses a multi-physical-field simulation calculation method and system for a high-voltage submarine cable anchoring device, and belongs to the technical field of ocean energy. The method comprises the following steps: constructing a finite element model of the submarine cable anchoring device based on a geometric model of the high-voltage submarine cable anchoring device; the finite element model of the submarine cable anchoring device carries out simulation area boundary condition and multi-physical field setting, after setting is completed, free tetrahedral mesh generation is carried out on a high-voltage submarine cable body and the anchoring device, the corresponding mesh size is selected according to the size of each part obtained after mesh generation, and the high-voltage submarine cable anchoring device is constructed. Obtaining a finite element simulation model of the submarine cable anchoring device; and in the finite element simulation model of the submarine cable anchoring device, performing multi-physics field coupling calculation to form a simulation calculation result. The method is based on finite element simulation software, three-dimensional modeling is carried out according to the actual arrangement condition of the high-voltage submarine cable anchoring device, and accurate description of physical fields around the anchoring device during operation of the high-voltage submarine cable is achieved.

The invention particularly discloses an application method of an efficient well flow unit for simulating a decompression wellbore in a three-dimensional finite element, and relates to the technical field of civil engineering precipitation. The method comprises the steps of firstly determining parameters such as a model calculation boundary, boundary conditions, permeability coefficients of soil layers, the position of a relief well and a water head; secondly, establishing a three-dimensional model to divide a delaunay tetrahedron unit grid, and simplifying a three-dimensional relief well into a one-dimensional well flow unit during modeling; then, on the basis of geometric properties of a tetrahedral mesh around a well flow unit and a unit flow weight coefficient, making a numerical solution equal to an analytical solution flow, and deducing to obtain a well flow unit water guide matrix; and finally, merging the well flow unit water guide matrix into the total stiffness matrix, and solving to obtain the high-precision flow of the decompression wellbore and the node water head of the model unit. According to the method, the calculation efficiency and the calculation precision are greatly improved, the precision is not changed in a large-grid-size model, the calculation time is greatly shortened, and the investment of calculation resources is reduced.

This invention belongs to the field of numerical electromagnetic field solution, specifically a mesh adaptive method based on reconstructive posterior error estimation. The invention first performs finite element modeling of the target microwave component, introducing boundary conditions and excitations to establish a corresponding electromagnetic simulation model. Then, a tetrahedral mesh is used to divide the solution domain, and finite element electromagnetic simulation analysis is performed on the model to calculate the electric field at the centroid of the four faces of the tetrahedral mesh. The least squares principle is then used to refit the electric field on the tetrahedral mesh to reconstruct a first-order linear fitting expression. Next, the reconstructed solution at the nodes is calculated using the reconstructed fitting expression, and posterior error estimation is performed based on the electric field at the nodes. Finally, the mesh is refined according to the error on the tetrahedral mesh, and finite element electromagnetic simulation analysis is performed again until the finite element solution meets the accuracy requirements. This invention has the advantages of simple engineering implementation, low computational cost, and high universality.

The invention discloses a tetrahedral mesh simplification method based on a graph neural network, and the method is characterized in that feature extraction is carried out on each mesh edge of each tetrahedral mesh unit in a tetrahedral mesh model, and the deletion probability of each mesh edge is predicted to determine a to-be-deleted mesh edge; performing deletion validity check on the to-be-deleted grid edges to obtain a to-be-deleted grid edge set; and finally, deleting the to-be-deleted grid edge set in batches until the to-be-deleted grid edge set is empty, and outputting a simplified tetrahedral grid model. The method has the advantages that feature extraction is carried out on the grid edges from multiple dimensions such as geometry, topology, quality, physics and space, the relation between the grid edge structure and simulation analysis precision can be automatically learned by introducing the graph neural network technology, the influence of the to-be-deleted grid edges on the overall grid analysis precision is predicted, and the accuracy of the whole grid analysis precision is improved. And intelligent grid simplification with analysis precision as a guide is realized.

The application provides a tetrahedron classification method and system based on a geological body surface grid, and relates to the technical field of geological modeling. The method comprises the following steps: acquiring closed surface grid data of a plurality of geological bodies; performing tetrahedron subdivision on the closed surface grid to obtain corresponding tetrahedron grids; performing category division on the subdivided tetrahedrons based on a zoning strategy and a priority strategy according to spatial geometric information and attribute labels of the geological bodies to obtain tetrahedron classification information; identifying contact surfaces in the generated tetrahedron grids, and generating a contact surface category matrix based on the boundary relationship between the plurality of geological bodies; and outputting a tetrahedron grid data structure containing the tetrahedron classification information and the contact surface category matrix. The application can significantly reduce manual operation, improve classification accuracy and simulation efficiency, and is suitable for complex geological numerical simulation tasks.

The invention provides a thermal coupling optimization method for a shank structure of a hydraulic robot, and belongs to the technical field of hydraulic robots and topological optimizing.The thermal coupling optimization method comprises the steps that a node-based thermal coupling topological optimization algorithm is adopted, a complex structure is discretized through an unstructured tetrahedral mesh, and the discretized complex structure is obtained; and a Helmholtz filtering technology and a Heaviside projection technology are introduced, so that the fairness and manufacturability of an optimization result are ensured. And with the purpose of minimizing the flexibility of the structure, intelligent material distribution of the robot shank structure is achieved under the constraint of the material volume. And the hydraulic humanoid robot with the hydraulic flow channel integrated in the structure is constructed according to the optimization result. The quality of the shank structure of the hydraulic humanoid robot is reduced, and the heat dissipation efficiency is remarkably improved. The traditional defect that light weight and heat dissipation design are carried out independently is effectively overcome, performance collaborative optimization is achieved, and the dynamic response and continuous working capacity of the robot is improved.

The embodiment of the invention discloses a grid generation method and electronic equipment, and the method comprises the steps: carrying out the first boundary recovery of a surface grid, and taking a first tetrahedral grid obtained through the first boundary recovery as a background grid; distributing points on the background grid to obtain a plurality of wall nodes; performing second boundary recovery on the surface grid and the wall nodes to generate a second tetrahedral grid internally containing wall units; and carrying out region decomposition on the second tetrahedral mesh to obtain a plurality of first sub-regions, and carrying out parallel mesh generation on each first sub-region. The grid can be divided efficiently with high quality, and the parallel efficiency is improved.

The invention discloses a three-dimensional anisotropic grid size field smoothing method and system. The method comprises the following steps: generating a background grid; setting an anisotropic measurement tensor for each node of the background grid; and establishing a measurement tensor gradient constraint of any point in the grid unit. And each grid unit is verified according to the measurement tensor gradient constraint. And modifying the measurement tensor of each node in the grid units which do not meet the measurement tensor gradient constraint until all the grid units meet the measurement tensor gradient constraint. The method comprises the following steps: storing a size field in an unstructured tetrahedron node, and defining the size field by using a measurement tensor field; the dimension field gradient constraint is constructed into a nonlinear convex optimization problem, and the optimization problem has a globally optimal solution; according to the solution, smooth size field transition can be obtained in the whole computational domain, meanwhile, the change value of the size field is made to be minimum, and smooth optimization of the anisotropic tetrahedral mesh is achieved.

The invention discloses an automatic reconstruction method and system for an isogeometric topology optimization result editable model, and the method comprises the following steps: obtaining an isogeometric topology optimization result, and obtaining hypersurface model data; extracting contour lines of each layer in a layered manner according to a set density threshold; arranging seed points through the contour line, dividing a background tetrahedral mesh, and deeply searching a mesh edge crossing a density threshold value; judging a corresponding relation between the contour lines, executing different reconstruction strategies according to different corresponding relations, and generating an NURBS curved surface by using an automatic skin technology and an adaptive fitting technology respectively; the contour lines at the opening are identified, the position relation between the cut area and the contour lines is determined, and cutting operation is executed to obtain a cut curved surface; and integrating the NURBS curved surface and the cutting curved surface, and outputting an editable entity. According to the method, the complexity of extracting the contour surface of the optimization result is effectively reduced, the precision of the result model is effectively improved, and the result has the advantages of editability and modifiability.

The present invention relates to the field of joint inversion, and specifically to a gravity-seismic joint focusing inversion method under unstructured grid division, comprising the following steps: performing unstructured tetrahedral grid division on the underground space; performing forward modeling on gravity data and seismic data respectively to obtain forward gravity data and forward seismic data; establishing an objective function for the forward gravity data and forward seismic data using a constraint function of minimum support of a fractal index; and obtaining density joint inversion results and velocity joint inversion results. The present invention can obtain higher-resolution joint inversion results in practical applications. Compared with traditional focused joint inversion ideas, the present invention can more finely characterize the distribution range of physical properties and complex stratum boundaries, so that gravity-seismic joint inversion under unstructured tetrahedral grid division with higher inversion resolution and field source characterization capabilities has better development in fields such as fine structure exploration.

The application relates to a method for estimating the biomechanical parameters of in-vivo organ tissues, which comprises the following steps: in-vivo organ tissue geometry modeling is performed to obtain a tetrahedral mesh structure of the in-vivo organ tissues; according to the obtained tetrahedral mesh structure of the in-vivo organ tissues, in-vivo organ tissue biomechanical model modeling is performed; according to the in-vivo organ tissue biomechanical model, in-vivo organ tissue boundary condition estimation is performed; and the strong tracking Kalman filter is used to estimate the biomechanical parameters of the in-vivo organ tissues under the current boundary condition estimation result. The application can estimate the biomechanical parameters of in-vivo organ tissues of human bodies under complex boundary conditions, and the estimated biomechanical parameters are more accurate.

The invention discloses an aircraft numerical simulation method based on an improved GMR-WENO algorithm and a medium, and relates to the field of aircraft performance tests.The method comprises the steps that a three-dimensional calculation area is determined, and tetrahedral mesh generation is carried out; setting fluid physical parameters of each grid at an initial moment; an improved GMR-WENO algorithm is adopted to carry out high-order reconstruction on fluid physical parameters; in the improved GMR-WENO algorithm, a real quadratic algebraic polynomial is constructed by applying an orthogonal basis function, and a virtual first-order polynomial and a virtual zero-order polynomial are constructed by applying an L2 projection technology; determining fluid physical parameters at the final moment based on the third-order reconstruction polynomial; and determining the aerodynamic performance of the aircraft according to the fluid physical parameters at the final moment. According to the method, the orthogonal basis function and the L2 projection technology are combined into the GMR-WENO method to simulate the distribution condition of the aerodynamic characteristics of the aircraft, and the efficiency and accuracy of performance testing of the aircraft are improved.

The invention relates to the field of geophysics and discloses a three-dimensional magnetotelluric inversion method for block-by-block continuous variation of conductivity. The method includes adding a model constraint term based on the conductivity of an unstructured tetrahedral grid node to an objective function to obtain an inversion objective function expression. The model constraint term is solved by minimizing the norm of the conductivity variation between a unit and surrounding units to obtain a model constraint term based on the conductivity of the tetrahedral grid node. The inversion objective function expression is gradient-solved. Specific expressions of elements in the stiffness matrix gradient under four different conditions are solved and the gradient components of the stiffness matrix corresponding to all nodes are solved, thereby achieving the solution of the objective function gradient in magnetotelluric inversion. The method realizes the updating of the node conductivity model during three-dimensional underground medium inversion, greatly reduces the unknowns generated in the inversion process, improves the uniqueness of the solution, and greatly shortens the time required for the inversion process to obtain a better inversion effect.

The invention belongs to the field of electromagnetic field numerical solution, relates to antenna electromagnetic simulation, and particularly provides an error field energy-based grid adaptive encryption method, which comprises the following steps of: modeling a target antenna, introducing corresponding excitation and boundary conditions, determining an adaptive frequency point and a solution frequency band, and establishing an electromagnetic simulation model; secondly, carrying out primary division and finite element electromagnetic simulation calculation on a computational domain by adopting a tetrahedral mesh to obtain an electric field at each element node of the tetrahedral mesh, calculating energy corresponding to an error field on an interface of each element, and carrying out posterior error estimation; and finally, calculating a grid encryption strategy according to a posterior error, including an encryption unit and an encryption size, performing simulation calculation again after encryption, and repeating the process until a solution meets a precision requirement. In conclusion, according to the method, the part, not meeting the constraint condition, of the electromagnetic field solution serves as an error source, corresponding energy serves as posterior error estimation, and grid self-adaptive encryption is achieved.

The invention provides a layered rock modeling method based on a three-dimensional Voronoi block, and the method comprises the steps: firstly dispersing a rock mass into a plurality of unit blocks with different shapes through a three-dimensional Voronoi block generation technology, and constructing a three-dimensional Voronoi model which can represent a real discrete structure in the rock mass; performing unstructured tetrahedral mesh generation on the three-dimensional Voronoi model by adopting a finite element mesh discretization method to form a plurality of discrete tetrahedral element blocks with different shapes, and constructing an initial rock mass model capable of being used for mechanical analysis; and finally, generating a rock layer with a natural irregular form in the initial rock mass model so as to obtain a three-dimensional layered rock model capable of simultaneously reflecting geometric features of the natural layer of the rock mass.

The invention provides a multi-source venue flow anomaly detection method and system based on spatio-temporal feature fusion, and the method comprises the following steps: constructing a tetrahedral mesh space of a venue in combination with a CIM and an indoor model, and mapping audience individuals in multi-source monitoring data into a dynamic trajectory particle swarm in a mesh; a real-time crowd rheological viscosity field is constructed based on a shear thickening fluid model by calculating the velocity gradient and the strain rate of a particle swarm. The viscosity field and the particle velocity field are combined, a dynamic abnormal area is recognized by solving a fluid vorticity evolution equation, a path failure risk area is recognized by calculating virtual shear stress of a channel boundary, and finally the two risk areas are fused to generate a final flow anomaly detection result. According to the invention, the disordered congestion phenomenon in the high-density crowd evacuation process can be accurately identified.

The present invention discloses a magnetotelluric simulation method for an arbitrary anisotropic conductivity tensor in spherical coordinate system, belonging to the technical field of geophysical forward modeling, including: determining the coordinates and observation frequencies of a measuring point array; constructing an earth background model and discretizing it using unstructured tetrahedral meshes to obtain unstructured meshes; applying an arbitrary anisotropic conductivity tensor in spherical coordinates to assign electrical properties to the unstructured meshes; applying orthogonal non-planar wave field sources to the outer meshes of the unstructured meshes and calculating the source term integrals of the non-planar wave field sources; calculating the mass matrix and stiffness matrix of the elements in the unstructured meshes and forming the overall element matrix according to the numbering relationship; constructing a corresponding simulation equation set according to the overall element matrix and the source term integrals and at the current observation frequency; solving the simulation equation set to achieve magnetotelluric simulation, so as to solve the technical problem that the existing magnetotelluric simulation technology cannot flexibly simulate the magnetotelluric responses of arbitrarily anisotropic media at the intercontinental scale.