13 results about "Volume mesh" patented technology

The invention relates to the technical field of medical image processing and three-dimensional reconstruction, and particularly discloses a reconstruction and analogue simulation method based on a cardiac image. The method comprises the following steps: firstly, preprocessing an input CT or MRI medical image, and automatically segmenting a heart multi-tissue structure by using an nnUNetv2 model, including a plurality of anatomical regions such as atrium, ventricle, myocardial tissue and blood pool; and then performing topology repair, smoothing processing and label resampling on the segmentation result to obtain a three-dimensional label body with a continuous structure and a complete boundary. And based on the optimized tag body, constructing a heart three-dimensional surface model by adopting a Marching Cubes algorithm, and generating a multi-material volume grid suitable for finite element analysis. According to an electrode position and a radio frequency parameter set by a user, a radio frequency ablation simulation model based on a Pennes biological heat conduction equation and an Arrhenius model is established, a temperature field and a tissue thermal damage range are calculated, and a simulation result is displayed in a three-dimensional mode in an overlapping mode. According to the method, the integrated process from medical image automatic segmentation to heart three-dimensional reconstruction and thermal simulation is realized, the segmentation precision, the modeling efficiency and the simulation reliability are improved, and the method can be applied to application scenes such as surgical planning, preoperative evaluation and medical teaching.

A method and system are provided for manufacturing an object using a mechatronic positioning system comprising an end effector (110) The object may be manufactured as a physical representation of a volumetric mesh model by: a. providing a straight rod (142) to physically represent an individual edge of the mesh model; b. with the end effector, causing the rod to assume a position and orientation relative to a previously manufactured part of the object at which position an end (144) of the rod contacts or is in welding proximity of an end of at least one previous rod of the previously manufactured part of the object; c. welding the end of the rod to the end of the at least one previous rod to physically establish a node connecting two or more individual edges of the mesh model; and repeating steps a)-c) for respective individual edges and nodes of the mesh model to iteratively build up the physical representation of the mesh model.

The present application belongs to the technical field of solid engine nondestructive testing and finite element analysis, and relates to a solid engine finite element analysis method based on CT image fusion modeling, which comprises the following steps: step S1: performing CT step-by-step scanning on key positions of a defect high-occurrence area of a solid engine to be tested to obtain real CT images of the defect part; step S2: constructing a cross-section model of a part to be simulated, simulating CT data of an unscanned area, and generating a simulated CT image; step S3: fusing the real CT image and the simulated CT image to generate a triangular facet mesh model; step S4: importing the triangular facet mesh model into 3-matic software to generate a volume mesh model that can be used for finite element analysis; and step S5: importing the volume mesh model into Abaqus finite element analysis software to perform health state evaluation. The present application fuses the simulated CT image and the real CT image, and effectively reduces the detection cost and technical difficulty.

The present invention presents a computer-implemented method for automatically identifying and sealing gaps in geometrical or three-dimensional models for simulation. The method involves creating a multi-volume mesh of the model, defining boundaries to distinguish inside and outside regions, and solving the Laplace equation to identify gaps. By adjusting the iso-surface of the equation's primary variable, the gaps are sealed at desired locations. The model is then divided into distinct inner and outer volumes. The process reduces manual intervention, ensures accurate simulation preparation, and allows user interaction for boundary definition and visualization. The invention streamlines model preparation for simulations, enhancing the efficiency and accuracy of design validation across various industries and allowing much more efficient analysis.

A computer-implemented method of generating a thin volume mesh in a Computer-Aided technology (CAx) model of an object is described. In the method, a volume region lying between a first surface mesh having a first set of mesh parameters and a second surface mesh having a second set of mesh parameters is selected. This volume region has a thickness corresponding to the distance between the first and second surface mesh. prismatic cell volume mesh is generated to fill the entire volume region when the volume region is thin. Whether or not the volume region is thin is given by a crisp value calculated using a fuzzy logic inference scheme including the fuzzy sets thin and non-thin, and wherein the relationship between the first and second sets of mesh parameters and the thickness determine the membership of the fuzzy sets thin and non-thin.

A technique generates a hierarchical three-dimensional structure or volume mesh and uses intelligent compaction using a Barycenter compact model. Any primitive cells or blocks can be represented physically by a Barycenter compact model (or Barycenter model), and any black box model can also be physically represented by a Barycenter compact model physically. A boundary condition between blocks is formulated by the Barycenter compact model. Boundary condition problems between blocks can be limited within two levels only if using the Barycenter compact model. A technique generates a hierarchical three-dimensional volume mesh and uses intelligent compaction using a Barycenter compact model.

The invention belongs to the technical field of solid engine nondestructive testing and finite element analysis, and relates to a solid engine finite element analysis method based on CT image fusion modeling, and the method comprises the following steps: S1, carrying out key part CT step-by-step scanning on a defect high-incidence area of a solid engine to be detected, and obtaining a real CT image of a defect part; s2, constructing a section model of a to-be-simulated part, simulating CT data of an unscanned area, and generating a simulated CT image; s3, fusing the real CT image and the simulation CT image to generate a triangular patch mesh model; s4, the triangular patch mesh model is imported into 3-matic software, and a volume mesh model capable of being used for finite element analysis is generated; and S5, importing the volume mesh model into Abaqus finite element analysis software, and carrying out health state evaluation. According to the method, the CT image generated through simulation is fused with the real CT image, so that the detection cost and the technical difficulty are effectively reduced.

This application provides an automatic RTM mesh generation method based on implicit distance mapping and normal growth, comprising: acquiring a triangular mesh on the surface of a composite material part; obtaining a local normal field on the part surface by calculating the unit normal vector of each triangular facet; using the implicit distance field as the geometric representation basis, converting the layup thickness into a distance offset value according to the thickness mapping relationship to generate an enhanced initial reference surface; projecting points on the part surface onto the implicit distance field through the thickness mapping relationship, calculating the signed distance value of each point, determining the nested region affiliation, and obtaining supplementary nested space affiliation labels; using the optimized material region as boundary constraint conditions, performing voxel growth operations layer by layer along the local normal field of each layer to generate an initial volume mesh corresponding to each layup; and outputting the final solid mesh for simulation analysis of resin transfer molding process flow and curing.

A computer-implemented method of generating a volume mesh between two proximate, disjoint, and opposing mesh surfaces of a three-dimensional object in a modelling system is described. In the method, a projected volume is determined, wherein a mesh volume having a first topology is generated when the volume reaches the opposing mesh surfaces within a distance determined by the local mesh size. A second volume mesh with a different topology is generated when the projected volume does not reach the opposing mesh surface.

The application provides a configuration self-adaptive determination method and device based on an arbitrary configuration Lagrange finite element, equipment and a medium, comprising: obtaining an initial configuration of a problem to be analyzed; based on the mechanical state parameters of the cells and nodes of the current time step and the previous time step, a continuously changing configuration interpolation parameter and a target function are constructed; based on an optimization algorithm, the optimal configuration parameter that makes the target function reach the optimal value is searched in the configuration interpolation parameter, and the intermediate reference configuration corresponding to the optimal configuration parameter is taken as the target reference configuration of the current time step; the target reference configuration is subjected to global nonlinear finite element analysis, so that the state variable of the current time step is updated based on the target reference configuration. Numerical abnormalities such as negative volume and mesh flipping caused by serious distortion of the current configuration are effectively avoided, and the simulation efficiency and numerical stability of the nonlinear finite element analysis are improved.

The invention provides a dynamic grid surface corner region grid distortion processing method, which comprises the following steps of: in a dynamic grid numerical simulation process with a continuous dynamic boundary, identifying a grid distortion risk of a surface corner region; and when a grid distortion risk is detected, performing grid distortion suppression by adopting at least one of a conditional fairing method, an adaptive movement method and a directional movement method. According to the method, at least one of the conditional fairing method, the self-adaptive moving method and the directional moving method is adopted to restrain the mesh distortion in order to solve the mesh distortion problem caused by sudden change of the normal direction of the nodes in the surface corner area in dynamic mesh numerical simulation, the mesh distortion can be effectively relieved, the occurrence of negative volume meshes can be delayed, and the calculation robustness can be improved.

This invention discloses a multi-level partitioning constraint method and apparatus for general mesh deformation problems, relating to the field of mesh deformation technology in numerical computation. The method includes: reading mesh data; partitioning the object surface mesh into multiple levels; constructing a local radial basis function interpolation system within each partition using a greedy algorithm; using the difference between the previous level deformation result and the target deformation result as the deformation target to progressively correct the positions of the object surface and volume mesh nodes; calculating the global deformation using radial basis functions in the first level, and limiting the local deformation range using dual-constraint radial basis functions in non-first levels; accelerating the calculation of dynamic and static boundary distances using distance search based on K-dimensional tree pre-screening; and outputting the deformed mesh. This invention avoids the high cost of direct global solution through multi-level partitioning and hierarchical point selection strategies, significantly reducing the computational cost of constructing a radial basis function interpolation system in large-scale 3D mesh deformation while maintaining mesh quality and deformation accuracy, effectively improving the efficiency of deformation calculation.

The invention discloses a structure domination surface grid encryption method based on local self-adaption, and the method comprises the steps: firstly carrying out the preprocessing of an input grid, and obtaining a to-be-encrypted vertex of a to-be-encrypted region through the screening of a topological relation; secondly, by judging whether the encryption method selected by the user is a bisection method or a trisection method, an encryption template corresponding to the encryption method is loaded, for the bisection method, a vertex to be encrypted is divided into boundary points and internal points, and boundary point rings are extracted in sequence; then marking boundary points and internal points based on a boundary point ring according to the type of the encryption template; and finally, encrypting the to-be-encrypted area units containing the mark vertexes to obtain a final encryption result, and completing grid encryption. According to the method, high-quality encryption of the encryption area and good transition between the encryption area and the transition area are achieved, time loss caused by reading of many irrelevant units which do not need to be encrypted during encryption of a large-size grid is avoided, and the encryption speed is increased.