CN116127814B

CN116127814B - Geotechnical engineering finite element model construction method in CAD environment and electronic equipment

Info

Publication number: CN116127814B
Application number: CN202310172527.1A
Authority: CN
Inventors: 许峙峰; 曾文轩; 陈旭勇; 吴巧云
Original assignee: Wuhan Institute of Technology
Current assignee: Wuhan Institute of Technology
Priority date: 2023-02-23
Filing date: 2023-02-23
Publication date: 2023-10-03
Anticipated expiration: 2043-02-23
Also published as: CN116127814A

Abstract

The invention provides a geotechnical engineering finite element model construction method and electronic equipment in a CAD environment, and relates to the technical field of finite element models. According to the invention, the geometric information comprehensive reader, the independent grid curved surface generator, the grid curved surface error repairing device, the grid curved surface compatible processor, the grid curved surface repartitioning device, the grid curved surface segmentation extractor and the finite element model generator are designed to complete the finite element model construction of geotechnical engineering objects such as surface topography, underground faults, slopes, foundation pits and tunnels, and the usability, quality, precision and rationality of finite element modeling analysis in the geotechnical engineering field are improved.

Description

Geotechnical engineering finite element model construction method in CAD environment and electronic equipment

Technical Field

The invention relates to the technical field of finite element models, in particular to a geotechnical engineering finite element model construction method and electronic equipment in a CAD environment.

Background

The finite element modeling process in the current geotechnical engineering field is complex and complicated, the model quality is difficult to control, and the method specifically has the following problems: 1, the utilization efficiency of a CAD system with powerful modeling function and good interactivity is low, and a finite element model needs to be reestablished in finite element analysis software through CAD drawings; 2, the lack of a comprehensive grid curved surface generation method of multi-type aggregate objects such as point cloud, curve, curved surface and the like causes complicated grid model establishment process of engineering structures such as surface topography, underground fault, side slope, foundation pit, tunnel and the like; 3, grid faults such as internal cavities, edge cracks, collision surfaces, protrusions and the like usually exist in the grid curved surface generated by data such as point clouds and the like, but effective tools for repairing the faults are lacked; 3, it is difficult to perform compatibility processing on a plurality of incompatible grid surfaces (such as boundary grid curved surfaces, surface topography grid curved surfaces, underground fault grid curved surfaces, slope grid curved surfaces, foundation pit grid curved surfaces and tunnel grid curved surfaces) and a grid surface set containing adjacent edges (such as near-surface junctions of the surface topography grid curved surfaces and the underground fault grid curved surfaces), so that a finite element model cannot be generated effectively; 5, the lack of fine control on the grid curved surface (such as the shape quality of the grid surface, the proportion of the triangular grid surface to the quadrilateral grid surface, the change of the grid size and the like) causes that the quality of the grid curved surface is difficult to control, so that the quality of the finally generated finite element model is low; 6, the lack of tools for effectively dividing the surface grid causes difficulty in setting load and boundary conditions; 7, the finite element model generated by the grid curved surface is low in quality, and the generated finite element model lacks effective information of the outer surface and the inner surface. The prior finite element modeling method has the defects, so that the problems of complicated process, low usability, difficult precision and quality meeting design requirements and the like exist in the finite element modeling of geotechnical engineering objects such as surface topography, underground faults, slopes, foundation pits, tunnels and the like.

Disclosure of Invention

The invention aims to provide a geotechnical engineering finite element model construction method and electronic equipment in a CAD (computer aided design) environment, and the method and the electronic equipment are used for improving usability and quality of constructing finite element modeling by combining a systematic method for constructing a grid curved surface and the finite element model with an interactive modeling environment provided by CAD software, so that the precision and the rationality of tunnel design are improved.

In order to achieve the above object, the present invention provides the following solutions:

a geotechnical engineering finite element model construction method in CAD environment comprises the following steps:

step 1.1: using a geometric information comprehensive reader to read geometric information of a geotechnical engineering finite element model to be constructed, wherein the geometric information comprises actually measured surface topography point cloud, underground fault point cloud, edge lines and edge faces, and curves representing slopes, foundation pits and tunnels in CAD drawings;

step 1.2: generating the read geometric information into a corresponding grid curved surface by using an independent grid curved surface generator and adding the corresponding grid curved surface into an independent grid curved surface set, wherein the grid curved surface comprises a surface topography grid curved surface, an underground fault grid curved surface, a side slope grid curved surface, a foundation pit grid curved surface and a tunnel grid curved surface;

step 1.3: repairing all grid curved surfaces by using a grid curved surface error repairing device, and constructing an independent grid curved surface set based on the repaired grid curved surfaces;

Step 1.4: constructing a compatible grid curved surface set by using a grid curved surface compatible processor according to the independent grid curved surface set;

step 1.5: according to the compatible grid curved surface set, utilizing a grid curved surface repartitor to construct a repartitioned grid curved surface set;

step 1.6: dividing and marking the repartitioned mesh surfaces in the repartitioned mesh surface set by using a mesh surface dividing extractor to obtain a divided mesh surface set; the marking process comprises the steps of adding load conditions and boundary conditions to the re-divided mesh curved surface after the segmentation process;

step 1.7: based on the segmented mesh surface set, a full-information finite element model is built by using a finite element model generator.

An electronic device, the electronic device being configured to perform a geotechnical engineering finite element model construction method in the CAD environment, comprising:

a memory for storing a computer program enabling the geotechnical engineering finite element model construction method in the CAD environment of claims 1 to 9;

and the processor is used for requesting operation resources from the general-purpose computer according to the instruction and selectively executing the specific functions of the geotechnical engineering finite element model construction method in the CAD environment according to any one of 1 to 9.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

According to the geotechnical engineering finite element model construction method and the electronic equipment in the CAD environment, the geometric information comprehensive reader, the independent grid surface generator, the grid surface error repairing device, the grid surface compatible processor, the grid surface repartitioning device, the grid surface segmentation extractor and the finite element model generator are designed to finish the finite element model construction of geotechnical engineering objects such as surface topography, underground faults, slopes, foundation pits and tunnels, and usability, quality, precision and rationality of finite element modeling analysis in the geotechnical engineering field are improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings that are needed in the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a workflow diagram of the construction of a mesh surface and finite elements in embodiment 1 of the present invention;

FIG. 2 is a flowchart illustrating the operation of the independent mesh surface generator of embodiment 1 of the present invention;

FIG. 3 is a flowchart illustrating the operation of the internal hole filling algorithm according to embodiment 1 of the present invention;

FIG. 4 is a flowchart of the edge crack repairing algorithm according to the embodiment 1 of the present invention;

FIG. 5 is a flowchart illustrating the operation of the mesh surface compatible processor of embodiment 1 of the present invention;

FIG. 6 is a flowchart illustrating the operation of the mesh surface repartitor in embodiment 1 of the present invention;

FIG. 7 is a flowchart of the mesh surface segmentation extractor of embodiment 1 of the present invention;

FIG. 8 is a flowchart of the finite element model generator of embodiment 1 of the present invention;

FIG. 9 is a flowchart of the first recursive solving algorithm in embodiment 1 of the present invention;

FIG. 10 is a flowchart of the second recursive solving algorithm in embodiment 1 of the present invention;

FIG. 11 is a flowchart of the third recursive solving algorithm in embodiment 1 of the present invention;

FIG. 12 is a flowchart of the fourth recursive solving algorithm in embodiment 1 of the present invention;

FIG. 13 is a schematic diagram showing the effect of the geometric information comprehensive reader in embodiment 2 of the present invention; fig. 13 (a) is a schematic view showing how the XYZ file is read by the geometrical information comprehensive reader in embodiment 2 of the present invention to be a point cloud effect; FIG. 13 (b) is a diagram showing the effect of the geometrical information comprehensive reader reading the OFF file as a curved grid in the embodiment 2 of the present invention; fig. 13 (c) is a schematic diagram showing the effect of the geometric information comprehensive reader reading DWG files according to embodiment 2 of the invention; fig. 13 (d) is a schematic view showing how the geometric information comprehensive reader reads the STL file as a curved surface effect in embodiment 2 of the present invention;

FIG. 14 is a schematic diagram showing the effect of the independent grid generator in embodiment 2 of the present invention; FIG. 14 (a) is a schematic diagram showing the effect of generating a mesh surface with a point cloud in the independent mesh generator according to embodiment 2 of the present invention; FIG. 14 (b) is a schematic diagram showing the effect of generating a mesh surface with a curve in the independent mesh generator according to embodiment 2 of the present invention; FIG. 14 (c) is a schematic diagram showing the effect of generating a mesh surface with a curved surface in the independent mesh generator according to embodiment 2 of the present invention; FIG. 14 (d) is a schematic diagram showing the effect of generating mesh surfaces with different geometry types in the independent mesh generator according to embodiment 2 of the present invention;

FIG. 15 is a schematic diagram showing the effect of the internal hole filling algorithm in embodiment 2 of the present invention;

FIG. 16 is a schematic diagram showing the effect of the edge crack repairing algorithm in embodiment 2 of the present invention;

FIG. 17 is a graph showing the comparison of the effects of the mesh surface compatible processor of embodiment 2 of the present invention; FIG. 17 (a) is a diagram showing the comparison of the set of mesh surfaces before and after the mesh surface compatible processor is used in embodiment 2 of the present invention; FIG. 17 (b) is a diagram showing the non-compatible mesh surface to mesh surface orientation before and after the mesh surface compatible processor is used in embodiment 2 of the present invention; FIG. 17 (c) is a diagram showing the comparison of adjacent mesh edges before and after the mesh surface compatible processor is used in embodiment 2 of the present invention;

FIG. 18 is a schematic diagram showing the effects of the grid surface repartitioning device according to embodiment 2 of the present invention; FIG. 18 (a) is a diagram showing the effect of mesh surface before and after the mesh surface repartitor is used in embodiment 2 of the present invention; FIG. 18 (b) is a diagram showing the effect of using a mesh surface near the front-to-back size information point of the mesh surface repartitor in embodiment 2 of the present invention;

FIG. 18 (c) is a diagram showing the effect of using mesh surfaces near the retaining points of the front and rear positions of the mesh surface repartitor in embodiment 2 of the present invention;

FIG. 19 is a schematic view showing the effect of the mesh surface segmentation extractor in embodiment 2 of the present invention;

FIG. 20 is a schematic diagram showing the effect of the finite element model generator according to embodiment 2 of the present invention;

FIG. 21 is a schematic diagram showing the effect of the first recursive solving algorithm in embodiment 2 of the present invention;

FIG. 22 is a schematic diagram showing the effect of the second recursive solving algorithm in embodiment 2 of the present invention;

FIG. 23 is a schematic diagram showing the effect of the third recursive solving algorithm in embodiment 2 of the present invention;

FIG. 24 is a schematic diagram showing the effect of the fourth recursive solving algorithm in embodiment 2 of the present invention;

FIG. 25 is a schematic view showing the effect of an exemplary geotechnical finite element model in example 3 of the present invention;

FIG. 26 is a schematic view showing the effect of the independent mesh surface set in embodiment 3 of the present invention;

FIG. 27 is a schematic view showing the effect of the curved surface of the grid of the subsurface fault in embodiment 3 of the present invention;

FIG. 28 is a schematic view showing the effect of the curved surface of the side slope and tunnel mesh in embodiment 3 of the present invention; FIG. 28 (a) is a schematic view showing the effect of generating a slope mesh surface from a slope curve and a curved surface in example 3 of the present invention; fig. 28 (b) is a schematic diagram showing the effect of generating a tunnel mesh curved surface from a tunnel curve and a curved surface in embodiment 3 of the present invention;

FIG. 29 is a schematic view showing the effect of the compatible mesh surface set in embodiment 3 of the present invention;

FIG. 30 is a diagram showing the effect of repartitioning the mesh surface set in embodiment 3 of the present invention;

FIG. 31 is a schematic view showing the effects of the segmented mesh surface set of embodiment 3 of the present invention;

FIG. 32 is a diagram showing the effect of the full information finite element model in embodiment 3 of the present invention;

FIG. 33 is a flowchart of the electronic device in embodiment 4 of the present invention;

fig. 34 is a schematic diagram of an example of a USB interface electronic device in embodiment 4 of the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.

Example 1

As shown in fig. 1, the embodiment provides a geotechnical engineering finite element model construction method in a CAD environment, which includes:

step 1.1: and using a geometric information comprehensive reader to read geometric information of the geotechnical engineering finite element model to be constructed, wherein the geometric information comprises actually measured surface topography point cloud, underground fault point cloud, edge lines and edge faces, and curves representing slopes, foundation pits and tunnels in CAD drawing.

Step 1.2: and generating the read geometric information into a corresponding grid curved surface by using an independent grid curved surface generator and adding the corresponding grid curved surface into an independent grid curved surface set, wherein the grid curved surface comprises a surface topography grid curved surface, an underground fault grid curved surface, a side slope grid curved surface, a foundation pit grid curved surface and a tunnel grid curved surface.

Step 1.3: repairing all grid curved surfaces by using a grid curved surface error repairing device, and constructing an independent grid curved surface set based on the repaired grid curved surfaces.

Step 1.4: and constructing a compatible grid surface set by using a grid surface compatible processor according to the independent grid surface set.

Step 1.5: and constructing a repartitioned grid surface set by using the grid surface repartitioner according to the compatible grid surface set.

Step 1.6: dividing and marking the repartitioned mesh surfaces in the repartitioned mesh surface set by using a mesh surface dividing extractor to obtain a divided mesh surface set; the marking process comprises the step of adding load conditions and boundary conditions to the re-divided mesh curved surface after the segmentation process. The load condition and the boundary condition are determined according to physical property parameters of the rock and soil in the research area to be detected. And after the construction of the full-information finite element model is completed, carrying out simulation on the rock and soil of the to-be-studied area based on the load condition and the boundary condition, and obtaining the results of stress, strain, displacement and the like of the rock and soil of the to-be-studied area. And according to the results of the stress, strain, displacement and the like of the rock and soil in the to-be-detected research area, carrying out geotechnical engineering construction scheme design on the to-be-detected research area, and building the geotechnical engineering in the to-be-detected research area according to the designed construction scheme.

Wherein the workflow of the independent mesh surface generator is as follows (as shown in fig. 2).

Step 2.1: and respectively generating point cloud information of each geometrical body in the geotechnical engineering finite element model to be constructed according to the geometrical information of the geotechnical engineering finite element model to be constructed, and adding the point cloud information of each geometrical body into the current point cloud set.

Step 2.2: and determining any point cloud in the current point cloud set as a first point cloud, and deleting the first point cloud from the current point cloud set.

Step 2.3: and determining any point cloud in the current point cloud set as a second point cloud.

Step 2.4: and merging the first point cloud and the second point cloud into the current point cloud, and acquiring the contour curved surface of the current point cloud as the current contour curved surface.

Step 2.5: and generating a current grid curved surface through the current contour curved surface and the current point cloud.

Step 2.6: and deleting the second point cloud from the current point cloud set, and updating the first point cloud to be the set of all grid nodes in the current grid curved surface.

Step 2.7: repeating the steps 2.3 to 2.6 until the current point cloud set is empty, and obtaining a plurality of grid curved surfaces.

The workflow of the mesh surface error healer is as follows.

Step 3.1: traversing all grid curved surfaces and performing internal hole filling processing on the grid curved surfaces.

Step 3.2: traversing all the grid curved surfaces and carrying out edge crack repairing treatment on the grid curved surfaces.

Specifically, the internal hole filling process includes (as shown in fig. 3):

step 4.1: determining any grid curved surface as a current grid curved surface, traversing all grid surfaces in the current grid curved surface, and classifying the edge grid edges into a first edge grid edge set; the number of grid surfaces connected by the edge grid edges is 1.

Step 4.2: determining all the closed grid boundary paths according to the first edge grid edge set, and generating a closed grid boundary path set.

Step 4.3: and generating a corresponding current patch grid curved surface according to any one of the closed grid boundary paths selected from the closed grid boundary path set as a current closed grid boundary path, and deleting the current closed grid boundary path from the closed grid boundary path set.

Step 4.4: judging whether the area of the current patch grid curved surface is smaller than the area threshold value of the current patch grid curved surface or not, and obtaining a first judging result; if the first judgment result is yes, filling the current patch grid to the patch mark corresponding to the current closed grid boundary path in the current grid curved surface.

Step 4.5: repeating steps 4.3 to 4.4 until the closed mesh boundary path set is empty.

Wherein the edge crack repair process includes (as shown in fig. 4):

step 5.1: traversing all grid edges in the current grid curved surface and classifying the edge grid nodes into an edge grid node set; edge mesh nodes are endpoints of edge mesh edges.

Step 5.2: traversing the edge grid nodes and determining the most unfavorable edge grid nodes according to the included angles of two adjacent edge grid edges of the edge grid nodes; the most unfavorable edge grid node is the edge grid node with the minimum included angle between the two adjacent edge grids.

Step 5.3: judging whether the included angle between two sides corresponding to the least favorable edge grid node and the distance between two side end points meet the repairing condition or not, and obtaining a second judging result; the repairing condition is that the included angle of two adjacent edge grid edges corresponding to the least favorable edge grid node is smaller than the threshold value of the included angle of two sides, and the distance between the other two end points of the two adjacent edge grid edges of the least favorable edge grid node is smaller than the threshold value of the crack opening distance; if the second judgment result is yes, generating a patch grid surface formed by the least favorable edge grid node and two adjacent edge grid edges, and filling the patch grid surface to the corresponding area of the least favorable edge grid node in the current grid curved surface.

Step 5.4: the current least favorable edge grid node is deleted from the set of edge grid nodes.

Step 5.5: repeating the steps 5.1 to 5.4 until the most unfavorable edge grid node does not exist.

The workflow of the mesh surface compatible processor is as follows (as shown in fig. 5):

step 6.1: traversing all independent grid curved surfaces in the independent grid curved surface set and classifying all edge grid edges into a second edge grid edge set.

Step 6.2: carrying out collinearly processing on the edge grid edges meeting the preset conditions in the second edge grid edge set to obtain a pre-collinearly grid curved surface set; the preset condition is that the midpoint distance and the included angle of the two sides are smaller than the corresponding threshold values.

Step 6.3: judging whether the pre-collinear grid curved surface set crosses the grid edge or not to obtain a third judging result; the crossing grid edge is a grid edge which has an intersection point with the grid surface in the independent grid curved surface corresponding to the repair object.

Step 6.4: and if the third judgment result is yes, carrying out compatible grid repartition on the grid surface connected with the crossing grid edge and the crossed grid surface.

Step 6.5: repeating the steps 6.1 to 6.4 until the third judgment result is negative, and forming a compatible grid curved surface set.

Wherein the workflow of the mesh surface repartitor is as follows (as shown in fig. 6):

step 7.1: marking size information points and position retention points in the compatible grid curved surface set, and forming a contour curved surface for each grid curved surface in the compatible grid curved surface set to obtain a contour curved surface set, wherein the size information points comprise the sizes of all connected grid edges, and the grid edges formed by the position retention points are required to be kept unchanged.

Step 7.2: and obtaining a shared boundary between all independent grid curved surfaces, generating a shared edge grid node on the shared boundary according to a preset grid size, and marking the shared edge grid node as a position retention point.

Step 7.3: traversing all contour surfaces in the contour surface set, establishing a fine repartitioning grid surface of the contour surface set and classifying the fine repartitioning grid surface set into the repartitioning grid surface set, wherein the grid surface establishment steps are as follows: firstly, position retaining points on the contour curved surface are used as grid nodes to establish a minimum grid curved surface capable of covering all the position retaining points, then, grid surface size specified by corresponding size information points is established near all the size information points on the contour curved surface, and the minimum grid curved surface capable of covering all the size information points is established, and finally, residual grid surfaces are generated on the contour curved surface based on the preset overall grid size and the grid size change rate.

Specifically, the workflow of the mesh surface segmentation extractor is as follows (as shown in fig. 7):

step 8.1: determining any one of the repartitioned mesh curved surfaces in the repartitioned mesh curved surface set as a current mesh curved surface, setting a first mark on the current mesh curved surface, and carrying out first recursion solution; the first recursive solution specifically includes (as shown in fig. 9): traversing all adjacent repartitioning grid curved surfaces of the current grid curved surface without the first mark, if the adjacent repartitioning grid curved surfaces are continuous grid curved surfaces and the connection failure angle between the adjacent repartitioning grid curved surfaces and the current grid curved surfaces is smaller than a first preset threshold value, setting the first mark on the adjacent repartitioning grid curved surfaces and carrying out first recursion solution; the continuous grid curved surface is a repartitioned grid curved surface with the number of repartitioned grid curved surfaces connected with all grid edges being 2.

Step 8.2: and dividing and fusing all grid surfaces with the first marks from the repartitioned grid surface set to form a current divided grid surface, and classifying the current divided grid surface into a divided grid surface set.

Step 8.3: repeating the steps 8.1 to 8.2 until the repartitioning mesh surface set is empty.

Step 8.4: and applying the grid surface marking characteristic information of the load condition and the boundary condition to the segmented grid surface set to obtain the segmented grid surface set.

Specifically, the method for constructing the full-information finite element model comprises (as shown in fig. 8):

step 9.1: and obtaining the grid curved surface set with the characteristic information of the grid curved surface marked in the segmented grid curved surface set as the characteristic information grid curved surface set.

Step 9.2: constructing a first split grid curved surface set and a second split grid curved surface set, traversing all split grid curved surfaces in the first split grid curved surface set, determining that any edge split grid curved surface is the current first split grid curved surface, and setting a second mark; the first set of segmented mesh surfaces, the second set of segmented mesh surfaces, and the third set of segmented mesh surfaces are all identical to the set of segmented mesh surfaces.

Step 9.3: performing second recursion solution on the current first segmentation grid curved surface; the second recursive solving algorithm specifically includes (as shown in fig. 10): traversing all adjacent segmentation grid curved surfaces without second marks of the current first segmentation grid curved surface, if the adjacent segmentation grid curved surfaces are continuous segmentation grid curved surfaces, setting the second marks on the adjacent segmentation grid curved surfaces and carrying out second recursion solving.

Step 9.4: and merging all the split grid curved surfaces with the second marks into a current open grid curved surface and classifying the current open grid curved surfaces into a characteristic information grid curved surface set, and deleting all the split grid curved surfaces with the second marks from the first split grid curved surface set.

Step 9.5: updating the current segmentation grid curved surface, and repeating the steps 9.2 to 9.4 until the first segmentation grid curved surface set is empty.

Step 9.6: traversing all the split grid curved surfaces in the second split grid curved surface set, determining any one continuous split grid curved surface as the current second split grid curved surface, and setting a third mark.

Step 9.7: carrying out third recursion solution on the current second split grid curved surface; the third recursive solution specifically includes (as shown in fig. 11): calculating the centroid average value of all grid curved surfaces containing the third mark, traversing all grid edges of the current second split grid curved surface, finding all adjacent split grid curved surfaces on the grid edges, setting the third mark on the adjacent split grid curved surfaces and carrying out third recursion solution if only one adjacent split grid curved surface is arranged on the grid edges, and if a plurality of adjacent split grid curved surfaces are arranged on the grid edges, finding a first adjacent split grid curved surface rotationally swept in the direction from the current split grid curved surface to the centroid average value of all grid curved surfaces containing the third mark by taking the current grid edge as an axis, setting the third mark on the adjacent split grid curved surfaces and carrying out third recursion solution.

Step 9.8: and fusing all the partitioned grid curved surfaces with the third marks into a current closed grid curved surface, taking the current closed grid curved surface as an outer surface to generate finite element entities and classifying the finite element entities into a finite element entity set.

Step 9.9: traversing all grid surfaces in the current closed grid curved surface, finding a continuous grid surface and setting a fourth mark.

Step 9.10: performing fourth recursion solution on all grid surfaces containing fourth marks; wherein the fourth recursive solving algorithm is (as shown in fig. 12): traversing all adjacent grid surfaces without fourth marks of the current grid surface, if the adjacent grid surfaces are continuous grid surfaces, setting fourth marks on the adjacent grid surfaces and carrying out fourth recursion solving.

Step 9.11: and deleting all grid surfaces with fourth marks from the segmented grid curved surfaces in a concentrated manner, and emptying the current closed grid curved surfaces.

Step 9.12: repeating the steps 9.7 to 9.11 until the segmented grid curved surface set is deleted to be empty, and obtaining a characteristic information grid curved surface set and a finite element entity set.

Step 9.13: and combining the finite element entity set into a finite element model, and adhering all grid curved surfaces in the characteristic information grid curved surface set to the finite element model to obtain the full information finite element model.

Example 2

The embodiment provides a grid surface and finite element model building program, which is essentially an insert for generating a grid surface and a finite element model under a RhinocerosCAD system. Since it is essentially a plug-in under the rhinoceros CAD system, the user can use the full functionality of the CAD system to facilitate its modeling. On the other hand, the software can perform various operations (such as forming a grid surface, repairing the grid surface, carrying out grid surface compatible processing, finely repartitioning the grid surface, carrying out grid surface segmentation extraction and the like) on the grid surface through the algorithm provided by the invention, and displaying the result in the CAD system. Finally, the software can form model files of various finite element software through the divided grid curved surfaces.

The software consists of seven functions, forming a complete flow of mesh generation to finite element modeling (as shown in fig. 1). The seven functions are respectively: 1, a geometric information comprehensive reader; 2, an independent grid curved surface generator; 3, a grid curved surface error repairing device; 4, a grid curved surface compatible processor; 5, a grid curved surface repartitor; 6, a grid curved surface segmentation extractor; and 7, a finite element model generator. The grid curved surface and finite element model construction logic built by the seven functions is as follows: firstly, using a geometric information comprehensive reader to read various types of geometric bodies (such as point clouds, curves, curved surfaces, grids and the like), wherein the geometric information is from different types of files such as DWG files, STL files, OFF files, XYZ files and the like; secondly, generating grids of the geometric bodies of different types by using an independent grid curved surface generator to form an independent grid curved surface corresponding to each geometric body; thirdly, repairing various errors (such as internal holes and edge cracks) in the grid formed in the third step by using a grid curved surface error repairing device to form an independent grid curved surface without errors; fourth, the independent grid curved surfaces representing different objects formed in the last step are subjected to compatibility processing through a grid curved surface compatibility processor, and a set of mutually compatible grid curved surface sets is formed; sixthly, performing high-quality fine grid repartition on the grid curved surface set formed in the last step by using a grid curved surface repartitor; seventh, carrying out surface segmentation extraction on the grid curved surface set formed in the last step, so that load and boundary conditions can be conveniently applied in the follow-up finite element analysis; eighth, generating a model file of the finite element software by using the mesh surface set formed in the last step. The first three parts (the geometrical information comprehensive reader, the independent grid curved surface generator and the grid curved surface error repairing device) form an independent grid curved surface generating unit, and the function of the independent grid curved surface generating unit is to generate an independent grid curved surface representing a certain geometrical body. On the other hand, in finite element analysis, the most common case is a system of multiple geometries, for which multiple independent mesh surfaces are required for compatibility processing and forming a mesh surface set. In addition, low quality mesh surfaces (e.g., including low quality mesh surfaces, excessive non-uniformity in mesh size, lack of detailed mesh surface size control, etc.) will result in low quality finite element models and result in simulation distortions. The grid surface set generating unit composed of the fourth to sixth parts (grid surface compatible processor, grid surface repartitioning device and grid surface dividing extractor) can solve the above problems. The last part is a finite element model generator whose function is to form a finite element model by the surface mesh set generated by the mesh surface set generating unit, and which can retain the entire mesh surface information.

The following will respectively describe each part of functions and technical schemes:

1. independent grid curved surface generating unit

The purpose of the independent grid curved surface generating unit is to solve the problem from various types of geometric body information input (such as CAD drawing files, point cloud files obtained by scanning, other types of geometric information files and the like) to forming an error-free independent grid curved surface, wherein (as shown in figure 1): the function of the geometric information comprehensive reader is to read various types of geometric information into a CAD system and establish corresponding geometric bodies (such as point cloud, curve, curved surface and the like); the independent grid curved surface generator is responsible for generating corresponding grid curved surfaces (such as topological grid curved surfaces corresponding to point clouds, grid curved surfaces corresponding to curves in a plan view, grid curved surfaces corresponding to curved surfaces and the like) by various geometric bodies, or generating a grid curved surface by integrating a plurality of aggregates of different types, such as generating a cone grid curved surface by points and a circular plane); grid surface generated and otherwise introduced in the first two steps often contain various errors (e.g., notches and holes), and a grid surface error healer is required to repair these errors. After these four parts of processing, a single mesh surface representing a single geometry and free of errors is formed. The specific functions and implementation schemes of each part in the independent mesh surface generation unit will be described below:

1.1 geometric information comprehensive reader: the function of the geometric information comprehensive reader is to read corresponding geometric information from files containing various geometric information, and establish and draw corresponding geometric bodies in a CAD system (as shown in fig. 13 (a) -13 (d)), and the specific implementation steps are as follows: firstly, reading and analyzing information in the file according to the file type, and then establishing a corresponding geometrical body, such as reading point coordinates of XYZ files, reading grid curved surfaces of OFF files, reading curve information of DWG files and reading curve information of STL files; a second step of establishing corresponding geometric bodies such as points, curves, curved surfaces, grids and the like through the information read in the first step; and thirdly, outputting the geometric body established in the first step to a Rhinoceros CAD environment, ending the algorithm and exiting.

1.2 independent mesh surface generator: the independent mesh surface generator generates corresponding meshes through various geometric bodies, and establishes and draws the resulting meshes in a rhinoceros cad system (as shown in fig. 14 (a) -14 (d)), and the specific implementation steps are as follows (as shown in fig. 2): firstly, reading information of a geometric body selected by a user from a rhinoceros CAD system; generating a point cloud of each geometry and classifying the point cloud into a current point cloud set, wherein a point cloud object can be classified into the current point cloud set directly, a curve object can form a point cloud by interpolation points on a curve of the curve object, a two-dimensional interpolation point on the curve object can form the point cloud by the curve object, and a grid curved surface object can extract grid nodes of the curve object to form the point cloud; thirdly, selecting one point cloud from the current point cloud set as a first point cloud and deleting the first point cloud from the current point cloud set; step four, selecting one from the rest point clouds as a second point cloud; fifthly, adding the first point cloud and the second point cloud into a current point cloud set and acquiring a contour curved surface of the current point cloud set by using an Alpha Shape algorithm; sixthly, generating a current grid curved surface through the contour curved surface and the current point cloud set by using a general grid curved surface generation algorithm (such as Advancingfront or Delaunay); eighth, deleting the second point cloud from the current point cloud set, and taking all grid nodes of the front grid curved surface as first point cloud; and ninth, repeating the third step to the eighth step until the current grid curved surface set is empty, outputting the front grid curved surface to the rhinoceros CAD system, ending the algorithm and exiting.

1.4 mesh surface error healer: the mesh surface error repairing device aims to provide a method for solving various errors (such as internal holes and edge cracks) contained in a mesh surface, and mainly comprises an internal hole filling module and an edge crack repairing module. The function of the internal hole filling module is to fill the holes in the grid (as shown in fig. 15), the algorithm is as follows (as shown in fig. 3): firstly, selecting a grid curved surface needing to be filled with internal holes as a current grid curved surface; traversing all grid faces in the current grid curved surface and classifying the edge grid edges into an edge grid edge set, wherein the edge grid edges are grid edges with the number of connected grid faces being 1; thirdly, determining all closed grid boundary paths according to the edge grid edge set and generating a closed grid boundary path set; a fourth step of selecting a closed grid boundary path from the closed grid boundary path set as a current closed grid boundary path and generating a corresponding current patch grid curved surface, wherein the patch grid curved surface can be generated by adopting a grid curved surface generation algorithm (such as AdvancingFront or Delaunay); fifthly, judging whether the area of the current patch grid curved surface is smaller than the area threshold of the current patch grid curved surface, and filling the current patch grid to the position corresponding to the closed grid boundary path in the current grid curved surface if the judging result is true; sixthly, deleting the current closed grid boundary path from the closed grid boundary path set; and seventhly, repeating the fourth step to the sixth step until the closed grid boundary path set is empty, outputting the current grid curved surface to the rhinoceros CAD system, and exiting. The edge crack repair module is used for filling an edge crack (shown in fig. 16), and the algorithm is as follows (shown in fig. 4): firstly, selecting a grid curved surface to be subjected to crack repair as a current grid curved surface, traversing all grid edges in the current grid curved surface, and classifying edge grid nodes into an edge grid node set, wherein the edge grid nodes are endpoints of the edge grid edges; traversing the edge grid nodes and determining the most unfavorable edge grid nodes according to the included angles of the edges of two adjacent edge grids of the edge grid nodes, wherein the most unfavorable edge grid nodes are the edge grid nodes with the minimum included angles of the edges of the two adjacent edge grids; thirdly, judging whether the included angle between two sides corresponding to the most unfavorable edge grid node and the distance between two edge points meet a restoration condition or not to obtain a judgment result, wherein the restoration condition is that the included angle between two adjacent edge grid edges corresponding to the most unfavorable edge grid node is smaller than a threshold value of the included angle between two sides, the distance between the other two end points of the two adjacent edge grid edges of the most unfavorable edge grid node is smaller than a threshold value of the crack opening distance, if the judgment result is true, generating a current patch grid surface formed by the most unfavorable edge grid node and the two adjacent edge grid edges thereof, and filling the current patch grid surface into a corresponding area of the most unfavorable edge grid node in the curved surface of the current grid; fourthly, deleting the current most unfavorable edge grid node from the edge grid node set; and fifthly, repeating the first step to the fourth step until the grid nodes with the least favorable edges do not exist, outputting the current grid curved surface to the rhinoceros CAD system, and exiting.

2. Grid curved surface set generating unit

In finite element analysis, which is typically encountered with a set of surfaces comprising a plurality of separate grids, it is required that on the one hand the grids must be compatible with each other and on the other hand that the grid surfaces be of high quality. In addition, finite element analysis requires a mesh surface that can distinguish between loading and boundary conditions. The purpose of the mesh surface set generation unit will be to generate a mesh surface set that can effectively generate a finite element model from a plurality of independent mesh surfaces, wherein (as shown in fig. 1): the grid curved surface compatibility processor is responsible for carrying out compatibility processing on a plurality of independent grid curved surfaces; the grid curved surface repartitioner can conduct high-quality grid repartition on a plurality of compatible grid curved surfaces; the grid surface segmentation extractor can effectively segment the grid surface so as to apply load conditions and boundary conditions in the follow-up finite element analysis. After the three parts are processed, a grid curved surface set capable of effectively generating a high-quality finite element model can be formed. The specific functions and implementation schemes of each part in the mesh surface set generating unit will be described below:

2.1 grid surface compatible processor

The mesh surface compatibility processor aims to solve the problem of multi-mesh incompatibility in finite element analysis. In finite element analysis, a common situation is encountered where a collection of independent mesh surfaces is involved, whereas finite element analysis requires that the meshes must be compatible with each other. At this point, all grids are required for compatible grid repartition. The existing grid compatible repartitioning procedure in the market can carry out compatible processing on a plurality of grids, but has the following problems: 1, algorithm efficiency is not high or stable; 2, the grid after the compatible treatment forms an integral grid which cannot distinguish the original objects; and 3, if a gap exists, the process 4 cannot be normally performed, and the grid surface size is difficult to finely control. The mesh surface compatible processor solves the above problem (as shown in fig. 17 (a) -17 (c), and the algorithm is as follows (as shown in fig. 5): the first step, all selected independent grid curved surfaces are classified into a current grid curved surface set, the grid curved surfaces in the current grid curved surface set are traversed, and all edge grid edges are classified into an edge grid edge set; secondly, carrying out collineation treatment on the edge grid edges which intensively meet collineation conditions, wherein the preset conditions are that the midpoint distance and the included angle of the two edges are smaller than corresponding threshold values; thirdly, judging whether crossing grid edges exist or not to obtain a judging result, wherein the crossing grid edges are grid edges with crossing points with grid surfaces; fourth, if the judging result is true, carrying out compatible grid repartition on the grid surface connected with the crossing grid edge and the crossed grid surface; and fifthly, repeating the first step, the fourth step and the judgment result to be false, outputting the front grid curved surface set to the Rhinoceros CAD system and exiting.

2.2 mesh surface repartitioning device

The mesh curved surface repartitioner aims to solve the problem that the mesh quality needs to be finely controlled in finite element analysis, such as the problems of mesh surface size and shape quality, the proportion of quadrilateral mesh surface to triangular mesh surface, the size of a mesh at a specific part, the specific edge needs to be kept unchanged, and the object classification of the set after mesh repartition. Most grid surface repartitioning algorithms in the market at present are not ideal for processing the fine partitioning problem. The mesh surface repartitor can effectively solve the above problem (the effect is shown in fig. 18 (a) -18 (c)), and the algorithm is as follows (shown in fig. 6): firstly, classifying all selected grid curved surfaces into a current grid curved surface set, and marking size information points and position retaining points on the current grid curved surface set, wherein the size information points prescribe the size of grid surfaces near the points, and grid edges formed by the position retaining points are required to be kept unchanged; secondly, forming a contour surface for each independent grid surface in the current grid surface set by using an alpha shape algorithm and classifying the contour surface into a contour surface set; thirdly, obtaining a shared boundary between all the independent grid curved surfaces, generating a shared edge grid node on the shared boundary according to a preset grid size, and marking the shared edge grid node as a position retaining point; fourth, traversing all the contour curved surfaces in the contour curved surface set, establishing a fine repartitioning grid curved surface and classifying the fine repartitioning grid curved surface into the repartitioning grid curved surface set, wherein the grid curved surface establishment steps are as follows: firstly, position retaining points on the contour curved surface are used as grid nodes to establish a minimum grid curved surface capable of covering all the position retaining points, then, grid surface sizes specified by corresponding size information points are established near all the size information points on the contour curved surface, and the minimum grid curved surface capable of covering all the size information points is established, and finally, a residual grid surface is generated on the contour curved surface based on a preset whole grid size and a grid size change rate; and fifthly, outputting the repartitioned mesh surface set to the rhinoceros CAD system and exiting.

2.2 grid curved surface segmentation extractor

The grid surface segmentation extractor is used for extracting certain parts of the grid surface and segmenting the parts from the original grid so as to facilitate the operations of adding load, boundary conditions and the like in finite element analysis. The grid curved surface segmentation extractor can extract all grid curved surfaces through one-step segmentation according to the damage angle and the natural section. The algorithm of the single-surface extraction module is as follows (as shown in fig. 19), and the algorithm is as follows (as shown in fig. 7): the method comprises the steps of firstly, classifying all selected independent grid curved surfaces into a current grid curved surface set, and setting a first mark for one grid surface in the current grid curved surface set; second, a first recursive solution is performed on all the mesh surfaces containing the first label to find the current segmented mesh surface (as shown in fig. 21), where the first recursive solution algorithm is (as shown in fig. 9): traversing all adjacent grid surfaces without a first mark of the current grid surface, if a certain adjacent grid surface is a continuous grid surface and the connection failure angle between the adjacent grid surface and the current grid surface is smaller than a preset threshold value, setting the first mark on the adjacent grid surface and performing first recursion solution on the first mark to divide and extract a grid curved surface, wherein the continuous grid surface is a grid edge with the number of the grid surfaces connected with all grid edges being 2; dividing and fusing all grid surfaces with the first marks from the current grid surface set to form a current grid surface, and classifying the current grid surface into a divided grid surface set; fourth, repeating the first step to the third step until the current grid curved surface set is empty; fifthly, marking characteristic information (such as grid surface names, loads, boundary conditions and the like) of grid surface marking to which load conditions and boundary conditions are required to be applied in the segmented grid surface set.

3. Finite element model generator

The finite element model generator is used for solving the problem of generating a finite element model through a grid curved surface. The finite element model generator can generate a three-dimensional grid model through the grid curved surface and further generate a model of common commercial finite element analysis software (such as ANSYS, ABAQUS, FLAC3D, MIDAS, etc.), and the generated finite element model has the following characteristics (as shown in fig. 20): 1, original information (such as curves and curved surfaces) of the grid curved surfaces can be reserved; 2, finite element units can be grouped according to the closed interval where the finite element units are located. The algorithm of the finite element model generator is as follows (as shown in fig. 8): the first step, all selected independent grid curved surfaces are classified into a current grid curved surface set, and all grid curved surfaces containing characteristic information are copied into a characteristic information grid curved surface set; traversing all grid surfaces in the current grid curved surface set, finding an edge grid surface and setting a second mark; third, performing a second recursive solution on all mesh surfaces containing the second label to find the current open edge surface (as shown in fig. 22), wherein the second recursive solution algorithm is (as shown in fig. 10): traversing all adjacent grid surfaces without second marks in the current grid surface, if the adjacent grid surfaces are continuous grid surfaces, setting the second marks on the adjacent grid surfaces and carrying out second recursion solving; fusing all grid surfaces with the second marks into a current open grid curved surface and classifying the current open grid curved surface into a characteristic information grid curved surface set, and deleting all grid surfaces with the second marks from the current grid curved surface set; fifth, repeating the first to fourth steps until the current open grid surface is empty; step six, traversing all grid surfaces in the segmented grid curved surface set, and finding a continuous grid surface to set a third mark; seventh, performing a third recursive solution on all mesh surfaces containing third marks to find the current closed edge surface (as shown in fig. 23), wherein the third recursive solution algorithm is as follows (as shown in fig. 11): calculating the centroid average value of all grid curved surfaces containing the third marks, traversing grid edges of all grid surfaces containing the third marks, finding all adjacent grid surfaces on the grid edges, setting the third marks on the adjacent grid surfaces and carrying out third recursion solution if only one adjacent grid surface exists on the grid edges, finding a first adjacent grid surface rotationally swept in the direction from the current grid surface to the centroid average value of all the grid curved surfaces containing the third marks by taking the current grid edge as an axis if a plurality of adjacent grid surfaces exist on the grid edges, setting the third marks on the adjacent grid surfaces and carrying out third recursion solution; eighth step, fusing all grid curved surfaces containing the third mark into a current closed edge curved surface, using a three-dimensional grid generation algorithm (such as Delaunay or OctTree) to generate finite element entities for the outer surface of the current closed grid curved surface and classifying the finite element entities into a finite element entity set; step nine, traversing the current closed grid curved surface, finding a continuous grid surface and setting a fourth mark; tenth, a fourth recursive solution is performed on all mesh surfaces containing the fourth label to find the current deletable mesh surface (as shown in fig. 24), wherein the fourth recursive solution algorithm is (as shown in fig. 12): traversing all adjacent grid surfaces without fourth marks in the current closed grid curved surface, if a certain adjacent grid surface is a continuous grid surface, setting the fourth marks on the adjacent grid surface and carrying out fourth recursion solution on the fourth marks; eleventh step, deleting all grid surfaces containing fourth marks from the current grid curved surface set; a twelfth step of repeating the sixth to eleventh steps until the current mesh surface set is empty; combining the finite element entity set into a finite element model, and adhering all grid curved surfaces in the characteristic information grid curved surface set to the finite element model; fourteenth step, a model file of commercial finite element analysis software (such as ANSYS, ABAQUS, FLAC3D, MIDAS) is formed according to the finite element model containing the grid surface information.

Example 3

The present embodiment provides a specific engineering application of the plug-in program in embodiment 2 to construction of a surface grid and a finite element model in an exemplary geotechnical engineering, which includes modeling of surface topography, bottom line faults, slopes, foundation pits, tunnels, and corresponding loading conditions and boundary conditions (as shown in fig. 25). The method provided by the embodiment is also commonly used for constructing grid curved surfaces and finite element models in other geotechnical engineering. The specific steps of the embodiments will be described below:

first, the geometric information of the actually measured surface topography point cloud, the edge curve and the boundary curve is read by using a geometric information comprehensive reader, and then an independent grid curve set is constructed by using an independent grid curve generator and a grid curve error healer (shown in fig. 26).

And secondly, using a geometric information comprehensive reader to read the geometric information of the actually measured underground fault point cloud, and then using an independent grid surface generator and a grid surface error repairing device to construct an underground fault grid surface (shown in fig. 27).

And thirdly, using a geometric information comprehensive reader to read geometric information of the side slope, the foundation pit and the tunnel in the CAD drawing, and then using an independent grid surface generator and a grid surface error repairing device to construct a side slope grid surface, a foundation pit grid surface and a tunnel grid surface (as shown in fig. 28 (a) -28 (b)).

Fourth, a grid surface compatible processor is used to construct a compatible grid surface set (as shown in fig. 29) from the outer contour curved surface grid surface, the underground fault grid surface, the slope grid surface, the foundation pit grid surface and the tunnel grid surface.

Fifth, a mesh surface repartitor is used to construct a repartitioned mesh surface set with a compatible mesh surface set (as shown in fig. 30).

Sixth, using the mesh surface segmentation extractor to re-divide the mesh surface set to construct a segmented mesh surface set, and marking loading conditions and boundary conditions on the corresponding mesh surface (as shown in fig. 31).

And seventhly, constructing a full-information finite element model containing the characteristic information grid curved surface set by using a finite element model generator and using the segmented grid curved surface set, inputting the full-information finite element model into finite element analysis software, adding load conditions and boundary conditions on the grid curved surface corresponding to the information grid curved surface set, inputting the residual simulation parameters, submitting the finite element simulation work and analyzing the simulation result (shown in fig. 32).

Example 4

The embodiment provides an electronic device, which can execute the geotechnical engineering finite element model construction method in the CAD environment according to embodiment 1, including:

And the memory is used for storing a computer program for realizing the geotechnical engineering finite element model construction method in the CAD environment.

And the processor is used for requesting operation resources from the general-purpose computer according to the instruction and selectively executing the specific functions of the geotechnical engineering finite element model construction method in the CAD environment described in the embodiment 1.

Specifically, the embodiment provides an electronic device using a USB interface 32-bit singlechip as a carrier, including a memory and a processor (as shown in fig. 34). The memory is used for storing a computer program, and the processor runs the computer program to enable the electronic equipment to execute the grid curved surface and finite element model construction method. The operating logic of the electronic device is as follows (as shown in fig. 33).

First, the user invokes the plug-in program of embodiment 1 by command.

In the second step, the plug-in embodiment 1 sends the function entry of the program to be run and the value or pointer of the input parameter to be run to the USB device through the X86 general-purpose computer.

And thirdly, the USB equipment generates a temporary executable program according to the input quantity of the second step and requests the X86 general-purpose computer to execute.

Fourth, the X86 general-purpose computer runs the temporary executable program and outputs the result.

Fifth, the X86 general-purpose computer destroys all resources of the temporary executable program.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.

The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to assist in understanding the methods of the present invention and the core ideas thereof; also, it is within the scope of the present invention to be modified by those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the invention.

Claims

1. The geotechnical engineering finite element model construction method in the CAD environment is characterized by comprising the following steps:

step 1.7: based on the segmented mesh surface set, constructing a full-information finite element model by using a finite element model generator;

the construction method of the full-information finite element model comprises the following steps:

Step 9.1: obtaining a grid curved surface set with characteristic information, which is a segmented grid curved surface marked with grid curved surface characteristic information, in the segmented grid curved surface set;

step 9.2: constructing a first split grid curved surface set and a second split grid curved surface set, traversing all split grid curved surfaces in the first split grid curved surface set, determining that any edge split grid curved surface is the current first split grid curved surface, and setting a second mark; the first split grid curved surface set, the second split grid curved surface set and the third split grid curved surface set are all identical to the split grid curved surface set;

step 9.3: performing second recursion solution on the current first segmentation grid curved surface; the second recursive solving algorithm specifically includes: traversing all adjacent segmentation grid curved surfaces without second marks of the current first segmentation grid curved surface, if the adjacent segmentation grid curved surfaces are continuous segmentation grid curved surfaces, setting the second marks on the adjacent segmentation grid curved surfaces and carrying out second recursion solution;

step 9.4: merging all the split grid curved surfaces with the second marks into a current open grid curved surface and classifying the current open grid curved surfaces into a characteristic information grid curved surface set, and deleting all the split grid curved surfaces with the second marks from the first split grid curved surface set;

Step 9.5: updating the current segmentation grid curved surface, and repeating the steps 9.2 to 9.4 until the first segmentation grid curved surface set is empty;

step 9.6: traversing all the split grid curved surfaces in the second split grid curved surface set, determining any one continuous split grid curved surface as the current second split grid curved surface, and setting a third mark;

step 9.7: carrying out third recursion solution on the current second split grid curved surface; the third recursive solution specifically includes: calculating the centroid average value of all grid curved surfaces containing the third mark, traversing all grid edges of the current second split grid curved surface, finding all adjacent split grid curved surfaces on the grid edge, setting the third mark on the adjacent split grid curved surfaces and carrying out third recursion solution if only one adjacent split grid curved surface is arranged on the grid edge, if a plurality of adjacent split grid curved surfaces are arranged on the grid edge, finding a first adjacent split grid curved surface which rotationally sweeps in the direction from the current split grid curved surface to the centroid average value of all grid curved surfaces containing the third mark by taking the current grid edge as an axis, setting the third mark on the adjacent split grid curved surfaces and carrying out third recursion solution;

Step 9.8: fusing all the partitioned grid curved surfaces with the third marks into a current closed grid curved surface, taking the current closed grid curved surface as an outer surface to generate finite element entities and classifying the finite element entities into a finite element entity set;

step 9.9: traversing all grid surfaces in the current closed grid curved surface, finding a continuous grid surface and setting a fourth mark;

step 9.10: performing fourth recursion solution on all grid surfaces containing fourth marks; wherein the fourth recursive solving algorithm is: traversing all adjacent grid surfaces without fourth marks of the current grid surface, if the adjacent grid surfaces are continuous grid surfaces, setting fourth marks on the adjacent grid surfaces and carrying out fourth recursion solving;

step 9.11: deleting all grid surfaces with fourth marks from the segmented grid curved surfaces in a concentrated manner, and emptying the current closed grid curved surfaces;

step 9.12: repeating the steps 9.7 to 9.11 until the segmented grid curved surface set is deleted to be empty, and obtaining a characteristic information grid curved surface set and a finite element entity set;

step 9.13: and combining the finite element entity set into a finite element model, and adhering all grid curved surfaces in the characteristic information grid curved surface set to the finite element model to obtain a full information finite element model.

2. The geotechnical engineering finite element model construction method in the CAD environment according to claim 1, wherein the workflow of the independent mesh surface generator is as follows:

step 2.1: respectively generating point cloud information of each geometrical body in the geotechnical engineering finite element model to be constructed according to the geometrical information of the geotechnical engineering finite element model to be constructed, and adding the point cloud information of each geometrical body into a current point cloud set;

step 2.2: determining any point cloud in the current point cloud set as a first point cloud, and deleting the first point cloud from the current point cloud set;

step 2.3: determining any point cloud in the current point cloud set as a second point cloud;

step 2.4: merging the first point cloud and the second point cloud into a current point cloud and acquiring a contour curved surface of the current point cloud as a current contour curved surface;

step 2.5: generating a current grid curved surface through the current contour curved surface and the current point cloud;

step 2.6: deleting the second point cloud from the current point cloud set, and updating the first point cloud to be a set of all grid nodes in the current grid curved surface;

3. The geotechnical engineering finite element model construction method in the CAD environment according to claim 1, wherein the workflow of the mesh surface error healer is as follows:

Step 3.1: traversing all grid curved surfaces and filling internal holes;

4. A method of constructing a geotechnical engineering finite element model in a CAD environment according to claim 3, wherein the internal hole filling process comprises:

step 4.1: determining any grid curved surface as a current grid curved surface, traversing all grid surfaces in the current grid curved surface, and classifying the edge grid edges into a first edge grid edge set, wherein the edge grid edges are grid edges with the number of connected grid surfaces being 1;

step 4.2: determining all closed grid boundary paths according to the first edge grid edge set, and generating a closed grid boundary path set;

step 4.3: according to any one of the closed grid boundary paths selected from the closed grid boundary path set as a current closed grid boundary path, generating a corresponding current patch grid curved surface, and deleting the current closed grid boundary path from the closed grid boundary path set;

step 4.4: judging whether the area of the current patch grid curved surface is smaller than the area threshold value of the current patch grid curved surface or not, and obtaining a first judging result; if the first judgment result is yes, filling the current patch grid to a patch mark corresponding to the current closed grid boundary path in the current grid curved surface;

Step 4.5: repeating steps 4.3 to 4.4 until the set of closed mesh boundary paths is empty.

5. The method for constructing a geotechnical engineering finite element model in a CAD environment according to claim 4, wherein the edge crack repairing process comprises:

step 5.1: traversing all grid edges in the current grid curved surface and classifying the edge grid nodes into an edge grid node set; the edge grid nodes are endpoints of edge grid edges;

step 5.2: traversing edge grid nodes and determining the most unfavorable edge grid nodes according to the included angles of two adjacent edge grid edges of the edge grid nodes, wherein the most unfavorable edge grid nodes are edge grid nodes with the minimum included angles of the two adjacent edge grid edges;

step 5.3: judging whether the included angle between two sides corresponding to the least favorable edge grid node and the distance between two side end points meet the repairing condition or not, and obtaining a second judging result; the repairing condition is that the included angle of two adjacent edge grid edges corresponding to the least favorable edge grid node is smaller than the threshold value of the included angle of two sides, and the distance between the other two end points of the two adjacent edge grid edges of the least favorable edge grid node is smaller than the threshold value of the crack opening distance; if the second judgment result is yes, generating a patch grid surface formed by the most unfavorable edge grid node and two adjacent edge grid edges thereof, and filling the patch grid surface into a corresponding area of the most unfavorable edge grid node in the current grid curved surface;

Step 5.4: deleting the current least favorable edge grid node from the edge grid node set;

6. The geotechnical engineering finite element model construction method in the CAD environment according to claim 1, wherein the workflow of the mesh surface compatible processor is as follows:

step 6.1: traversing all independent grid curved surfaces in the independent grid curved surface set and classifying all edge grid edges into a second edge grid edge set;

step 6.2: carrying out collinearly processing on the edge grid edges which meet the preset conditions in the second edge grid edge set to obtain a pre-collinearly grid curved surface set; the preset condition is that the midpoint distance and the included angle of the two sides are smaller than the corresponding threshold values;

step 6.3: judging whether the pre-collinear grid curved surface set has a crossing grid edge or not to obtain a third judging result, wherein the crossing grid edge is a grid edge with an intersection point with a grid surface;

step 6.4: if the third judgment result is yes, carrying out compatible grid repartition on the grid surface connected with the crossing grid edge and the crossed grid surface;

7. The geotechnical engineering finite element model construction method in the CAD environment according to claim 1, wherein the workflow of the mesh surface repartitor is as follows:

step 7.1: marking size information points and position retention points in the compatible grid curved surface set, and forming a contour curved surface for each grid curved surface in the compatible grid curved surface set to obtain a contour curved surface set, wherein the size information points comprise the sizes of all connected grid edges, and the grid edges formed by the position retention points are required to be kept unchanged;

step 7.2: obtaining a shared boundary between all the independent grid curved surfaces, generating a shared edge grid node on the shared boundary according to a preset grid size, and marking the shared edge grid node as a position retention point;

8. The geotechnical engineering finite element model construction method in the CAD environment according to claim 1, wherein the workflow of the mesh surface segmentation extractor is as follows:

step 8.1: determining any grid curved surface in the repartitioned grid curved surface set as a current grid curved surface, setting a first mark on the current grid curved surface, and carrying out first recursion solution on the first mark; the first recursive solution specifically includes: traversing all adjacent repartitioning grid curved surfaces of the current grid curved surface without the first mark, if the adjacent repartitioning grid curved surfaces are continuous grid curved surfaces and the connection failure angle between the adjacent repartitioning grid curved surfaces and the current grid curved surfaces is smaller than a first preset threshold value, setting the first mark on the adjacent repartitioning grid curved surfaces and carrying out first recursion solution; the continuous grid curved surface is a repartitioned grid curved surface with the number of repartitioned grid curved surfaces connected with all grid edges being 2;

step 8.2: dividing and fusing all grid surfaces with first marks from the repartitioning grid curved surface set into current divided grid curved surfaces, and classifying the current divided grid curved surfaces into a divided grid curved surface set;

step 8.3: repeating 8.1 to 8.2 until the repartitioned mesh surface set is empty;

9. An electronic device, wherein the electronic device is configured to perform the geotechnical engineering finite element model construction method in the CAD environment according to any one of claims 1 to 8, and the method comprises:

a memory for storing a computer program enabling the geotechnical engineering finite element model construction method in the CAD environment of claims 1 to 8;

and the processor is used for requesting operation resources from the general computer according to the instruction and selectively executing the specific functions of the geotechnical engineering finite element model construction method in the CAD environment according to any one of 1 to 8.