CN116167258B

CN116167258B - Finite element face unit grid creation method for multi-round hole planar metal mesh

Info

Publication number: CN116167258B
Application number: CN202211359504.3A
Authority: CN
Inventors: 欧阳金惠; 张翰
Original assignee: China Three Gorges Corp
Current assignee: China Three Gorges Corp
Priority date: 2022-11-01
Filing date: 2022-11-01
Publication date: 2024-04-23
Anticipated expiration: 2042-11-01
Also published as: CN116167258A

Abstract

The invention discloses a method for creating a finite element plane unit grid of a multi-round-hole planar metal mesh, which comprises the steps of creating a round hole in a first row and a first column of a preset rectangular area of the multi-round-hole planar metal mesh, creating a corresponding coordinate system in the round hole, and determining four coordinate points and four sections of circular arc edges; obtaining at least one first area through a preset first connection method based on at least one coordinate point and/or at least one section of arc edge of each round hole in a preset rectangular area; and carrying out cell division on each first surface area to generate finite element surface cell grids with arbitrary density corresponding to each first surface area. The method for creating the finite element face unit grid of the multi-round hole planar metal mesh provided by the invention adopts a modeling mode from a bottom layer to a high layer, avoids failure caused by excessive Boolean subtraction operation, and ensures that the mesh with thousands of small round holes can be successfully created.

Description

Finite element face unit grid creation method for multi-round hole planar metal mesh

Technical Field

The invention relates to the technical field of finite element face unit grid generation, in particular to a method for creating a finite element face unit grid of a multi-round-hole plane metal mesh.

Background

Drum screens are an important cooling device for pressurized water reactors of nuclear power plants. Each drum-shaped filter screen consists of a steel member such as a spoke and hundreds of multi-round-hole plane metal meshes, and thousands of small round holes are processed in each multi-round-hole plane metal mesh. Compared with the profile steel member, the metal round hole filter screen is a weak part of the drum-shaped filter screen, so that the metal round hole filter screen is frequently damaged when the drum-shaped filter screen runs.

In the prior art, the simulation of the mesh structure of the weakest part of the drum filter screen is not required, and neither the whole drum filter screen finite element model nor the finite element model of a single rectangular mesh is used for simulating the actual round holes of the mesh, but the calculation model of the rectangular mesh is simplified without holes.

However, because stress concentration occurs in the mesh with holes, the calculation result of the mesh non-hole simplified model is necessarily smaller than the actual stress of the mesh with holes, and the actual stress state of the mesh with holes cannot be accurately calculated and analyzed.

Disclosure of Invention

In view of the above, the embodiment of the invention provides a method for creating a finite element face unit grid of a multi-round hole planar metal mesh, which aims to solve the technical problem that in the prior art, when analyzing the actual stress state of a mesh with holes, the creation of a single finite element face unit grid of a porous metal rectangular mesh cannot be realized.

The technical scheme provided by the invention is as follows:

In a first aspect, an embodiment of the present invention provides a method for creating a finite element plane unit mesh of a multi-round hole planar metal mesh, where the method for creating a finite element plane unit mesh of a multi-round hole planar metal mesh includes: creating a round hole in a first row of a preset rectangular area of the multi-round hole planar metal mesh, taking an origin of the round hole as a coordinate, taking a horizontal diameter of the round hole as an X axis and a vertical diameter of the round hole as a Y axis, building a corresponding coordinate system in the round hole, and determining four coordinate points and four sections of circular arc sides in the round hole based on the coordinate system, wherein the X axis is right positive direction, the Y axis is positive direction, each coordinate point is respectively an intersection point of an angular bisector of four quadrants in the coordinate system corresponding to the round hole and the round hole, an arc is formed between every two adjacent coordinate points, the preset rectangular area is obtained by a preset processing method based on the round hole, the preset rectangular area comprises m round holes distributed along the horizontal direction and n round holes distributed along the vertical direction, m is more than or equal to2, n is a positive integer, the radius of each round hole is r, the circle center distance of any two adjacent round holes in the m round holes is d ₁, and the distance between two adjacent round holes distributed along the horizontal direction is ₂,r＜min(d₁/2,d₂/2; and carrying out cell division on each first surface area to generate finite element surface cell grids with arbitrary density corresponding to each first surface area.

Optionally, in one possible implementation manner of the first aspect, the circular holes in the ith row and the circular holes in the jth row in the preset rectangular area are staggered along a horizontal direction, a staggering distance is d ₁/2, i is even, j is odd, the four coordinate points include a first coordinate point, a second coordinate point, a third coordinate point and a fourth coordinate point, the first coordinate point is an intersection point of an angular bisector of the first quadrant and the circular holes in the coordinate system, the second coordinate point is an intersection point of an angular bisector of the second quadrant and the circular holes in the coordinate system, the third coordinate point is an intersection point of an angular bisector of the third quadrant and the circular holes in the coordinate system, the fourth coordinate point is an intersection point of an angular bisector of the fourth quadrant and the circular holes in the coordinate system, the fourth arc side includes a first arc side, a second arc side and a third arc side, the first arc side characterizes an intersection point of the first arc side and the second arc side, and the third arc side characterizes an intersection point of the third arc side and the fourth arc side characterizes the arc; the method further comprises the steps of: determining a fifth coordinate point and a sixth coordinate point corresponding to each round hole of the ith row and the first column in the preset rectangular area based on the second coordinate point and the third coordinate point of each round hole of the ith row and the first column in the preset rectangular area, wherein the fifth coordinate point is obtained by copying the second coordinate point and moving the second coordinate point leftwards in the horizontal direction, and the sixth coordinate point is obtained by copying the third coordinate point and moving the third coordinate point leftwards in the horizontal direction; determining at least one second area based on the second coordinate point, the third coordinate point, the fifth coordinate point and the sixth coordinate point, wherein the second area represents the fifth coordinate point, the sixth coordinate point, the second coordinate point, the third coordinate point and the second circular arc edge of each round hole of the ith row and the first column and the third coordinate point, the fourth coordinate point and the third coordinate point of each round hole of the (j+2) th row and the first column in the preset rectangular area; and carrying out cell division on each second surface area to generate finite element surface cell grids with arbitrary density corresponding to each second surface area.

Optionally, in a possible implementation manner of the first aspect, the four arc edges further include a fourth arc edge, and the fourth arc edge characterizes an arc formed between the first coordinate point and the fourth coordinate point; the method further comprises the steps of: determining a fifth coordinate point and a sixth coordinate point corresponding to each round hole in the jth row and the mth column in the preset rectangular area based on the first coordinate point and the fourth coordinate point of each round hole in the jth row and the mth column in the preset rectangular area, wherein the fifth coordinate point is obtained by copying the first coordinate point and moving the first coordinate point to the right in the horizontal direction, and the sixth coordinate point is obtained by copying the fourth coordinate point and moving the fourth coordinate point to the right in the horizontal direction; determining at least one second area based on the first coordinate point, the fourth coordinate point, the fifth coordinate point and the sixth coordinate point, wherein the second area represents a closed area in each closed loop formed by the fifth coordinate point, the sixth coordinate point, the first coordinate point, the fourth circular arc edge, the fourth coordinate point of each circular hole in the j+1th row and m-th column, the second circular arc edge, the third circular arc edge and the fourth coordinate point of each circular hole in the j+2th row and m-th column in the preset rectangular area; and carrying out cell division on each second surface area to generate finite element surface cell grids with arbitrary density corresponding to each second surface area.

Optionally, in a possible implementation manner of the first aspect, the multi-round hole planar metal mesh is composed of a first rectangular side, a second rectangular side, a third rectangular side and a fourth rectangular side, including a first end point, a second end point, a third end point and a fourth end point, where the first rectangular side characterizes one long side in a vertical direction formed between the first end point and the second end point in the multi-round hole planar metal mesh; the method further comprises the steps of: determining at least one seventh coordinate point on the first rectangular side based on the second coordinate point of each round hole of the 1 st column in the preset rectangular area; determining at least one eighth coordinate point on the first rectangular side based on the third coordinate point of each round hole of the 1 st column in the preset rectangular area; determining at least one third area characterizing a closed region within each closed loop formed by the second coordinate point, the third coordinate point, the second circular arc edge, the seventh coordinate point and the eighth coordinate point of each circular hole of a j+1 th row and column in the preset rectangular region, the fifth coordinate point, the sixth coordinate point, the seventh coordinate point and the eighth coordinate point of each circular hole of a j+2 th row and column in the preset rectangular region, based on the at least one seventh coordinate point, the at least one eighth coordinate point, the second coordinate point, the third coordinate point and the sixth coordinate point; and carrying out cell division on each third surface domain to generate finite element surface cell grids with arbitrary density corresponding to each third surface domain.

Optionally, in a possible implementation manner of the first aspect, the fourth rectangular edge characterizes another long edge in a vertical direction formed between a third end point and a fourth end point in the multi-round hole planar metal mesh; the method further comprises the steps of: determining at least one seventh coordinate point on the fourth rectangular side based on the first coordinate point of each round hole of the mth column in the preset rectangular area; determining at least one eighth coordinate point on the fourth rectangular side based on the fourth coordinate point of each round hole of the m-th column in the preset rectangular area; determining at least one third area characterizing a closed region within each closed loop formed by the fifth coordinate point, the sixth coordinate point, the seventh coordinate point and the eighth coordinate point of each round hole of a j+1th row and column in the preset rectangular region, the first coordinate point, the fourth circular arc edge, the seventh coordinate point and the eighth coordinate point of each round hole of a j+2th row and column in the preset rectangular region, based on the at least one seventh coordinate point, the at least one eighth coordinate point, the first coordinate point, the fourth coordinate point, the fifth coordinate point and the sixth coordinate point of each round hole of a j-th row and column in the preset rectangular region; and carrying out cell division on each third surface domain to generate finite element surface cell grids with arbitrary density corresponding to each third surface domain.

Optionally, in a possible implementation manner of the first aspect, the second rectangular edge characterizes a short edge in a vertical direction formed between a first end point and a third end point in the multi-round hole planar metal mesh; the method further comprises the steps of: determining at least one ninth coordinate point on the second rectangular side based on the second coordinate point of each round hole of the nth row in the preset rectangular area; determining at least one tenth coordinate point on the second rectangular side based on the first coordinate point of each round hole of the nth row in the preset rectangular area; determining an eleventh coordinate point on the second rectangular side based on the fifth coordinate point of the circular hole of the nth row and the mth column in the preset rectangular area; determining at least one third area including the first coordinate point, the second coordinate point, the first circular arc side, the ninth coordinate point, the tenth coordinate point, a closed area within each closed loop formed by the second coordinate point and the ninth coordinate point of each circular hole of the nth row and the jth column in the preset rectangular area, and the tenth coordinate point, the first coordinate point, the fifth coordinate point and the closed area within each closed loop formed by the ninth coordinate point, the second coordinate point and the ninth coordinate point of each circular hole of the nth row and the jth column in the preset rectangular area based on the fifth coordinate point, the at least one ninth coordinate point, the at least one tenth coordinate point, the first coordinate point and the second coordinate point; and carrying out cell division on each third surface domain to generate finite element surface cell grids with arbitrary density corresponding to each third surface domain.

Optionally, in a possible implementation manner of the first aspect, the third rectangular edge characterizes another short edge in a vertical direction formed between the second end point and the fourth end point in the multi-round hole planar metal mesh; the method further comprises the steps of: determining at least one ninth coordinate point on the third rectangular side based on the third coordinate point of each round hole of the 1 st row in the preset rectangular area; determining at least one tenth coordinate point on the third rectangular side based on the fourth coordinate point of each round hole of the 1 st row in the preset rectangular area; determining an eleventh coordinate point on the third rectangular side based on the sixth coordinate point of the round hole of the 1 st row and the m-th column in the preset rectangular area; determining at least one third area including the third coordinate point, the fourth coordinate point, the third circular arc side, the ninth coordinate point, the tenth coordinate point, a closed area within each closed loop formed by the third coordinate point and the ninth coordinate point of each circular hole of the 1 st row and the 1 st column in the preset rectangular area, and the tenth coordinate point, the fourth coordinate point, the sixth coordinate point and the closed area within each closed loop formed by the fourth coordinate point, the third coordinate point of each circular hole of the 1 st row and the 1 st column in the preset rectangular area based on the sixth coordinate point, the at least one ninth coordinate point, the at least one tenth coordinate point, the eleventh coordinate point, the third coordinate point and the fourth coordinate point; and carrying out cell division on each third surface domain to generate finite element surface cell grids with arbitrary density corresponding to each third surface domain.

Optionally, in a possible implementation manner of the first aspect, the method further includes: determining a third area based on the third coordinate point, the eighth coordinate point, the ninth coordinate point and the second end point of the multi-round hole planar metal mesh of the 1 st row and 1 st column in the preset rectangular area; determining a third area based on the sixth coordinate point, the eighth coordinate point, the eleventh coordinate point and the fourth end point of the multi-round hole planar metal mesh of the 1 st row and the m th column in the preset rectangular area; determining a third area based on the second coordinate point, the seventh coordinate point, the ninth coordinate point and the first end point of the multi-round hole planar metal mesh of the nth row and the 1 st column in the preset rectangular area; determining a third area based on the fifth coordinate point, the seventh coordinate point, the eleventh coordinate point and the third end point of the multi-round hole planar metal mesh of the nth row and the mth column in the preset rectangular area; and carrying out cell division on each third surface domain to generate finite element surface cell grids with arbitrary density corresponding to each third surface domain.

The technical scheme provided by the invention has the following effects:

the finite element face unit grid creation method of the multi-round hole plane metal mesh provided by the embodiment of the invention adopts a modeling mode from a bottom layer to a high layer (point/line- & gt face), avoids failure caused by excessive Boolean subtraction operation (mesh reduction of the whole mesh), and ensures that the mesh with thousands of small round holes can be successfully created.

Drawings

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

FIG. 1 is a schematic view of a multi-round hole planar metal mesh structure according to an embodiment of the present invention;

FIG. 2 is a flow chart of a method of finite element face cell grid creation of a multi-round hole planar metal mesh according to an embodiment of the invention;

FIG. 3 is a schematic diagram of edge and point numbering of a single circular hole according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of the hole mesh arrangement and hole numbering within a predetermined rectangular area EFGH according to an embodiment of the invention;

FIG. 5 is a schematic view of a circular hole distance according to an embodiment of the present invention;

FIG. 6a is a schematic diagram of a first area A1 according to an embodiment of the invention;

FIG. 6b is a schematic diagram of a first area A2 according to an embodiment of the invention;

FIG. 6c is a schematic diagram of a first area A3 according to an embodiment of the invention;

FIG. 6d is a schematic diagram of a first area A4 according to an embodiment of the invention;

FIG. 6e is a schematic diagram of a first area A5 according to an embodiment of the invention;

FIG. 6f is a schematic diagram of first areas A1-A5 according to an embodiment of the invention;

fig. 7 is a schematic diagram of the left and right two-sided alignment points in the preset rectangular area EFGH according to the embodiment of the present invention;

FIG. 8 is a schematic diagram of a second domain A6 according to an embodiment of the invention;

FIG. 9 is a schematic diagram of areas A1 through A6 according to an embodiment of the invention;

FIG. 10 is a multi-round hole planar metal mesh ABCD peripheral edge spot according to an embodiment of the invention;

FIG. 11 is a schematic view of a third domain A7 according to an embodiment of the invention;

Fig. 12 is another schematic diagram of the hole mesh arrangement and hole numbering within the preset rectangular area EFGH according to an embodiment of the present invention.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. 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.

The embodiment of the invention provides a method for creating a finite element plane unit grid of a multi-round-hole planar metal mesh, which is shown in fig. 1, wherein the length of the multi-round-hole planar metal mesh ABCD is L1, and the width of the multi-round-hole planar metal mesh is W1.

As shown in fig. 2, the method comprises the steps of:

Step 101: creating a round hole in a first row of a preset rectangular area of the multi-round hole planar metal mesh, taking an origin of the round hole as a coordinate, taking a horizontal diameter of the round hole as an X axis and a vertical diameter of the round hole as a Y axis, building a corresponding coordinate system in the round hole, and determining four coordinate points and four sections of circular arc sides in the round hole based on the coordinate system, wherein the X axis is right positive direction, the Y axis is positive direction, each coordinate point is respectively an intersection point of an angular bisector of four quadrants in the coordinate system corresponding to the round hole and the round hole, an arc is formed between every two adjacent coordinate points, the preset rectangular area is obtained by a preset processing method based on the round hole, the preset rectangular area comprises m round holes distributed along the horizontal direction and n round holes distributed along the vertical direction, m is more than or equal to 2, n is a positive integer, the radius of each round hole is r, the circle center distance of any two adjacent round holes in the m round holes is d ₁, and the distance between two adjacent round holes distributed along the horizontal direction is ₂,r＜min(d₁/2,d₂/2;

Specifically, as shown in fig. 3, a corresponding coordinate system XOY is established in any of the circular holes C11 created, and the positive direction is defined to the right of the X axis and the positive direction is defined to the Y axis.

Further, the preset processing method may include:

Firstly, translating the copy round hole C11;

Specifically, according to the round hole design data of the multi-round hole planar metal mesh, the round hole C11 is taken as a female parent, and a preset rectangular area EFGH shown in fig. 4 is formed through translation and replication. The translational replication method can be used as follows:

(1) Translation replication one by one: the circular holes C11 are copied one by one to the other circular hole positions shown in fig. 4.

(2) Translation replication in rows: by translating the copying round hole C11, the 1 st row of round holes C11-Cm 1 are formed, and then the 1 st row of round holes C11-Cm 1 are copied to the 2 nd row to the n th row according to the positions of the round holes in each row in FIG. 4.

(3) Translation replication in columns: by copying the round holes C11, the 1 st row round holes C11-C1 n are formed, and then the 1 st row round holes C11-C1 n are copied to the 2 nd to m th rows according to the positions of the round holes in each row in FIG. 4.

(4) Hybrid translational replication: multiple rows of round holes or multiple columns of round holes are formed through a row-by-row replication or column-by-column replication method, and then the multiple rows of round holes or the multiple columns of round holes are replicated to other round hole positions shown in fig. 4.

Secondly, creating each round hole by creating a local coordinate system of each round hole;

Specifically, first, at the center of each circular hole as shown in fig. 4, local coordinate systems of each circular hole are created, the number of which coincides with the number of circular holes.

Secondly, according to the created local coordinate systems, creating round holes shown in fig. 3 under each local coordinate system, wherein each round hole consists of 4 sections of circular arc edges and4 points; the 4 sections of arc edges are l ₁、l₂、l₃ and l ₄ respectively; the 4 coordinate points are P1 (r, < 45 °), P2 (r, < 135 °), P3 (r, < 225 °), and P4 (r, < 315 °) from quadrant 1 to quadrant 4, respectively.

Through any of the above processing methods, a preset rectangular area EFGH can be determined in the multi-round hole planar metal mesh ABCD, as shown in fig. 1; and the preset rectangular area EFGH includes m×n circular holes as shown in fig. 4.

As shown in fig. 5, m round holes (i.e., each row of round holes) are formed along the FG direction, and the center-to-center distance between adjacent round holes is d ₁; n rows of round holes are formed along the FE direction, the distance between two adjacent rows of round holes along the FE direction is d ₂, and r is less than min (d ₁/2,d₂/2);

further, as shown in fig. 3, four coordinate points are P1 (r, < 45 °), P2 (r, < 135 °), P3 (r, < 225 °), and P4 (r, < 315 °), respectively. Wherein r represents the radius of the round hole, and the value can be 1.5 mm-4.0 mm according to the actual requirement of the drum-shaped rotary filter screen (DL/T1257-2013) and engineering; angle 45 degrees, angle 135 degrees, angle 225 degrees and angle 315 degrees respectively represent the included angles between the angular bisector corresponding to each coordinate point and the positive X axis; the four arc edges are respectively an arc l ₁ between two adjacent coordinate points P1 and P2, an arc l ₂ between P2 and P3, an arc l ₃ between P3 and P4 and an arc l ₄ between P4 and P1.

Step 102: and obtaining at least one first surface area through a preset first connection method based on at least one coordinate point and/or at least one section of circular arc edge of each circular hole in the preset rectangular area, wherein the first surface area comprises a closed area in each closed ring formed between any adjacent circular holes in the preset rectangular area, and each closed ring consists of at least one coordinate point and/or at least one section of circular arc edge of each circular hole in the adjacent circular holes.

The preset first connection method is determined based on specific arrangement positions of each round hole in a preset rectangular area and at least one coordinate point and/or at least one section of circular arc edge of each round hole. Further, the specific arrangement position of each circular hole in the preset rectangular region may include the circular holes in even/odd rows.

Specifically, different coordinate points and/or different circular arc edges of different circular holes are connected to obtain different first areas.

(One): for a circle Cij (where i=1, m-1,1; j=1, n, 1), a first area A1 is created with Cij _p1,Cij_p4,C(i+1)j_p3,C(i+1)j_p2 as the vertex, as shown in fig. 6 a.

Wherein (i=1, m-1, 1) represents i from 1 to m-1, with each increment of 1; if (i=1, m-1, 2) then i is from 1 to m-1, each increment being 2; and the other is the same.

(J=1, n, 1) means j is from 1 to n, with each increment being 1; if (j=1, n, 2) then j is from 1 to n, each increment being 2; and the other is the same.

Cij _p1 represents the P1 point of circle Cij, C (i+1) j _p3 represents the P3 point of circle C (i+1) j; and the other is the same.

The quadrangular area A1 is composed of 4 lines in total of the circular arc edge l ₄ of the circle Cij, the circular arc edge l ₂ of the circle C (i+1) j, the line connecting the point Cij _p1 with the point C (i+1) j _p2, and the line connecting the point Cij _p4 with the point C (i+1) j _p3. The following is the same.

The line between two adjacent points in the circle adopts an arc edge, and the connecting line (such as the connecting line between the points) between the points of different circles is a straight line.

(II): a first area A2 is created as shown in fig. 6 b.

Specifically, if n is an even number, for a circle Cij (where i=1, m-1,1; j=1, n, 2), a first area A2 is created with the following 4 points for vertices: cij _p1,Ci(j+1)_p3,Ci(j+1)_p4,C(i+1)j_p2;

if n is an odd number, for a circle Cij (where i=1, m-1,1; j=1, n-1, 2), a quadrilateral area A2 is created with the following 4 points as vertices: cij _p1,Ci(j+1)_p3,Ci(j+1)_p4,C(i+1)j_p2;

(III) creating a first area A3, as shown in FIG. 6 c.

Specifically, if n is an even number, for a circle Cij (where i=2, m,1; j=1, n, 2), a first area A3 is created with the following 4 points as vertices: cij _p1,Cij_p2,C(i－1)(j+1)_p4,Ci(j+1)_p3;

If n is an odd number, for a circle Cij (where i=2, m,1; j=1, n-1, 2), a first area A3 is created with the following 4 points as vertices: cij _p1,Cij_p2,C(i－1)(j+1)_p4,Ci(j+1)_p3;

(IV) creating a first area A4, as shown in FIG. 6 d.

Specifically, if n is an even number, for a circle Cij (where i=1, m-1,1; j=2, n-2, 2), a first area A4 is created for vertices with the following 4 points: cij _p1,Cij_p2,Ci(j+1)_p4,C(i+1)(j+1)_p3;

if n is an odd number, for a circle Cij (where i=1, m-1,1; j=2, n-1, 2), a first area A4 is created with the following 4 points as vertices: cij _p1,Cij_p2,Ci(j+1)_p4,C(i+1)(j+1)_p3;

(fifth) a first area A5 is created as shown in fig. 6 e.

Specifically, if n is an even number, for a circle Cij (where i=1, m-1,1; j=2, n-2, 2), a first area A5 is created for vertices with the following 4 points: cij _p1,C(i+1)j_p2,C(i+1)(j+1)_p4,C(i+1)(j+1)_p3;

If n is an odd number, for a circle Cij (where i=1, m-1,1; j=2, n-1, 2), a first area A5 is created with the following 4 points as vertices: cij _p1,C(i+1)j_p2,C(i+1)(j+1)_p4,C(i+1)(j+1)_p3;

in summary, the first areas A1-A5 can be obtained, as shown in FIG. 6 f.

Step 103: and carrying out cell division on each first surface area to generate finite element surface cell grids with arbitrary density corresponding to each first surface area.

Specifically, the first areas A1-A5 are quadrilateral, and the quadrilateral surface units can be used for meshing. The meshing method is as follows:

Each line segment (comprising straight lines and circular arcs) is divided into equal segment numbers (the segment number is not less than 2), and each quadrilateral area is divided by adopting a mapping method; the number of different equal segments on each side can be set according to the requirement, and the first area of each quadrangle is divided by adopting a mapping method or a non-mapping method.

As an optional implementation manner of the embodiment of the present invention, round holes in the ith row and round holes in the jth row in the preset rectangular area are staggered along a horizontal direction, a staggering distance is d ₁/2, i is an even number, j is an odd number, the four coordinate points include a first coordinate point, a second coordinate point, a third coordinate point and a fourth coordinate point, the first coordinate point is an intersection point of an angular bisector of the first quadrant and the round holes in the coordinate system, the second coordinate point is an intersection point of an angular bisector of the second quadrant and the round holes in the coordinate system, the third coordinate point is an intersection point of an angular bisector of the third quadrant and the round holes in the coordinate system, the fourth coordinate point is an intersection point of an angular bisector of the fourth quadrant and the round holes in the coordinate system, the fourth coordinate point includes a first arc edge, a second arc edge and a third arc edge, the first arc edge characterizes an intersection point of the first arc edge and the second arc edge, and the fourth arc edge characterizes an intersection point of the third arc edge and the arc edge characterizing an arc.

Specifically, as shown in fig. 3, the first coordinate point, the second coordinate point, the third coordinate point, and the fourth coordinate point are a point P1, a point P2, a point P3, and a point P4, respectively; the first arc edge, the second arc edge and the third arc edge are an arc l ₁, an arc l ₂ and an arc l ₃ respectively.

The method further comprises the steps of: and determining a fifth coordinate point and a sixth coordinate point corresponding to each round hole of the ith row and the first column in the preset rectangular area based on the second coordinate point and the third coordinate point of each round hole of the ith row and the first column in the preset rectangular area, wherein the fifth coordinate point is obtained by copying the second coordinate point and moving the second coordinate point leftwards in the horizontal direction, and the sixth coordinate point is obtained by copying the third coordinate point and moving the third coordinate point leftwards in the horizontal direction.

Specifically, as shown in fig. 7, since the round holes in the even rows are staggered by d ₁/2 along FG compared to the round holes in the odd rows, to complement the two end areas, the left points of the circles in the 1 st column of the even rows (i.e., the first column of the i-th row) need to be complemented:

By copying two points C1j _p2 and C1j _p3 of an even-numbered line circle Cij (where j=2, n, 2) in the X-direction by-d ₁/2, i.e., copying and moving the two points to the left in the X-axis by the interleaving distance d ₁/2 in the horizontal direction, two new points can be obtained with numbers C1j _p5 and C1j _p6, i.e., a fifth coordinate point and a sixth coordinate point, respectively.

Determining at least one second area based on the second coordinate point, the third coordinate point, the fifth coordinate point and the sixth coordinate point, wherein the second area represents the fifth coordinate point, the sixth coordinate point, the second coordinate point, the third coordinate point and the second circular arc edge of each round hole of the ith row and the first column and the third coordinate point, the fourth coordinate point and the third coordinate point of each round hole of the (j+2) th row and the first column in the preset rectangular area;

Specifically, the second area A6 is shown as the left area in fig. 8. The closing area in each closing ring is formed by a fifth coordinate point P5, a sixth coordinate point P6, a second coordinate point P2, a third coordinate point P3, a second circular arc edge l ₂ between the second coordinate point and the third coordinate point, a first coordinate point P1, a second coordinate point P2, a first circular arc edge l ₁, and a third coordinate point P3, a fourth coordinate point P4, and a third circular arc edge l ₃ of each circular hole in the j+2th row and first column.

For example, in fig. 8, the closed region formed between the circles C11, C12 and C13 is formed by the fifth coordinate point C12 _p5, the sixth coordinate point C12 _p6, the second coordinate point C12 _p2, the third coordinate point C12 _p3, the second circular arc edge l ₂, and the first coordinate point C11 _p1, the second coordinate point C11 _p2, the first circular arc edge l ₁, and the third coordinate point C13 _p3, the fourth coordinate point C13 _p4, and the third circular arc edge l ₃ of the circle C12.

In an alternative embodiment, the second panel A6 is formed by a plurality of such closed regions.

As shown in fig. 8, each closed loop area involves 3 different round holes and includes 3 different areas, and the creation methods of the 3 different areas are different according to the positions of the rows and the columns where the 3 different round holes are located, specifically as follows:

if n is an even number, for circle C1j (where j=2, n-2, 2), the following 3 quadrilateral areas are created with 4 points each:

(1)C1j_p3,C1j_p6,C1(j－1)_p2,C1(j－1)_p1；

(2)C1j_p3,C1j_p6,C1j_p5,C1j_p2；

(3)C1j_p2,C1j_p5,C1(j+1)_p3,C1(j+1)_p4；

if n is an odd number, for circle C1j (where j=2, n-1, 2), the following 3 quadrilateral areas are created with 4 points each:

(1)C1j_p3,C1j_p6,C1(j－1)_p2,C1(j－1)_p1；

(2)C1j_p3,C1j_p6,C1j_p5,C1j_p2；

(3)C1j_p2,C1j_p5,C1(j+1)_p3,C1(j+1)_p4；

wherein when n is an even number, for a circle C1n, the following 2 quadrilateral areas are created with 4 points, respectively:

(1)C1n_p3,C1n_p6,C1(n－1)_p2,C1(n－1)_p1；

(2)C1n_p3,C1n_p6,C1n_p5,C1n_p2；

And carrying out cell division on each second surface area to generate finite element surface cell grids with arbitrary density corresponding to each second surface area. The specific dividing method refers to the dividing method of step 106, and will not be described herein.

As an optional implementation manner of the embodiment of the present invention, the four arc edges further include a fourth arc edge, and the fourth arc edge characterizes an arc formed between the first coordinate point and the fourth coordinate point;

specifically, as shown in fig. 3, the fourth arc edge is an arc l ₄.

The method further comprises the steps of: and determining a fifth coordinate point and a sixth coordinate point corresponding to each round hole in the jth row and the mth column in the preset rectangular area based on the first coordinate point and the fourth coordinate point of each round hole in the jth row and the mth column in the preset rectangular area, wherein the fifth coordinate point is obtained by copying the first coordinate point and moving the first coordinate point to the right in the horizontal direction, and the sixth coordinate point is obtained by copying the fourth coordinate point and moving the fourth coordinate point to the right in the horizontal direction.

Specifically, as shown in fig. 7, since the round holes in the even rows are staggered by d ₁/2 along FG compared to the round holes in the odd rows, to complement the two end surface areas, it is also necessary to complement the right point of the m-th (m-th) round in the odd rows:

By copying the two points Cmj _p1 and Cmj _p4 of the odd-numbered circles Cmj (where j=2, n, 2) d ₁/2 in the X-direction, i.e., copying and moving the two points to the right in the X-axis by the staggered distance d ₁/2 in the horizontal direction, two new points can be obtained with numbers Cmj _p5 and Cmj _p6, i.e., the fifth coordinate point and the sixth coordinate point, respectively.

Determining at least one second area based on the first coordinate point, the fourth coordinate point, the fifth coordinate point and the sixth coordinate point, the second area characterizing a closed area in each closed loop formed by the fifth coordinate point, the sixth coordinate point, the first coordinate point, the fourth circular arc edge, the fourth coordinate point of each circular hole in the (j+1) th row and the (m+2) th column, the second circular arc edge, the third circular arc edge and the fourth coordinate point of each circular hole in the (j+2) th row and the (m+2) th column in the preset rectangular area

Specifically, the second area A6 is shown as the right area in fig. 8. The closing area in each closing ring is formed by a fifth coordinate point P5, a sixth coordinate point P6, a first coordinate point P1, a fourth coordinate point P4, a fourth arc edge l ₄, four coordinate points (P1, P2, P3, P4) of each round hole in the j+1th row and m-th column, a second arc edge l ₂, a third arc edge l ₃, and a fourth coordinate point P4 and a sixth coordinate point P6 of each round hole in the j+2th row and m-th column.

For example, in fig. 8, the closed region formed between the circles Cm1, cm2, and Cm3 is formed by the fifth coordinate point P5, the sixth coordinate point P6, the first coordinate point P1, the fourth coordinate point P4, the fourth circular arc edge l ₄, and the four coordinate points Cm2 _p1、Cm2_p2、Cm2_p3、Cm2_p4, the second circular arc edge l ₂, the third circular arc edge l ₃, and the fourth coordinate point Cm3 _p4 and the sixth coordinate point Cm3 _p6 of the circle Cm3 of the circle Cm 1.

for circle Cm1, the following 2 quadrilateral areas are created with 4 points each:

(1)Cm1_p4,Cm1_p6,Cm1_p5,Cm1_p1；

(2)Cm1_p1,Cm2_p3,Cm2_p4,Cm1_p5；

If n is an even number, for circle Cmj (where j=3, n-1, 2), the following 3 quadrilateral areas are created with 4 points each:

(1)Cmj_p4,Cmj_p6,Cmj_p5,Cmj_p1；

(2)Cmj_p1,Cm(j+1)_p3,Cm(j+1)_p4,Cmj_p5；

(3)Cmj_p4,Cm(j－1)_p2,Cm(j－1)_p1,Cmj_p6；

If n is an odd number:

For circle Cmj (where j=3, n-2, 2), the following 3 quadrilateral areas are created with 4 points each:

(1)Cmj_p4,Cmj_p6,Cmj_p5,Cmj_p1；

(2)Cmj_p1,Cm(j+1)_p3,Cm(j+1)_p4,Cmj_p5；

(3)Cmj_p4,Cm(j－1)_p2,Cm(j－1)_p1,Cmj_p6；

for a circle Cmn, the following 2 quadrilateral areas are created with 4 points each:

(1)Cmn_p4,Cmn_p6,Cmn_p5,Cmn_p1；

(2)Cmn_p4,Cm(n－1)_p2,Cm(n－1)_p1,Cmn_p6；

In summary, the resulting first areas A1-A5 and second area A6 are shown in FIG. 9.

As an optional implementation manner of the embodiment of the present invention, the multi-round hole planar metal mesh is composed of a first rectangular side, a second rectangular side, a third rectangular side and a fourth rectangular side, and includes a first end point, a second end point, a third end point and a fourth end point, where the first rectangular side represents a long side formed between the first end point and the second end point in the multi-round hole planar metal mesh along a vertical direction; the fourth rectangular side represents the other long side in the vertical direction formed between the third end point and the fourth end point in the multi-round hole planar metal mesh; the second rectangular edge represents a short edge which is formed between a first end point and a third end point in the multi-round hole planar metal mesh and is in a vertical direction; the third rectangular edge represents the other short edge in the vertical direction formed between the second end point and the fourth end point in the multi-round hole planar metal mesh;

specifically, as shown in fig. 1, the multi-round hole planar metal mesh ABCD includes four end points (A, B, C, D) and four rectangular sides AB, AD, BC, and CD. The first rectangular side is AB, the second rectangular side is AD, the third rectangular side is BC, and the fourth rectangular side is CD.

It is also necessary to create a corresponding mesh in the middle portion of the multi-round hole planar metal mesh ABCD and the preset rectangular area EFGH and form a surface area.

First, creating corresponding points on four rectangular sides of the multi-round hole planar metal mesh ABCD, including:

(1) Generating a middle point of the first rectangular edge AB (excluding two end points of the line segment AB, the following applies): determining at least one seventh coordinate point on the first rectangular side based on the second coordinate point of each round hole of the 1 st column in the preset rectangular area; and determining at least one eighth coordinate point on the first rectangular side based on the third coordinate point of each round hole of the 1 st column in the preset rectangular area.

Specifically, the intermediate point of the first rectangular side AB includes at least one seventh coordinate point P7 and at least one eighth coordinate point P8. Wherein, the seventh coordinate point P7 is determined according to the second coordinate point of each round hole in the 1 st column; the eighth coordinate point P8 is determined based on the third coordinate point P3 of each circular hole of the 1 st column.

As shown in fig. 10, the point corresponding to the point C1j _p2 (where j=1, n, 1) is C1j _p7, i.e., the point C1j _p2 is the same as the Y coordinate of the point C1j _p7; the point corresponding to point C1j _p3 (where j=1, n, 1) is C1j _p8, i.e., point C1j _p3 is the same Y coordinate as C1j _p8 of the point.

(2) Generating a middle point of the fourth rectangular side CD: determining at least one seventh coordinate point on the fourth rectangular side based on the first coordinate point of each round hole of the mth column in the preset rectangular area; and determining at least one eighth coordinate point on the fourth rectangular side based on the fourth coordinate point of each round hole of the m-th column in the preset rectangular area.

The intermediate points of the fourth rectangular side CD include at least one seventh coordinate point P7 and at least one eighth coordinate point P8. Wherein, the seventh coordinate point P7 is determined according to the second coordinate point P2 of each round hole in the mth column; the eighth coordinate point P8 is determined based on the third coordinate point P3 of each circular hole of the mth column.

As shown in fig. 10, the point corresponding to point Cmj _p1 (where j=1, n, 1) is Cmj _p7, i.e., point Cmj _p1 is the same as the Y coordinate of point Cmj _p7; the point corresponding to point Cmj _p4 (where j=1, n, 1) is Cmj _p8, i.e., point Cmj _p4 is the same Y coordinate as point Cmj _p8.

(3) Generating a middle point of the second rectangular side AD: determining at least one ninth coordinate point on the second rectangular side based on the second coordinate point of each round hole of the nth row in the preset rectangular area; determining at least one tenth coordinate point on the second rectangular side based on the first coordinate point of each round hole of the nth row in the preset rectangular area; and determining an eleventh coordinate point on the second rectangular side based on the fifth coordinate point of the circular hole of the nth row and the mth column in the preset rectangular area.

The intermediate points of the second rectangular sides AD include at least one ninth coordinate point, at least one tenth coordinate point, and an eleventh coordinate point. Wherein, the ninth coordinate point P9 is determined according to the second coordinate point P2 of each circular hole of the nth row; the tenth coordinate point P10 is determined according to the first coordinate point P1 of each circular hole of the nth row; the eleventh coordinate point is determined based on the fifth coordinate point P5 of the circular hole of the nth row and the mth column.

Specifically, as shown in fig. 10, the point corresponding to the point Cin _p2 (where i=1, m, 1) is Cin _p9, i.e., the point Cin _p2 is identical to the X coordinate of the point Cin _p9; the point corresponding to point Cin _p1 (where i=1, m, 1) is Cin _p10, i.e., point Cin _p1 is the same X coordinate as point Cin _p10.

If n is an odd number, generating a point Cmn _p11 corresponding to the point Cmn _p5, namely, the point Cmn _p5 is the same as the X coordinate of the point Cmn _p11;

if n is an even number, a point C1n _p11 corresponding to the point C1n _p5, that is, the point C1n _p5 has the same X coordinate as the point C1n _p11 is generated.

(4) Generating a middle point of the third rectangular side BC: determining at least one ninth coordinate point on the third rectangular side based on the third coordinate point of each round hole of the 1 st row in the preset rectangular area; determining at least one tenth coordinate point on the third rectangular side based on the fourth coordinate point of each round hole of the 1 st row in the preset rectangular area; and determining an eleventh coordinate point on the third rectangular side based on the sixth coordinate point of the round hole of the 1 st row and the m-th column in the preset rectangular area.

Specifically, as shown in fig. 10, the point corresponding to the point Ci1 _p3 (where i=1, m, 1) is Ci1 _p9, that is, the point Ci1 _p3 is the same as the X coordinate of the point Ci1 _p9; the point corresponding to the point Ci1 _p4 (where i=1, m, 1) is Ci1 _p10, i.e., the point Ci1 _p4 is the same as the X coordinate of the point Ci1 _p10; the point corresponding to point Cm1 _p6 is Cm1 _p11, i.e. point m1 _p6 is the same X coordinate as point Cm1 _p11.

Next, a third area A7 is created from the created points, including:

(one) create part 1 quadrilateral area of A7 (i.e., area adjacent to AB): determining at least one third area characterizing a closed region within each closed loop formed by the second coordinate point, the third coordinate point, the second circular arc edge, the seventh coordinate point and the eighth coordinate point of each circular hole of a j+1 th row and column in the preset rectangular region, the fifth coordinate point, the sixth coordinate point, the seventh coordinate point and the eighth coordinate point of each circular hole of a j+2 th row and column in the preset rectangular region, and the third coordinate point and the eighth coordinate point of each circular hole of a j+2 th row and column in the preset rectangular region, based on the at least one seventh coordinate point, the at least one eighth coordinate point, the second coordinate point, the third coordinate point and the sixth coordinate point.

Specifically, as shown in fig. 11, the third area A7 is a quadrangular area adjacent to the first rectangular side AB, that is, a quadrangular area having points P7, P8 of PA, PB and 1 st row circular holes as vertices.

The closed area in each closed ring is formed by a second coordinate point P2, a third coordinate point P3, a second circular arc edge l ₂, a seventh coordinate point P7, an eighth coordinate point P8, a fifth coordinate point P5, a sixth coordinate point P6, a seventh coordinate point P7 and an eighth coordinate point P8 of each circular hole in the j+1th row and column, and a third coordinate point P3 and an eighth coordinate point P8 of each circular hole in the j+2th row and column.

For example, in fig. 11, the closed region formed between the circle C11, the circle C12, and the circle C13 is formed by closed loops of the second coordinate point C11 _p2, the third coordinate point C11 _p3, the second circular arc side l ₂, the seventh coordinate point C11 _p7, the eighth coordinate point C11 _p8, the fifth coordinate point C12 _p5, the sixth coordinate point C12 _p6, the seventh coordinate point C12 _p7, and the eighth coordinate point C12 _p8 of the circle C11, and the third coordinate point C13 _p3 and the eighth coordinate point C13 _p8 of the circle C13.

In an alternative embodiment, the third area A7 is formed by a plurality of such closed areas.

As shown in fig. 11, each closed loop region involves 3 different circular holes and contains 4 different regions. For example, the closed area formed between circles C11, C12, and C13 includes the area formed by C11 _p2、C11_p3、l₂、C11_p7、C11_p8; c11 _p7、C11_p8、C11_p2、C12_p6 is a quadrilateral area of vertices; c12 _p7、C12_p8、C12_p5、C12_p6 is a quadrilateral area with vertices and C12- _p7、C12_p8、C13_p8、C13_p3 is a quadrilateral area with vertices.

According to the different positions of the rows and the columns of the 4 different round holes, the creation methods of the 4 different areas are different, and the specific steps are as follows:

If n is an even number:

for the circles C1j of the odd rows (where j=1, n-1, 2), a quadrangular area with C1j _p8、C1j_p7、C1j_p2、C1j_p3 as the vertex and a quadrangular area with C1j _p7、C1(j+1)_p8、C1(j+1)_p6、C1j_p2 as the vertex are generated, respectively;

for even rows of circles C1j (where j=2, n-2, 2), generating a quadrilateral area with C1j _p8、C1j_p7、C1j_p5、C1j_p6 as the vertex and a quadrilateral area with C1j _p7、C1(j+1)_p8、C1(j+1)_p3、C1j_p5 as the vertex, respectively;

For a circle C1n of even lines, generating a quadrilateral area with C1n _p8、C1n_p7、C1n_p5、C1n_p6 as a vertex and a quadrilateral area with C1n _p7、PA、C1n_p11、C1n_p5 as a vertex;

If n is an odd number:

for the odd-numbered circles C1j (where j=1, n-2, 2), generating a quadrangular area with C1j _p8、C1j_p7、C1j_p2、C1j_p3 as the vertex and a quadrangular area with C1j _p7、C1(j+1)_p8、C1(j+1)_p6、C1j_p2 as the vertex, respectively;

For even rows of circles C1j (where j=2, n-1, 2), generating a quadrilateral area with C1j _p8、C1j_p7、C1j_p5、C1j_p6 as the vertex and a quadrilateral area with C1j _p7、C1(j+1)_p8、C1(j+1)_p3、C1j_p5 as the vertex, respectively;

For the circles C1n of the odd rows, a quadrangular area having C1n _p8、C1n_p7、C1n_p2、C1n_p3 as a vertex is generated.

The part 1 quadrilateral area of A7 (i.e., adjacent to AB) further includes: determining a third area based on the third coordinate point, the eighth coordinate point, the ninth coordinate point and the second end point of the multi-round hole planar metal mesh of the 1 st row and 1 st column in the preset rectangular area; and determining a third area based on the second coordinate point, the seventh coordinate point, the ninth coordinate point and the first end point of the multi-round hole planar metal mesh of the nth row and the 1 st column in the preset rectangular area.

In particular, the method comprises the steps of,

① Generating a quadrilateral area taking C11 _p3、C11_p8、C11_p9 and PB as vertexes;

② For a circle C1n of an odd number row (n is an odd number), a quadrangular area having C1n _p7、PA、C1n_p9、C1n_p2 as a vertex is generated.

(II) create part 2 quadrilateral area of A7 (i.e., area adjacent to CD): determining at least one third area characterizing a closed region within each closed ring formed by the fifth coordinate point and the eighth coordinate point of each round hole of a j-th row and m-th column in the preset rectangular region based on the at least one seventh coordinate point, the at least one eighth coordinate point, the first coordinate point, the fourth arc side, the seventh coordinate point and the eighth coordinate point, the fifth coordinate point of each round hole of a j-th row and m-th column in the preset rectangular region, the sixth coordinate point, the seventh coordinate point and the eighth coordinate point, the first coordinate point of each round hole of a j+1th row and m-th column in the preset rectangular region, the fourth arc side, the seventh coordinate point and the eighth coordinate point, and the sixth coordinate point of each round hole of a j+2th row and m-th column

Specifically, as shown in fig. 11, the closed region in each closed loop is formed by a fifth coordinate point P5, a sixth coordinate point P6, a seventh coordinate point P7, and an eighth coordinate point P8 of each circular hole of the jth row and the mth column, a first coordinate point P1, a fourth coordinate point P4, a fourth circular arc edge l ₄, a seventh coordinate point P7, and an eighth coordinate point P8 of each circular hole of the jth+1th row and the mth column, and a sixth coordinate point P6 and an eighth coordinate point P8 of each circular hole of the jth+2row and the mth column.

For example, in fig. 11, the closed area formed between the circle Cm1, the circle Cm2, and the circle Cm3 is formed by a closed loop of the fifth coordinate point Cm1 _p5, the sixth coordinate point Cm1 _p6, the seventh coordinate point Cm1 _p7, the eighth coordinate point Cm1 _p8, the first coordinate point Cm2 _p1, the fourth coordinate point Cm2 _p4, the fourth circular arc edge l ₄, the seventh coordinate point Cm2 _p7, the eighth coordinate point Cm2 _p8, and the sixth coordinate point Cm3 _p6 and the eighth coordinate point Cm3 _p8 of the circle Cm 3.

As shown in fig. 11, each closed loop region involves 3 different circular holes and contains 4 different regions. For example, the closed area formed between circles Cm1, cm2, and Cm3 includes: cm1 _p5、Cm1_p6、Cm1_p7、Cm1_p8 is the quadrilateral area of the vertex; cm1 _p5、Cm1_p7、Cm2_p4、Cm2_p8 is the quadrilateral area of the vertex, and Cm2 _p1、Cm2_p4、l₄、Cm2_p7、Cm2_p8 forms the area; cm2 _p1、Cm2_p7、Cm3_p6、Cm3_p8 is the quadrilateral area of the vertex.

If n is an even number:

For the odd rows of circles Cmj (where j=1, n-1, 2), a quadrilateral area with Cmj _p8、Cmj_p7、Cmj_p5、C1j_p6 as the vertex and a quadrilateral area with Cmj _p7、Cm(j+1)_p8、Cm(j+1)_p4、Cmj_p5 as the vertex are generated, respectively;

for even rows of circles Cmj (where j=2, n-2, 2), a quadrilateral area with Cmj _p8、Cmj_p7、Cmj_p1、Cmj_p4 as the vertex and a quadrilateral area with Cmj _p7、Cm(j+1)_p8、Cm(j+1)_p6、Cmj_p1 as the vertex are generated, respectively;

For even rows of circles Cmj (where j=n), a quadrilateral area with Cmj _p8、Cmj_p7、Cmj_p1、Cmj_p4 as the vertex and a quadrilateral area with Cmj _p7、PD、Cmj_p10、Cmj_p1 as the vertex are generated, respectively.

If n is an odd number:

for the odd rows of circles Cmj (where j=1, n-2, 2), a quadrilateral area with Cmj _p8、Cmj_p7、Cmj_p5、Cmj_p6 as the vertex and a quadrilateral area with Cmj _p7、Cm(j+1)_p8、Cm(j+1)_p4、Cmj_p5 as the vertex are generated, respectively;

For even rows of circles Cmj (where j=2, n-1, 2), a quadrilateral area with Cmj _p8、Cmj_p7、Cmj_p1、Cmj_p4 as the vertex and a quadrilateral area with Cmj _p7、Cm(j+1)_p8、Cm(j+1)_p6、Cmj_p1 as the vertex are generated, respectively;

for the odd-numbered rows of circles Cmj (where j=n), a quadrilateral area with Cmj _p8、Cmj_p7、Cmj_p5、Cmj_p6 as the vertex is generated.

Creating the part 2 quadrilateral area of A7 (i.e., the area adjacent to the CD) further comprises: determining a third area based on the sixth coordinate point, the eighth coordinate point, the eleventh coordinate point and the fourth end point of the multi-round hole planar metal mesh of the 1 st row and the m th column in the preset rectangular area; and determining a third area based on the fifth coordinate point, the seventh coordinate point, the eleventh coordinate point and the third end point of the multi-round hole planar metal mesh of the nth row and the mth column in the preset rectangular area.

In particular, the method comprises the steps of,

① Generating a quadrilateral area with Cm1 _p6、Cm1_p8、Cm1_p11 and PC as vertexes;

② For the circles Cmn of the odd rows, a quadrangular area with Cmn _p7、PD、Cmn_p11、Cmn_p5 as the vertex is generated.

(III) creating a part 3 quadrilateral area of A7 (i.e., an area adjacent to AD): and determining at least one third area based on the fifth coordinate point, the at least one ninth coordinate point, the at least one tenth coordinate point, the eleventh coordinate point, the first coordinate point and the second coordinate point, wherein the third area comprises a closed area in each closed loop formed by the first coordinate point, the second coordinate point, the first circular arc edge, the ninth coordinate point, the tenth coordinate point, the second coordinate point of each circular hole in the nth row and the (j+1) th column in the preset rectangular area, and a closed area in each closed loop formed by the tenth coordinate point, the first coordinate point, the fifth coordinate point and the eleventh coordinate point of each circular hole in the nth row and the (m+1) th column in the preset rectangular area.

Specifically, as shown in fig. 11, the third face region includes a closed region within each closed loop formed by a first coordinate point P1, a second coordinate point P2, a first circular arc edge l ₁, a ninth coordinate point P9, a tenth coordinate point P10, a second coordinate point P2, and a ninth coordinate point P9 of each circular hole of the nth row and the j+1th column;

For example, a closed region formed between the circles C1n and C2n in fig. 11 includes a quadrangular region formed by the first coordinate point C1n _p1, the second coordinate point C1n _p2, the first circular arc side l ₁, the ninth coordinate point C1n _p9, the tenth coordinate point C1n _p10 of the circle C1n, and a quadrangular region formed by the first coordinate point C1n _p1, the tenth coordinate point C1n _p10, the second coordinate point C2n _p2 and the ninth coordinate point C2n _p9 of the circle C1 n.

The third face region further includes a closed region within a closed loop formed by a tenth coordinate point P10, a first coordinate point P1, a fifth coordinate point P5, and an eleventh coordinate point P11 of the circular hole of the nth row and mth column.

For example, in fig. 11, the third area corresponding to the circle Cmn is a quadrilateral area with Cmn _p1、Cmn_p10、Cmn_p11、Cmn_p5 as the vertex.

For different areas, the creation methods of the different areas are different according to the difference of the number of rows and the number of columns, and the specific steps are as follows:

If n is an even number:

(1) Generating a quadrilateral area taking C1n _p11、C1n_p5、C1n_p2、C1n_p9 as a vertex;

(2) For a circle Cin (where i=1, m-1, 1), generating a quadrangular region with Cin _p1、Cin_p2、Cin_p9、Cin_p10 as a vertex and a quadrangular region with Cin _p1、Cin_p10、C(i+1)n_p9、C(i+1)n_p2 as a vertex, respectively;

(3) For a circle Cin (where i=m), a quadrilateral area with Cin _p1、Cin_p2、Cin_p9、Cin_p10 as the vertex is generated.

If n is an odd number:

(1) For a circle Cin (where i=1, m-1, 1), generating a quadrangular region with Cin _p1、Cin_p2、Cin_p9、Cin_p10 as a vertex and a quadrangular region with Cin _p1、Cin_p10、C(i+1)n_p9、C(i+1)n_p2 as a vertex, respectively;

(2) For a circle Cin (where i=m), a quadrangular area with Cin _p1、Cin_p2、Cin_p9、Cin_p10 as a vertex and a quadrangular area with Cin _p1、Cin_p10、Cin_p11、Cin_p5 as a vertex are generated, respectively.

(IV) creating part 4 quadrilateral area of A7 (i.e., area adjacent to BC): determining at least one third area based on the sixth coordinate point, the at least one ninth coordinate point, the at least one tenth coordinate point, the eleventh coordinate point, the third coordinate point, and the fourth coordinate point, the third area including the third coordinate point, the fourth coordinate point, the third circular arc side, the ninth coordinate point, the tenth coordinate point, a closed area within each closed loop formed by the third coordinate point and the ninth coordinate point of each circular hole of the 1 st row and the 1 st column in the preset rectangular area, and the tenth coordinate point, the fourth coordinate point, the sixth coordinate point, and the closed area within the closed loop formed by the circular hole of the 1 st row and the m column in the preset rectangular area.

Specifically, as shown in fig. 11, the third face region includes a closed region within each closed loop formed by a third coordinate point P3, a fourth coordinate point P4, a third circular arc edge l ₃, a ninth coordinate point P9, and a tenth coordinate point P10 of each circular hole of the 1 st row and the j 1 st column, and the third coordinate point P3 and the ninth coordinate point P9 of each circular hole of the 1 st row and the j 1 st column;

For example, the closed region formed between the circles C11 and C21 in fig. 11 includes a quadrangular region formed by the third coordinate point C11 _p3, the fourth coordinate point C11 _p4, the third circular arc side l ₃, the ninth coordinate point C11 _p9, and the tenth coordinate point C11 _p10 of the circle C11, and a quadrangular region formed by the fourth coordinate point C11 _p4, the tenth coordinate point C11 _p10, the third coordinate point C21 _p3, and the tenth coordinate point C21 _p10 of the circle C11.

The third face region further includes a closed region within a closed loop formed by a tenth coordinate point P10, a fourth coordinate point P4, a sixth coordinate point P6, and an eleventh coordinate point P11 of the circular holes of the 1 st row and the m-th column.

For example, in fig. 11, the third area corresponding to the circle Cmn is a quadrangular area with C1m _p10、C1m_p4、C1m_p6、C1m_p11 as the vertex.

The creation methods of different areas are different, and specifically the method is as follows:

(1) For circle Ci1 (where i=1, m-1, 1), a quadrangular area with Ci1 _p3、Ci1_p4、Ci1_p10、Ci1_p9 as the vertex and a quadrangular area with Ci1 _p4、Ci1_p10、C(i+1)1_p9、C(i+1)1_p3 as the vertex are generated, respectively;

(2) For the circle Ci1 (where i=m), a quadrangular area with Ci1 _p3、Ci1_p4、Ci1_p10、Ci1_p9 as a vertex and a quadrangular area with Ci1 _p4、Ci1_p10、Ci1_p11、Ci1_p6 as a vertex are generated, respectively.

And carrying out cell division on each third surface domain to generate finite element surface cell grids with arbitrary density corresponding to each third surface domain.

Specifically, opposite sides (including straight lines and circular arcs) of each quadrangle are divided into the same equal number of segments (the number of segments should not be less than 2); the number of segments of adjacent edges can be the same or different; dividing each quadrilateral area by adopting a mapping method; the number of different equal segments on each side can be set according to the requirement, and the quadrilateral areas can be divided by adopting a mapping method or a non-mapping method.

In an alternative embodiment, the arrangement of the round holes in the preset rectangular area EFGH obtained in step 104 may further be: the second row of circular holes is offset by d ₁/2 in the negative X-axis direction relative to the first row of circular holes, as shown in FIG. 12.

The method for creating the finite element face unit grid of the multi-round hole plane metal mesh provided by the embodiment of the invention is also applicable to a round hole arrangement structure shown in fig. 12.

Although embodiments of the present invention have been described in connection with the accompanying drawings, various modifications and variations may be made by those skilled in the art without departing from the spirit and scope of the invention, and such modifications and variations fall within the scope of the invention as defined by the appended claims.

Claims

1. A method for creating a finite element face cell grid of a multi-round hole planar metal mesh, the method comprising:

Creating a round hole in a first row of a preset rectangular area of the multi-round hole planar metal mesh, taking an origin of the round hole as a coordinate, taking a horizontal diameter of the round hole as an X axis and a vertical diameter of the round hole as a Y axis, building a corresponding coordinate system in the round hole, and determining four coordinate points and four sections of circular arc sides in the round hole based on the coordinate system, wherein the X axis is right positive direction, the Y axis is positive direction, each coordinate point is respectively an intersection point of an angular bisector of four quadrants in the coordinate system corresponding to the round hole and the round hole, an arc is formed between every two adjacent coordinate points, the preset rectangular area is obtained by a preset processing method based on the round hole, the preset rectangular area comprises m round holes distributed along the horizontal direction and n round holes distributed along the vertical direction, m is more than or equal to 2, n is a positive integer, the radius of each round hole is r, the circle center distance of any two adjacent round holes in the m round holes is d ₁, and the distance between two adjacent round holes distributed along the horizontal direction is ₂,r＜min(d₁/2,d₂/2;

Obtaining at least one first surface area based on at least one coordinate point and/or at least one section of circular arc edge of each circular hole in the preset rectangular area through a preset first connection method, wherein the first surface area comprises a closed area in each closed ring formed between any adjacent circular holes in the preset rectangular area, each closed ring is composed of at least one coordinate point and/or at least one section of circular arc edge of each circular hole in the adjacent circular holes, and the preset first connection method is determined based on the specific arrangement position of each circular hole in the preset rectangular area and the at least one coordinate point and/or at least one section of circular arc edge of each circular hole;

and carrying out cell division on each first surface area to generate finite element surface cell grids with arbitrary density corresponding to each first surface area.

2. The method according to claim 1, wherein round holes in an i-th row and round holes in a j-th row in the preset rectangular area are staggered along a horizontal direction, a staggered distance is d ₁/2, i is even, j is odd, the four coordinate points comprise a first coordinate point, a second coordinate point, a third coordinate point and a fourth coordinate point, the first coordinate point is an intersection point of an angular bisector of a first quadrant and the round holes in the coordinate system, the second coordinate point is an intersection point of an angular bisector of a second quadrant and the round holes in the coordinate system, the third coordinate point is an intersection point of an angular bisector of a third quadrant and the round holes in the coordinate system, the fourth coordinate point is an intersection point of an angular bisector of a fourth quadrant and the round holes in the coordinate system, the fourth coordinate point includes a first arc edge, a second arc edge and a third arc edge, the first arc edge characterizes an intersection point of the first arc edge and the second arc edge, the third arc edge characterizes an arc between the first arc edge and the third arc edge, and the fourth arc edge characterizes an arc between the third arc edge and the arc;

The method further comprises the steps of:

Determining a fifth coordinate point and a sixth coordinate point corresponding to each round hole of the ith row and the first column in the preset rectangular area based on the second coordinate point and the third coordinate point of each round hole of the ith row and the first column in the preset rectangular area, wherein the fifth coordinate point is obtained by copying the second coordinate point and moving the second coordinate point leftwards in the horizontal direction, and the sixth coordinate point is obtained by copying the third coordinate point and moving the third coordinate point leftwards in the horizontal direction;

And carrying out cell division on each second surface area to generate finite element surface cell grids with arbitrary density corresponding to each second surface area.

3. The method of claim 2, wherein the four arc edges further comprise a fourth arc edge that characterizes an arc formed between the first coordinate point and the fourth coordinate point;

The method further comprises the steps of:

Determining a fifth coordinate point and a sixth coordinate point corresponding to each round hole in the jth row and the mth column in the preset rectangular area based on the first coordinate point and the fourth coordinate point of each round hole in the jth row and the mth column in the preset rectangular area, wherein the fifth coordinate point is obtained by copying the first coordinate point and moving the first coordinate point to the right in the horizontal direction, and the sixth coordinate point is obtained by copying the fourth coordinate point and moving the fourth coordinate point to the right in the horizontal direction;

Determining at least one second area based on the first coordinate point, the fourth coordinate point, the fifth coordinate point and the sixth coordinate point, wherein the second area represents a closed area in each closed loop formed by the fifth coordinate point, the sixth coordinate point, the first coordinate point, the fourth circular arc edge, the fourth coordinate point of each circular hole in the j+1th row and m-th column, the second circular arc edge, the third circular arc edge and the fourth coordinate point of each circular hole in the j+2th row and m-th column in the preset rectangular area;

4. The method of claim 3, wherein the multi-round planar metal mesh is comprised of a first rectangular side, a second rectangular side, a third rectangular side, and a fourth rectangular side, including a first end point, a second end point, a third end point, and a fourth end point, the first rectangular side characterizing a long side in a vertical direction formed between the first end point and the second end point in the multi-round planar metal mesh; the method further comprises the steps of:

Determining at least one seventh coordinate point on the first rectangular side based on the second coordinate point of each round hole of the 1 st column in the preset rectangular area;

determining at least one eighth coordinate point on the first rectangular side based on the third coordinate point of each round hole of the 1 st column in the preset rectangular area;

Determining at least one third area characterizing a closed region within each closed loop formed by the second coordinate point, the third coordinate point, the second circular arc edge, the seventh coordinate point and the eighth coordinate point of each circular hole of a j+1 th row and column in the preset rectangular region, the fifth coordinate point, the sixth coordinate point, the seventh coordinate point and the eighth coordinate point of each circular hole of a j+2 th row and column in the preset rectangular region, based on the at least one seventh coordinate point, the at least one eighth coordinate point, the second coordinate point, the third coordinate point and the sixth coordinate point;

5. The method of claim 4, wherein the fourth rectangular edge characterizes another long edge in the vertical direction formed between a third end point and a fourth end point in the multi-round hole planar metal mesh; the method further comprises the steps of:

determining at least one seventh coordinate point on the fourth rectangular side based on the first coordinate point of each round hole of the mth column in the preset rectangular area;

determining at least one eighth coordinate point on the fourth rectangular side based on the fourth coordinate point of each round hole of the m-th column in the preset rectangular area;

Determining at least one third area characterizing a closed region within each closed loop formed by the fifth coordinate point, the sixth coordinate point, the seventh coordinate point and the eighth coordinate point of each round hole of a j+1th row and column in the preset rectangular region, the first coordinate point, the fourth circular arc edge, the seventh coordinate point and the eighth coordinate point of each round hole of a j+2th row and column in the preset rectangular region, based on the at least one seventh coordinate point, the at least one eighth coordinate point, the first coordinate point, the fourth coordinate point, the fifth coordinate point and the sixth coordinate point of each round hole of a j-th row and column in the preset rectangular region;

6. The method of claim 5, wherein the second rectangular edge characterizes a short edge in a vertical direction formed between a first end point and a third end point in the multi-round hole planar metal mesh; the method further comprises the steps of:

Determining at least one ninth coordinate point on the second rectangular side based on the second coordinate point of each round hole of the nth row in the preset rectangular area;

Determining at least one tenth coordinate point on the second rectangular side based on the first coordinate point of each round hole of the nth row in the preset rectangular area;

determining an eleventh coordinate point on the second rectangular side based on the fifth coordinate point of the circular hole of the nth row and the mth column in the preset rectangular area;

Determining at least one third area including the first coordinate point, the second coordinate point, the first circular arc side, the ninth coordinate point, the tenth coordinate point, a closed area within each closed loop formed by the second coordinate point and the ninth coordinate point of each circular hole of the nth row and the jth column in the preset rectangular area, and the tenth coordinate point, the first coordinate point, the fifth coordinate point and the closed area within each closed loop formed by the ninth coordinate point, the second coordinate point and the ninth coordinate point of each circular hole of the nth row and the jth column in the preset rectangular area based on the fifth coordinate point, the at least one ninth coordinate point, the at least one tenth coordinate point, the first coordinate point and the second coordinate point;

7. The method of claim 6, wherein the third rectangular edge characterizes another short edge in a vertical direction formed between the second end point and the fourth end point in the multi-round hole planar metal mesh; the method further comprises the steps of:

Determining at least one ninth coordinate point on the third rectangular side based on the third coordinate point of each round hole of the 1 st row in the preset rectangular area;

Determining at least one tenth coordinate point on the third rectangular side based on the fourth coordinate point of each round hole of the 1 st row in the preset rectangular area;

determining an eleventh coordinate point on the third rectangular side based on the sixth coordinate point of the round hole of the 1 st row and the m-th column in the preset rectangular area;

Determining at least one third area including the third coordinate point, the fourth coordinate point, the third circular arc side, the ninth coordinate point, the tenth coordinate point, a closed area within each closed loop formed by the third coordinate point and the ninth coordinate point of each circular hole of the 1 st row and the 1 st column in the preset rectangular area, and the tenth coordinate point, the fourth coordinate point, the sixth coordinate point and the closed area within each closed loop formed by the fourth coordinate point, the third coordinate point of each circular hole of the 1 st row and the 1 st column in the preset rectangular area based on the sixth coordinate point, the at least one ninth coordinate point, the at least one tenth coordinate point, the eleventh coordinate point, the third coordinate point and the fourth coordinate point;

8. The method of claim 7, wherein the method further comprises:

Determining a third area based on the third coordinate point, the eighth coordinate point, the ninth coordinate point and the second end point of the multi-round hole planar metal mesh of the 1 st row and 1 st column in the preset rectangular area;

Determining a third area based on the sixth coordinate point, the eighth coordinate point, the eleventh coordinate point and the fourth end point of the multi-round hole planar metal mesh of the 1 st row and the m th column in the preset rectangular area;

Determining a third area based on the second coordinate point, the seventh coordinate point, the ninth coordinate point and the first end point of the multi-round hole planar metal mesh of the nth row and the 1 st column in the preset rectangular area;

Determining a third area based on the fifth coordinate point, the seventh coordinate point, the eleventh coordinate point and the third end point of the multi-round hole planar metal mesh of the nth row and the mth column in the preset rectangular area;