JPH10289257A - Three-dimensional mesh correcting method, transformational analyzing device and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct nodes on a three-dimensional mesh surface that includes collapsed elements to prevent analysis precision from deteriorating due to the three-dimensional mesh that includes collapsed elements in three-dimensional transformational analysis due to a finite-element method. SOLUTION: A surface node extracting part 1 extracts the data of nodes existing on the surface of a three-dimensional mesh based on three-dimensional mesh data which are stored in a 1st data file 9 and include collapsed elements, and store it in a surface node data file 5. A move node designating part 2 designates a node (move node) of a move correction object among extracted nodes, and a free curved surface/free curve generating part 3 generates a free curved surface or a free curve with the move node and its ambient node group and stores it in a free curved surface/free curve data file 6. A designation node moving part 4 moves the move node on the generated free curved surface or free curve, corrects three-dimensional mesh and stores the three-dimensional mesh after correction in a 2nd data file 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a three-dimensional mesh as an aggregate of a plurality of elements made of a polyhedron and performs a three-dimensional deformation analysis by a finite element method. The present invention relates to a method of correcting a three-dimensional mesh for preventing the analysis accuracy from being deteriorated by the three-dimensional mesh, a deformation analysis device using the method, and a recording medium on which a computer program for executing the method is recorded.

[0002]

2. Description of the Related Art In the analysis by the finite element method, an object to be analyzed is divided into small polygonal or polyhedral finite regions called elements and replaced with a mesh as an aggregate of these elements, and a material constant is assigned to this. Further, by solving a balancing equation obtained by giving boundary conditions such as constraints and loads, the displacement, strain, and distortion generated in each element in the mesh when the object to be analyzed is deformed by applying a reduction or the like. It is performed in a procedure for obtaining a change in a physical quantity such as a stress.

The types of elements used for deformation analysis are triangular and quadratic in two-dimensional analysis, and four in three-dimensional analysis.
There are each element of a face, a pentahedron, and a hexahedron. It is known that the shapes of these elements greatly affect the analysis accuracy by the finite element method. That is, in order to improve the analysis accuracy by the finite element method, a two-dimensional mesh of a regular polygon (regular triangular or square) element is used in the two-dimensional analysis, and a three-dimensional mesh of a regular polyhedron (regular tetrahedron or cube) is used in the three-dimensional analysis. A dimensional mesh is needed.

For example, in many metal plastic working processes typified by metal forging and the like, since the amount of deformation from a material to a final product is large, the amount of reduction of a die until the final deformation in an actual process is reached. During the execution of the analysis operation that continues while increasing stepwise, some of the elements in the mesh generated for the material before machining are greatly deformed, and extremely crushed elements occur, and subsequent analysis is performed Accuracy deteriorates.

For this reason, conventionally, when an element that has been partially collapsed occurs in the mesh during the analysis, the continuation of the analysis is temporarily suspended, and the mesh is corrected for the analysis target including the collapsed element at that time. Then, the analysis is restarted using the corrected mesh, thereby avoiding the above-described deterioration in accuracy.

[0006] Such a mesh correction method includes a method of performing a new mesh division on the shape of the surface of the mesh in which the collapsed element has occurred, and a method of moving a node of the mesh in which the collapsed element has occurred. There is a method of repeating the local shape operation, that is, the modification of the mesh.

[0007] As a conventional method of correcting a deformed two-dimensional mesh, a “Laplacian-isoparametric grid generat” is used.
ion scheme ”JMCEA, (1976), pp.749-756, there is a method of smoothing (modifying the mesh by moving nodes, etc.) by the Laplace method / isoparametric method. Nodes inside the mesh are smoothed, and smoothing by the Laplace method / isoparametric method is 3
A method of expanding to a three-dimensional mesh and smoothing nodes inside the three-dimensional mesh has also been proposed in, for example, JP-A-3-29057.

[0008] Another smoothing method disclosed in Japanese Patent Application Laid-Open No. 4-268674, which is known as a conventional technique, is as follows.
It is as follows. FIG. 8 is a diagram for explaining the method.
It is a schematic diagram of a dimensional mesh. When optimizing the mesh division, the position of the node after optimization is determined by the position of the center of gravity of the four surface elements a, b, c, and d related to the node A and the movement weight of the element determined by the stress and the like. Decided. However, the positions of the nodes after the optimization deviate from the original curved surface.
Therefore, these surface elements a, b, c, and d are projected onto a coordinate plane in the direction of the maximum component of the normal vector of the surface to be two-dimensional,
Based on the two-dimensional coordinates of each of the nodes constituting the four-dimensional surface elements, the moved node is placed on a curved surface passing through the eight nodes B to I excluding the moving nodes of the four surface elements. Correct to ride.

[0009]

In the three-dimensional deformation analysis by the finite element method, as described above, in order to prevent the three-dimensional mesh including the crushed element from deteriorating the analysis accuracy, the three-dimensional mesh including the crushed element is used. Need to be corrected. In a method generally used as this correction technique, in which nodes inside the three-dimensional mesh including crushed elements are smoothed, since the nodes on the surface of the three-dimensional mesh are fixed, the mesh near the surface is There is a problem that is hardly fixed.

When smoothing is performed not only on the nodes inside the three-dimensional mesh including the crushed elements but also on the nodes on the surface, the shape of the elements near the surface can be corrected. For example, in the method disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 4-268674, when a three-dimensional mesh including a crushed element is a lattice mesh, nodes on the surface of the mesh are mapped on a plane and smoothed, Nodes on the surface are smoothed by inverse mapping on the surface of the mesh.

However, the methods disclosed in the above-mentioned JP-A-3-29057 and JP-A-4-268674 target a special three-dimensional mesh of hexahedral elements arranged regularly. In other words, the methods disclosed in these two publications employ a grid-like arrangement as shown in FIG.
Although it can be applied to a special three-dimensional grid mesh of a face element, a general three-dimensional non-grid mesh of a hexahedral element not arranged in a grid and a four-dimensional mesh of four elements as shown in FIGS.
It cannot be applied to a three-dimensional mesh in which three-dimensional elements such as a face, a pentahedron and a hexahedron are mixed. As described above, conventionally, there is a problem that the shape of the target three-dimensional mesh is limited.

The present invention has been made in view of such circumstances, and includes three-dimensional deformation analysis using the finite element method, which includes a crushed element in order to prevent deterioration in analysis accuracy due to a three-dimensional mesh including the crushed element. A method of correcting nodes on the surface of a three-dimensional mesh, and a device used for implementing the method, particularly suitable for use when a relatively large deformation occurs in a metal die forging or the like, and a hexahedron A method for correcting a three-dimensional mesh applicable to a three-dimensional non-mesh mesh of elements and a three-dimensional mesh in which tetrahedral, pentahedral, and hexahedral elements are mixed, a deformation analysis device using this method, and the method are implemented. It is an object of the present invention to provide a recording medium on which a computer program for recording is recorded.

[0013]

According to a first aspect of the present invention, there is provided a method of correcting a three-dimensional mesh, comprising: a collection of a plurality of elements each comprising a polyhedron, the analysis object being represented by a three-dimensional mesh having a plurality of nodes. A method of correcting a three-dimensional mesh including a crushed element when a part of the element is crushed with the progress of the deformation during the execution of the numerical analysis with the three-dimensional deformation includes the crushed element. Extracting a node existing on the surface of the three-dimensional mesh; generating a free-form surface defined by one specified node and a group of nodes around the extracted node; Moving on a curved surface.

According to a third aspect of the present invention, there is provided a method for modifying a three-dimensional mesh, comprising a set of a plurality of polyhedral elements and a numerical value accompanied by a three-dimensional deformation of an object to be analyzed represented by a three-dimensional mesh having a plurality of nodes. A method for correcting a three-dimensional mesh including a crushed element when a part of the element is crushed as the deformation proceeds while performing the analysis, the method comprising: Extracting an existing node, generating a free curve defined by one specified node and a group of nodes around the extracted node, and moving the specified node on the free curve And characterized in that:

According to a third aspect of the present invention, in the method for modifying a three-dimensional mesh according to the first or second aspect, the three-dimensional mesh is a three-dimensional lattice mesh composed entirely of hexahedral elements, and the entirety is hexahedral elements. And a three-dimensional mesh in which elements of tetrahedron, pentahedron, and hexahedron are mixed.

According to a fourth aspect of the present invention, there is provided a deformation analyzing apparatus for performing a three-dimensional deformation analysis of an object to be analyzed using a three-dimensional mesh having a plurality of nodes, which is an aggregate of a plurality of elements formed of a polyhedron. A means for extracting a node existing on the surface of the three-dimensional mesh including the crushed element when a part of the element is crushed; a means for specifying one node from the extracted nodes; It is characterized by comprising means for generating a free-form surface defined by one node and a group of nodes around the node, and means for moving the designated node on the free-form surface.

According to a fifth aspect of the present invention, there is provided a deformation analysis apparatus for performing a three-dimensional deformation analysis of an object to be analyzed using a three-dimensional mesh having a plurality of nodes, which is an aggregate of a plurality of elements formed of a polyhedron. A means for extracting a node existing on the surface of the three-dimensional mesh including the crushed element when a part of the element is crushed; a means for specifying one node from the extracted nodes; It is characterized by comprising means for generating a free curve defined by one node and a group of nodes around the node, and means for moving the specified node on the free curve.

According to a sixth aspect of the present invention, during the execution of a numerical analysis involving a three-dimensional deformation of an object to be analyzed represented by a three-dimensional mesh having a plurality of nodes, which is an aggregate of a plurality of elements made of a polyhedron. In addition, when a part of the element is crushed as the deformation proceeds, the crushed element includes the crushed element.
Extracting a node existing on the surface of the three-dimensional mesh including a crushed element in a recording medium on which a computer program for correcting the three-dimensional mesh is recorded; and inputting a designation for specifying one node from the extracted nodes. Receiving and specifying one node;
Generating a free-form surface defined by two nodes and a group of nodes around the node, and receiving the input for moving the specified node on the free-form surface, and moving the specified node. A computer program is recorded.

According to a seventh aspect of the present invention, during the execution of a numerical analysis involving a three-dimensional deformation of an object to be analyzed represented by a three-dimensional mesh having a plurality of nodes, which is an aggregate of a plurality of elements made of a polyhedron. In addition, when a part of the element is crushed as the deformation proceeds, the crushed element includes the crushed element.
Extracting a node existing on the surface of the three-dimensional mesh including a crushed element in a recording medium on which a computer program for correcting the three-dimensional mesh is recorded; and inputting a designation for specifying one node from the extracted nodes. Receiving and specifying one node;
Generating a free curve defined by two nodes and a group of nodes around the node, and receiving the input for moving the specified node on the free curve, and moving the specified node. A computer program is recorded.

A recording medium according to claim 8 is a computer for performing a three-dimensional deformation analysis of an object to be analyzed by using a three-dimensional mesh having a plurality of nodes, which is an aggregate of a plurality of elements formed of a polyhedron. A program for causing a computer to extract nodes existing on the surface of a three-dimensional mesh including a crushed element when a part of the element is crushed in a recording medium having readable program code means. Code means, program code means for causing the computer to generate a free-form surface defined by one node designated by external input from the extracted nodes and a group of surrounding nodes, and Program code means for causing the computer to move in accordance with an external input on the free-form surface. And wherein the Rukoto.

A recording medium according to a ninth aspect is a computer for performing a three-dimensional deformation analysis of an object to be analyzed by using a three-dimensional mesh having a plurality of nodes, which is an aggregate of a plurality of elements formed of a polyhedron. A program for causing a computer to extract nodes existing on the surface of a three-dimensional mesh including a crushed element when a part of the element is crushed in a recording medium having readable program code means. Code means, program code means for causing the computer to generate a free curve defined by one node designated by external input from the extracted nodes and a group of surrounding nodes, and Program code means for causing the computer to move in accordance with an external input on the free curve. And wherein the Rukoto.

In the present invention, when a part of an element is crushed during the execution of the numerical analysis using the three-dimensional mesh, a node existing on the surface of the three-dimensional mesh including the crushed element is extracted. Next, one of the extracted nodes is designated as a node to be moved and corrected, and a free-form surface or a free curve defined by the specified node to be moved and modified and a group of surrounding nodes is generated. Then, the node to be moved and corrected is moved on this free-form surface or free curve. In the present invention, as described above, the node to be moved and corrected is moved on a free-form surface or a free curve defined by an arbitrary group of nodes around the node to correct the three-dimensional mesh. A special three-dimensional mesh, consisting of three regular hexahedral elements arranged in a grid.
Not only applicable to three-dimensional meshes, but also three-dimensional meshes of non-lattice-shaped hexahedral elements that are not arranged in a grid, and a mixture of tetrahedral, pentahedral, and hexahedral three-dimensional elements that are general three-dimensional mesh It can be applied to a three-dimensional mesh.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments.

FIG. 1 is a block diagram showing a configuration of a three-dimensional mesh correcting apparatus according to the present invention. As shown in the figure, the three-dimensional mesh correction apparatus A of the present invention includes a surface node extraction unit 1 and
A moving node designation unit 2, a free-form surface / free-curve generation unit 3,
It comprises a designated node moving section 4, a surface node data file 5, and a free-form surface / free curve data file 6. An input unit 7 having a pointing device 8 such as a mouse is connected to the input side of the three-dimensional mesh correction apparatus A, and a display unit 11 such as a CRT display is connected to the output side. Furthermore, 3
A first data file 9 for storing three-dimensional mesh data including crushed elements is connected to an input side of the three-dimensional mesh correction apparatus A, and a second data file for storing the corrected three-dimensional mesh data is similarly stored on the output side. Data file 10 is connected.

The surface node extraction unit 1 extracts nodes existing on the surface of the three-dimensional mesh including the crushed element based on the three-dimensional mesh data including the crushed element stored in the first data file 9. . The data of the nodes existing on the surface of the extracted three-dimensional mesh is stored in the surface node data file 5. The moving node designation unit 2 displays the surface node data in the surface node data file 4 on the display unit 11 and, in response to an operation input from the input unit 7, a node to be moved and corrected (hereinafter referred to as a moving node). ).

The free-form surface / free-curve generating unit 3 generates a free-form surface or a free curve defined by a moving node and a group of nodes around the moving node. The data of the generated free-form surface or free-form curve is stored in the free-form surface / free-form curve data file 6.

The designated node moving section 4 displays the free curved surface or free curve data of the free curved surface / free curve data file 6 on the display section 11, and designates the designated moving node in response to an operation input from the input section 7. While moving on the display section 11 on a free-form surface or a free-form curve, the display section 11 is moved to correct a three-dimensional mesh including a crushed element. Note that when the designated moving node is moved, the movement is performed while dragging on a free-form surface or a free curve using the pointing device 8 of the input unit 7. The corrected three-dimensional mesh data is stored in the second data file 10.

Next, the operation of the present invention will be described. The present invention has the following first, second, and third steps. In the first step, the three-dimensional mesh data including the crushed elements stored in the first data file 9 is read out, and based on the data, the three-dimensional mesh data extracted by the surface node extraction unit 1 exists on the surface of the three-dimensional mesh. Is stored in the surface node data file 5. In the second step, the free-form surface / free-curve generating unit 3 generates a free-form surface or free-form curve based on the moving node designated by the moving-node designating unit 2 and a group of nodes around the moving node. It is stored in the curve data file 6. In the third step, the moving node is moved and corrected by the specified node moving unit 4, and the corrected three-dimensional mesh data is stored in the second data file 10.

Next, based on FIG. 2 to FIG.
The detailed processing of the steps will be described. FIG. 2 shows the first
It is a flowchart which shows the flow of a process in a step. In FIG. 2, the element surface number j of the element number i is expressed as F _ij, and it is assumed that F _ij = 0: not the surface of the mesh, and F _ij = 1: the surface of the mesh.

First, it is set that all surfaces of all elements are mesh surfaces (S1). Next, element number i ₁
It is determined whether or not the element surface number j ₁ of the element surface number j ₂ and the element surface number j ₂ of the element number i ₂ are the same surface based on whether the same node is shared (S2). If they are the same surface, 0 is stored since F _i1j1 and F _i2j2 are opposite surfaces and not the surface of the mesh (S3). It is checked whether the determination in S2 has been made for all elements (S4).
When the processing is completed for all the elements, the data of the nodes on the surface of the mesh existing on the element surface number j of the element number i with F _ij = 1 is stored in the surface node data file 5 (S
5).

FIG. 3 is a flowchart showing the flow of the process in the second step. First, the surface node data in the surface node data file 5 is displayed on the display unit 11, and the moving node is designated by the input unit 7 (S6). Next, the instruction of the input unit 7 for moving the designated moving node is
It is determined whether the instruction is to generate a free-form surface or a free curve (S7).

If the instruction is to generate a free-form surface,
A free-form surface is generated from the designated moving node and the surrounding nodes, and stored in the free-form surface / free curve data file 6 (S8). On the other hand, if the instruction is to generate a free curve, two or more arbitrary nodes are selected from a group of nodes around the specified moving node (S9). Next, a free curve is generated from the designated moving node and the selected node group, and stored in the free-form surface / free curve data file 6 (S10).

FIG. 4 is a flowchart showing the flow of the process in the third step. The data of the free-form surface or free-form curve in the free-form surface / free-form data file 6 is displayed on the display unit 11, and the pointing device 8 of the input unit 7 is used.
Thus, the designated moving node is moved while sequentially displaying the designated moving node on the free-form surface or the free curve, thereby correcting the three-dimensional mesh, and storing the corrected three-dimensional mesh data in the second data file 10 (S11). .

FIG. 5 is a diagram showing an example of movement of a designated moving node on a free-form surface. A node p indicated by a circle in FIG. 5A is a movement specified from a plurality of nodes existing on the surface of the three-dimensional mesh extracted by the surface node extraction unit 1 based on the data of the first data file 9. It is a node. The free-form surface s shown in FIG. 5B is defined by a moving node p and a group of nodes q indicated by ● around the moving node p. At this time, an intermediate node is provided between the moving node p and the surrounding nodes,
A free-form surface s may be defined as the node group q, and the node group is selected by the pointing device 8 and the node group q
May be defined as a free-form surface s. The broken line on the free-form surface s in the figure is an auxiliary line for indicating that the free-form surface s is a curved surface, and does not mean a lattice. Then, as shown in FIG. 5C, the moving node p is dragged and moved by the pointing device 8 on the free-form surface s.

FIG. 6 is a diagram showing an example of movement of a designated moving node on a free curve. A node p indicated by a circle in FIG. 6A is a movement specified from a plurality of nodes existing on the surface of the three-dimensional mesh extracted by the surface node extraction unit 1 based on the data of the first data file 9. It is a node. A free curve c shown in FIG. 6B is defined by a moving node p and a group of two or more nodes q indicated by marks ● around the moving node p. At this time, an intermediate node may be provided between the node p to be moved and the surrounding nodes, and a free curve c may be defined as the node group q. Alternatively, the node may be selected by the pointing device 8 and the node group q may be freely selected. Curve c may be defined.
Further, a free curve c passing through the node p to be moved may be defined from the free curved surface s defined by the node p to be moved and the surrounding node group q. Then, as shown in FIG. 6C, the moving node p is dragged and moved by the pointing device 8 on the free curve c.

The use of a free curve has the following advantages. If the node to be moved and modified exists on the ridge line of the 3D mesh, if this node is moved on a free curve defined by the nodes of the ridge line of the 3D mesh, the external shape of the 3D mesh Can be held.

According to the above-described method, a moving node specified from nodes extracted as nodes existing on the surface of the three-dimensional mesh is converted into a free-form surface or a free-form surface defined by the moving node and surrounding nodes. By moving on a free curve, a three-dimensional mesh including a crushed element can be modified.

In order to correct a three-dimensional mesh by moving a designated moving node on a free-form surface or a free curve, the correction method of the present invention uses a special three-dimensional mesh of hexahedral elements regularly arranged in a grid. Can be applied. The present invention is also applicable to a general three-dimensional mesh of hexahedral elements not arranged in a grid (non-lattice) and a three-dimensional mesh in which three-dimensional elements such as tetrahedron, pentahedron, and hexahedron are mixed. The correction method is applicable, and there is no restriction on the configuration of the three-dimensional mesh.

In the above embodiment of the present invention, FIG.
The case where the three-dimensional mesh correction device A having the configuration shown in FIG. However, in the method of the present invention, a recording medium storing a computer program including the above-described first to third steps is mounted on a general-purpose computer, and a CPU as an arithmetic processing unit and a storage means provided in the computer It is also possible to use a RAM. FIG. 7 is a schematic diagram showing an embodiment in such a case.
RM in the figure is a recording medium such as a magnetic disk and an optical disk. In the recording medium RM, the first step shown in FIG.
A computer program including the second step shown in FIG. 3 and the third step shown in FIG. 4 is recorded. When the recording medium RM is loaded into the disk drive D of the general-purpose computer C and read, the computer C loads the computer program recorded on the recording medium RM, and executes the first to third steps described above. Is executed, and as a result, the three-dimensional mesh including the crushed element is corrected.

[0040]

According to the present invention, by moving nodes on the surface of a three-dimensional mesh including crushed elements on a free-form surface or a free curve, the three-dimensional mesh can be modified. Thus, it is possible to prevent the deformation analysis accuracy from being deteriorated by the three-dimensional mesh including the crushed element.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a three-dimensional mesh correction device of the present invention.

FIG. 2 is a flowchart showing a flow of processing in a first step.

FIG. 3 is a flowchart showing a processing flow in a second step.

FIG. 4 is a flowchart showing a flow of processing in a third step.

FIG. 5 is a diagram illustrating an example in which a moving node is moved on a free-form surface.

FIG. 6 is a diagram illustrating an example in which a moving node is moved on a free curve.

FIG. 7 is a schematic view showing another embodiment of the method of the present invention.

FIG. 8 is a schematic diagram of a three-dimensional mesh for explaining a conventional method.

FIG. 9 is a schematic diagram showing a three-dimensional lattice mesh and a three-dimensional non-lattice mesh.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface node extraction part 2 Moving node designation part 3 Free curved surface / free curve generation part 4 Designated node movement part 5 Surface node data file 6 Free curved surface / free curve data file 7 Input part 8 Pointing device 9 First data file 10 Second Data file 11 Display unit A 3D mesh correction device c Free curve s Free-form surface p Moving node (node to be corrected) q Node group

Claims (9)

[Claims] 1. During the execution of a numerical analysis involving a three-dimensional deformation of an object to be analyzed represented by a three-dimensional mesh having a plurality of nodes, which is an aggregate of a plurality of elements made up of a polyhedron, Extracting a node existing on the surface of the three-dimensional mesh including the crushed element in the method for correcting the three-dimensional mesh including the crushed element when a part of the element is crushed; A three-dimensional mesh comprising: a step of generating a free-form surface defined by one node specified from the nodes and a group of nodes around the node; and a step of moving the specified node on the free-form surface. How to fix. 2. During the execution of a numerical analysis involving a three-dimensional deformation of an analysis target represented by a three-dimensional mesh having a plurality of nodes, which is an aggregate of a plurality of elements made up of a polyhedron, Extracting a node existing on the surface of the three-dimensional mesh including the crushed element in the method for correcting the three-dimensional mesh including the crushed element when a part of the element is crushed; A three-dimensional mesh, comprising: a step of generating a free curve defined by one node specified from the nodes and a group of nodes around the node; and a step of moving the specified node on the free curve. How to fix. 3. The three-dimensional mesh includes a three-dimensional lattice mesh composed entirely of hexahedral elements, a three-dimensional non-grid mesh composed entirely of hexahedral elements, and a tetrahedral, pentahedral, 3. The method for correcting a three-dimensional mesh according to claim 1, wherein the method is selected from a three-dimensional mesh in which hexahedral elements are mixed. 4. A deformation analysis apparatus for performing a three-dimensional deformation analysis of an object to be analyzed using a three-dimensional mesh having a plurality of nodes, which is an aggregate of a plurality of elements formed of a polyhedron,
Means for extracting nodes existing on the surface of the three-dimensional mesh including the crushed element when a part of the element is crushed; means for specifying one node from the extracted nodes; A deformation analysis apparatus comprising: means for generating a free-form surface defined by a node and a group of nodes around the node; and means for moving the specified node on the free-form surface. 5. A deformation analysis device for performing a three-dimensional deformation analysis of an analysis object using a three-dimensional mesh having a plurality of nodes, which is an aggregate of a plurality of elements formed of a polyhedron,
Means for extracting nodes existing on the surface of the three-dimensional mesh including the crushed element when a part of the element is crushed; means for specifying one node from the extracted nodes; A deformation analysis device comprising: means for generating a free curve defined by a node and a group of nodes around the node; and means for moving the specified node on the free curve. 6. During the execution of a numerical analysis involving a three-dimensional deformation of an analysis target represented by a three-dimensional mesh having a plurality of nodes, which is an aggregate of a plurality of elements made up of a polyhedron, When a part of the element is crushed, a node present on the surface of the three-dimensional mesh including the crushed element in a recording medium storing a computer program for correcting the three-dimensional mesh including the crushed element. Extracting, a step of specifying one node by receiving an input for specifying one node from the extracted nodes, and a step of forming a free-form surface defined by the specified one node and a group of nodes around the specified node. Generating a specified node, and moving the specified node in response to an input for moving the specified node on the free-form surface. A recording medium characterized by recording a gram. 7. During the execution of a numerical analysis involving a three-dimensional deformation of an object to be analyzed represented by a three-dimensional mesh having a plurality of nodes, which is an aggregate of a plurality of elements formed of a polyhedron, When a part of the element is crushed, a node present on the surface of the three-dimensional mesh including the crushed element in a recording medium storing a computer program for correcting the three-dimensional mesh including the crushed element. Extracting, a step of receiving an input for designating one node from the extracted nodes, and designating one node, and forming a free curve defined by the designated one node and a group of surrounding nodes. Generating a specified node, and moving the specified node in response to an input for moving the specified node on the free curve. A recording medium characterized by recording a gram. 8. A computer-readable program code means for performing a three-dimensional deformation analysis of an object to be analyzed using a three-dimensional mesh having a plurality of nodes, which is an aggregate of a plurality of elements formed of a polyhedron. Program code means for causing the computer to extract nodes existing on the surface of a three-dimensional mesh including the crushed element when a part of the element is crushed, and the extracted node Program code means for causing the computer to generate a free-form surface defined by one node designated by an external input and a group of nodes around the node; and externally inputting the designated node on the free-form surface Program code means for causing the computer to move according to body. 9. A computer-readable program code means for performing a three-dimensional deformation analysis of an object to be analyzed using a three-dimensional mesh having a plurality of nodes, which is an aggregate of a plurality of elements formed of a polyhedron. Program code means for causing the computer to extract nodes existing on the surface of a three-dimensional mesh including the crushed element when a part of the element is crushed, and the extracted node Program code means for causing the computer to generate a free curve defined by one node specified by an external input and a group of nodes around the node, and inputting the specified node on the free curve by an external input Program code means for causing the computer to move according to body.