JP6295093B2 - Finite element analysis apparatus and plate element dividing method - Google Patents

Description

  The present invention relates to a finite element analysis apparatus and a plate element dividing method, and is particularly suitable for use in a finite element analysis apparatus that divides a constituent surface of a three-dimensional object generated by CAD into plate elements.

  2. Description of the Related Art Conventionally, a CAE (Computer Aided Engineering) system has been provided as a tool for using computer technology to support product design, manufacturing, and advance examination of process design. In the finite element method which is one of the analysis methods of the CAE system, the inside of the shape to be analyzed is divided into elements in a small finite range. Each finite element has a plurality of nodes at its boundary.

  That is, in the finite element method, the shape to be analyzed is represented by a node group having coordinate information and a finite element group represented by interpolating the node group. In particular, when the analysis target is a surface, the shape is expressed by a plate element group having three to four nodes. Generation of a plate element group so as to cover the entire surface of a composite surface generated by CAD is called plate element division. In order to simplify the analysis calculation, there is also a method in which only triangular plate elements represented by three nodes are handled.

  FIG. 10 is a diagram showing an image of a result of dividing one surface of the composite surface into plate elements. A composite surface expresses one shape by bonding a plurality of constituent surfaces together with boundary lines. The component surface has an effective range surrounded by a plurality of boundary line loops, and each boundary line is shared by the two component surfaces as a boundary between the component surfaces.

  In the finite element method, based on the plate element group generated by the plate element division and the boundary condition, a linear simultaneous equation for the coordinate value and displacement of the node is constructed and solved, and the shape and each point after deformation are calculated. It is possible to output analysis results such as stress distribution. However, the number of equations constituting the simultaneous equations and the number of variables obtained by calculation are proportional to the number of nodes, and accordingly, the memory area and calculation time required for the calculation increase on the order of squares. Therefore, since it is impossible to increase the number of nodes without darkness, it is necessary to divide the elements as a fairly rough approximation. When the boundary line of the component surface is a curve, it is required to divide the curve at as large a pitch as possible to approximate a polygonal line, and to divide the region surrounded by the approximated polygonal line into as large a plate element group as possible.

  However, when the division pitch is increased, a phenomenon occurs in which the division cannot be performed because the broken lines approximating the boundary line between the two constituent surfaces intersect each other. FIG. 11 is a diagram for explaining this phenomenon. FIG. 11 shows an example in which narrow ring-shaped boundary lines 111 and 112 formed by two concentric circles are represented by broken lines 113 and 114, respectively, which are divided at as large a pitch as possible. Here, the inner boundary line 111 is approximated by a quadrangular broken line 113 having four break points, and the outer peripheral boundary line 112 is approximated by a hexagonal broken line 114 having six break points.

  In this case, as shown in FIG. 11, a broken line 113 that approximates the inner boundary line 111 and a broken line 114 that approximates the outer boundary line 112 intersect at an intersection 115. 113 and 114 cannot be divided. Conventionally, in order to avoid this, at the stage where two boundary lines are approximated by a polygonal line, whether or not there is an intersection between the polygonal lines is inspected, and if there is an intersection, the division pitch is reduced and recalculation is performed. The presence / absence of an intersection is determined by converting each break point of the broken line into a value in the parameter space of the constituent surface and performing an intersection inspection in the parameter space.

  However, if the division pitch is reduced when there is an intersection, the linear simultaneous equations that must be solved become complicated, and there is a problem that the memory area and calculation time required for calculation increase.

  In addition, the technique which enabled it to obtain | require the positional relationship of a polygon and the arbitrary points on the same plane at high speed is proposed (for example, refer patent document 1).

Japanese Patent Laid-Open No. 10-198808

  The present invention has been made to solve the above-described problems, and is a finite element analysis apparatus that approximates a curved line shape by a broken line having a plurality of broken points and divides the approximated shape into plate elements. An object of the present invention is to divide a curve shape with as large a pitch as possible to approximate a polygonal line, and to divide it into plate element groups with as large a pitch as possible.

  In order to solve the above-described problem, the present invention relates to a polygonal line approximated with respect to the boundary line of the first component surface when the boundary line of the curved shape of the component surface is approximated by a polygonal line having a plurality of fold points. The presence / absence of an intersection is determined by determining whether all the break points are inside the broken line approximated with respect to the second component surface. When it is determined that at least one of the fold points set for the first component surface is outside the polygonal line approximated for the second component surface, from the boundary line of the second component surface Among the approximate broken lines, in the section of the line segment where the broken point related to the first component surface is outside, a broken point is added on the boundary line of the second component surface to re-create the broken line related to the second component surface. I am trying to configure it.

  According to the present invention configured as described above, when it is determined that there is an intersection between the polygonal line approximated with respect to the first component plane and the polygonal line approximated with respect to the second component plane, division of the polygonal line is performed. Instead of reducing the pitch, it is possible to avoid the occurrence of the intersection only by adding a break point in the broken line section where the intersection occurs and reconstructing the broken line. As a result, the curve shape of the boundary line can be divided at the largest possible pitch and approximated by a broken line, and the region defined by the approximated broken line can be divided into plate element groups at the largest possible pitch.

It is a block diagram which shows the function structural example of the finite element analysis apparatus by this embodiment. It is a figure for demonstrating a response | compatibility with parameter space and three-dimensional space. It is a figure for demonstrating the inside / outside determination of the point with respect to the loop in two-dimensional space. It is a figure for demonstrating the processing content by the inside / outside determination part of this embodiment. It is a figure for demonstrating the half plane set by the inside / outside determination part of this embodiment. It is a figure for demonstrating the operation | movement regarding the reconstruction of a broken line by the broken line approximation part of this embodiment. It is a figure which shows the example of the process dependence registered by the dependence registration part of this embodiment. It is a flowchart which shows the operation example of the finite element analysis apparatus by this embodiment. It is a flowchart which shows the operation example of the finite element analysis apparatus by this embodiment. It is a figure which shows the image of the result of having divided the plate | board element of one surface of the composite surface of a three-dimensional object. It is a figure for demonstrating the phenomenon where the broken line which approximated the boundary line of a structure surface crosses.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a functional configuration example of the finite element analysis apparatus according to the present embodiment. As shown in FIG. 1, the finite element analysis apparatus of the present embodiment includes a broken line approximation unit 1, a plate element generation unit 2, an inside / outside determination unit 3, a dependency relationship registration unit 4, and a processing order setting unit 5 as its functional configuration. It is prepared for.

  Each of the functional blocks 1 to 5 can be configured by any of hardware, DSP (Digital Signal Processor), and software. For example, when configured by software, each of the functional blocks 1 to 5 is actually configured by including a CPU, RAM, ROM, etc. of a computer, and a program stored in a recording medium such as RAM, ROM, hard disk, or semiconductor memory. Is realized by operating.

  The polygonal line approximation unit 1 inputs data of a three-dimensional object generated by CAD, and when the boundary line of the configuration surface of the three-dimensional object is a curved line, the curved line is converted into a broken line having a plurality of broken points. Approximate. Here, as an example, as shown in FIG. 11, it is assumed that two narrow ring-shaped boundary lines 111 and 112 are approximated by broken lines 113 and 114 that are divided at a pitch as large as possible.

  For example, the circumference of the boundary lines 111 and 112 is divided by the reference pitch (the length of one side of the polygonal line), and if the remainder value is equal to or less than a predetermined value, the reference pitch is used, and the remainder is a predetermined value. If it is larger, the number of divisions (number of break points) of the boundary lines 111 and 112 is determined according to the rule of decreasing the pitch and increasing the number of divisions. The example of FIG. 11 shows a state in which the inner peripheral boundary line 111 is approximated by a quadrilateral broken line 113 having four break points, and the outer peripheral boundary line 112 is approximated by a hexagonal broken line 114 having six break points. ing.

  The plate element generation unit 2 generates a plate element in a region defined by the broken line approximated by the broken line approximation unit 1. That is, the plate element generation unit 2 generates a plate element group so as to cover the entire composite surface of a three-dimensional object generated by CAD. A known method can be applied to the generation of the plate element group. Since the plate element group generation process itself is not the subject of the present invention, a detailed description thereof will be omitted.

  When there is no intersection between the polygonal lines approximated by the polygonal line approximating unit 1, the plate element group generated in the region defined by the polygonal line can be adopted as it is. On the other hand, when there is an intersection between approximated broken lines, the broken lines are reconstructed as described below. In this case, the plate element generation unit 2 generates a plate element in an area defined by the reconstructed broken line.

  The inside / outside determination unit 3 is configured such that all of the break points on the broken line approximated by the broken line approximation unit 1 with respect to the boundary line of the first component surface (hereinafter referred to as the break points related to the first component surface) are the second component surface. It is determined whether it is inside a polygonal line approximated with respect to the boundary line (hereinafter referred to as a polygonal line related to the second component surface). For example, in the example of FIG. 11, it is assumed that the inner periphery of the ring shape is the first component surface and the outer periphery is the second component surface. In this case, the inside / outside determination unit 3 determines whether or not all four break points on the broken line 113 approximated from the inner boundary line 111 are present inside the broken line 114 approximated with respect to the outer boundary line 112. Determine.

  As described above, according to the present embodiment, each break point of the broken line is converted into a parameter space value of the component plane as in the conventional method, and the presence or absence of intersection is determined by regarding the broken line in the three-dimensional space as the broken line in the parameter space. Instead of using the coordinate values of the three-dimensional space, the presence / absence of an intersection is determined. Since the line segment on the parameter space of the component plane may be bent in the three-dimensional space, it may be insufficient to perform the cross inspection of the parameter space alone. For example, when the concentric constituent surfaces are defined not as planes but as rotation planes, the constant parameter line is arcuate as shown in FIG. 2, and therefore, no intersection can be detected in the parameter space.

  On the other hand, in this embodiment, it is determined using the coordinate values of the three-dimensional space whether or not all the break points related to the first component surface are inside the polygonal line related to the second component surface. Thus, it is determined whether or not an intersection has occurred between the polygonal line 113 approximated from the boundary line 111 of the first component surface and the polygonal line 114 approximated from the boundary line 112 of the second component surface.

  Below, the principle of the inside / outside determination of the break point will be described. As shown in FIG. 3, in the case of a two-dimensional space, whether a certain point is inside or outside the loop, whether the number of intersections between the semi-infinite straight line from the starting point in any direction and the loop is even or odd It can be determined by. That is, in the case of a point inside the loop surrounded by the two concentric boundary lines 101 and 102, the boundary lines 101 and 102 are counted without counting the starting points in consideration of the semi-infinite straight line 103 toward the effective side of the loop. If you count the number of other intersections with, they should all be odd numbers.

  The boundary lines 101 and 102 are set with traveling directions A and B which are opposite to each other along the circumference, and it is determined in advance which is the inner side and which is the outer side with respect to the traveling directions A and B. Is defined. That is, a region that is on the outside as viewed from the inner boundary line 101 and on the inner side as viewed from the outer boundary line 102 is an inner region of the loop. The loop surface has front and back surfaces, and the effective side and the invalid side of the loop are defined by the relationship between the front and back direction of the surface and the traveling direction of the boundary lines 101 and 102.

  The inside / outside determination unit 3 extends this concept to a three-dimensional space, and sets a plane (indicated by arrows 201 to 204) at the positions of the break points 211 to 214 with respect to the first component plane as shown in FIG. Thus, the presence / absence of intersection is determined depending on whether the number of intersections between the planes 201 to 204 and the broken lines 113 and 114 is even or odd. Specifically, the inside / outside determination unit 3 is a polygonal line approximated from the half planes 201 to 204 from the respective folding points 211 to 214 toward the effective side of the folding points 211 to 214 and the boundary line 111 of the first component surface. 113 and the broken line 114 approximated from the boundary line 112 of the second component surface, all four of the folding points 211 to 214 related to the first component surface are bent lines 114 related to the second component surface. It is determined whether it is inside.

  The half planes 201 to 204 are represented by the bisected direction of the angle formed by two broken lines that are connected to each other on the effective side of the plane determined with respect to the surface direction of the constituent surface and the traveling direction of the boundary line. It is decided by letting. That is, as shown in FIG. 5, the effective of the break point 301 is determined from the normal direction V1 of the constituent surface at the break point 301 and the bisection direction V2 of the two break lines 302 and 303 connected to the break point 301. A half-plane 304 toward the side is determined.

  In the example of FIG. 4, of the four folding points 211 to 214 regarding the first component surface, two folding points 211 and 213 are half-planes 201 to 204 set on the effective side of the folding points 211 and 213. The number of intersections with the broken lines 113 and 114 is an odd number of one. Therefore, it can be determined that the two fold points 211 and 213 related to the first configuration surface are inside the fold line 114 related to the second configuration surface.

  On the other hand, among the four fold points 211 to 214 related to the first component surface, the remaining two fold points 212 and 214 are the half planes 201 to 204 set on the effective side of the fold points 212 and 214 and the fold line 113. , 114 is an even number of zero crossings. Therefore, it can be determined that the two fold points 212 and 214 related to the first component surface are not inside the fold line 114 related to the second component surface, that is, located outside.

  The above-described broken line approximation unit 1 has the second configuration when the inside / outside determination unit 3 determines that at least one of the broken points related to the first component surface is outside the broken line related to the second component surface. Reconstruct the polyline on the face. In the example of FIG. 4, since it is determined that the two fold points 212 and 214 related to the first component surface are outside the fold line 114 related to the second component surface, the polygonal line approximation unit 1 is a polygonal line related to the second component surface. Reconfigure.

  FIG. 6 is a diagram for explaining the operation related to the reconstruction of the broken line by the broken line approximation unit 1. As shown in FIG. 6, the broken line approximating unit 1 includes a line segment 401 in which folding points 212 and 214 related to the first component surface are outside of the broken line 114 approximated from the boundary line 112 of the second component surface. , 402, fold points 411 and 412 on the boundary line of the second component surface are added to reconstruct the polygonal line related to the second component surface. That is, the line segment 401 is reconfigured into a broken line 401 ', and the line segment 402 is reconfigured into a broken line 402'. As described above, the polygonal line 114 is reconstructed by adding the folding points 411 and 412 in the section of the line segments 401 and 402 where the intersection occurs without reducing the division pitch of the polygonal line 114 related to the second component surface. Just by avoiding the occurrence of intersections.

  In addition, if it is going to avoid a crossing by adding the break point regarding the 2nd composition surface as mentioned above, it will affect the 3rd composition surface adjacent to the 2nd composition surface, and about the boundary line of the 2nd composition surface An intersection may occur between the reconstructed broken line and the broken line approximated with respect to the boundary line of the third component surface. In this case, it is very troublesome to add a break point to a boundary line that has already been divided because it is necessary to divide the plate elements that have already been divided into adjacent constituent surfaces. Therefore, a mechanism for changing the processing order of the component planes and re-dividing is necessary. The configuration for executing this subdivision is the dependency registration unit 4 and the processing order setting unit 5.

  When the inside / outside determination unit 3 determines that at least one of the break points related to the first configuration surface is outside the polygonal line related to the second configuration surface, the dependency registration unit 4 The processing dependency between the surface and the second component surface is registered and stored. In the case of the above-described example, the dependency relationship registration unit 4 determines that the second configuration surface has a dependency relationship from the first configuration surface, for example, the first configuration surface is “parent” and the second configuration surface is “child”. ”Is registered. Each time the processing of the polygonal line approximation unit 1 and the inside / outside determination unit 3 is performed on two component surfaces, the dependency relationship registration unit 4 sets the two component surfaces as the first component surface and the second component surface, and processes between them. Dependencies are registered and stored as necessary.

  On the other hand, when the polygonal line relating to the second component surface is reconfigured by the polygonal line approximating unit 1, the inside / outside determination unit 3 has all the polygonal points set for the second component surface including the added polygonal points, It is determined whether or not the boundary line of the third constituent surface adjacent to the second constituent surface is inside a polygonal line approximated. Here, when the inside / outside determination unit 3 determines that at least one of the fold points related to the second configuration surface is outside the fold line related to the third configuration surface, the dependency relationship registration unit 4 The processing dependency between the configuration surface and the third configuration surface is also registered and stored.

  When the inside / outside determination unit 3 determines that at least one of the broken points related to the second configuration surface is outside the broken line related to the third configuration surface, the processing order setting unit 5 uses the dependency relationship registration unit 4 to Based on the registered processing dependency, the processing order of a plurality of constituent surfaces is changed. In this case, the polygonal line approximation unit 1 and the inside / outside determination unit 3 re-execute processing according to the processing order changed by the processing order setting unit 5.

  For example, as shown in FIG. 7A, when the process dependency relationships regarding a plurality of component surfaces are represented in a tree shape, the processing order setting unit 5 reverses the tree of the process dependency relationships in reverse. Change the processing order. In the example of FIG. 7A, the processing order is set so that the third component plane is processed with the highest priority, and then the second component plane and the first component plane are processed.

  On the other hand, as shown in FIG. 7B, when a loop is detected without following the processing dependency relationships of a plurality of component surfaces in a tree shape, the polygonal line approximation unit 1 and the inside / outside determination unit 3 The process up to the reconstruction of the broken line by adding the broken line approximation and the broken point to the boundary line is implemented. Further, the plate element generation unit 2 generates plate elements in units of constituent planes when the polygonal line approximation and the polygonal line reconstruction are finished for all the constituent planes. As described above, each time the polygonal line approximation unit 1 performs the polygonal line approximation of the boundary line for one component surface, the plate element generation unit 2 does not perform the plate element division, but performs the polygonal line approximation for all the component surfaces. The problem of dependency loops is dealt with by dividing plate elements on the component plane.

  8 and 9 are flowcharts showing an operation example of the finite element analysis apparatus according to the present embodiment configured as described above. First, the polygonal line approximation unit 1 extracts one from a plurality of constituent surfaces constituting a three-dimensional object (step S1). Then, it is determined whether or not the boundary line of the extracted component surface is a curved shape (step S2). If the boundary is a curved shape, the curved shape is approximated by a broken line having a plurality of broken points (step S3). . On the other hand, when the polygonal line approximation unit 1 determines that the boundary line of the component surface is not a curved shape, the process transitions to step S4.

  When the boundary line of the component surface is a curved shape, the plate element generation unit 2 generates a plate element in the region defined by the broken line approximated by the broken line approximation unit 1 in step S3 (step S4). Further, when the boundary line of the component surface is not a curved shape, that is, when the boundary line is a straight line shape, the plate element generation unit 2 has a plate element within the region defined by the boundary line of the component surface extracted in step S1. Is generated (step S4).

  Next, the inside / outside determination unit 3 places all the fold points on the broken line approximated with respect to the boundary line of the first component surface by the broken line approximation unit 1 inside the broken line approximated with respect to the boundary line of the second component surface. It is determined whether or not (step S5). In addition, since this determination cannot be performed at the stage where the polygonal line approximation unit 1 first approximates the component surface to the polygonal line, the process returns to step S1 without performing the determination.

  When the inside / outside determination unit 3 determines that all the broken points related to the first component surface are inside the broken line related to the second component surface, the polygonal line approximation unit 1 selects all the component surfaces of the three-dimensional object. It is determined whether or not processing has been performed (step S6). When all the constituent surfaces have been processed, the processing of the flowchart shown in FIG. 8 ends. On the other hand, if an unprocessed component surface remains, the process returns to step S1 and the broken line approximation unit 1 extracts the next component surface.

  In the above step S5, when the inside / outside determination unit 3 determines that at least one of the break points related to the first component surface is outside the polygonal line related to the second component surface, the dependency relationship registration unit 4 The processing dependency between the first configuration surface and the second configuration surface is registered and stored (step S7).

  The broken line approximating unit 1 folds on the boundary line of the second component surface in the section of the line segment where the break point is outside the broken line regarding the first boundary surface among the broken lines related to the second component surface. A point is added to reconstruct a polygonal line related to the second component surface (step S8). And the board element production | generation part 2 re-executes the production | generation of a board element about the area | region prescribed | regulated by the reconfigure | reconstructed broken line (step S9).

  Furthermore, the inside / outside determination unit 3 includes all the break points related to the second component surface including the break points added in step S8 inside the broken line related to the third component surface adjacent to the second component surface. It is determined whether or not (step S10). Here, when the broken line is not approximated for the third component surface, or when it is determined that all the broken points related to the second component surface are inside the broken line related to the third component surface, Returns to step S1, and the polygonal line approximation unit 1 extracts the next component surface.

  On the other hand, when the inside / outside determination unit 3 determines that at least one of the broken points related to the second configuration surface is outside the broken line related to the third configuration surface, the dependency relationship registration unit 4 The processing dependency relationship between the configuration plane and the third configuration plane is registered and stored (step S11). Then, the processing order setting unit 5 determines whether or not a loop exists in the processing dependency relationship based on the processing dependency relationship registered by the dependency relationship registration unit 4 (step S12).

  Here, when there is no loop in the process dependency relationship, the process order setting unit 5 changes the process order of the plurality of components based on the process dependency relationship (step S13). Thereafter, the process returns to step S1. In this case, the polygonal line approximation unit 1 extracts the first component surface according to the processing order changed by the processing order setting unit 5.

  On the other hand, when the processing order setting unit 5 determines that there is a loop in the processing dependency relationship, the broken line approximation unit 1 and the inside / outside determination unit 3 perform boundary lines for each component plane by the processing in steps S14 to S23 illustrated in FIG. Up to the reconstruction of the broken line by adding the broken line approximation and the broken point. At this time, the dependency registration unit 4 and the processing order setting unit 5 also perform processing as necessary.

  And the plate element production | generation part 2 produces | generates a plate element for every structural surface unit after the broken line approximation and the reconstruction of a broken line are completed about all the structural surfaces (step S24). Note that the processing in steps S14 to S23 is the same as the processing in steps S1 to S13, except that there is no plate element division processing in steps S4 and S9 and loop determination processing in step S12.

  As described above in detail, in the present embodiment, when the boundary line of the curved shape of the component surface is approximated by a broken line having a plurality of break points, all of the polygonal lines approximated with respect to the boundary line of the first component surface It is determined whether or not the folding point is inside the broken line approximated with respect to the boundary line of the second component surface. When it is determined that at least one of the fold points related to the first component surface is outside the fold line related to the second component surface, the fold point is outside of the polygonal line related to the second component surface. In the section of the line segment, the broken line on the boundary line is added to reconstruct the broken line related to the second component surface.

  According to this embodiment configured as described above, when there is an intersection between a polygonal line approximated with respect to the boundary line of the first component surface and a polygonal line approximated with respect to the boundary line of the second component surface, the polygonal line The generation of the intersection can be avoided simply by adding a break point in the section of the line segment in which the intersection occurs, and reconstructing the broken line instead of reducing the division pitch. As a result, the curve shape of the boundary line can be divided at the largest possible pitch and approximated by a broken line, and the region defined by the approximated broken line can be divided into plate element groups at the largest possible pitch.

  In the present embodiment, whether or not there is an intersection between the polygonal line related to the first component surface and the polygonal line related to the second component surface is determined by the inside / outside determination of the polygonal point. Thereby, the intersection which cannot be detected by the intersection inspection of the parameter space as in the conventional case can be reliably detected.

  Moreover, in this embodiment, as a result of adding a crease point to the polygonal line related to the second component surface, the added crease point is outside the polygonal line relating to the third component surface adjacent to the second component surface. In such a case, the processing order is changed based on the processing dependency between the constituent surfaces, and the polygonal line approximation is re-executed. As a result, it is possible to avoid the phenomenon of division failure on the boundary line of the configuration surface without reducing the division pitch of the broken line.

  The above-described embodiments are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention should not be interpreted in a limited manner. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

DESCRIPTION OF SYMBOLS 1 Broken line approximation part 2 Board element production | generation part 3 Inside / outside determination part 4 Dependency registration part 5 Process order setting part

Claims (5)

A finite element analysis device for dividing a constituent surface of a three-dimensional object into plate elements,
When the boundary line of the configuration surface is a curved line shape, a polygonal line approximation unit that approximates the curved line shape with a broken line having a plurality of bending points;
A plate element generation unit that generates the plate element in a region defined by a polygonal line approximated by the polygonal line approximation unit;
Whether or not all the broken points related to the broken line approximated with respect to the boundary line of the first component surface by the broken line approximating unit are inside the broken line approximated to the boundary line of the second component surface, from the broken point. An inside / outside determination unit that determines based on the number of times a half plane toward the effective side of the break point intersects with a broken line approximated from each boundary line of the first configuration surface and the second configuration surface ,
When the inside / outside determination unit determines that at least one of the fold points related to the first component surface is outside the polygonal line related to the second component surface, the broken line approximation unit In the section of the line segment in which the fold point related to the first component surface is outside of the fold line related to the surface, a fold point is added on the boundary line of the second component surface and the polygonal line related to the second component surface A finite element analysis device characterized by reconfiguring. When the inside / outside determination unit determines that at least one of the fold points related to the first configuration surface is outside the fold line related to the second configuration surface, the first configuration surface and the second configuration surface A dependency registration unit for registering and storing the process dependency relationship with the configuration surface;
A processing order setting unit that sets the processing order of a plurality of components based on the processing dependency registered by the dependency registration unit;
When the broken line relating to the second component surface is reconfigured by the broken line approximating unit, the inside / outside determining unit determines that all of the broken points related to the second component surface including the added broken point are third. Determine if it is inside the polyline on the component surface,
If the inside / outside determination unit determines that at least one of the broken points related to the second component surface is outside the broken line related to the third component surface, the processing order setting unit registers the dependency relationship Change the processing order of the plurality of component surfaces based on the processing dependency registered by the unit,
The finite element analysis apparatus according to claim 1, wherein the broken line approximation unit and the inside / outside determination unit re-execute processing according to the processing order changed by the processing order setting unit.   The finite element analysis apparatus according to claim 2, wherein the processing order setting unit changes the processing order of the plurality of constituent surfaces so as to trace the processing dependency in a tree shape.   When the processing order setting unit detects a loop without following the processing dependencies of the plurality of component surfaces in a tree shape, the polygonal line approximation unit and the inside / outside determination unit include a polygonal line approximation of a boundary line as a component surface unit and Performs the process up to the reconstruction of the polygonal line by adding the polygonal points, and the plate element generation unit generates the plate element for each component plane when the reconstruction of the polygonal line approximation unit and the polygonal line is completed for all the component planes. The finite element analysis apparatus according to claim 3, wherein: A plate element dividing method for dividing a constituent surface of a three-dimensional object into plate elements by a finite element analyzer,
A first step of approximating the curved line shape by a broken line having a plurality of broken points when the boundary line of the component surface is a curved line shape,
A second step in which the plate element generation unit of the finite element analysis device generates the plate element in a region defined by a polygonal line approximated by the polygonal line approximation unit;
The inside / outside determination unit of the finite element analysis apparatus includes an inside of a broken line in which all the broken points related to the broken line approximated with respect to the boundary line of the first component surface are approximated with respect to the boundary line of the second component surface. The number of times the half plane from the fold point toward the effective side of the fold point intersects with the fold line approximated from each boundary line of the first component surface and the second component surface. A third step of determining based on
When the inside / outside determination unit determines that the broken line approximation unit of the finite element analysis apparatus has at least one of the broken points related to the first component surface outside the broken line related to the second component surface. In the section of the line segment where the fold point related to the first component surface is outside of the fold line related to the second component surface, a fold point is added on the boundary line of the second component surface to A fourth step of reconstructing the polygonal line for the two constituent surfaces;
A plate element division, wherein the plate element generation unit of the finite element analysis device includes a fifth step of generating the plate element in a region defined by a broken line reconstructed by the broken line approximation unit. Method.

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