JP2024007142A - Structure design support device, structure design support method, program and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure design support device capable of identifying a portion having a larger impact on rigidity at a specific portion, a structure design support method, a program and a storage medium.

SOLUTION: A structure design support device 10 includes: nodal point information storage part 22 configured to store nodal point information showing a position at a first state and a position at a second state of nodal points disposed on a structure model composed of a plurality of components; a change rate calculation part 12 configured to set one point selected from among the nodal points as a reference point, and calculate, by each evaluation point being a nodal point other than the reference point from among the nodal points, an absolute value of a change rate between the first state and the second state of a distance between the reference point and the evaluation point. The change rate calculation part 12 associates the absolute value of the change rate by each evaluation point with evaluation point identification information identifying an evaluation point and stores in the nodal point information storage part 22.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a structure design support device, a structure design support method, a program, and a recording medium.

Conventionally, various structure design support apparatuses have been proposed for evaluating and analyzing structures at the design stage of various structures. A computer is generally used as a structure design support device, and programs for causing a computer to evaluate and analyze structures and systems implementing the programs have been proposed. Such structure design support equipment constructs a model that represents the entire structure to be designed or each component that makes up the structure divided into small regions (elements), and uses this model to calculate external forces. The design is performed by simulating the response to the application of , and using the obtained results.

For example, Patent Document 1 describes a structural analysis technique that focuses on changes in the relative positional relationship with other components due to the application of external force to each component constituting a structure. Specifically, Patent Document 1 describes the position of an evaluation point provided on a structure made up of a plurality of parts in the first state, the position in the second state, and any one of the plurality of parts. a first evaluation point belonging to the reference part, and a first evaluation point belonging to the reference part, using the evaluation point information acquired by the evaluation point information acquisition section; Calculate an evaluation value representing the magnitude of change between the first state and the second state in a positional relationship with a second evaluation point belonging to a comparison part different from the reference part to which the evaluation point belongs. Disclosed is a structure design support device comprising: an evaluation value calculation unit;

Patent No. 6278122

However, in the technique of Patent Document 1, evaluation is performed using a vector that indicates in which direction parts that reduce the rigidity of the structure are present, but if the member at the end of the vector has a double structure, In some cases, it was not possible to determine which member contributed. Furthermore, when multiple vectors are displayed, evaluation may become difficult.

The present invention was made in view of the above circumstances, and includes a structure design support device, a structure design support method, a program, and a record, which can easily identify parts that have a large influence on the rigidity of a specific part. The purpose is to provide a medium.

In order to solve the above problems, the present invention proposes the following means.
(1) The structure design support device according to aspect 1 of the present invention provides node information indicating the position in a first state and the position in a second state of a node provided in a structure model composed of a plurality of parts. A node information storage unit that stores; one point selected from the nodes is determined as a reference point, and for each evaluation point that is a node other than the reference point among the nodes, the distance between the reference point and the evaluation point; a rate of change calculation unit that calculates the absolute value of the rate of change between the first state and the second state; The absolute value of the rate of change for each evaluation point is stored in the node information storage unit in association with evaluation point identification information for identifying the evaluation point.
(2) Aspect 2 of the present invention is the structure design support device of aspect 1, which includes:
The rate of change calculation unit may store the evaluation point where the absolute value of the rate of change is equal to or greater than a threshold value in the node information storage unit so as to be able to identify the evaluation point as a large strain evaluation point.
(3) Aspect 3 of the present invention is the structure design support device according to aspect 1 or 2, in which an image that allows the absolute value of the rate of change for the evaluation point to be visually recognized at the position of the evaluation point in the structure model is provided. The image forming apparatus may further include an image creating section that creates an image.
(4) Aspect 4 of the present invention is the structure design support apparatus according to aspect 2, in which two or more of the large strain evaluation points have a distance between them that is equal to or less than a preset threshold. The apparatus may further include an evaluation point group setting section that sets a set of large strain evaluation points as a large strain evaluation point group.
(5) Aspect 5 of the present invention is the structure design support apparatus according to aspect 4, in which the group of large strain evaluation points and the isolated large strain evaluation point which is the large strain evaluation point not included in the group of large strain evaluation points are provided. and the sum of 2 or more, and the relative displacement between the reference point and the large strain evaluation point or the isolated large strain evaluation point having the largest absolute value of the rate of change among the large strain evaluation points is The apparatus may include an analysis unit that performs analysis processing of the structure model under regulated rigid body conditions.
(6) Aspect 6 of the present invention is the structure design support apparatus according to aspect 5, in which the analysis unit performs analysis processing under the rigid body condition to determine the shape of the structure having the largest rate of change among the group of large strain evaluation points. The rigid body evaluation value after rigid body conversion is calculated for the large strain evaluation point or the isolated large strain evaluation point, and the rigid body evaluation value before rigid body conversion and the rigid body evaluation value after rigid body conversion are obtained by analysis processing without adding the rigid body conversion condition. Based on this, a constraint target point whose displacement with respect to the reference point should be restricted may be specified.
(7) In a seventh aspect of the present invention, in the structure design support apparatus according to the sixth aspect, the analysis process may be a modal analysis process.
(8) Aspect 8 of the present invention is the structure design support device according to aspect 1 or 2,
Among the evaluation points, the rate of change calculation unit associates component identification information that identifies the component to which the evaluation point belongs to the evaluation point identification information with the evaluation point identification information for evaluation points that belong to a plurality of parts constituting the structure model. It may be stored in the information storage unit.
(9) In a ninth aspect of the present invention, in the structure design support apparatus according to aspect 8, a part unit for the part is determined based on each of the absolute values of the rate of change for all the evaluation points belonging to the part. The evaluation value calculation unit may further include an evaluation value calculation unit that calculates an evaluation value, and the evaluation value calculation unit may store the component unit evaluation value in association with the evaluation point identification information in the node information storage unit.
(10) A structure design support method according to aspect 10 of the present invention provides node information representing the position in a first state and the position in a second state of a node provided in a structure model composed of a plurality of parts. A first step of storing; one selected point among the nodes is determined as a reference point, and for each evaluation point that is a node other than the reference point among the nodes, the distance between the reference point and the evaluation point is determined; a second step of calculating the absolute value of the rate of change between the first state and the second state;
In the second step, the absolute value of the rate of change for each evaluation point calculated in the first step is stored in association with evaluation point identification information that identifies the evaluation point.
(11) The program according to aspect 11 of the present invention includes:
computer,
of nodes in a structure model consisting of multiple parts,
position in the first state;
position in the second state;
a node information storage unit that stores node information representing;
One selected point among the nodes is set as a reference point, and for each evaluation point that is a node other than the reference point among the nodes, the first state of the distance between the reference point and the evaluation point; a change rate calculation unit that calculates an absolute value of the change rate between the second state and the second state;
to make it function, and
The rate of change calculation unit is operated to store the absolute value of the rate of change for each evaluation point in the node information storage unit in association with evaluation point identification information for identifying the evaluation point.
(12) A computer-readable recording medium according to aspect 12 of the present invention records the program according to aspect 11.

According to the above aspects of the present invention, it is possible to provide a structure design support device, a structure design support method, a program, and a recording medium that can easily identify parts that have a large influence on the rigidity of a specific part. I can do it.

1 is a schematic block diagram showing the configuration of a structure design support apparatus 10 according to a first embodiment of the present invention. It is a flowchart explaining the operation of the rate of change calculation unit 12 in the first embodiment. It is a diagram showing an example of a database in the first embodiment. It is a schematic block diagram showing the composition of structure design support device 10B concerning a 2nd embodiment of the present invention. It is a flowchart explaining operation of change rate calculation part 12B in a 2nd embodiment. It is a flowchart explaining operation of evaluation point group setting part 14 in a 2nd embodiment. It is a figure explaining a group of large strain evaluation points and an isolated large strain evaluation point. It is a flow chart explaining operation of analysis part 15 in a 2nd embodiment. It is a schematic block diagram showing the composition of structure design support device 10C concerning a 3rd embodiment. It is a flow chart explaining operation of evaluation value calculation part 16 in a 3rd embodiment. It is a figure which shows the example of a display by the structure design support apparatus 10 in an Example. FIG. 12 is a diagram of the display example of FIG. 11 viewed from another perspective. It is a figure which shows the result of evaluation between nodes. FIG. 14 is a diagram showing the results of FIG. 13 from another perspective. FIG. 7 is a diagram for explaining the rigidization conditions in Example 2-1. FIG. 7 is a diagram for explaining the rigidization conditions in Comparative Example 2-1.

(First embodiment)
The first embodiment will be described below with reference to the drawings. In the following embodiments, as an example of the purpose of structural analysis in the design stage of a structure, the purpose is to improve the rigidity of the structure. However, the purpose of structural analysis at the design stage of a structure is not only to improve the rigidity of the structure, but also to reduce the weight while ensuring the rigidity of the structure, and to analyze the collision of the structure, etc. It is possible to analyze the constructed structure.

FIG. 1 is a schematic block diagram showing the configuration of a structure design support apparatus 10 according to the first embodiment. The structure design support device 10 evaluates the rigidity of a structure made up of a plurality of parts using a virtual model (hereinafter referred to as a structure model). The structure model is assembled from a plurality of parts joined by, for example, welding, caulking, bolts, etc. The structure design support device 10 includes a processing section 21, a node information storage section 22, and a display section 23. The processing section 21 includes a node information acquisition section 11 , a rate of change calculation section 12 , and an image creation section 13 .

The node information acquisition unit 11 acquires node information representing the position in the first state and the position in the second state of a node provided in the structure model to be evaluated. The first state is, for example, a state where no external load is applied to the structure model. The first state may be a state in which the structure model is not deformed. The second state is, for example, a state in which an external load is applied to the structure model (for example, a state in which the maximum expected load is applied). The second state may be a state in which the eigenmode of the structure model is deformed. A node is, for example, a vertex of an element in the finite element method when the deformation of the structure in each state is analyzed by the finite element method. Nodal information is calculated by analyzing the structure model using the finite element method. Note that the node information may be calculated by, for example, numerical simulation other than the finite element method.

The node information storage unit 22 stores the node information acquired by the node information acquisition unit 11. That is, the node information storage unit 22 stores node information representing the position in the first state and the position in the second state of a node provided in a structure model composed of a plurality of parts. The rate of change calculation unit 12 determines one selected point among the nodes as a reference point, and calculates the first state and the distance between the reference point and the evaluation point for each evaluation point that is a node other than the reference point among the nodes. , the absolute value of the rate of change between the state and the second state is calculated. The rate of change calculation unit 12 stores the absolute value of the rate of change for each evaluation point in the node information storage unit 22 in association with evaluation point identification information that identifies the evaluation point. The evaluation point identification information is, for example, a code (node ID) that identifies a node. Further, the rate of change calculation unit 12 calculates, among the evaluation points, parts identification information that identifies the part to which the evaluation point belongs, for evaluation points belonging to a plurality of parts constituting the structure model, to identify the evaluation point. The information is stored in the node information storage unit in association with the information. That is, it is preferable that the rate of change calculation unit 12 store part identification information that identifies the part to which the evaluation point belongs in the node information storage unit 22 in association with the evaluation point identification information. The component identification information is, for example, a code (component ID) that identifies the component. It is preferable that the absolute value of the rate of change, the evaluation point identification information, and the component identification information be stored as a database in the node information storage unit 22. The details of how the change rate calculation unit 12 calculates the absolute value of the conversion rate will be described later.

The image creation unit 13 creates an image in which the absolute value of the rate of change for the evaluation point can be visually recognized at the position of the evaluation point in the structure model. The image generation unit 13 generates, for example, a three-dimensional image of the structure model in which the absolute value of the rate of change of each evaluation point calculated by the rate of change calculation unit 12 is expressed in shading. Note that the absolute value of the rate of change of each evaluation point may be expressed in color rather than in shading.

The display unit 23 may display the large strain evaluation points of the rate of change calculation unit 12 together with evaluation point identification information, or may display a three-dimensional image created by the image creation unit 13.

(Structure design support method)
The structure design support method of the first embodiment includes a first method that stores node information representing the position in a first state and the position in a second state of a node provided in a structure model composed of a plurality of parts. One point selected from among the nodes is determined as a reference point, and for each evaluation point that is a node other than the reference point among the nodes, the distance between the reference point and the evaluation point is calculated. and a second process of calculating the absolute value of the rate of change between the first state and the second state, and in the second process, for each evaluation point calculated in the first process. The absolute value of the rate of change is stored in association with evaluation point identification information that identifies the evaluation point. A structure design support method using the structure design support apparatus 10 will be described below.

In the first process, the node information storage unit 22 stores node information representing the position in the first state and the position in the second state of a node provided in a structure model composed of a plurality of parts.

The method for calculating the absolute value of the rate of change in the second process will be described below. FIG. 2 is a flowchart illustrating the operation of the rate of change calculation unit 12. Specifically, the second process will be explained. In Figure 2, the first state is a non-load state where no load is applied to the structure model, and the second state is a maximum load state where the maximum expected load is applied to the structure model. Explain. The following example is an example of the present invention, and the first state is not limited to the non-load state. Similarly, the second state is not limited to the maximum load state.

The rate of change calculation unit 12 performs the processes of steps S1 to S8 for each node included in the node information stored in the node information storage unit 22 (steps S1 to S8). In step S1, one selected point among the nodes is determined as a reference point i. The method of setting the reference point i is not particularly limited. Examples of the reference point i include a seat attachment point and a load input point. Alternatively, the reference point i may be set by calculating the evaluation value using the method described in Japanese Patent No. 6278122. In step S2, the change rate calculation unit 12 reads the first state position (X coordinate, Y coordinate, Z coordinate) and second state position of the reference point i from the node information storage unit 22.

Next, in step S3, specifically, the change rate calculation unit 12 sets an evaluation point j that is a node other than the reference point among the nodes (for example, initial value j=0). In step S4, the change rate calculation unit 12 reads the positions of the first state (here, the non-load state) and the second state (here, the maximum load state) of the evaluation point j from the node information storage unit 22. .

In step S5, the change rate calculation unit 12 calculates the distance F0 i,j in the first state and the distance F1 _i,j in the second state from the evaluation point j, which is a node other than the reference point _i among the nodes. do. For example, the X coordinate of reference point i in the first state is X _i , the Y coordinate is Y _i , the Z coordinate is Z _i , and the X coordinate of evaluation point j in the first state is X _j . , the Y coordinate is _Yj , and the Z coordinate is _Zj , the distance F0 _i,j is calculated by the following equation (1).

The rate of change calculation unit 12 uses the positions read in steps S2 and S4 to calculate the distance F1 _i,j between the reference point i and the evaluation point j in the second state (step S5). For example, the X coordinate of reference point i in the second state is X _1i , the Y coordinate is Y _1i , the Z coordinate is Z _1i , and the X coordinate of evaluation point j in the second state is X _1j . When the Y coordinate is Y _1j and the Z coordinate is Z _1j , the distance F1 _i,j is calculated by the following equation (2).

The change rate calculation unit 12 calculates the absolute value of the change rate dF _i,j = (F1 _{i ,j} - F0 _i,j )/F0 _i, j from the distance F0 _i,j to the distance F1 i,j ( Step S6).
The larger the original distance between the reference point i and _the evaluation point _{j ,} the greater the amount of change in distance. can reduce the impact of

In step S7, the change rate calculation unit 12 stores the node information in association with the evaluation point identification information that identifies the evaluation point j, and the absolute value of the change rate dF _i,j of the evaluation point j calculated by the change rate calculation unit 12. The information is stored in the section 22. For example, the rate of change calculation unit 12 stores the absolute value of the rate of change dF _i,j of the evaluation point j calculated by the rate of change calculation unit 12 as a database as shown in FIG. It is stored in the node information storage unit 22 in association with the information. In the example of FIG. 3, the node information storage unit 22 uses the node ID 34728 as a reference point, and stores the coordinates of the first state (x0, y0, z0), the coordinates of the second state (x1, y1, z1), and the coordinates of the second state of each node. Stores the distance (unit: mm) between the reference point i and each node (evaluation point) j in the first state, the distance between the reference point i and each evaluation point j in the second state, and the absolute value of the rate of change in distance. are doing. FIG. 3 shows whether the absolute values of the rate of change in distance with respect to the reference point are distributed in the same way in some regions of the structure model. The absolute value of the distance means the degree of contribution.

Next, the process proceeds to step S8. In step S8, the rate of change calculation unit 12 determines whether there is any unprocessed evaluation point j. If there is an unprocessed evaluation point j (YES in step S8), the process returns to step S3, and one of the unprocessed evaluation points j is selected and processed. If there is no unprocessed evaluation point j (NO in step S8), the loop from steps S3 to S8, that is, the process ends.

In this way, the structure design support device 10 and the structure design support method use the node information to calculate the reference point i and the evaluation point j for each evaluation point j between the first state and the second state. calculate the absolute value of the rate of change in the distance between the first state and the second state, and store the absolute value of the calculated rate of change in association with evaluation point identification information that identifies evaluation point j. do.

Thereby, it is possible to specify the evaluation point j that makes a large contribution (absolute value of rate of change) to the spatial distortion of the reference point i when changing from the first state to the second state. The evaluation point j that makes a large contribution to the spatial distortion of the reference point i when changing from the first state to the second state is a node that has a large influence on the stiffness. Therefore, by strengthening this evaluation point j, it is expected that the rigidity of the structure will increase. Therefore, it is possible to more easily detect a region suitable for increasing the rigidity of a target region (for example, a seat attachment region).

Further, the rate of change calculation unit 12 may specify a predetermined number of evaluation points j in order from the one with the largest absolute value of the rate of change. The predetermined number can be set as appropriate depending on the synthesis of the target structure.
The identified evaluation point j becomes a node to be reinforced. This result may be displayed on the display unit 23.

Thereby, the evaluation point j that has a large influence on the rigidity when changing from the first state to the second state can be specified more precisely. When the state changes, the evaluation point j that has a large relative displacement with respect to the reference point i may have lowered the rigidity of the structure. Therefore, by strengthening this evaluation point j, it is expected that the rigidity of the structure will further increase.

In addition, by repeating the process of implementing this evaluation method, determining the evaluation point j at which a countermeasure is to be taken, and implementing the countermeasure there, a better structure can be designed. By repeating the process, you can find hidden areas that need to be addressed.

Each step of the present embodiment described above may be configured to be automatically performed by the structure design support apparatus 10.

Moreover, by recording a program for realizing the functions of the structure design support apparatus 10 in FIG. A structure design support device 10 may also be realized. Note that the "computer system" herein includes hardware such as an OS and peripheral devices.

Furthermore, the term "computer system" includes the homepage providing environment (or display environment) if a WWW system is used.
Furthermore, the term "computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, ROMs, and CD-ROMs, and storage devices such as hard disks built into computer systems. Furthermore, a "computer-readable recording medium" refers to a storage medium that dynamically stores a program for a short period of time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. It also includes devices that retain programs for a certain period of time, such as volatile memory inside a computer system that serves as a server or client. Further, the above-mentioned program may be one for realizing a part of the above-mentioned functions, or may be one that can realize the above-mentioned functions in combination with a program already recorded in the computer system.

(Second embodiment)
Next, a second embodiment will be described with reference to FIG. 4. Note that, in the second embodiment, the same components as those in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted, and only the different points will be explained. FIG. 4 is a schematic block diagram showing the configuration of a structure design support apparatus 10B according to the second embodiment. The structure design support device 10B evaluates the rigidity of a structure made up of a plurality of parts using a virtual model (hereinafter referred to as a structure model). The structure design support device 10B includes a processing section 21B, a node information storage section 22, and a display section 23. The processing section 21B includes a node information acquisition section 11, a rate of change calculation section 12B, an image creation section 13, an evaluation point group setting section 14, and an analysis section 15.

The change rate calculation unit 12B determines one selected point among the nodes as a reference point, and calculates the first state and the distance between the reference point and the evaluation point for each evaluation point that is a node other than the reference point among the nodes. , the absolute value of the rate of change between the state and the second state is calculated. The rate of change calculation unit 12B stores the absolute value of the rate of change for each evaluation point in the node information storage unit 22 in association with evaluation point identification information that identifies the evaluation point. At this time, the rate of change calculation unit 12B stores the evaluation point where the absolute value of the rate of change is equal to or greater than the threshold value α1 in the node information storage unit 22 so as to be identifiable as a large strain evaluation point. Further, it is preferable that the rate of change calculation section 12B stores component identification information for identifying the component to which the evaluation point belongs in association with the evaluation point identification information in the node information storage section 22. It is preferable that the absolute value of the rate of change, the evaluation point identification information, and the component identification information be stored as a database in the node information storage unit 22.

The evaluation point group setting unit 14 sets a set of two or more large strain evaluation points, of which the distance between the large strain evaluation points is less than or equal to a preset threshold value β1, as a large strain evaluation point group, among the large strain evaluation points. do. Details of the method for setting the large strain evaluation point group will be described later.

The analysis unit 15 determines whether the sum of the large strain evaluation point group set by the evaluation point group setting unit 14 and the isolated large strain evaluation point which is a large strain evaluation point not included in the large strain evaluation point group is 2 or more. At a certain time, the relative displacement between the reference point and the large strain evaluation point with the largest absolute value of the rate of change among the large strain evaluation points (hereinafter sometimes referred to as the maximum strain evaluation point) or the isolated large strain evaluation point Analyze the structure model under rigid body conditions that are regulated. In this case, the total of the maximum strain evaluation point and the isolated large strain evaluation point is 2 or more. The rigidization condition in which relative displacement is regulated is, for example, a condition in which the reference point i and the maximum strain evaluation point or the isolated large strain evaluation point are connected by a rigid beam.
In addition, the analysis unit 15 calculates the rigid body evaluation value after rigid body conversion for the maximum strain evaluation point or the isolated large strain evaluation point in the group of large strain evaluation points by the analysis process under the above-mentioned rigid body conversion conditions, and A constraint target point whose displacement with respect to the reference point should be regulated is specified based on the rigid body evaluation value before rigid body conversion and the rigid body evaluation value after rigid body conversion obtained by the analysis process under the condition that no conversion condition is added.

(Structure design support method)
The structure design support method in the second embodiment will be described below. The structure design support method in the second embodiment includes the above-mentioned first process, a second process of calculating the absolute value of the rate of change, a third process of setting a large strain evaluation point group, and a constraint target. and a fourth step of specifying the point. The second process, third process, and fourth process using the structure design support apparatus 10B will be described below.

Calculation of the absolute value of the rate of change (second process) in the second embodiment will be explained. FIG. 5 is a flowchart illustrating the operation of the rate of change calculation section 12B. The rate of change calculation unit 12B performs the processes of steps S1 to S8 for each node included in the node information stored in the node information storage unit 22 (steps S1 to S8). In step S1, one selected point among the nodes is determined as a reference point i. The method of setting the reference point i is not particularly limited. Examples of the reference point i include a seat attachment point and a load input point. Alternatively, the reference point i may be set by calculating an evaluation value using a method described later. In step S2, the change rate calculation unit 12B reads the first state position (X coordinate, Y coordinate, Z coordinate) and the second state position of the reference point i from the node information storage unit 22.

Next, in step S3, specifically, the change rate calculation unit 12B sets an evaluation point j that is a node other than the reference point among the nodes (for example, initial value j=0). In step S4, the change rate calculation unit 12B reads the positions of the first state (here, the non-load state) and the second state (here, the maximum load state) of the evaluation point j from the node information storage unit 22. .

In step S5, the change rate calculation unit 12B calculates the distance F0 i,j in the first state and the distance F1 _i,j in the second state from the evaluation point j, which is a node other than the reference point _i among the nodes. do.

The change rate calculation unit 12B uses the positions read in steps S2 and S4 to calculate the distance F1 _i,j between the reference point i and the evaluation point j in the second state (step S5).

The change rate calculation unit 12B calculates the absolute value of the change rate dF _i,j = (F1 _{i ,j} - F0 _i,j )/F0 _i, j from the distance F0 _i,j to the distance F1 i,j ( Step S6).

In step S7B, the rate of change calculation unit 12B stores the absolute value of the rate of change dF _i,j of the evaluation point j in the node information storage unit 22 in association with evaluation point identification information that identifies the evaluation point j. At this time, the rate of change calculation unit 12B identifiably stores the evaluation point j at which the absolute value of the rate of change is equal to or greater than the threshold value α1 in the node information storage unit 22 as a large strain evaluation point. The threshold value α1 can be set as appropriate depending on the target rigidity of the structure.

Next, the process proceeds to step S8. In step S8, the rate of change calculation unit 12B determines whether there is any unprocessed evaluation point j. If there is an unprocessed evaluation point j (YES in step S8), the process returns to step S3, and one of the unprocessed evaluation points j is selected and processed. If there is no unprocessed evaluation point j (NO in step S8), the loop from steps S3 to S8, that is, the process ends.

(How to set large strain evaluation point cloud)
Next, a method (third process) for setting a large strain evaluation point group from the large strain evaluation points obtained above will be explained. By setting a group of large distortion evaluation points, the number of processes can be reduced in the method for specifying points to be constrained, as will be described later. FIG. 6 is a flowchart illustrating a method for setting a large strain evaluation point group. The evaluation point group setting section 14 performs the processes from steps S11 to S19 based on the node information and evaluation point identification information stored in the node information storage section 22 (steps S11 to S19).

In step S11, the evaluation point group setting unit 14 sets one selected point among the large strain evaluation points stored in the node information storage unit 22 as a reference large strain evaluation point k (for example, initial value k=0). . In step S12, the evaluation point group setting unit 14 reads the position (X coordinate, Y coordinate, Z coordinate) of the reference large strain evaluation point k in the first state from the node information storage unit 22.

Next, in step S13, the evaluation point group setting unit 14 sets a comparative large strain evaluation point l, which is a large strain evaluation point other than the reference large strain evaluation point k, among the large strain evaluation points (for example, an initial value l =0). In step S14, the evaluation point group setting unit 14 reads the position (X coordinate, Y coordinate, Z coordinate) of the comparatively large strain evaluation point l in the first state from the node information storage unit 22.

In step S15, the evaluation point group setting unit 14 calculates the distance F2 _k,l between the reference large strain evaluation point k and the comparative large strain evaluation point l in the first state. For example, the X coordinate of the reference large strain evaluation point k in the first state is X _k , the Y coordinate is Y _k , the Z coordinate is Z _k , and the comparative large strain evaluation point l in the first state is When the X coordinate is _Xl , the Y coordinate is _Yl , and the Z coordinate is _Zl , the distance F2k _,l is calculated by the following equation (3).

In step S16, if the distance F2 _k,l is equal to or less than the threshold value β1 (YES in step S16), the reference large strain evaluation point k and the comparative large strain evaluation point l are set as the same large strain evaluation point group (step S17). The threshold value β1 can be set as appropriate depending on the purpose. The value of the threshold β1 is a variable depending on the target part, the mesh of the finite element method, the design phase, etc. The threshold value β1 may be set in advance or may be set by an operator operating the structure design support apparatus 10B. At this time, the evaluation point group setting section 14 stores information on which large strain evaluation point group it belongs to in the node information storage section 22 in association with the large strain evaluation point identification information that identifies the large strain evaluation point. The large strain evaluation point identification information is, for example, a code (large strain evaluation point ID) that identifies the large strain evaluation point. The information as to which large distortion evaluation point group it belongs to is a code (large distortion evaluation point group ID) that specifies the large distortion evaluation point group. If the distance F2 _k,l is not less than the threshold value β1 (No in step S16), the process advances to step S18.

Next, the process proceeds to step S18. In step S18, the evaluation point group setting unit 14 determines whether there is any unprocessed comparative large strain evaluation point l. If there is an unprocessed comparative large strain evaluation point l (YES in step S18), the process returns to step S13, and one point is selected from the unprocessed comparative large strain evaluation points and processed. If there is no unprocessed comparative large strain evaluation point l (NO in step S18), the process advances to step S19.

In step S19, the evaluation point group setting unit 14 determines whether there is any unprocessed reference large strain evaluation point k. If there is an unprocessed reference large strain evaluation point k (YES in step S19), the process returns to step S11, and an unprocessed large strain evaluation point (a large strain evaluation point that has not been selected as a reference large strain evaluation point) is determined. One point is selected as the reference large strain evaluation point and processed. If there is no unprocessed large strain evaluation point k (NO in step S18), the process advances to step S20. In addition, in the above process, each step for setting the large distortion evaluation point group may be omitted between two points for which the distance F2 _k,l has been calculated.

In step S20, the evaluation point group setting unit 14 stores large strain evaluation points that do not belong to any large strain evaluation point group as isolated large strain evaluation points in the node information storage unit 22, and ends the process. Also, at this time, the evaluation point group setting unit 14 stores the large strain evaluation point with the largest absolute change rate among the large strain evaluation point groups as the maximum strain evaluation point in the node information storage unit 22. good.

FIG. 7 is a diagram illustrating a large strain evaluation point group and an isolated large strain evaluation point. FIG. 7 is a cross section including a component A1 and a component B1 that constitute a structure. Part A1 is provided with nodes a1 to a5, and part B1 is provided with nodes b1 to b4. The large strain evaluation points are node b1, node b2, node a2, and node a5. A set of nodes b1, b2, and a2, where the distance F2 _k,l is equal to or less than the threshold value β1, becomes one large distortion evaluation point group. Node a5, which is not included in the large strain evaluation point group, is an example of an isolated large strain evaluation point.

(Method of specifying constraint target points)
Next, a method (fourth process) for identifying a constraint target point, which is a node that makes a particularly large contribution to suppressing the displacement of the reference point i, will be described. The constraint target point is a point whose displacement with respect to the reference point i should be restricted. The number of constraint target points is not particularly limited, and is 1 or more. For example, a plurality of constraint target points may be set to improve rigidity.

FIG. 8 is a flowchart of a method for specifying a constraint target point. The analysis unit 15 performs the processes of steps S31 to S34 based on the information of the reference point i, the maximum strain evaluation point, and the isolated large strain evaluation point stored in the node information storage unit 22 (steps S31 to S34).

In step S31, the analysis unit 15 performs an analysis process on the structure model without adding the above-described rigidization condition, and calculates a rigid body evaluation value before rigidization. The analysis process is not particularly limited, and may include modal analysis, rigidity analysis, static torsional stiffness, frequency response analysis (transfer function identification), collision analysis, and running analysis. The analysis process can be performed using a known method. Modal analysis is preferable as the analysis process. When modal analysis is performed as the analysis process, for example, the rigid body evaluation value before rigid body transformation is a natural frequency, but the rigid body evaluation value before rigid body transformation is not limited to the natural frequency.

In step S32, the analysis unit 15 sets an analysis point n selected from each maximum strain evaluation point and each isolated large strain evaluation point. In step S33, the analysis unit 15 performs an analysis process on the structure model under rigid conditions in which relative displacement between the reference point and the analysis point n is regulated. The analysis process in step S32 is the same as the analysis process in step S31, and the parameters (e.g. natural frequency) that will be the rigid body evaluation value after rigid body conversion to be evaluated are the same as the parameters that will be the rigid body evaluation value before rigid body conversion in step S31. are the same. For example, if the rigid body evaluation value before rigid body transformation is a natural frequency, the rigid body evaluation value after rigid body transformation also becomes a natural frequency.

Next, proceed to step 34. In step 34, it is determined whether there is any unprocessed analysis point n. If there is an unprocessed analysis point n (YES in step S34), the process returns to step S31, and one of the unprocessed analysis points n is selected and processed. If there is no unprocessed item at the analysis point n (NO in step S34), the loop from steps S31 to S34 is completed. In other words, the process ends.

In this way, the structure design support device 10B and the structure design support method use the node information to determine the reference point i and the evaluation point j for each evaluation point j between the first state and the second state. calculate the absolute value of the rate of change in the distance between the first state and the second state, and store the absolute value of the calculated rate of change in association with evaluation point identification information that identifies evaluation point j. do. In addition, the structure design support device 10B and the structure design support method are configured such that, among the large strain evaluation points where the absolute value of the rate of change is equal to or greater than the threshold value α1, the distance between the large strain evaluation points is equal to or less than a preset threshold value β1. A set of two or more large strain evaluation points is set as a large strain evaluation point group. Then, the structure design support device 10B and the structure design support method connect the reference point to the large strain evaluation point or the isolated large strain evaluation point having the largest absolute value of the rate of change among the group of large strain evaluation points. Analyze the structure model under rigid body conditions with relative displacement regulated.

Thereby, it is possible to specify the evaluation point j that makes a large contribution (absolute value of rate of change) to the spatial distortion of the reference point i when changing from the first state to the second state. Furthermore, the evaluation point group setting section 14 sets the large distortion evaluation point group, thereby making it possible to shorten the analysis process of the analysis section 15. In addition, the analysis unit 15 analyzes the structure under rigidization conditions in which the relative displacement with the large strain evaluation point having the largest absolute value of the rate of change among the large strain evaluation points or the isolated large strain evaluation point is regulated. By performing model analysis processing, it is possible to specify restraint target points whose displacement relative to the reference point should be regulated. This facilitates the design of the structure model.

In addition, by repeating the process of implementing this evaluation method, determining the evaluation point j at which a countermeasure is to be taken, and implementing the countermeasure there, a better structure can be designed. By repeating the process, you can find hidden areas that need to be addressed.

Each step described above may be configured to be automatically performed by the structure design support apparatus 10B.

A structure is created by recording a program for realizing the functions of the structure design support apparatus 10B in FIG. A design support device 10B may also be implemented.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG. 9. In addition, in the third embodiment, the same parts as those in the first embodiment and the second embodiment are given the same reference numerals, the explanation thereof is omitted, and only the different points will be explained. FIG. 10 is a schematic block diagram showing the configuration of a structure design support apparatus 10C according to the third embodiment. The structure design support device 10C evaluates the rigidity of a structure made up of a plurality of parts using a virtual model (hereinafter referred to as a structure model). The structure design support apparatus 10C includes a processing section 21C, a node information storage section 22, and a display section 23. The processing section 21C includes a node information acquisition section 11, a rate of change calculation section 12, an image creation section 13, and an evaluation value calculation section 16.

The evaluation value calculation unit 16 calculates a component unit evaluation value Emi for the component based on the respective absolute values of the rate of change for all evaluation points j belonging to the component. A method for calculating the component unit evaluation value Emi will be described later. Furthermore, the evaluation value calculation unit 16 stores the component unit evaluation value Emi in the node information storage unit 22 in association with the evaluation point identification information.

(Structure design support method)
The structure design support method according to the third embodiment includes a first process, a second process, and a fifth process of calculating a component unit evaluation value. Here, a method of calculating component unit evaluation values using the structure design support apparatus 10C will be described. Descriptions of other processes will be omitted.

FIG. 10 is a flowchart of a method for calculating component unit evaluation values. The evaluation value calculation unit 16 calculates a component unit evaluation value Emi of the rate of change of the component m based on the absolute value of the change value of each node stored in the node information storage unit 22. In step S41, part m is set (eg, initial value m=0). In step S42, the evaluation value calculation unit 16 reads the absolute value of the rate of change of each evaluation point j belonging to the part m from the node information storage unit 22.

Next, in step S43, the evaluation value calculation unit 16 calculates the component unit evaluation value Emi for the component m based on the absolute value of the rate of change of each evaluation point j belonging to the component m. Specifically, the evaluation value calculation unit 16 calculates the average value of the absolute value of the distance change rate dF _i,j calculated for the reference point i, regarding the evaluation point j of the component m, as the component unit evaluation value Emi. The component unit evaluation value Emi is calculated by the following formula (4). However, j is j belonging to part m, and n is the number of evaluation points j belonging to part m. Further, in step 43, the evaluation value calculation unit 16 stores the component unit evaluation value Emi in the node information storage unit 22 in association with the evaluation point identification information.

If there is a node with a unique value, the evaluation value of each component is likely to be affected. By using the average value shown by equation (4) as the component unit evaluation value Emi, it is possible to easily identify components that make a large contribution to the reference point i.

Next, the process proceeds to step S44. In step S44, the evaluation value calculation unit 16 determines whether there is any unprocessed part m. If there is an unprocessed part m (YES in step S44), the process returns to step S41, and one of the unprocessed parts m is selected and processed. If there is no unprocessed part m (NO in step 44), the loop from steps S41 to S44 is ended.

In this way, the structure design support device 10C and the structure design support method use the node information to determine the reference point i and the evaluation point j for each evaluation point j between the first state and the second state. calculate the absolute value of the rate of change in the distance between the first state and the second state, and store the absolute value of the calculated rate of change in association with evaluation point identification information that identifies evaluation point j. do. Further, the structure design support device 10C and the structure design support method calculate a component unit evaluation value Emi of the component m.

Thereby, it is possible to specify the evaluation point j that makes a large contribution (absolute value of rate of change) to the spatial distortion of the reference point i when changing from the first state to the second state. In addition, by the evaluation value calculation unit 16 calculating the component unit evaluation value Emi, it is possible to easily identify, for example, a component that makes a large contribution to the improvement of rigidity.

Each step described above may be configured to be automatically performed by the structure design support apparatus 10C.

By recording a program for realizing the functions of the structure design support device 10C in FIG. 9 on a computer-readable recording medium, and having the computer system read and execute the program recorded on the recording medium, A design support device 10C may also be implemented.

(Example 1)
In Example 1, an example will be shown in which a vehicle body is analyzed by the structure design support apparatus 10 as an example of a structure. In this embodiment, the first state is a state in which the vehicle body B, which is a structural model, is not deformed. The second state is a state in which the eigenmode deformation of the vehicle body torsional deformation occurs.

FIG. 11 is a diagram showing an example of display by the structure design support apparatus 10. FIG. 12 is a diagram of the display example of FIG. 11 viewed from another perspective. In the display examples shown in FIGS. 11 and 12, the first state is a state in which no deformation has occurred in the vehicle body, which is a structural model, and the second state is a state in which deformation in the eigenmode of the vehicle body torsional deformation has occurred. This is an example of a display when the structure design support apparatus 10 performs and displays an analysis for a vehicle body. As indicated by the arrow points in FIG. 12, evaluation points that make a large contribution to the reference point (large strain evaluation points) are displayed in a darker shade. As shown in FIG. 12, by using the structure design support apparatus 10, it is possible to easily specify the area to be connected to the reference point as a darkly shaded area.

FIG. 13 is a diagram showing the results of evaluation using the method described in Japanese Patent No. 6278122, that is, between nodes. FIG. 14 is a diagram showing the results of FIG. 13 from another perspective. As shown in FIGS. 13 and 14, regions with high spatial distortion can be seen, but it is not clear which region should be fastened. In the case of FIGS. 13 and 14, the parts to be fastened, such as the bracket and the roof rail outer, must be further considered.

(Example 2)
Next, an example will be shown in which a large strain evaluation point is analyzed under rigid conditions in which relative displacement is regulated. In this example, a modal analysis was performed by connecting the reference point and the evaluation point with a rigid beam that does not displace. For the structure model, the first state is a state in which no deformation has occurred in the vehicle body, which is the structure model, and the second state is a state in which deformation in the eigenmode of the vehicle body torsional deformation has occurred. The support device 10B performed the analysis process. FIG. 15 and FIG. 16 are diagrams for explaining the rigidization conditions. FIG. 15 is an example of a structure model (Example 2-1) in which a reference point and a large strain evaluation point with a large rate of change in distance are connected by a rigid beam. FIG. 16 is an example of a structure model (Comparative Example 2-1) in which a reference point and an evaluation point with a small rate of change in distance are connected by a rigid beam. Table 1 shows the results of analysis processing performed using the structure design support apparatus 10B under these rigid body conditions. Table 1 shows a reference example with no rigidization condition in which rigid beams are not connected, Example 2-1 in which large strain evaluation points and reference points are connected with rigid beams, and example 2-1 in which evaluation points with small displacement and reference points are connected with rigid beams. The results of connected Comparative Example 2-1 are shown. The natural frequency f (Hz) of the torsion mode of the reference example is the rigid body evaluation value before rigid body conversion, and the natural frequency f (Hz) of the torsion mode of Example 2-1 and Comparative Example 2-1 is the rigid body evaluation value after rigid body conversion. Become. As shown in Table 1, Example 2-1, which was connected to a large strain evaluation point with a large rate of change in distance from the reference point, had a larger natural frequency. On the other hand, in Comparative Example 2-1, the increase in natural frequency f from Reference Example 2-1 was small.

In this way, by using the absolute value of the rate of change in the distance between the reference point i and the evaluation point j by the structure design support device 10, it is possible to easily specify the portion to be fastened. Furthermore, when a plurality of parts are displayed, the constraint target points can be clarified by performing analysis processing using the method described above. Thereby, rigidity can be improved more efficiently. That is, the structure design support apparatus 10 can more easily detect a region that has a large influence on the rigidity of a specific region.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and design changes may be made without departing from the gist of the present invention.

Each aspect of the present invention can be widely applied to a structure design support device, a structure design support method, a program, and a recording medium for evaluating and analyzing structures at the design stage of various structures. Each aspect of the present invention makes it possible to realize a structure design support device, a structure design support method, a program, and a recording medium that can easily identify parts that have a large influence on the rigidity of a specific part.

10 Structure design support device, 11 Node information acquisition unit, 12 Change rate calculation unit, 13 Image creation unit, 14 Evaluation point group setting unit, 15 Analysis unit, 16 Evaluation value calculation unit

Claims (12)

of nodes in a structure model consisting of multiple parts,
position in the first state;
position in the second state;
a node information storage unit that stores node information representing;
One selected point among the nodes is set as a reference point, and for each evaluation point that is a node other than the reference point among the nodes, the first state of the distance between the reference point and the evaluation point; a change rate calculation unit that calculates an absolute value of the change rate between the second state and the second state;
Equipped with,
The rate of change calculation unit stores the absolute value of the rate of change for each evaluation point calculated by the rate of change calculation unit in the node information storage unit in association with evaluation point identification information that identifies the evaluation point. A structure design support device featuring: 2. The rate-of-change calculation unit stores the evaluation points at which the absolute value of the rate of change is equal to or greater than a threshold value in the nodal information storage unit in a manner that allows them to be identified as large-strain evaluation points. Structure design support device. 3. The method according to claim 1, further comprising an image creation unit that creates an image in which the absolute value of the rate of change for the evaluation point can be visually recognized at the position of the evaluation point in the structure model. Structure design support device. An evaluation point group setting unit that sets a set of two or more of the large strain evaluation points, of which the distance between the large strain evaluation points is equal to or less than a preset threshold, as a large strain evaluation point group. The structure design support device according to claim 2, further comprising: a structure design support device according to claim 2; The sum of the large strain evaluation point group and the isolated large strain evaluation point that is the large strain evaluation point not included in the large strain evaluation point group is 2 or more,
The structure is made rigid under conditions where relative displacement between the reference point and the large strain evaluation point or the isolated large strain evaluation point having the largest absolute value of the rate of change among the large strain evaluation point group is regulated. 5. The structure design support apparatus according to claim 4, further comprising an analysis section that performs analysis processing of a body model. The analysis unit obtains a rigid body evaluation value after rigid body conversion for the large strain evaluation point or the isolated large strain evaluation point having the largest rate of change among the group of large strain evaluation points by analysis processing under the rigid body conversion condition. and specify a constraint target point whose displacement with respect to the reference point should be regulated based on the rigid body evaluation value before rigid body transformation and the rigid body evaluation value after rigid body transformation obtained by analysis processing without adding the rigid body transformation condition. The structure design support device according to claim 5, characterized in that: The structure design support apparatus according to claim 6, wherein the analysis process is a modal analysis process. Among the evaluation points, the change rate calculation unit associates component identification information that identifies the component to which the self belongs with the evaluation point identification information with respect to the evaluation points that belong to a plurality of parts constituting the structure model, and calculates the evaluation points from the node. 3. The structure design support device according to claim 1, wherein the structure design support device stores the information in an information storage unit. further comprising an evaluation value calculation unit that calculates a part unit evaluation value for the part based on each of the absolute values of the rate of change for all the evaluation points belonging to the part,
9. The structure design support apparatus according to claim 8, wherein the evaluation value calculation section stores the component unit evaluation value in association with the evaluation point identification information in a node information storage section. of nodes in a structure model consisting of multiple parts,
position in the first state;
position in the second state;
a first process of storing node information representing;
One selected point among the nodes is set as a reference point, and for each evaluation point that is a node other than the reference point among the nodes, the first state of the distance between the reference point and the evaluation point; a second step of calculating the absolute value of the rate of change with respect to the second state;
has,
In the second process,
A structure design support method, characterized in that the absolute value of the rate of change for each evaluation point calculated in the first step is stored in association with evaluation point identification information for identifying the evaluation point. computer,
of nodes in a structure model consisting of multiple parts,
position in the first state;
position in the second state;
a node information storage unit that stores node information representing;
One selected point among the nodes is set as a reference point, and for each evaluation point that is a node other than the reference point among the nodes, the first state of the distance between the reference point and the evaluation point; a change rate calculation unit that calculates an absolute value of the change rate between the second state and the second state;
to make it function, and
The rate of change calculation section is configured to function so as to store the absolute value of the rate of change for each evaluation point in the node information storage section in association with evaluation point identification information for identifying the evaluation point. program. A computer-readable recording medium recording the program according to claim 11.

Images