Structural design support device, structural design support method, program, and recording medium

Abstract

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

Description

[Technical Field]

[0001] The present invention relates to a structural design support device, a structural design support method, a program, and a recording medium. [Background technology]

[0002] Conventionally, various structural design support devices have been proposed for evaluating and analyzing structures during the design phase. Generally, computers are used as structural design support devices, and programs for having the computer evaluate and analyze structures, as well as systems that implement these programs, have been proposed. In such structural design support devices, a model is constructed that represents the entire structure to be designed or each component of the structure divided into small regions (elements). This model is used to simulate the response to the application of external forces, and the obtained results are used to carry out the design.

[0003] For example, Patent Document 1 describes a structural analysis technique that focuses on the change in the relative positional relationship between each component constituting a structure and other components due to the application of external forces to each component. Specifically, Patent Document 1 discloses a structural design support device comprising: an evaluation point information acquisition unit that acquires evaluation point information representing the position in a first state, the position in a second state, and which of the multiple components an evaluation point provided on a structure composed of multiple components belongs to; and an evaluation value calculation unit that uses the evaluation point information acquired by the evaluation point information acquisition unit to calculate an evaluation value representing the magnitude of the change between the first state and the second state in the positional relationship between a first evaluation point belonging to a reference component and a second evaluation point belonging to a comparison component different from the reference component to which the first evaluation point belongs. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Patent No. 6278122 [Overview of the Initiative] [Problems to be Solved by the Invention]

[0005] However, in the technology of Patent Document 1, although evaluation is performed using a vector indicating the direction in which a component that reduces the rigidity of a structure exists, when the member at the tip of the vector has a double structure, it may not be possible to determine which member contributes. In addition, when a plurality of vectors are displayed, evaluation may become difficult.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a structure design support device, a structure design support method, a program, and a recording medium that can easily identify a site that has a large influence on the rigidity of a specific site. [Means for Solving the Problems]

[0007] 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 includes a node information storage unit that stores node information representing the position of a node provided in a structure model composed of a plurality of components in a first state and the position of the node in a second state; a change rate calculation unit that determines one selected node among the nodes as a reference point, and calculates an absolute value of a change rate between the first state and the second state of the distance between the reference point and an evaluation point, which is a node other than the reference point among the nodes. The change rate calculation unit stores the absolute value of the change rate for each evaluation point calculated by the change rate calculation unit 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 according to Aspect 1, The change rate calculation unit may store, in the node information storage unit, the evaluation point whose absolute value of the change rate is equal to or greater than a threshold value as a large deformation evaluation point so as to be identifiable. (3)Aspect 3 of the present invention may further include an image creation unit that creates an image visible at the position of the evaluation point in the structure model with respect to the absolute value of the rate of change of the evaluation point in the structure design support device of Aspect 1 or 2. (4)Aspect 4 of the present invention may further include an evaluation point group setting unit that sets, as a large strain evaluation point group, a set of two or more large strain evaluation points among the large strain evaluation points where the distance between the large strain evaluation points is less than or equal to a preset threshold in the structure design support device of Aspect 2. (5)Aspect 5 of the present invention is in the structure design support device of Aspect 4, and the total of the large strain evaluation point group and the isolated large strain evaluation points that are large strain evaluation points not included in the large strain evaluation point group is two or more, and the relative displacement between the reference point and the large strain evaluation point having the largest absolute value of the rate of change among the large strain evaluation point group or the isolated large strain evaluation point is restricted. The structure model may be provided with an analysis unit that performs an analysis process. (6)Aspect 6 of the present invention is in the structure design support device of Aspect 5, and the analysis unit calculates a rigid body evaluation value after rigidification for the large strain evaluation point having the largest rate of change or the isolated large strain evaluation point among the large strain evaluation point group by the analysis process under the rigidification condition, and based on the rigid body evaluation value before rigidification and the rigid body evaluation value after rigidification by the analysis process under the condition without adding the rigidification condition, a restraint target point whose displacement with respect to the reference point should be restricted may be specified. (7)Aspect 7 of the present invention may be such that the analysis process in the structure design support device of Aspect 6 is a modal analysis process. (8)Aspect 8 of the present invention is in the structure design support device of Aspect 1 or 2. The rate of change calculation unit may store, in the node information storage unit, component identification information for identifying the component to which it belongs in association with the evaluation point identification information for evaluation points belonging to a plurality of components constituting the structure model among the evaluation points. (9) Aspect 9 of the present invention is a structural design support device of aspect 8, further comprising an evaluation value calculation unit that calculates a component unit evaluation value for a component based on the absolute value of the rate of change for all evaluation points belonging to the component, wherein the evaluation value calculation unit stores the component unit evaluation value in a node information storage unit in association with the evaluation point identification information. (10) A structural design support method according to aspect 10 of the present invention includes: a first step of storing node information representing the position in a first state and the position in a second state of nodes provided in a structural model composed of a plurality of parts; and a second step of determining one selected point from among the nodes as a reference point, and for each evaluation point which is a node other than the reference point among the nodes, calculating the absolute value of the rate of change of the distance between the reference point and the evaluation point between the first state and the second state; The system has the following characteristics: In the second process, the absolute value of the rate of change for each evaluation point calculated in the first process is stored in association with evaluation point identification information that identifies the evaluation point. (11) The program of embodiment 11 of the present invention is Computers, Nodes in a structural model composed of multiple parts, Position in the first state, Position in the second state, A node information storage unit that stores node information representing; A change rate calculation unit that determines one selected point from the aforementioned nodes as a reference point, and calculates the absolute value of the rate of change of the distance between the reference point and the evaluation point between the first state and the second state for each evaluation point which is a node other than the reference point; To make it function, and, The rate of change calculation unit is configured 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 that identifies the evaluation point. (12) The computer-readable recording medium of aspect 12 of the present invention records the program described in aspect 11. [Effects of the Invention]

[0008] According to the above aspects of the present invention, it is possible to provide a structural design support device, a structural design support method, a program, and a recording medium that can easily identify parts that have a significant influence on the rigidity of a particular part. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic block diagram showing the configuration of a structural design support device 10 according to the first embodiment of the present invention. [Figure 2] This is a flowchart illustrating the operation of the rate of change calculation unit 12 in the first embodiment. [Figure 3] This figure shows an example of a database in the first embodiment. [Figure 4] This is a schematic block diagram showing the configuration of the structural design support device 10B according to the second embodiment of the present invention. [Figure 5] This is a flowchart illustrating the operation of the rate of change calculation unit 12B in the second embodiment. [Figure 6] This is a flowchart illustrating the operation of the evaluation point cloud setting unit 14 in the second embodiment. [Figure 7] This diagram illustrates the large strain evaluation point group and isolated large strain evaluation point. [Figure 8] This is a flowchart illustrating the operation of the analysis unit 15 in the second embodiment. [Figure 9] This is a schematic block diagram showing the configuration of the structural design support device 10C according to the third embodiment. [Figure 10] This is a flowchart illustrating the operation of the evaluation value calculation unit 16 in the third embodiment. [Figure 11] This figure shows an example of the display by the structural design support device 10 in the embodiment. [Figure 12] This is a view of the display example in Figure 11 from a different perspective. [Figure 13] This figure shows the results of the evaluation between the nodes. [Figure 14] This figure shows the results of Figure 13 from a different perspective. [Figure 15]This is a diagram illustrating the rigidification conditions in Example 2-1. [Figure 16] This is a diagram illustrating the rigidification conditions in Comparative Example 2-1. [Modes for carrying out the invention]

[0010] (First Embodiment) The first embodiment will be described below with reference to the drawings. In the following embodiment, the objective of improving the rigidity of a structure is described as an example of the purpose of structural analysis during the design phase of a structure. However, the purpose of structural analysis during the design phase of a structure is not limited to improving the rigidity of the structure; it is also possible to perform structural analysis according to needs, such as reducing weight while ensuring rigidity of the structure, or performing collision analysis of the structure.

[0011] Figure 1 is a schematic block diagram showing the configuration of the structural design support device 10 according to the first embodiment. The structural design support device 10 evaluates the rigidity of a structure consisting of multiple parts using a virtual model (hereinafter referred to as the structural model). The structural model is assembled from multiple parts joined together, for example, by welding, riveting, bolting, etc. The structural design support device 10 has a processing unit 21, a node information storage unit 22, and a display unit 23. The processing unit 21 has a node information acquisition unit 11, a rate of change calculation unit 12, and an image creation unit 13.

[0012] The node information acquisition unit 11 acquires node information representing the position of nodes in the structural model to be evaluated in a first state and in a second state. The first state is, for example, a state in which no external load is applied to the structural model. The first state may also be a state in which no deformation occurs in the structural model. The second state is, for example, a state in which an external load is applied to the structural model (for example, a state in which the maximum expected load is applied). The second state may be a state in which deformation of the structural model's eigenmodes occurs. Nodes are, for example, the vertices of elements in the finite element method when the deformation of the structure in each state is analyzed using the finite element method. Node information is calculated by analyzing the structural model using the finite element method. Note that node information may also be calculated by numerical simulation other than the finite element method.

[0013] 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 nodes provided in a structural model composed of multiple parts. The rate of change calculation unit 12 sets one selected point among the nodes as a reference point and calculates the absolute value of the rate of change of the distance between the reference point and the evaluation point between the first state and the second state for each evaluation point, which is a node other than the reference point. 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 that identifies the node (node ​​ID). Furthermore, for evaluation points that belong to multiple parts that constitute the structural model, the rate of change calculation unit 12 stores part identification information that identifies the part to which it belongs in association with the evaluation point identification information in the node information storage unit. In other words, it is preferable that the rate of change calculation unit 12 stores component identification information, which identifies the component to which the evaluation point belongs, in association with the evaluation point identification information in the node information storage unit 22. 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 are stored as a database in the node information storage unit 22. Details of the method for calculating the absolute value of the conversion rate by the rate of change calculation unit 12 will be described later.

[0014] The image creation unit 13 creates an image in which the absolute value of the rate of change for an evaluation point is visible at the location of that evaluation point in the structural model. For example, the image creation unit 13 generates a three-dimensional image of the structural model in which the absolute value of the rate of change for each evaluation point calculated by the rate of change calculation unit 12 is represented by shades of gray. Alternatively, the absolute value of the rate of change for each evaluation point may be represented in color instead of shades of gray.

[0015] The display unit 23 may display the large strain evaluation points from the rate of change calculation unit 12 along with evaluation point identification information, or it may display the three-dimensional image created by the image creation unit 13.

[0016] (Structure design support method) The structural design support method of the first embodiment includes: a first process of storing node information representing the position in a first state and the position in a second state of nodes provided in a structural model composed of multiple parts; and a second process of determining one selected point from among the nodes as a reference point, and calculating the absolute value of the rate of change of the distance between the reference point and the evaluation point between the first state and the second state for each evaluation point which is a node other than the reference point; wherein in the second process, the absolute value of the rate of change for each evaluation point calculated in the first process is stored in association with evaluation point identification information that identifies the evaluation point. The structural design support method when using the structural design support device 10 will be described below.

[0017] In the first process, the node information storage unit 22 stores node information representing the position of a node in a structural model composed of multiple parts in a first state and its position in a second state.

[0018] The method for calculating the absolute value of the rate of change in the second process will be explained below. Figure 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 an unloaded state where no load is applied to the structural model, and the second state is a maximum load state where the maximum load assumed to be applied to the structural model is used as an example. The following example is an example of the present invention, and the first state is not limited to an unloaded state. Similarly, the second state is not limited to a maximum load state.

[0019] The change rate calculation unit 12 performs the processes of steps S1 to S8 for each of the nodes 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 defined as the reference point i. The method for setting the reference point i is not particularly limited. The reference point i may be, for example, a sheet attachment point, a load input point, etc. Also, the reference point i may be set by calculating an evaluation value by the method described in Japanese Patent No. 6278122. In step S2, the change rate calculation unit 12 reads out the position (X coordinate, Y coordinate, Z coordinate) of the reference point i in the first state and the position in the second state from the node information storage unit 22.

[0020] Next, in step S3, specifically, the change rate calculation unit 12 sets an evaluation point j which 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 out the positions of the evaluation point j in the first state (here, the unloaded state) and the second state (here, the maximum load state) from the node information storage unit 22.

[0021] In step S5, the change rate calculation unit 12 calculates the distance F0 in the first state between the evaluation point j, which is a node other than the reference point i, i,j and the distance F1 in the second state. i,j For example, when the X coordinate of the reference point i in the first state is X i and the Y coordinate is Y i and the Z coordinate is Z i and the X coordinate of the evaluation point j in the first state is X j and the Y coordinate is Y j and the Z coordinate is Z j then the distance F0 i,j is calculated by the following formula (1).

[0022]

Equation

[0023] The change rate calculation unit 12 uses the positions read in steps S2 and S4 to calculate the distance F1 in the second state between the reference point i and the evaluation point ji,j Calculate (Step S5). For example, the X coordinate of reference point i in the second state is X 1i And the Y coordinate is Y 1i And the Z coordinate is Z 1i And the X coordinate of the evaluation point j in the second state is X 1j And the Y coordinate is Y 1j And the Z coordinate is Z 1j When this is the case, the distance F1 i,j This is calculated using the following formula (2).

[0024]

number

[0025] The rate of change calculation unit 12 calculates the distance F0 i,j Distance from F1 i,j Rate of change to dF i,j =(F1 i,j -F0 i,j ) / F0 i,j Calculate the absolute value of (Step S6). The larger the original distance between the reference point i and the evaluation point j, the greater the change in distance, but distance F0 i,j Distance from F1 i,j Rate of change to dF i,j By using this method, the effect of this distance can be reduced.

[0026] In step S7, the rate of change calculation unit 12 calculates the rate of change dF of the evaluation point j calculated by the rate of change calculation unit 12. i,j The absolute value of is stored in the node information storage unit 22 in association with evaluation point identification information that identifies the evaluation point j. The rate of change calculation unit 12 stores the rate of change dF of the evaluation point j calculated by the rate of change calculation unit 12 in a database, for example, as shown in Figure 3. i,jThe absolute value of is stored in the node information storage unit 22 in association with evaluation point identification information that identifies the evaluation point j. In the example in Figure 3, the node information storage unit 22 uses node ID 34728 as the reference point and stores the coordinates of the first state (x0, y0, z0), the coordinates of the second state (x1, y1, z1), the distance (in 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 of distance. Figure 3 shows whether the absolute value of the rate of change of distance relative to the reference point is distributed in the same way in a part of the structural model. The absolute value of distance represents the degree of contribution.

[0027] Next, the process proceeds to step S8. In step S8, the rate of change calculation unit 12 determines whether there are any unprocessed evaluation points j. If there are any unprocessed evaluation points j (YES in step S8), the process returns to step S3, selects one of the unprocessed evaluation points j, and processes it. If there are no unprocessed evaluation points j (NO in step S8), the loop from step S3 to S8, i.e., the process ends.

[0028] In this manner, the structural design support device 10 and the structural design support method use node information to calculate the absolute value of the rate of change between the distance between the reference point i and the evaluation point j for each evaluation point j between the first state and the second state, and store the calculated absolute value of the rate of change in association with evaluation point identification information that identifies the evaluation point j.

[0029] This allows us to identify evaluation points j that have a large contribution (absolute value of the rate of change) to the spatial strain at reference point i when the structure changes from the first state to the second state. Evaluation points j that have a large contribution to the spatial strain at reference point i when the structure changes from the first state to the second state are nodes that have a large influence on stiffness. Therefore, by strengthening these evaluation points j, it can be expected that the stiffness of the structure will increase. Thus, it becomes easier to detect parts that are suitable for increasing the stiffness of the target part (for example, the mounting part of a sheet).

[0030] Furthermore, the rate of change calculation unit 12 may identify a predetermined number of evaluation points j in order from those with the largest absolute values ​​of the rate of change. The predetermined number can be set appropriately according to the synthesis of the target structure. The identified evaluation point j becomes the node that will be targeted for reinforcement or other improvements. This result may be displayed on the display unit 23.

[0031] This allows for more precise identification of evaluation point j that has a significant impact on stiffness when the state changes from the first to the second state. Evaluation point j that exhibits a large relative displacement with respect to the reference point i when the state changes may be reducing the stiffness of the structure. Therefore, strengthening this evaluation point j can be expected to further increase the stiffness of the structure.

[0032] Furthermore, by repeatedly implementing this evaluation method, determining the evaluation point j where countermeasures should be taken, and then implementing those countermeasures, a better structure can be designed. Through repeated implementation, hidden areas that require countermeasures can be identified.

[0033] Each step of this embodiment described above may be configured to be performed automatically by the structural design support device 10.

[0034] Alternatively, the structural design support device 10 may be realized by recording a program for realizing the functions of the structural design support device 10 in Figure 1 onto a computer-readable recording medium, loading the program recorded on this recording medium into a computer system, and executing it. The term "computer system" here includes hardware such as the operating system and peripheral devices.

[0035] Furthermore, "computer system" shall also include the homepage provisioning environment (or display environment) if a WWW system is being used. Furthermore, "computer-readable recording media" refers to portable media such as flexible disks, magneto-optical disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into computer systems. Moreover, "computer-readable recording media" also includes those that dynamically hold programs for a short period of time, such as communication lines used when transmitting programs via networks such as the Internet or communication lines such as telephone lines, and those that hold programs for a certain period of time, such as volatile memory inside computer systems that act as servers or clients in such cases. In addition, the above-mentioned programs may be for the purpose of realizing some of the functions described above, and may also be programs that can realize the above-mentioned functions in combination with programs already recorded in the computer system.

[0036] (Second Embodiment) Next, a second embodiment will be described with reference to Figure 4. In the second embodiment, the same reference numerals are used for parts that are the same as those in the first embodiment, and their descriptions are omitted; only the differences will be described. Figure 4 is a schematic block diagram showing the configuration of the structural design support device 10B according to the second embodiment. The structural design support device 10B evaluates the rigidity of a structure consisting of multiple parts using a virtual model (hereinafter referred to as the structural model). The structural design support device 10B includes a processing unit 21B, a node information storage unit 22, and a display unit 23. The processing unit 21B includes a node information acquisition unit 11, a rate of change calculation unit 12B, an image creation unit 13, an evaluation point cloud setting unit 14, and an analysis unit 15.

[0037] The rate of change calculation unit 12B sets one selected node as a reference point and calculates the absolute value of the rate of change of the distance between the reference point and the evaluation point between the first state and the second state for each evaluation point, which is a node other than the reference point. 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 in the node information storage unit 22 evaluation points in which the absolute value of the rate of change is equal to or greater than the threshold α1, so that they can be identified as large strain evaluation points. Furthermore, it is preferable that the rate of change calculation unit 12B stores in the node information storage unit 22 part identification information that identifies the part to which the evaluation point belongs, in association with the evaluation point identification information. It is preferable that the absolute value of the rate of change, the evaluation point identification information, and the part identification information are stored as a database in the node information storage unit 22.

[0038] The evaluation point group setting unit 14 sets a group of two or more large strain evaluation points, where the distance between them is less than or equal to a predetermined threshold β1, as a large strain evaluation point group. Details of how to set the large strain evaluation point group will be described later.

[0039] When 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, the analysis unit 15 performs analysis processing of the structural model under rigidification conditions in which 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 point group (hereinafter sometimes referred to as the maximum strain evaluation point) or the isolated large strain evaluation point is restricted. In this case, the sum of the maximum strain evaluation point and the isolated large strain evaluation point is 2 or more. The rigidification conditions in which relative displacement is restricted are, for example, conditions 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. Furthermore, the analysis unit 15 calculates the rigid body evaluation value after rigidification for the maximum strain evaluation point or isolated large strain evaluation point among the large strain evaluation point group by performing analysis processing under the rigidification conditions described above, and identifies the constrained point whose displacement relative to the reference point should be restricted based on the rigid body evaluation value before rigidification obtained by analysis processing under conditions without the rigidification conditions and the rigid body evaluation value after rigidification.

[0040] (Structure design support method) The structural design support method in the second embodiment will be described below. The structural design support method in the second embodiment includes the first process described above, a second process of calculating the absolute value of the rate of change, a third process of setting up a large strain evaluation point group, and a fourth process of identifying the constrained points. The second process, the third process, and the fourth process using the structural design support device 10B will be described below.

[0041] The calculation of the absolute value of the rate of change in the second embodiment (second process) will be explained. Figure 5 is a flowchart illustrating the operation of the rate of change calculation unit 12B. The rate of change calculation unit 12B performs the processes from 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 set as the reference point i. The method of setting the reference point i is not particularly limited. Examples of reference point i include a sheet mounting point and a load input point. Alternatively, the reference point i may be set by calculating an evaluation value using the method described later. In step S2, the rate of change calculation unit 12B reads the position of the reference point i in the first state (X coordinate, Y coordinate, Z coordinate) and the position in the second state from the node information storage unit 22.

[0042] Next, in step S3, specifically, the rate of change calculation unit 12B sets an evaluation point j, which is a node other than the reference point (for example, an initial value of j=0). In step S4, the rate of change calculation unit 12B reads the positions of the evaluation point j in the first state (in this case, the unloaded state) and the second state (in this case, the maximum load state) from the node information storage unit 22.

[0043] In step S5, the rate of change calculation unit 12B calculates the distance F0 in the first state between the evaluation point j, which is a node other than the reference point i among the nodes. i,j and distance F1 in the second state i,j Calculate.

[0044] The rate of change calculation unit 12B uses the positions read in steps S2 and S4 to calculate the distance F1 between the reference point i and the evaluation point j in the second state. i,j Calculate (Step S5).

[0045] The rate of change calculation unit 12B calculates the distance F0 i,j Distance from F1 i,j Rate of change to dF i,j =(F1 i,j -F0 i,j ) / F0 i,j Calculate the absolute value of (Step S6).

[0046] In step S7B, the rate of change calculation unit 12B calculates the rate of change dF of the evaluation point j. i,j The absolute value of the rate of change is stored in association with evaluation point identification information that identifies the evaluation point j and the node information storage unit 22. At this time, the rate of change calculation unit 12B stores in the node information storage unit 22 evaluation points j where the absolute value of the rate of change is greater than or equal to the threshold α1 as large strain evaluation points. The threshold α1 can be set appropriately according to the stiffness of the target structure.

[0047] Next, the process proceeds to step S8. In step S8, the rate of change calculation unit 12B determines whether there are any unprocessed evaluation points j. If there are any unprocessed evaluation points j (YES in step S8), the process returns to step S3 and selects one of the unprocessed evaluation points j to process. If there are no unprocessed evaluation points j (NO in step S8), the loop from step S3 to S8, i.e., the process ends.

[0048] (How to set up a large strain evaluation point group) Next, we will explain the method for setting a group of large strain evaluation points from the large strain evaluation points obtained above (the third process). By setting a group of large strain evaluation points, the number of processes in the method for identifying constrained points can be reduced, as will be described later. Figure 6 is a flowchart illustrating the method for setting a group of large strain evaluation points. The evaluation point group setting unit 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 unit 22 (steps S11 to S19).

[0049] In step S11, the evaluation point group setting unit 14 selects one point from the large strain evaluation points stored in the node information storage unit 22 and sets it as the 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 first state of the reference large strain evaluation point k from the node information storage unit 22.

[0050] Next, in step S13, the evaluation point group setting unit 14 sets a comparison 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, 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 first state of the comparison large strain evaluation point l from the node information storage unit 22.

[0051] In step S15, the evaluation point group setting unit 14 determines the distance F2 in the first state between the reference large strain evaluation point k and the comparison large strain evaluation point l. k,l Calculate the following. For example, the X coordinate of the reference large strain evaluation point k in the first state is X k And the Y coordinate is Y k And the Z coordinate is Z k Therefore, the X-coordinate of the comparison large strain evaluation point l in the first state is X l And the Y coordinate is Y l And the Z coordinate is Z l When this is the case, the distance F2 k,l This is calculated using the following formula (3).

[0052]

number

[0053] In step S16, distance F2 k,lIf the value is less than or equal to threshold β1 (YES in step S16), the reference large strain evaluation point k and the comparison large strain evaluation point l are set as the same large strain evaluation point group (step S17). Threshold β1 can be set appropriately depending on the purpose. The value of threshold β1 is a variable corresponding to the target part, the finite element method mesh, the design phase, etc. Threshold β1 may be set in advance, or it may be set by an operator operating the structural design support device 10B. At this time, the evaluation point group setting unit 14 stores in the node information storage unit 22 information on which large strain evaluation point group it belongs to, in association with 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 that identifies the large strain evaluation point (large strain evaluation point ID). The information on which large strain evaluation point group it belongs to is a code that identifies the large strain evaluation point group (large strain evaluation point group ID). Distance F2 k,l If the result is not below the threshold β1 (No in step S16), proceed to step S18.

[0054] Next, the process proceeds to step S18. In step S18, the evaluation point group setting unit 14 determines whether there are any unprocessed points among the comparative large strain evaluation points l. If there are any unprocessed points among the comparative large strain evaluation points l (YES in step S18), the process returns to step S13 and selects one of the unprocessed comparative large strain evaluation points to process. If there are no unprocessed points among the comparative large strain evaluation points l (NO in step S18), the process proceeds to step S19.

[0055] In step S19, the evaluation point group setting unit 14 determines whether there are any unprocessed reference large strain evaluation points k. If there are any unprocessed reference large strain evaluation points k (YES in step S19), the process returns to step S11, and one of the unprocessed large strain evaluation points (large strain evaluation points not selected as reference large strain evaluation points) is selected as the reference large strain evaluation point and processed. If there are no unprocessed large strain evaluation points k (NO in step S18), the process proceeds to step S20. Note that in the above process, distance F2 k,l For two points that have already been calculated, the steps for setting up the large strain evaluation point group may be omitted.

[0056] In step S20, the evaluation point group setting unit 14 stores the 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 terminates the process. Alternatively, at this time, the evaluation point group setting unit 14 may also store the large strain evaluation point with the largest absolute rate of change among each large strain evaluation point group as the maximum strain evaluation point in the node information storage unit 22.

[0057] Figure 7 illustrates the large strain evaluation point group and isolated large strain evaluation points. Figure 7 shows a cross-section including parts A1 and B1 that constitute the structure. Part A1 has nodes a1 to a5, and part B1 has nodes b1 to b4. The large strain evaluation points are nodes b1, b2, a2, and a5. Distance F2 k,l The set of nodes b1, b2, and a2, where the threshold β1 is less than or equal to β1, constitutes a large strain 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.

[0058] (Method for identifying the points subject to constraint) Next, we will explain the method for identifying constrained points, which are nodes that make a particularly large contribution to suppressing the displacement of reference point i (the fourth step). A constrained point is a point whose displacement relative to reference point i should be restricted. The number of constrained points is not particularly limited and can be one or more. For example, multiple constrained points may be set to improve rigidity.

[0059] Figure 8 is a flowchart of the method for identifying the constrained points. The analysis unit 15 performs the processing from 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).

[0060] In step S31, the analysis unit 15 performs an analysis on the structural model without adding the rigidification conditions described above, and calculates the pre-rigidification rigidity evaluation value. The analysis process is not particularly limited and includes modal analysis, stiffness analysis, static torsional stiffness, frequency response analysis (transfer function identification), collision analysis, and driving analysis. The analysis process can be carried out using known methods. Modal analysis is preferred as the analysis process. When modal analysis is performed as the analysis process, for example, the pre-rigidification rigidity evaluation value is a natural frequency, but the pre-rigidification rigidity evaluation value is not limited to a natural frequency.

[0061] 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 analysis processing on the structural model under rigidification conditions in which the relative displacement between the reference point and analysis point n is restricted. The analysis processing in step S32 is the same as the analysis processing in step S31, and the parameters that become the rigid body evaluation value after rigidification (e.g., natural frequency) are the same as the parameters that become the rigid body evaluation value before rigidification in step S31. For example, if the rigid body evaluation value before rigidification is a natural frequency, the rigid body evaluation value after rigidification will also be a natural frequency.

[0062] Next, proceed to step 34. In step 34, determine whether there are any unprocessed analysis points n. If there are any unprocessed analysis points n (YES in step S34), return to step S31 and select one of the unprocessed analysis points n to process. If there are no unprocessed analysis points n (NO in step S34), terminate the loop from steps S31 to S34. In other words, end the process.

[0063] In this way, the structural design support device 10B and the structural design support method use node information to calculate the absolute value of the rate of change of the distance between the reference point i and the evaluation point j between the first state and the second state for each evaluation point j between the first state and the second state, and store the calculated absolute value of the rate of change in association with evaluation point identification information that identifies the evaluation point j. Furthermore, the structural design support device 10B and the structural design support method set a group of large strain evaluation points, which are large strain evaluation points whose absolute value of the rate of change is greater than or equal to a threshold α1, and whose distance between large strain evaluation points is less than or equal to a preset threshold β1.Then, the structural design support device 10B and the structural design support method perform analysis processing of the structural model under rigidification conditions in which the relative displacement between the reference point and the large strain evaluation point or the isolated large strain evaluation point with the largest absolute value of the rate of change among the large strain evaluation point group is restricted.

[0064] This makes it possible to identify evaluation point j that has a large contribution (absolute value of the rate of change) to the spatial strain at reference point i when it changes from the first state to the second state. In addition, by setting a large strain evaluation point group in the evaluation point group setting unit 14, the analysis processing of the analysis unit 15 can be shortened. Furthermore, by performing analysis processing of the structural model under rigidification conditions in which the relative displacement with respect to the large strain evaluation point or the isolated large strain evaluation point with the largest absolute value of the rate of change among the large strain evaluation point group is restricted, the analysis unit 15 can identify the constrained points whose displacement with respect to the reference point should be restricted. This makes it easier to design the structural model.

[0065] Furthermore, by repeatedly implementing this evaluation method, determining the evaluation point j where countermeasures should be taken, and then implementing those countermeasures, a better structure can be designed. Through repeated implementation, hidden areas that require countermeasures can be identified.

[0066] Each of the steps described above may be configured to be performed automatically by the structural design support device 10B.

[0067] The structural design support device 10B in Figure 9 may be realized by recording a program for realizing its functions on a computer-readable recording medium, loading the program recorded on this recording medium into a computer system, and executing it.

[0068] (Third embodiment) Next, a third embodiment will be described with reference to Figure 9. In the third embodiment, the same reference numerals are used for parts that are the same as those in the first and second embodiments, and their descriptions are omitted; only the differences will be described. Figure 10 is a schematic block diagram showing the configuration of the structural design support device 10C according to the third embodiment. The structural design support device 10C evaluates the rigidity of a structure consisting of multiple parts using a virtual model (hereinafter referred to as the structural model). The structural design support device 10C has a processing unit 21C, a node information storage unit 22, and a display unit 23. The processing unit 21C has a node information acquisition unit 11, a rate of change calculation unit 12, an image creation unit 13, and an evaluation value calculation unit 16.

[0069] The evaluation value calculation unit 16 calculates a component-specific evaluation value Emi for a component based on the absolute value of the rate of change for all evaluation points j belonging to that component. The method for calculating the component-specific evaluation value Emi will be described later. The evaluation value calculation unit 16 also stores the component-specific evaluation value Emi in the node information storage unit 22 in association with the evaluation point identification information.

[0070] (Structure design support method) The structural design support method according to the third embodiment includes a first process, a second process, and a fifth process for calculating component-level evaluation values. Here, we will describe the method for calculating component-level evaluation values ​​using the structural design support device 10C. Descriptions of the other processes will be omitted.

[0071] Figure 10 is a flowchart of the method for calculating the component unit evaluation value. The evaluation value calculation unit 16 calculates the component unit evaluation value Emi of the rate of change of 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, component m is set (for example, 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 component m from the node information storage unit 22.

[0072] Next, in step S43, the evaluation value calculation unit 16 calculates a component unit evaluation value Emi for component m based on the absolute values ​​of the rate of change of each evaluation point j belonging to component m. Specifically, the evaluation value calculation unit 16 calculates the rate of change of distance dF calculated for the reference point i. i,j The average value of the absolute value of the evaluation point j of part m is calculated as the part unit evaluation value Emi. The part unit evaluation value Emi is calculated by the following formula (4). Here, j is the j belonging to part m, and n is the number of evaluation points j belonging to part m. In step 43, the evaluation value calculation unit 16 stores the part unit evaluation value Emi in the node information storage unit 22 in association with the evaluation point identification information.

[0073]

number

[0074] The presence of nodes with unique values ​​can easily influence the evaluation values ​​at the component level. By using the average value shown in equation (4) as the component-level evaluation value Emi, it becomes easier to identify components that have a large contribution to the reference point i.

[0075] Next, the process proceeds to step S44. In step S44, the evaluation value calculation unit 16 determines whether there are any unprocessed parts m. If there are any unprocessed parts m (YES in step S44), the process returns to step S41, selects one of the unprocessed parts m, and processes it. If there are no unprocessed parts m (NO in step 44), the loop from steps S41 to S44 ends.

[0076] In this way, the structural design support device 10C and structural design support method use node information to calculate the absolute value of the rate of change of the distance between the reference point i and the evaluation point j between the first state and the second state for each evaluation point j between the first state and the second state, and store the calculated absolute value of the rate of change in association with evaluation point identification information that identifies the evaluation point j. Furthermore, the structural design support device 10C and structural design support method calculate the component unit evaluation value Emi of component m.

[0077] This makes it possible to identify evaluation point j that has a large contribution (absolute value of the rate of change) to the spatial strain at reference point i when the state changes from the first state to the second state. In addition, by having the evaluation value calculation unit 16 calculate the component-level evaluation value Emi, it becomes easier to identify components that have a large contribution to, for example, the improvement of rigidity.

[0078] Each of the steps described above may be configured to be performed automatically by the structural design support device 10C.

[0079] The structural design support device 10C in Figure 9 may be realized by recording a program for realizing its functions on a computer-readable recording medium, loading the program recorded on this recording medium into a computer system, and executing it.

[0080] (Example 1) Example 1 shows an example of a vehicle body as an example of a structure, analyzed using the structural design support device 10. In this example, the first state is a state in which no deformation occurs in the vehicle body B, which is the structural model. The second state is a state in which deformation of the eigenmode of torsional deformation of the vehicle body occurs.

[0081] Figure 11 shows an example of a display by the structural design support device 10. Figure 12 is a view of the display example in Figure 11 from a different perspective. The display examples in Figures 11 and 12 show the display when the structural design support device 10 performs an analysis on a vehicle body when the first state is a state in which no deformation has occurred on the vehicle body, which is a structural model, and the second state is a state in which deformation of the eigenmode of torsional deformation of the vehicle body has occurred. As indicated by the points indicated by the arrows in Figure 12, evaluation points that have a large contribution to the reference point (large strain evaluation points) are displayed with a darker shade. As shown in Figure 12, by using the structural design support device 10, the area that should be fastened to the reference point can be easily identified as a darker shade.

[0082] Figure 13 shows the results of the method described in Japanese Patent Publication No. 6278122, i.e., the evaluation between nodes. Figure 14 shows the results of Figure 13 from a different perspective. As shown in Figures 13 and 14, areas with high spatial distortion are visible, but it is not clear which parts should be fastened to. In the case of Figures 13 and 14, the parts to be fastened, such as brackets and roof rail outers, must be further considered.

[0083] (Example 2) Next, we show an example of analysis performed under rigidity conditions where relative displacement is restricted with respect to large strain evaluation points. In this example, the reference point and the evaluation points were connected by rigid beams that do not displace, and modal analysis was performed. For the structural model, the first state was defined as a state in which no deformation occurs in the vehicle body, which is the structural model, and the second state was defined as a state in which deformation of the natural modes of torsional deformation of the vehicle body occurs. The structural design support device 10B performed the analysis processing. Figures 15 and 16 are diagrams to explain the rigidity conditions. Figure 15 is an example of a structural model (Example 2-1) in which the reference point and large strain evaluation points with a large rate of change in distance are connected by rigid beams. Figure 16 is an example of a structural model (Comparative Example 2-1) in which the reference point and evaluation points with a small rate of change in distance are connected by rigid beams. Table 1 shows the results of the analysis processing performed using the structural design support device 10B under these rigidity conditions. Table 1 shows the results for a reference example without rigidity conditions (no rigid beam connection), Example 2-1 where a large strain evaluation point and a reference point were connected by a rigid beam, and Comparative Example 2-1 where an evaluation point with small displacement was connected to a reference point by a rigid beam. The natural frequency f(Hz) of the torsional mode in the reference example is the rigid body evaluation value before rigidity, while the natural frequency f(Hz) of the torsional mode in Example 2-1 and Comparative Example 2-1 is the rigid body evaluation value after rigidity. 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, showed a larger natural frequency. On the other hand, Comparative Example 2-1 showed a smaller increase in natural frequency f compared to Reference Example 2-1.

[0084] [Table 1]

[0085] In this way, by using the absolute value of the rate of change of the distance between the reference point i and the evaluation point j, as determined by the structural design support device 10, the parts that should be fastened can be easily identified. Furthermore, when multiple parts are displayed, the points subject to constraint can be clearly identified by performing analysis processing using the method described above. This makes it possible to improve rigidity more efficiently. In other words, the structural design support device 10 can more easily detect parts that have a significant impact on the rigidity of a particular part.

[0086] While embodiments of this invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and may include design modifications and the like that do not depart from the spirit of this invention. [Industrial applicability]

[0087] Each aspect of the present invention can be broadly applied to structural design support devices, structural design support methods, programs, and recording media for evaluating and analyzing structures during the design phase of various structures. Each aspect of the present invention makes it possible to realize structural design support devices, structural design support methods, programs, and recording media that can easily identify parts that have a significant influence on the rigidity of a particular part. [Explanation of Symbols]

[0088] 10. Structural design support device, 11. Node information acquisition unit, 12. Rate of change calculation unit, 13. Image creation unit, 14. Evaluation point cloud setting unit, 15. Analysis unit, 16. Evaluation value calculation unit

Claims

1. Nodes in a structural model composed of multiple parts, Position in the first state, Position in the second state, A node information storage unit that stores node information representing; A change rate calculation unit that determines one selected point from the aforementioned nodes as a reference point, and calculates the absolute value of the rate of change of the distance between the reference point and the evaluation point between the first state and the second state for each evaluation point which is a node other than the reference point among the aforementioned nodes; Equipped with, The structural design support device is characterized in that 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.

2. The structural design support device according to claim 1, characterized in that the rate of change calculation unit stores in the node information storage unit the evaluation points for which the absolute value of the rate of change is equal to or greater than a threshold, so that they can be identified as large strain evaluation points.

3. The structural design support device according to claim 1 or 2, further comprising an image creation unit that creates an image in which the absolute value of the rate of change for the evaluation point is visible at the location of the evaluation point in the structural model.

4. The structural design support device according to claim 2, further comprising a point group setting unit that sets a group of two or more large strain evaluation points, from among the large strain evaluation points, where the distance between the large strain evaluation points is less than or equal to a preset threshold, as a large strain evaluation point group.

5. The sum of the large strain evaluation point group and the isolated large strain evaluation point that is not included in the large strain evaluation point group is 2 or more. The structural design support device according to claim 4, further comprising an analysis unit that performs analysis of the structural model under rigidification conditions in which 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 point group is restricted.

6. The structural design support device according to claim 5, characterized in that the analysis unit calculates a rigid body evaluation value after rigidification for the large strain evaluation point or the isolated large strain evaluation point with the largest rate of change among the large strain evaluation point group by performing an analysis process under the rigidification condition, and identifies a constrained point whose displacement relative to the reference point should be restricted based on the rigid body evaluation value before rigidification obtained by an analysis process under conditions without the rigidification condition and the rigid body evaluation value after rigidification.

7. The structural design support device according to claim 6, wherein the analysis process is a modal analysis process.

8. The structural design support device according to claim 1 or 2, characterized in that the rate of change calculation unit stores in the node information storage unit, in association with the evaluation point identification information, a component identification information that identifies the component to which it belongs, for evaluation points belonging to a plurality of components constituting the structural model from among the evaluation points.

9. The system further comprises an evaluation value calculation unit that calculates a component-specific evaluation value for a component based on the absolute value of the rate of change for all of the evaluation points belonging to that component, The structural design support device according to claim 8, characterized in that the evaluation value calculation unit stores the component unit evaluation value in the node information storage unit in association with the evaluation point identification information.

10. Nodes in a structural model composed of multiple parts, Position in the first state, Position in the second state, A first process that stores node information representing; A second process involves setting one selected point from the aforementioned nodes as a reference point, and for each evaluation point which is a node other than the reference point, calculating the absolute value of the rate of change of the distance between the reference point and the evaluation point between the first state and the second state; The computer executes this, In the second process described above, A structural design support method characterized in that the computer stores the absolute value of the rate of change for each evaluation point calculated in the first process in association with evaluation point identification information that identifies the evaluation point.

11. Computers, Nodes in a structural model composed of multiple parts, Position in the first state, Position in the second state, A node information storage unit that stores node information representing; A change rate calculation unit that determines one selected point from the aforementioned nodes as a reference point, and calculates the absolute value of the rate of change of the distance between the reference point and the evaluation point between the first state and the second state for each evaluation point which is a node other than the reference point among the aforementioned nodes; To make it function, and, A program characterized in that the rate of change calculation unit is configured 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 that identifies the evaluation point.

12. A computer-readable recording medium having the program described in claim 11 recorded on it.

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