JP4747794B2 - Automatic analysis apparatus and automatic analysis method - Google Patents

Description

  The present invention relates to an automatic analysis apparatus and an automatic analysis method for performing structural analysis by FEM (Finite Element Method).

  Conventionally, for example, when designing a vehicle part, the natural frequency, rigidity, bending characteristics, etc. of the vehicle part are analyzed assuming the stress applied when the vehicle part is mounted on the vehicle and the vehicle travels. To be done.

  In this analysis process, CAD (computer aided design) data is taken in, and a stress input point of the vehicle part, a fixed point, and a reading point for detecting a state when stress is input to the input point are designated. Thereafter, the 3D data of the vehicle part is divided into meshes, boundary conditions are added, and an analysis result such as a displacement amount at the reading point is obtained.

  In such an analysis process, input points, fixed points, reading points, and boundary conditions are input to the vehicle part represented by CAD data. The relative relationship among the point, the fixed point, and the reading point is maintained as it is. This is because certain rules such as an input point and an input direction of stress based on the operation of the part are added to the part in the vehicle part. Further, this certain rule needs to be set again every time the dimensions of the vehicle parts are changed. Furthermore, for example, when designing a crankshaft, it is necessary to designate a cylindrical surface representing a crankpin, a cylindrical surface representing a crank journal, and a stress input direction on the screen, and specify a location where a certain rule is applied.

  Furthermore, when the dimensions of the vehicle parts are changed, an operation for setting the mesh node at the input point and giving the input condition, an operation for setting the mesh node at the fixed point and giving the constraint condition, and a reading point It is necessary to set the nodes of the mesh.

  By the way, in the vehicle component analysis work using the above-described conventional finite element method, there are cases where the designer wants to obtain the natural frequency and rigidity at various dimensions by changing the dimensions of the component. However, in the software using the conventional finite element method, even if the dimensions of some vehicle parts are changed, the relative positional relationship such as the input point, the fixed point, and the reading point is changed and changed. As described above, it is necessary to newly perform complicated operations such as designation of input points, fixed points, reading points, and addition of conditions.

  Therefore, the present invention has been proposed in view of the above-described circumstances, and an automatic analyzer that can easily obtain the analysis result of the structural analysis target even when the dimensions of the structural analysis target are changed. And it aims at providing an automatic analysis method.

The present invention is an automatic analysis apparatus and an automatic analysis method for performing structural analysis according to a finite element method, and in order to solve the above-described problems, three-dimensional data to be structurally analyzed is acquired in advance, input points, fixed points, accepting an operation input by a designer to change the size of the site in which is represented by three-dimensional data reading point is set structure analyzed, according to change of size of the site in the accepted structure analyzed, three-dimensional representing the site The shape in the data and the shape in the three-dimensional data representing the part other than the relevant part are changed in conjunction, a mesh representing the structural analysis target is created from the three-dimensional data of the changed shape, and predetermined based on the changed shape new fixed point according to setting the position of the new input points according to the rules of the input point, the modified fixed point rule which is previously determined based on the shape Position Set, to set the position of a new reading point according to the changed shape Based on predetermined reading point rule is applied to a new input point in accordance stress setting rules applied to the input point stress set the analysis conditions including the position of the input point of the structure analyzed, and the position of the structural analysis target fixed point, the position of the reading point of the structure analyzed, and a stress applied to the input point And according to the analysis conditions, the state of the new reading point when the stress is input to the new input point is analyzed by the finite element method.

  According to the automatic analysis apparatus and the automatic analysis method of the present invention, when the size of a part in the structural analysis target is changed, not only the part but also three-dimensional data of other parts are linked in conjunction with the change in dimension. In addition to being able to change automatically, the analysis conditions can also be automatically reset to easily provide the analysis results.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The present invention is applied, for example, to an automatic analyzer configured as shown in FIG. 1 and operating according to the processing procedure shown in FIG. The automatic analysis apparatus shown in FIG. 1 performs an FEM (Finite Element Method) process to obtain a result such as a natural frequency or a rigidity of a structural analysis target, and an automatic analysis processing unit 1 for obtaining a structural analysis target 3 A CAD data input unit 2 that acquires CAD (computer aided design) data that is dimension data, a result output unit 3 that outputs an analysis result by the automatic analysis processing unit 1, and an operation input unit 4 that is operated by a designer. It is connected.

  In this automatic analysis device, first, when CAD data to be subjected to structural analysis is designated by a designer's operation input to the operation input unit 4, the CAD data input unit 2 acquires the corresponding CAD data and performs automatic analysis processing. Supply to part 1. Then, the automatic analysis processing unit 1 displays CAD data on a display (not shown) or the like.

  This CAD data is template data for design and incorporates information such as position information necessary for FEM analysis. As a result, the automatic analysis apparatus inputs CAD data and necessary analysis information included in the CAD data from a server apparatus or the like that stores the CAD data, and supplies the CAD data to the automatic analysis processing unit 1.

  When the automatic analysis processing unit 1 acquires CAD data and analysis necessary information, the automatic analysis processing unit 1 performs FEM analysis processing, obtains the natural frequency, rigidity, and the like of the structural analysis target, and causes the result output unit 3 to display the result. In this FEM analysis process, the input points, fixed points, and reading points of the structure analysis target are set according to the operation of the operation input unit 4, and the structure analysis target set with each point is set to a finite number of meshes. When the boundary condition is set by dividing, it is a process for obtaining the stress, displacement, etc. at the reading point when the stress is applied to the input point. At this time, it is assumed that material properties such as a plate thickness, Young's modulus, mass, density, and the like to be structurally analyzed are set in each mesh. Thereby, the rigidity of the structural analysis target can be obtained. Further, this FEM analysis process can also obtain the frequency at the reading point when it is designated by the operation of the operation input unit 4 that the stress and the frequency are applied to the input point to be structurally analyzed.

  By the way, at the time of designing the structural analysis target, it is necessary to obtain an optimum dimension for realizing the required performance even if the structural analysis target is the same type. For this purpose, it is necessary to perform an FEM analysis for each of various dimensions for comparison. On the other hand, when the designer operates the operation input unit 4 to instruct the dimensional change of the structural analysis target, the automatic analysis processing unit 1 automatically obtains and presents the processing result of the FEM analysis reflecting the instruction. To do.

  The automatic analysis processing unit 1 performs processing as shown in FIG. 2 when the designer changes the dimension of the structural analysis target for FEM analysis. Hereinafter, the processing of the automatic analysis processing unit 1 will be described. In this processing, as shown in FIG. 3A, the structural analysis target is divided into the crank pin 101, the crank arms 102A and 102B, and the crank journals 103A and 103B. A case where the bending rigidity of the crankshaft is obtained by FEM analysis will be described. Further, this processing is performed within the CAD data representing the crankshaft, and an input point 11 is set at the upper end of the crank pin 101 in the vertical direction in the figure and fixed to the lower end of the crank journal 103A, 103B in the vertical direction in the figure. A case where the dimensions of the crankshaft are changed in a state where the points 12A and 12B are set and the reading point 13 is set at the lower end in the vertical direction of the crankpin 101 in the drawing will be described.

  The automatic analysis processing unit 1 inputs an operation input signal for changing the dimensions of the crankshaft in step S1 of FIG. For example, the automatic analysis processing unit 1 starts from the operation input unit 4 in a state where the lateral width dimension of the crankpin 101 is A as shown in FIG. 3A, and the lateral width dimension of the crankpin 101 as shown in FIG. An operation input signal indicating that is changed to B is input.

  Next, in step S2, the automatic analysis processing unit 1 changes the CAD data so that the shape of the crankpin 101 represented by the CAD data becomes the horizontal width dimension B in accordance with the operation input signal input in step S1. .

  At this time, the automatic analysis processing unit 1 identifies the position information of the crankpin 101 among the information necessary for analysis of the CAD data by the ID, and changes the identified position information to the position information of the changed dimension. As a result, the width of the crankpin 101 is changed from A to B, the vertical dimension of the crankpin 101 is reduced, and the vertical dimension of the crankpin 101 is reduced. At this time, the automatic analysis processing unit 1 defines a rule defining the relationship (size ratio) of the vertical dimension of the crankpin 101 to the horizontal dimension of the crankpin 101 and the vertical length of the crank journals 103A and 103B with respect to the horizontal dimension of the crankpin 101 The vertical dimensions of the crankpin 101 and the crank journals 103A and 103B are changed in accordance with the change in the horizontal width dimension of the crankpin 101 in accordance with the rule defining the relationship (size ratio) with the dimensions.

  As described above, the automatic analysis processing unit 1 automatically defines the three-dimensional shape of the crankpin 101 in conjunction with the dimensional change by the operation of the operation input unit 4.

  Next, in step S3, the automatic analysis processing unit 1 performs processing for dividing the CAD data whose dimensions have been changed in step S2 into meshes. Here, the material characteristics before the dimension change and the like are applied to the mesh after the dimension change.

  Next, in step S4, the automatic analysis processing unit 1 sets boundary conditions for the mesh created in step S3. At this time, the automatic analysis processing unit 1 is set to the input point rule set to the crankpin 101 constituting the crankshaft, the fixed point rule set to the crank journals 103A and 103B, and the crankpin 101. According to the rule of the reading point, a new input point 11 ′ is set at the center position in the width direction of the crank pin 101 and at the upper end of the crank pin 101, and the center position in the width direction of the crank pin 101 is New fixed points 12A ′ and 12B ′ are set at the lower end of 101.

  In the case of a crankshaft, the rule for setting the input point is to set the upper end of the crankpin 101 at the center position in the width direction, and the rule for setting the fixed point is the lower end of the crank journals 103A and 103B. The reading point is set at the lower end of the crank pin 101 and at the center position in the width direction.

  In step S4, the automatic analysis processing unit 1 sets the stress or displacement applied to the input point 11 '. The stress setting rule is that the input point 11 ′ set as shown in FIG. 4 (A) has the same stress or displacement as the input point 11 set before the dimension change as shown in FIG. 4 (B). The amount is to be set.

  Next, in step S5, the automatic analysis processing unit 1 performs FEM analysis to obtain the stress or displacement amount at the reading point 13 ′ when the stress or displacement amount is applied to the input point 11 ′, and in step S6, The result output unit 3 can display the analysis result of the FEM analysis.

  As described in detail above, according to the automatic analyzer to which the present invention is applied, even if the width of the crankpin 101 is changed among the parts of the crankshaft by the designer, the dimension can be changed. In conjunction with this, not only the crankpin 101 but also the CAD data of the crank journals 103A and 103B can be automatically changed, and the boundary conditions can be automatically reset to provide the FEM analysis result.

  The above-described embodiment is an example of the present invention. For this reason, the present invention is not limited to the above-described embodiment, and various modifications can be made depending on the design and the like as long as the technical idea according to the present invention is not deviated from this embodiment. Of course, it is possible to change.

It is a block diagram which shows the functional structure of the automatic analyzer to which this invention is applied. It is a flowchart which shows the process sequence of the automatic analyzer to which this invention is applied. It is a figure for demonstrating the shape update process of CAD data when the dimension of the crankpin of a crankshaft is changed. It is a figure for demonstrating the update process of the boundary conditions at the time of changing the dimension of the crankpin of a crankshaft.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic analysis processing part 2 CAD data input part 3 Result output part 4 Operation input part 11 Input point 12 Fixed point 13 Reading point

Claims (2)

An automatic analyzer that performs structural analysis according to the finite element method,
Means for obtaining three-dimensional data to be analyzed;
Means for receiving an operation input by a designer that is expressed by the three-dimensional data and changes the size of a part in a structural analysis target in which an input point, a fixed point, and a reading point are set in advance ;
Means for interlockingly changing the shape in the three-dimensional data representing the part and the shape in the three-dimensional data representing other than the part according to the change in the dimension of the part in the received structural analysis target;
Means for creating a mesh representing the structural analysis object from the three-dimensional data of the changed shape;
Set the position of a new input point according to the rule of the input point predetermined based on the changed shape, and set the position of the new fixed point according to the rule of the fixed point predetermined based on the changed shape Then , the position of a new reading point is set according to the rule of the reading point determined in advance based on the changed shape, and the stress to be applied to the new input point is set according to the setting rule of the stress applied to the input point. And changing the analysis conditions including the position of the input point of the structural analysis target, the position of the fixed point of the structural analysis target, the position of the reading point of the structural analysis target, and the stress applied to the input point Means to
An automatic analysis apparatus comprising: means for analyzing, by a finite element method, the state of the new reading point when stress is input to the new input point according to the analysis condition. An automatic analysis method for performing structural analysis according to the finite element method,
A data input unit acquiring three-dimensional data to be structurally analyzed;
Operation input section includes a step of accepting previously input point, fixed point, an operation input by a designer to change the size of the site in the reading point structure analyzed expressed in the three-dimensional data set,
The automatic analysis processing unit changes the shape in the three-dimensional data representing the part and the shape in the three-dimensional data representing the part other than the part according to the change in the size of the part in the structural analysis target received by the operation input unit. Steps,
The automatic analysis processing unit creating a mesh representing the structural analysis object from the three-dimensional data of the changed shape;
The automatic analysis processing unit sets a position of a new input point according to a rule of an input point determined in advance based on the changed shape, and newly sets in accordance with a rule of a fixed point determined in advance based on the changed shape. set the position of the Do fixed point, to set the position of a new reading point according to the changed shape based on predetermined reading point rules, the new input in accordance with the setting rules for the stress applied to the input point The stress applied to the point is set, the position of the input point of the structural analysis target, the position of the fixed point of the structural analysis target, the position of the reading point of the structural analysis target, and the stress applied to the input point Changing analysis conditions including: and
Automatic the automatic analyzing process unit, which according to the analysis conditions, characterized in that it comprises a steps of analyzing the state of the new read point when the stress is input to the new input point by the finite element method analysis method.

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