JP2014127030A - Method and system for generating structural analysis model - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structural analysis model generation method which efficiently generates a structural analysis model of a structure having an internal space.SOLUTION: A computer executes wrapping processing which covers an outer peripheral surface of an air model 1 which is defined by an outer shape of an internal space of an intake manifold, with a predetermined wall thickness, and processing of extracting the air model 1 by Boolean operation from a wrapping model 5 generated by the wrapping processing, to generate a structural analysis model 6 of the intake manifold.

Description

  The present invention relates to a method and a generation system for generating a structural analysis model of a structure.

  Conventionally, a technique described in Patent Document 1 is known as a technique for generating a structural analysis model by a computer. In the technique described in Patent Document 1, a model for structural analysis of a space formed inside is generated from shape data of an entire structure created by a CAD system.

  In general, when designing a structure in which a fluid flows, an air model defined by the outer shell shape of the internal space is first generated by a CAD system. Then, after analyzing the fluid flow using this air model, an air model reflecting the result of the analysis is determined. When the air model is completed in this way, shape data of a structure having an internal space corresponding to the air model is created by the CAD system, and various structural analyzes are performed using the structural analysis model generated based on the shape data. Done.

JP 2009-53903 A

  In the above method, after the air model is completed, it is necessary to determine the shape data of the structure by the CAD system using the air model, and to generate the structure analysis model based on the shape data. As a result of structural analysis, when it is necessary to change the structural analysis model, it is necessary to correct the shape data of the structure by the CAD system each time. For this reason, it takes a lot of time to generate the structural analysis model from the air model, and it is desired to improve the efficiency of the series of processing.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a method for generating a structural analysis model capable of efficiently generating a structural analysis model of a structure having an internal space. It is in.

  A method for generating a model for structural analysis to solve the above-described problems includes a lapping process for covering an outer peripheral surface with a certain thickness with respect to an air model defined by an outer shell shape of an internal space of a structure, and the lapping process. The computer is caused to execute a process of extracting the volume of the air model from the wrapping model generated by the above-mentioned by Boolean operation and generating a model for structural analysis of the structure.

  In addition, a structure analysis model generation system for solving the above problems is a system for generating a structure analysis model of a structure by a computer, and is an air model defined by the outer shell shape of the internal space of the structure. On the other hand, a means for executing a lapping process that covers the outer peripheral surface with a certain thickness and a volume analysis of the air model are extracted from the lapping model generated by the lapping process by a Boolean operation to generate a structural analysis model for the structure. Means for executing processing.

  According to the above method and configuration, a lapping model in which an outer wall having a certain thickness is provided on the air model can be generated by performing lapping processing on the shape data of the air model by a computer. Then, by removing the volume of the air model from the wrapping model by Boolean calculation, a structural analysis model in which a space having the same shape as the air model is formed can be generated in a short period of time.

  In addition, the thickness of the structural analysis model can be changed as appropriate by changing the conforming parameter at the time of the lapping process. Therefore, even if the wall thickness is changed or the air model is changed, the structural analysis model can be generated in a short period of time by re-wrapping the air model. By performing various structural analyzes using the structural analysis model prior to the creation of shape data by the CAD system, the time required for the design change can be shortened.

In the method for generating a structural analysis model, the computer may further execute processing for adding a reinforcing portion that partially increases the rigidity of the structural analysis model.
According to the above method, structural analysis such as strength simulation and vibration simulation can be applied to an actual structure by adding a reinforcing part such as ribs and bosses to partially increase rigidity to the structural analysis model. It can be done in the form.

In the method for generating a model for structural analysis, it is preferable that the wall thickness is set to a general wall thickness that is set for each structure.
Various structures have a wall thickness that is lightest, that is, a general wall thickness, while ensuring sufficient rigidity against an external force that acts in an environment where the structure is used. By lapping the air model with this general thickness as in the above method, structural analysis can be performed using a structural analysis model close to the final form of the structure, and structural analysis can be performed efficiently. Will be able to.

  The above method can be applied, for example, when generating a model for structural analysis of the intake manifold.

(A)-(e) is a figure which shows typically the procedure of the production | generation method of the model for structural analysis. (A) is a top view of the structural analysis model, (b) a side view of the structural analysis model.

  Hereinafter, an embodiment of a method and system for generating a structural analysis model will be described with reference to FIGS. 1 and 2. In the following description, an intake manifold structural analysis model will be described as an example. In addition, a series of processing when generating the structural analysis model is executed by a computer.

  As shown in FIG. 1A, first, the shape data of the air model 1 defined by the outer shell shape of the internal space of the intake manifold is read into a computer. The shape data of the flanges 2 and 3 for connecting the intake manifold to the cylinder head and the throttle valve body are also read into the computer. The shape data of the air model 1 and the flanges 2 and 3 are both created using a CAD system.

  Next, as shown in FIG.1 (b), each flange 2 and 3 is arrange | positioned in the predetermined position of the air model 1, and those relative positional relationship is decided. Thereafter, as shown in FIG. 1 (c), a lapping process for covering the outer peripheral surface of the air model 1 with a constant general thickness is executed. Here, in the lapping process, small unevenness present on the outer peripheral surface of the air model 1 is ignored, and the same process is performed on the assumption that such unevenness does not exist.

  For example, when the outer peripheral surface is formed by covering the outer peripheral surface with the general thickness when the interval between the outer peripheral surfaces of the hollow portions 4 formed in the air model 1 is narrower than twice the general thickness, the outer walls overlap each other. It will be. Therefore, the wrapping process is executed along the outer peripheral surface on the assumption that the outer peripheral surfaces that are closest to each other are continuous with respect to the recessed portion 4. As a result, the recessed portion 4 becomes an outer wall, and a lapping model 5 having a solid inside is generated.

  Here, the general wall thickness is a wall thickness that is set so that the weight is minimized while ensuring sufficient rigidity against an external force that acts in the use environment of the intake manifold. For example, the general thickness of the intake manifold is set to 2 to 3 mm in consideration of its material and physical properties. The wall thickness set in the lapping process is stored in the computer as a changeable parameter. By changing this parameter, it is possible to easily change the wall thickness during the lapping process.

  Next, as shown in FIG. 1 (d), the wrapping model 5 generated by the wrapping process and the flanges 2 and 3 that have determined the relative positional relationship with the air model 1 are coupled by a Boolean operation. Further, the portion protruding from the flanges 2 and 3 in the lapping model 5 to which the flanges 2 and 3 are coupled is deleted.

  Thereafter, as shown in FIG. 1E, a process of extracting the volume of the air model 1 from the wrapping model 5 by Boolean calculation is executed. By a series of these processes, an intake manifold structural analysis model 6 is generated in which a space having the same shape as the air model 1 is formed and the wall thickness is set to a general wall thickness.

  Further, as shown in FIG. 2, a process of coupling the lattice-like ribs 7 curved along the outer peripheral surface of the structural analysis model 6 to the structural analysis model 6 by Boolean operation is executed. The final structural analysis model 6 is completed by such a series of processes.

Next, the operation of the method for generating the structural analysis model 6 will be described.
By wrapping the CAD data of the air model 1 with a computer, a wrapping model 5 in which an outer wall having a general wall thickness is provided for the air model 1 is generated. Then, by removing the volume of the air model 1 from the wrapping model 5 by Boolean calculation, a structural analysis model 6 in which a space having the same shape as the air model 1 is formed is generated. In addition, by appropriately changing the wall thickness in the lapping process, the time for creating a plurality of structural analysis models 6 is shortened. Furthermore, by adding the lattice-like ribs 7 to the structural analysis model 6, structural analysis such as strength simulation and vibration simulation is performed in a form that matches the actual structure.

According to the embodiment described above, the following effects can be obtained.
(1) The structural analysis model 6 can be efficiently generated from the air model 1. Further, even when the wall thickness is changed or the air model 1 is changed, the structural analysis model can be created in a short time by performing the lapping process on the air model 1 again. Therefore, various structural analyzes using the structural analysis model can be performed prior to the creation of the shape data by the CAD system, and the time required for the design change can be shortened.

  (2) By adding lattice-like ribs 7 to the structural analysis model 6, structural analysis such as strength simulation and vibration simulation can be performed in conformity with the actual structure.

  (3) Since the air model 1 is lapped with a general wall thickness, the structural analysis using the structural analysis model 6 close to the final form of the structure can be performed, and the structural analysis can be performed efficiently. become able to.

In addition, the said one Embodiment can also be implemented with the following forms which changed this suitably.
In the above-described embodiment, the process of adding the grid-like ribs 7 is exemplified as the final process when generating the structural analysis model 6. It may be another reinforcing part that can partially increase the rigidity. Moreover, you may make it add two or more by combining those structures suitably. Even if it is such a structure, the effect similar to said (1)-(3) can be acquired.

  In each of the above embodiments, the method for generating the structure analysis model 6 for the intake manifold has been exemplified. Similarly, the structure analysis model for other structures such as the exhaust manifold, the cylinder head, the cylinder block, and the like may be generated. it can. Even if it is such a structure, the effect similar to said (1)-(3) can be acquired.

  In each of the above embodiments, the lapping process is executed with the general thickness, but the thickness may be changed to a thickness other than the general thickness. Even if it is such a structure, the effect similar to said (1) and (2) can be acquired.

  In each of the above embodiments, the process of adding the reinforcing portion to the structural analysis model is executed by the computer, but such a process may be omitted. Even if it is such a structure, the effect similar to said (1) can be acquired.

  DESCRIPTION OF SYMBOLS 1 ... Air model, 2, 3 ... Flange, 4 ... Recessed part, 5 ... Lapping model, 6 ... Model for structural analysis, 7 ... Rib.

Claims (5)

On the computer,
A lapping process that covers the outer peripheral surface of the air model defined by the outer shell shape of the internal space of the structure with a certain thickness;
A method for generating a structural analysis model for executing a process for generating a structural analysis model of a structure by extracting a volume fraction of the air model from a wrapping model generated by the wrapping process by a Boolean operation. On the computer,
The method for generating a structural analysis model according to claim 1, further comprising executing a process of adding a reinforcing portion that partially increases the rigidity of the structural analysis model. The method for generating a structural analysis model according to claim 1, wherein the thickness is a general thickness that is set separately for each structure. The method for generating a structural analysis model according to any one of claims 1 to 3, wherein the structural analysis model is a structural analysis model of an intake manifold. A system for generating a structural analysis model of a structure by a computer,
Means for performing a lapping process for covering the outer peripheral surface of the air model defined by the outer shell shape of the internal space of the structure with a certain thickness;
A structure analysis model generation system comprising: means for extracting a volume integral of the air model from the wrapping model generated by the wrapping process by a Boolean operation and generating a structure analysis model of the structure.