JP2002073705A - Method for preparing stress analysis model for bogie frame of rolling stock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for preparing a stress analysis model for a bogie frame of rolling stock, capable of easily displaying stress required in the stress analysis on the of the bogie frame as a whole. SOLUTION: The bogie frame of the rolling stock is divided into many meshes, a plate model 2 part and a solid model 1 part are made to coexist in the meshes, and stress analysis is performed by a finite element method. A thin film model 3, having the same material characteristic as that of the plate model 2 and sharing the same point with an outer surface 1a of the solid model 1, is adhered to the outer surface 1a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preparing a stress analysis model of a bogie frame of a railway vehicle, which is used when performing a stress analysis on a bogie frame of a bogie frame of a railway vehicle by using a finite element method. is there.

[0002]

2. Description of the Related Art Conventionally, as a method of analyzing stress acting on a bogie frame (welded structure) of a railway vehicle, stress analysis using a finite element method (FEM) has been widely performed. When such a stress analysis is performed, the bogie frame of the railway vehicle is divided into a large number of meshes, and each of the meshes is divided into a plate model having no plate thickness (CQUAD4, CTR | A
Usually, as 3), a stress analysis model is created and performed. Then, a predetermined load is applied to such a stress analysis model, and the stress state in that case is calculated.

[0003] Then, the stress analysis result obtained by such an operation is divided into a plurality of stages of the stress value of each mesh in relation to the bogie frame, and displayed in different colors for each stage. It is also known that the stress state of the entire bogie frame can be recognized at a glance. In other words, by looking at the color of the part where the stress of the bogie frame is to be known, it is determined how much the stress of that part is.

[0004] When a more sophisticated stress analysis is required, or when the mesh size is smaller than the thickness of the plate model, a stress analysis model composed of only the plate model as described above is used. Even if it is created and stress analysis is performed using the stress analysis model, the stress state cannot be accurately calculated.

Therefore, in such a case, a stress analysis model is created as a solid model instead of a plate model for all the meshes of the entire bogie frame, or a part of the bogie frame (predicted to be severe in strength). A part of the mesh is partially used as a solid model, and the remaining part is used as a plate model to create a stress analysis model.

[0006]

However, when a stress analysis model is created as a solid model for the entire bogie frame, the calculation process becomes complicated and the calculation process takes time, while a part of the bogie frame is required. When creating a stress analysis model using a solid model partially, the stress (average stress) at the center position of the mesh in the plate model part of the stress analysis model when performing arithmetic processing On the other hand, in the solid model part, the stress at the corner position of the mesh is required, so in the plate model part and the solid model part,
The stresses at different parts are calculated, and the output results are output in different formats. Therefore, as described above, even if the results of the stress analysis are to be displayed together in relation to the bogie frame, they cannot be displayed at the same time.

More specifically, after stress calculation, if a command for plotting a stress value in relation to a bogie frame is issued, as shown in FIG. 4, only the stress analysis results for the plate model portion of the stress analysis model are obtained. As a result, the plot is plotted in relation to the bogie frame, and the stress analysis result for the solid model portion is not displayed in relation to the bogie frame. That is, as described above, since the output format of the solid model portion is different from that of the plate model portion unless special processing is performed, the calculation result cannot be displayed. Will be displayed in black. On the other hand, when processing is performed so that a portion of the solid model can be plotted and a command to plot a stress value in relation to the bogie frame is obtained, the result is as shown in FIG.
The stress analysis results for the plate model portion are not plotted, but are displayed in black, and only the solid model portion is displayed in relation to the bogie frame.

In the case where the plate model portion and the solid model portion coexist as described above, if the stress of both portions is to be output simultaneously, the stress value of any surface of the cube of the solid model is determined. But,
It is necessary to accurately determine whether the necessary stress value is to be displayed for that portion, and to manually determine the surface to be displayed, which is very time-consuming.

The present invention provides a method for creating a stress analysis model for a bogie frame of a railway vehicle, in which a required stress can be easily displayed in relation to the bogie frame in a stress analysis of the entire bogie frame. The purpose is to do.

[0010]

In order to achieve the above object, a method for creating a stress analysis model for a bogie frame of a railway vehicle according to the present invention is to divide a bogie frame of a railway vehicle into a large number of meshes, A part of the mesh is a plate model, the other part is a solid model, a stress analysis model is created, using a finite element method, a method for creating a stress analysis model of a bogie frame of a railway vehicle performing a stress analysis, A thin film model having the same material properties as the plate model and sharing the same point as the surface is attached to the outer surface of the solid model, and the stress analysis is performed on the solid model as a thin film model. Things. In addition, "to make the stress analysis be performed as a thin film model for the solid model part" means that, in terms of calculation, a command is issued to perform the calculation for the solid model but not to output the calculation result. This means that for the solid model part, the arithmetic processing for the thin film model is performed.

According to the method for creating a stress analysis model according to the present invention, a thin film model having the same material properties as a plate model and sharing the same point as the outer surface is attached to the outer surface of the solid model. When a load is applied to the stress analysis model to displace the solid model, the thin film model sharing a point with the outer surface of the solid model also displaces.

Accordingly, in the solid model portion, the arithmetic processing is performed on the thin film model even though it is a solid model, so that the thin film model of the solid model is replaced by another thin film model as if it were a plate model. It is processed in the same way as the part. Therefore, even if the solid model is partially used in the stress analysis model,
By using the thin film model, the same output results can be obtained for the solid model part as when the plate model is used, and both the plate model part and the solid model part are related in relation to the bogie frame. It is possible to plot stress values in Also, as described above, the same output results can be obtained for the solid model part as for the plate model part, so as to consider which surface of the solid model requires stress during arithmetic processing as in the past. Since it is not necessary to perform an operation for displaying the data, the processing is easy and the efficiency is high.

[0013] Even after the stress calculation, if the calculation is performed by another program and the solid model is partially provided, the same calculation processing could not be conventionally performed. Therefore, the same output result as that of the plate model can be obtained for the solid model, so that it is not necessary to treat them differently.
Even when the post-processing after the stress calculation processing is developed, no special processing is required, which is convenient.

In such a case, as in the second aspect of the present invention,
The coupling between the thin-film model and the solid model is performed using rigid elements, and rotation is not allowed, so that the thin-film model can be displaced by following the displacement of the outer surface of the solid model without difficulty. It is desirable to do so.

It is preferable that the solid model is a two-layer model, and is connected to the plate model at the overlapping portion.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory view showing the principle of a method for creating a stress analysis model of an underframe of a railway vehicle according to the present invention.

The method according to the present invention divides a bogie frame of a railway vehicle into a number of meshes, mixes them with a plate model portion and a solid model portion, and performs stress analysis using a finite element method. As shown in FIG. 1, as shown in FIG. 1, an outer surface 1 a of a partially existing solid model 1 has a constant thickness having the same material properties as a plate model 2 existing in other portions. (For example, 0.02m
The thin film model 3 of m) is attached and stress analysis is performed by the finite element method. Here, the solid model 1
The reason why the thin film model 3 to be attached to the substrate is to have a certain thickness is that if the thickness is too small, it will not be able to withstand the bending (buckling) when it bends, and the error will occur. Is caused.

Here, the portion where the solid model 1 is used is mainly a portion having a large plate thickness, and is a portion where a more detailed calculation result of stress analysis is required. Further, the thin film model 3 is attached to all the outer surfaces of the solid model 1, and stress analysis is performed on all the outer surfaces, and stress is obtained. Of the bogie frame 1 as a result
Will be displayed in relation to. Further, the portion to be used as the solid model 1 is usually a portion where a detailed stress analysis result is desired to be known.

Since the thin film model 3 shares the same point as the outer surface 1a of the solid model 1 to be pasted, when the entire solid model 1 is displaced by a load, the thin film model 3 also becomes in contact with the outer surface 1a of the solid model 1. They will be displaced together. That is, the displacement of the outer surface 1a of the solid model 1 is regarded as the displacement of the thin film model 3 attached to the outer surface 1a, and the stress is calculated based on the displacement. Here, the thin film model 3 is connected to the solid model 1 by a rigid element at a point a so as to be surely displaced together with the outer surface 1a of the solid model 1, and rotation is not allowed. For the same reason, the plate model 2 is connected to the solid model 1 (point b) by a rigid element, and rotation is not allowed.

When the stress evaluated by the plate model 2 is on the A-plane side, the thin film model 3 is stuck at least on the side of the point a of the solid model 1 to match the stress, and conversely, the evaluation is made by the plate model. When the stress is on the B side,
The thin film model 3 needs to be stuck at least on the side of the point c of the solid model 1.

As shown in FIG. 1, the solid model 1 is a model 1A, 1B (having the same thickness) in which two models are stacked one above the other, and a point b at the overlapping portion of the models 1A, 1B.
In, the plate model 2 is combined. Thus, point b is
The plate model 2 and the solid model 1 are shared. Also at this point b, the plate model 2 is connected to the solid model 1 by a rigid element, and rotation is not allowed.

As described above, when the stress analysis by the finite element method is performed on the bogie frame of the railway vehicle by mixing the plate model 2 and the solid model 1 with the finite element method, as described above. , And a stress analysis is performed, the plate model 2 is attached to the outer surface 1a of the solid model 1.
Since the thin film model 3 having the same material characteristics as the above and having the same point as the outer surface 1a is attached, when the solid model 1 is displaced by the applied load, the thin film model 3 becomes the outer surface 1a of the solid model 1 And will be displaced together.

At the time of calculating the stress, a command has been issued to the effect that the solid model 1 is not to be processed in the calculation, and the calculation of the thin film model 3 is to be performed for the solid model 1 portion. Will be For example,
When the solid model has six outer surfaces, the thin film model 3 is usually attached to each outer surface 1a, and the stress value is obtained for each of the six surfaces.

Therefore, stress analysis is performed on the thin film model 3 on the outer surface 1a of the solid model 1,
The operation of the part of the solid model 1 is also performed in the same manner as the other parts of the plate model 2, and the result of the operation is obtained in the same format as that of the plate model. Therefore, even when the solid model 1 is partially used, the same type of stress evaluation is realized. As a result, when the result is displayed in relation to the bogie frame after the stress calculation processing, it is merely instructed to plot the stress of the plate model.
As shown in (1), the portion of the solid model 1 (thin film model 3) and the portion of the plate model 2 are simultaneously output and displayed. In FIGS. 2 and 3, as in the case shown in FIGS. 4 to 6 described above, by changing the color for each predetermined range of stress values, the stress state acting on the bogie frame can be seen at a glance. It is made to be able to grasp.

Further, since the solid model 1 is also analyzed and processed in the same manner as the plate model 2 as if it were the plate model 2, the stress analysis in which the solid model 1 and the plate model 2 coexist is performed. Even when the stress values of the two models 1 and 2 are output simultaneously in relation to the bogie frame in the model, it is not necessary to consider which surface of the solid model 1 is to be displayed before the arithmetic processing. Eliminates the need for cumbersome processing on data, making it easier to process.

Further, even after the stress calculation processing, when the calculation is performed by another program, the solid model 1 may be partially used.
In the case where the thin film model 3 is used, the same calculation processing could not be conventionally performed because the output format (output) is different between the solid model 1 and the plate model 2. The output format can be made common between the plate model 2 and the thin film model 3 (solid model 1), which is convenient for post-processing.

[0028]

The present invention is embodied as described above, and has the following effects.

According to the method for preparing a stress analysis model of a bogie frame of a railway vehicle according to the present invention, when a plate model portion and a solid model portion are mixed, the same material as the plate model is provided on the outer surface of the solid model. Since a thin film model having characteristics and sharing the same point with the outer surface is attached, the solid model part can be processed in the same manner as other plate model parts, and the output format (output) G) can be shared. Therefore, even if a solid model is partially used, the same type of stress evaluation can be realized. For a stress analysis model in which two models, a plate model and a solid model, are mixed,
The stresses of the plate model and the solid model can be output simultaneously.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing the principle of a method for creating a stress analysis model of an underframe of a railway vehicle according to the present invention.

FIG. 2 is an explanatory diagram showing a result of analysis using an analysis model created by a method according to the present invention.

FIG. 3 is an enlarged view of the main part.

FIG. 4 is a diagram showing an entire bogie frame as a result of a conventional analysis.

FIG. 5 is an enlarged view of the main part.

FIG. 6 is a diagram showing an analysis result of a solid model part.

[Explanation of symbols]

 1 solid model 1a outer surface 2 plate model 3 thin film model

Claims (3)

[Claims] 1. A bogie frame of a railway vehicle is divided into a large number of meshes, a part of the meshes is used as a plate model, and the other part is used as a solid model to create a stress analysis model and use a finite element method. In the method for creating a stress analysis model of a bogie frame of a railway vehicle performing a stress analysis, a thin film model having the same material properties as the plate model and sharing the same point as the surface is attached to an outer surface of the solid model. A method for creating a stress analysis model of a bogie frame of a railway vehicle, wherein a stress analysis is performed on a portion of the solid model as a thin film model. 2. The method according to claim 1, wherein the coupling between the thin film model and the solid model is performed using a rigid element, and rotation is not allowed. 3. The method according to claim 1, wherein the solid model is a two-layer model, and the solid model is combined with the plate model at the overlapping portion.