JP3025062B2 - Optimization design system for thin plate products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for optimizing the design of a thin plate product, and more particularly to a system for assisting a computer in designing a molded product (CAE).

[0002]

2. Description of the Related Art Thin plate-shaped products, for example, toilet pans,
The strength is maintained by providing grid-like ribs on the bottom surface at predetermined intervals. Further, on the bottom surface of the toilet pan, reinforcing bolt legs serving also as attachments are provided at four corner positions.

[0003] When designing such a thin toilet pan, a prototype was conventionally produced and various experiments were carried out to determine the final shape. As a result, it took a long time to develop the system, and in some cases, the system was overdesigned in consideration of safety more than necessary.

In recent years, various types of C have been developed in order to solve such problems as an increase in the development period and overdesign.
The AE program has been introduced.

[0005] For example, CAE for structural analysis for obtaining displacement, stress, natural frequency, temperature distribution, etc. when a load or heat is applied.
Program, CAE program for structural sensitivity analysis that determines the degree of influence of design variables (thickness, elastic modulus, etc.) on the response (displacement, stress, etc.) of interest, changing design variables (thickness) within the range of constraints A CAE program for structural optimization analysis or the like for obtaining a design variable that minimizes the weight by repeating structural analysis is one such example.

[0006]

However, each of the various CAE programs described above has conventionally been used independently, and has not been used in association with any other program.
Also, even if it is related, it is difficult to determine under what conditions to associate each program,
Since it is difficult to develop a system that associates such a program, it has not been provided at all in the past.

The present invention has been made in view of the above circumstances, and an object of the present invention is to associate such various CAE programs under certain conditions, thereby optimizing a thin plate product that can be designed for product optimization. It is to provide a design system.

[0008]

In order to solve the above-mentioned problems, an optimization design system for a thin plate-shaped product according to the present invention provides a displacement amount of each portion by applying a load to each portion of a thin plate-shaped product which is an initial design product. And a structural analysis unit that compares whether the maximum displacement is within a range of a reference value set in advance, and the maximum displacement obtained by the structure analysis unit is within the range of the reference value. If it is outside, the degree of influence on the amount of displacement, stress, etc. when changing the design variables such as the thickness, elastic modulus, etc. of each part of the thin sheet-shaped product based on the amount of displacement of each part, and the influence thereof are determined. The structural sensitivity analysis unit that reinforces the most effectively reinforceable part of the sheet-shaped product determined based on the degree, and the maximum displacement obtained by the structural analysis unit is within the range of the reference value. In some cases, and based on the degree of influence determined by the structural sensitivity analysis unit, the maximum displacement amount by structural analysis after reinforcing the most effective reinforcing part of the thin plate-shaped product is within the range of the reference value. In the case of, a structure optimization analysis unit that minimizes the product weight by increasing or decreasing the thickness of the thin plate product within a range that satisfies certain constraints is adopted.

[0009]

In the case of designing a toilet pan having reinforcing ribs provided in a grid pattern at predetermined intervals and reinforcing bolt legs provided at four corners of the bottom surface as a thin plate product, a structural analysis is performed. In the section, the amount of displacement of each section is obtained by applying a load to each section of the toilet pan, which is an initially designed product, and the maximum displacement is obtained. Then, the maximum displacement amount is compared with a reference value range set in advance.

If the obtained maximum displacement is out of the range of the preset reference value, the structural sensitivity analysis unit determines that the strength is insufficient, and then based on the displacement of each part of the toilet pan. In addition, the degree of influence (sensitivity) on displacement, stress, and the like when design variables such as plate thickness and elastic modulus of each part of the toilet pan are changed is determined. In other words, it is possible to determine which part of the toilet pan should be reinforced most effectively from this degree of influence, so that a bolt bolt for reinforcement is provided in the part that can be reinforced most effectively, and structural analysis is performed again. I do.

If the maximum displacement obtained as a result of the structural analysis is out of the range of the reference value, the structural sensitivity analyzing section again performs the same sensitivity analysis as described above. The structure sensitivity analysis unit repeats the above processing until the maximum displacement amount obtained by the structure analysis unit falls within the range of the reference value.

When the maximum displacement obtained by the structural analysis section is within the range of the reference value, and when the toilet pan is most effectively reinforced based on the degree of influence obtained by the structural sensitivity analysis section. If the maximum displacement by the structural analysis after reinforcing the possible portion with the bolt legs is within the range of the reference value, the structural optimization analysis unit determines that the maximum displacement is within a range that satisfies certain constraints (for example, if the maximum displacement is The product weight is minimized by increasing or decreasing the thickness of the toilet pan within the range of the provided reference value).

[0013] Thus, since the structural analysis, the structural sensitivity analysis, and the structural optimization analysis can be related under a certain condition, it is possible to optimize the design of a thin plate product.

[0014]

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

FIG. 1 is a block diagram showing an electrical configuration of a system for optimizing the design of a thin product according to the present invention.

In FIG. 1, the output of the structural analysis unit 11 for obtaining the maximum displacement by applying a load to a thin product, which is an initial design product, is based on design variables such as the thickness and elastic modulus of each part of the thin product. The output of the structural sensitivity analysis unit 12 is guided to the structural analysis unit 11 and the structure optimization analysis unit 13. The output of the structure analysis unit 11 is also guided to the structure optimization analysis unit 13.

The structural optimization analyzing unit 13 is a block for minimizing the product weight by reducing the thickness of the thin product within a range satisfying a certain constraint condition. The configuration is guided to an output unit 14 to which a device, a printing device, and the like are connected.

Next, the operation of the optimization design system having the above configuration will be described with reference to the flowchart shown in FIG.

However, in the present embodiment, a case will be described in which the system of the present invention is applied to a toilet pan 20 having the shape shown in FIG.

The toilet pan 20 shown in FIG. 3 has an initial design shape of 1170 mm long and 870 mm wide as an initial shape.
Mm, and the interval between the grid-like ribs 22 formed on the bottom surface is 10 mm.
0 mm. Also, ribs 22 are provided at the four corners of the bottom surface.
The reinforcing bolt legs 23 ...
Is formed. Reference numeral 24 in the drawing is a drain pipe hole.

In the optimized design system of the present invention, first, the structural analysis unit 11 sets the toilet pan 2 having the initial design shape described above.
Input 0 data.

The structural analysis unit 11 performs a structural analysis based on the input data to obtain a displacement amount of each part by applying a load to each part of the toilet pan 20,
The maximum displacement is obtained (step S1). It is assumed that the maximum displacement at this time is 8.95 mm.

The structural analysis unit 11 compares the maximum displacement with a reference value (for example, a range of 1 mm to 3 mm) set inside (step S2). And
In this case, since the maximum displacement is out of the range of the reference value (that is, in this case, the strength is insufficient), the structural analysis unit 11 uses the toilet pan 20 of the input initial design shape. The part that can be reinforced is taken out of the data (step S3), and the taken out data is provided to the structural sensitivity analysis unit 12 together with the displacement data.

The structural sensitivity analysis unit 12 then changes the design variables such as the plate thickness and the elastic modulus of each part based on the displacement amount and the like of each part of the toilet pan 20 and affects the displacement amount and the stress. The degree (sensitivity) is obtained (step S4).

The degree of influence is calculated and obtained by taking into account the magnitude of the inclination of the tangent line to the response when the design variables such as the plate thickness and the elastic modulus of each part are changed. Then, since it is possible to determine which of the reinforceable portions of the toilet pan 20 is most effective to reinforce based on the magnitude of the sensitivity coefficient (step S5), the most effective reinforcement is performed. One reinforcing bolt leg 23 is provided in a portion where the cutting can be performed (step S6).

In this embodiment, a bolt leg 23 is provided at a position indicated by a black circle in FIG. However, as described above, the positions where the bolt legs 23 can be provided are set in advance, and the structural sensitivity analysis unit 12 moves the bolt legs 23 from the set positions to the most effective position. Will be provided.

Then, a new bolt leg 2 is thus obtained.
3 again using the toilet pan 20 provided with
In 1, a structural analysis is performed to determine the displacement of each part by applying a load to each part of the toilet pan 20, and to determine the maximum displacement thereof (step S <b> 7).

When the maximum displacement obtained as a result of the structural analysis is out of the range of the reference value (step S8).
Returns to the operation of step S3 again. Then, the structural analysis unit 11 again takes out the reinforceable portion from the data of the toilet pan 20 having the initial design shape (Step S3),
The extracted data is provided to the structural sensitivity analyzer 12 together with the displacement data.

In the structural sensitivity analysis section 12, the toilet pan 2
Based on the displacement amount of each part of 0, etc., the degree of influence (sensitivity) on the displacement amount, stress and the like when changing the design variables such as the plate thickness and the elastic modulus of each part is obtained (step S4).

Then, from this degree of influence, the toilet pan 20
Since it is known which of the reinforceable portions is most effective to reinforce (step S5), one reinforcement bolt leg 23 is provided in the most effective portion. It is provided (step S6).

Then, the bolt leg 2 is newly added in this manner.
Structural analysis is performed again in the structural analysis unit 11 using the toilet pan 20 (not shown) provided with 3 and the displacement amount of each part is obtained by applying a load to each part of the toilet pan 20, and the maximum displacement amount is obtained. (Step S
7).

In the structural sensitivity analyzing section 12, the above processing (steps S3 to S3) is performed until the maximum displacement obtained in the structural analyzing section 11 falls within the range of the reference value in step S8.
Step S7) is repeated.

When the maximum displacement obtained by the structural analysis unit 11 is within the range of the reference value (step S
2) and the maximum displacement by structural analysis after the most effective portion of the toilet pan 20 is reinforced with the bolt legs 23 based on the degree of influence obtained by the structural sensitivity analysis unit 12 is within the range of the reference value. In some cases (step S8), the structure optimization analysis unit 13 increases the wall thickness of the toilet pan 20 within a range that satisfies a certain constraint (for example, a range of a maximum displacement amount that is separately provided). By reducing
The product weight is minimized (step S9).

The data of the toilet pan 20 having the final shape determined in this way is provided to the output unit 14.
When a display device such as a CRT is connected to the output unit 14, the toilet pan 20 having the final shape is displayed on the screen of the display device. When a printing device is connected to the output unit 14, the toilet pan 20 having the final shape is printed on the recording paper (step S10).

Incidentally, as a result of performing the above-described optimization processing on the toilet pan 20 having the initial design shape shown in FIG. 3, it was possible to reduce the total mass by 39% as compared with before the optimization.

[0036]

The optimization design system for a thin plate product according to the present invention is constructed as a series of systems in which the structural analysis section, the structural sensitivity analysis section, and the structural optimization analysis section are associated under certain conditions. This has the effect that optimization design by reinforcing the bolt legs can be performed in a short period of time and efficiently, especially at the bottom ribs of a thin product.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an electric configuration of an optimization design system for a thin plate product according to the present invention.

FIG. 2 is a flowchart illustrating the operation of the optimization design system of the present invention.

FIG. 3 is a perspective view of a toilet pan as an example of a thin product to which the optimization design system of the present invention is applied.

[Explanation of symbols]

 11 Structural analysis unit 12 Structural sensitivity analysis unit 13 Structural optimization analysis unit 14 Output unit

Claims (1)

(57) [Claims] 1. A method for determining the amount of displacement of each part by applying a load to each part of a thin plate product which is an initial design product, and determining whether the maximum displacement is within a range of a reference value set in advance. When the maximum displacement obtained by the structural analysis unit is out of the range of the reference value, the thickness and elasticity of each part of the thin sheet-shaped product are determined based on the displacement of each part. The amount of displacement when changing design variables such as the rate, the degree of influence on stress, etc. are determined, and reinforcement is applied to the most effective reinforcement of the thin plate-shaped product determined based on the degree of influence. A structural sensitivity analysis unit to be performed, and when the maximum displacement obtained by the structural analysis unit is within the range of the reference value, and based on the degree of influence obtained by the structural sensitivity analysis unit, the most effective of the thin plate-shaped product is obtained. In the case the maximum amount of displacement due to structural analysis after reinforced portion can be reinforced is within the range of the reference value, the
A structure optimization analysis unit for minimizing the product weight by increasing or decreasing the thickness of the thin plate product within a range satisfying certain constraints. Design system.