JP2003223480A - Optimal shape design method and system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optimal shape design method capable of easily and appropriately designing the optimal shape of a structure and to provide an optimal shape design system using the same. <P>SOLUTION: This optimal shape design method is characterized in providing an optimization control part 2a detecting a correlation among CAD data M for the structure defined by a CAD part 2b, a dynamic response quantity detected by a CAE (computer aided engineering) structure analysis part 2d, production affirmative/negative information determined by a production affirmative/negative part 2e, and production cost information detected by a cost calculation part 2f; changing the CAD data M of the structure till the dynamic response quantity satisfies design conditions of the structure based on the correlation and the optimal shape of the structure producible at the minimum production cost is detected; renewing the correlation based on the changed CAD data M, and detecting the optimal shape of the structure based on the renewed correlation. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and system for designing an optimum shape of a structure.

[0002]

2. Description of the Related Art Conventionally, in designing an optimum shape of a structure, there is a design method in which the size and shape function of each part of the structure are used as design variables, and the CAE structure analysis is performed by changing the design variables to search for the optimum shape. Has been taken.

In this conventional design method, the design variables are defined by the coordinates of the nodes included in the CAE data,
A method of finding the optimum shape by moving the node coordinates is used.

Further, in designing a cushioning material in cushioning packaging, a designing method that relies on the intuition and experience of the designer with reference to the cushioning performance data of the plate-shaped cushioning material is generally used, and although CAD is used, CAE is used. There is no design system of the optimum shape that can be used together with the structural analysis and can be optimized including moldability and manufacturing cost.

[0005]

However, in the method of determining the optimum shape by defining the design variables by the coordinates of the nodes included in the CAE data and moving the coordinates of the nodes as in the prior art described above, The optimal shape finally obtained will be expressed as CAE data.

Therefore, it is necessary to convert the CAE data into CAD data again in order to create CAD data for drawings and production. However, there is no program for automatically converting this CAE data into CAD data, and the designer is currently doing it manually.

Further, since the shape is changed by moving the coordinates of the nodes included in the CAE data, the number of elements does not change and distorted elements are generated, which may deteriorate the analysis accuracy in CAE structural analysis. Also, it may not be possible to deal with complicated shape changes.

In addition, designing an optimum shape that minimizes the volume of a structure by restricting mechanical quantities such as strength is performed in various fields, but whether or not moldability and manufacturing cost are dealt with at the same time. There is no optimum shape design system, and it is common to evaluate the formability and cost by determining the mechanical optimum shape and judge whether it is appropriate, and review the shape constraint conditions again if necessary. In some cases, optimization calculation was performed again.

The present invention is to solve the above-mentioned problems.
It is an object of the present invention to provide an optimum shape design method capable of easily and accurately designing an optimum shape of a structure and an optimum shape design system using the same.

[0010]

A typical configuration of the optimum shape designing method according to the present invention for achieving the above object is as follows.
C of the structure created based on the design data of the structure
AD data is converted to CAE data, and the mechanical response amount is detected by CAE structural analysis for the structure shape converted to the CAE data, and it is determined whether or not the structure shape defined as the CAD data can be manufactured. Detecting the correlation between the CAD data of the structure, the mechanical response amount, and the feasibility of manufacturing, and based on the correlation, the mechanical response amount satisfies the design condition of the structure,
And, the CAD data of the structure is changed until the optimum shape of the structure is detected so that the structure can be manufactured, and the CAD data of the structure and the dynamics are based on the changed CAD data of the structure. Dynamic response amount, the correlation between the production availability is updated, the mechanical response amount based on the updated correlation satisfies the design condition of the structure,
The optimum shape of the structure is detected so that the structure can be manufactured.

Since the present invention is configured as described above, the CAD data of the structure, the mechanical response amount detected by the CAE structural analysis for the structure shape converted from the CAD data to the CAE data, and the manufacturability CAD data of the structure until the optimum shape of the structure is detected so that the mechanical response amount satisfies the design condition of the structure based on the correlation and Is changed, and the CAD data of the structure, the mechanical response amount, and the correlation of the manufacturability are updated based on the changed CAD data of the structure, and the mechanical relationship is updated based on the updated correlation. The optimum shape of the structure can be easily and accurately designed by detecting the optimum shape of the structure such that the response amount satisfies the design condition of the structure and can be manufactured.

A typical configuration of the optimum shape design system according to the present invention is such that an input means for inputting design data of a structure and a structure based on the design data of the structure input by the input means. CAD means for defining the shape,
CAD / CAE conversion means for converting CAD data of the structure defined by the CAD means into CAE data,
CAE structure analysis means for detecting a mechanical response amount for the structure shape converted into the CAE data, and the CAD
Manufacturing availability determination means for determining whether or not to manufacture the structure shape defined by the means, CAD data of the structure defined by the CAD means, mechanical response amount detected by the CAE structure analysis means, and Detecting a correlation with the manufacturability information judged by the manufacturability judgment means, and based on the correlation, the mechanical response amount satisfies the design condition of the structure and can be manufactured. CAD of the structure until the optimum shape of the object is detected
The data is changed, the CAD data of the structure, the mechanical response amount, and the production availability are updated based on the changed CAD data of the structure, and the updated correlation is displayed. Optimization control means for detecting the optimum shape of the structure so that the mechanical response amount satisfies the design condition of the structure and can be manufactured based on the above; and the optimization control means detects the optimum shape. Display means for outputting and displaying the optimum shape of the structure.

Since the present invention is constructed as described above, the CAD data of the structure inputted by the input means and the CAD data of the structure are inputted.
/ CAE conversion means detects the correlation between the mechanical response amount detected by the CAE structure analysis means for the shape of the structure converted from the CAD data to the CAE data, and the manufacturability information judged by the manufacturability judgment means. Based on the correlation, the CAD data of the structure is changed until the mechanical response satisfies the design condition of the structure and the optimum shape of the structure is detected so that the structure can be manufactured. CA of the structure based on CAD data of the structure
The correlation between the D data, the mechanical response amount, and the manufacturability is updated, and based on the updated correlation, the mechanical response amount satisfies the design condition of the structure and can be manufactured. The optimization control means can detect the optimum shape of the structure, and the display means can output and display the optimum shape of the structure. This makes it possible to easily and accurately design the optimum shape of the structure.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As an example of the optimum shape designing method and designing system according to the present invention, one embodiment when applied to the designing method and designing system of the optimum shape of a cushioning material used for cushioning packaging will be described in detail. To explain. FIG. 1 is a block diagram showing a schematic configuration of an optimum shape design system according to the present invention, FIG. 2 is a flowchart showing an example of a processing procedure at the time of detecting an optimum shape, and FIG. 3 is a CAD showing a shape of a cushioning material at an initial design stage. The data shown in FIG. 4 and the CAD shown in FIG.
FIG. 5 is a diagram showing how data is converted to CAE data, FIG. 5 is a diagram showing a correlation between CAD data of a structure, a mechanical response amount, fabrication availability, and fabrication cost, and FIG. 6 is a process for obtaining an optimum shape. In FIG. 7, an example of the shape of the cushioning material that does not satisfy the design condition is shown by CAD data, and FIG. 7 is a diagram showing an example of the optimum shape of the cushioning material by CAD data.

In FIG. 1, reference numeral 1 denotes a structure to be designed, which is an article manufactured by using a molding die, for inputting design data necessary for designing a cushioning material used for cushioning packaging. Is an input device as an input means of the above, and is an input device capable of inputting design data through a keyboard or a mouse provided in a personal computer or the like, or a communication line such as the Internet.

Reference numeral 2 is an arithmetic processing unit for performing a predetermined arithmetic processing based on the design data input by the input unit 1 to calculate the optimum shape of the cushioning material which is a structure, and 3 is the arithmetic processing unit 2. A display device such as a CRT (cathode ray tube) or a printer, which serves as a display means for outputting and displaying the optimum shape of the buffer material, the display device 3 reads and outputs a design result stored in a database file or the like. It also has a display function.

The arithmetic processing unit 2 controls the arithmetic processing performed by the arithmetic processing unit, and uses the optimization control unit 2a serving as an optimization control unit for detecting the optimum shape of the cushioning material that is the structure, and the input device 1. A CAD unit 2b serving as CAD means for defining the structure shape of the buffer material based on the input design data of the buffer material serving as the structure, and a CAD of the buffer material serving as the structure defined by the CAD unit 2b. A CAD / CAE conversion unit 2c that is a CAD / CAE conversion unit that converts data into CAE data, and a CAE structural analysis that detects a mechanical response amount by CAE structural analysis for the structure shape of the cushioning material that is converted into the CAE data. CAE structure analysis unit 2 as means
d, a production availability determination unit 2e serving as a production availability determination unit that determines production availability of the buffer material structure shape defined by the CAD unit 2b, and a buffer material structure shape defined by the CAD unit 2b. It is configured to include a cost calculation unit 2f or the like, which serves as a cost calculation unit that detects the cost.

In the optimization control section 2a, as shown in FIG. 5 and described later, the CAD data created by the CAD section 2b on the basis of the design data of the buffer material serving as the structure and the CAE structure analysis section 2d detect the CAD data. The determined mechanical response amount, the production availability information determined by the production availability determination unit 2e, and the cost calculation unit 2
In addition to detecting the correlation with the manufacturing cost information detected in f, a buffer that can be manufactured based on this correlation, the mechanical response amount satisfies the design condition of the buffer material, and is the minimum manufacturing cost. The CAD data of the cushioning material is changed until the optimum shape of the material is detected, and based on the changed CAD data, the CAD data and the CAE structure analysis unit 2
The mechanical response amount newly detected in d, the manufacturability information judged again in the manufacturability judgment unit 2e, and the cost calculation unit 2
The previous correlation is updated based on the production cost information newly detected in f, the mechanical response amount satisfies the design condition of the cushioning material based on the updated correlation, and the production is possible. In addition, the optimization calculation process is performed to detect the optimum shape of the cushioning material that is the structure so as to minimize the manufacturing cost.

In this embodiment, when the manufacturability judgment unit 2e judges that the manufacturability is possible, when the cushioning material and the molding die are released from each other, with respect to the drawing direction a shown in FIGS. 3, 6 and 7. The manufacturability is judged by the fact that the outer circumference of the cross-sectional shape of each cross section divided by a plurality of vertical planes is projected from the drawing direction a and does not intersect.

Further, as an example of the mechanical response amount detected by the CAE structure analysis unit 2d, the maximum deceleration occurring in the object to be buffered packed by the buffer material is set to be detected in this embodiment.

Next, with reference to FIG. 2, an example of a processing procedure until the optimum shape of the cushioning material as the structure is detected by the optimum shape designing method according to the present invention will be described. First, in step S1, design data of a cushioning material to be a structure to be designed is input via a keyboard or a communication line such as the Internet as the input device 1.

For example, when designing the optimum shape of the cushioning material for cushioning packaging, the design data include the shape, weight, drop height, drop direction, design allowable value (for example,
Maximum deceleration, maximum stress, maximum strain that occurs in the buffered object, maximum stress that occurs in the buffer material, maximum strain, and allowable mechanical response amount such as the coefficient of restitution), buffered object (packaged item), Enter the mechanical properties of the material used for the outer box and cushioning material (for example, stress / strain curve, Poisson's ratio, density, etc.). In addition, the dimensions of the outer box such as a cardboard box, the position of the buffered object to be stored in the outer box, and the like are also input as design conditions as necessary.

For the mechanical property values of the materials to be used for the object to be buffered, the outer box, and the buffer material, a storage device or a database file storing various kinds of data is prepared in advance,
From here, search for mechanical property values according to the material used,
You may make it utilize this.

In the arithmetic processing unit 2, when these design data are input, the process proceeds to step S2, and the initial design shape of the cushioning material is set by using the CAD unit 2b, for example, the CAD data M as shown in FIG. Create ₁ . At this time, shape data (for example, dimensions, angles, presence or absence of ribs or holes, etc.) that are design variables are defined. In addition to the method of newly creating this design initial shape, the CAD data M of the previously designed case may be selected from a database or the like and used.

Then, the process proceeds to step S3, step S6 and step S7, and the following processing is performed in each of steps S3, S6 and S7 for the design data input in step S1 and the CAD data M defined in step S2.

First, in step S3, CAD / CAE is performed.
The CAD data M defined in step S2 by the conversion unit 2c including the design data input in step S1 is CA.
E Convert to CAE data N used for structural analysis. As a result, for example, the CAE data N ₁ shown in FIG. 4 is obtained.

C provided in the CAD / CAE converter 2c
As a program for converting the AD data M into the CAE data N, for example, a general-purpose automatic element division program such as KUBRIX (trade name) manufactured by Simulation Works, Inc. is applied.

Next, the process proceeds to step S4, and the CAE structure analysis section 2d creates the CAE created in step S3.
A drop impact analysis is performed on the data N. For this drop impact analysis, for example, Hibbitt, Karlsson & Sorensen, Inc.
Made by ABAQUS (trade name), MECALOG SARL made by RADIOSS
(Product name), Livermore Software Technology Corporat
LS-DYNA (product name) manufactured by ion, Engineering Systems Inte
A general-purpose CAE program such as PAM-CRASH (trade name) manufactured by rnational SA is applied.

Next, the process proceeds to step S5, and a mechanical response amount is calculated from the result of the drop impact analysis executed in step S4, which compares the magnitude with a design allowable value such as the maximum deceleration of the object to be buffered. . To calculate the mechanical response amount, a post processor provided in the general-purpose CAE program may be applied, or a program for outputting the analysis result as text data and editing the data may be created and used.

On the other hand, in step S6, the manufacturing feasibility determination unit 2e appropriately applies the draft for the mold release when the CAD data M defined in step S2 is manufactured using the molding die. Whether it can be manufactured or not is judged by judging whether or not it is manufactured.

In the determination as to whether or not the molding is possible, each cross section of the cushioning material divided by a plurality of planes perpendicular to the drawing direction a is the drawing direction a.
On the other hand, a program for checking that the cross-sectional area gradually decreases and that the outer circumference or inner circumference of the cross section does not intersect the outer circumference or inner circumference of another cross section when viewed from the drawing direction a, or Some CAD software (eg Soli
The draft check function provided in d Works Corporation's Solid Works; product name) may be applied.

In step S7, the cost calculation unit 2
In f, the manufacturing cost is calculated for the CAD data M defined in step S2. For example, when a bead foam molding is used as the cushioning material, a value obtained by multiplying the volume of CAD data M corresponding to the amount of material used by the unit price of the material as the material cost, and the running cost of the molding machine as the processing cost are applied. , The production cost is calculated.

When an extruded foamed product is used as the cushioning material, a material cost is a value obtained by dividing the unit cost of the original fabric by the number of original fabrics taken into consideration for plate cutting, the cutting cost as the processing cost, the heat pasting process cost, The die cost is applied and the manufacturing cost is calculated.

Then, the process proceeds to step S8, and the design variables of the CAD data M ₁ shown in FIG. 3 are used by using the mechanical response amount, the production availability information, and the production cost information calculated in step S5, step S6 and step S7. And the amount of mechanical response,
For example, referring to FIG.
The optimum shape of the cushioning material that can be manufactured based on this correlation, the mechanical response amount satisfies the design tolerance of the cushioning material to be designed, and the manufacturing cost is the minimum is derived based on this correlation. .

In the process of obtaining the optimum shape of the cushioning material to be designed, for example, the CAD data M shown in FIGS.
If there is a cushioning material shape that does not satisfy the design conditions as in ₂ (unmanufacturable, the mechanical response amount exceeds the design allowable value) or the manufacturing cost becomes cheaper, step until the optimum shape is obtained. The process proceeds from step S8 to step S2, and as shown in FIG. 5, the CAD data M is changed to update the correlation with the mechanical response amount, the manufacturability, and the manufacturing cost, and finally the optimum shape is obtained.

In FIG. 5, starting from the CAD data M ₁ shown in FIG. 3, the CAD data is sequentially changed to CAD data M2, M3, ..., M8. At the ninth time, for example, the optimum cushioning material as shown in FIG. It shows how the CAD data Mopt of the shape is obtained. A general-purpose optimization program such as iSight (trade name) manufactured by Engineous Software Inc. is applied to the optimization control unit 2a for obtaining the optimum shape of the cushioning material to be designed.

In the present embodiment, since the CAD data M is used as the design variable, it is easy to create the drawing and NC data for machining for the obtained optimum shape.

Further, since the CAD data M is divided into elements every time the shape is changed, distorted elements are less likely to occur, the analysis accuracy in CAE structural analysis is unlikely to deteriorate, and ribs and holes are increased. It can easily handle complex shape changes.

Further, not only the mechanical response amount but also the manufacturing feasibility and the manufacturing cost are added to the optimization conditions, so that the optimum shape having higher productivity including the workability and the economical efficiency can be obtained.

In the above embodiment, the case where the cushioning material is applied as the structure has been described, but the present invention is not limited to this, and various other structures can be applied. In this case, a general-purpose CAE program used in the CAE structure analysis unit 2d may be changed according to the structure to be designed, and the mechanical response amount to be evaluated and the manufacturing cost calculation method may be changed.

[0041]

Since the present invention has the above-described structure and operation, the CAD data of a structure and the structure shape obtained by converting the CAD data into the CAE data are CAE.
Detect the correlation between mechanical response amount detected by structural analysis and manufacturability, and based on the correlation, the mechanical response amount satisfies the design condition of the structure and can be manufactured. CA of the structure until the optimum shape of the object is detected
D data is changed, based on the changed CAD data of the structure, the CAD data of the structure, the mechanical response amount, and the correlation of manufacturing availability are updated, and based on the updated correlation The optimum shape of the structure can be easily and accurately designed by detecting the optimum shape of the structure such that the mechanical response amount satisfies the design condition of the structure and can be manufactured.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an optimum shape design system according to the present invention.

FIG. 2 is a flowchart showing an example of a processing procedure at the time of detecting an optimum shape.

FIG. 3 is a diagram showing the shape of the cushioning material at the initial design stage as CAD data.

FIG. 4 is a diagram showing a state in which the CAD data shown in FIG. 3 is converted into CAE data.

FIG. 5 is a diagram showing a correlation among CAD data of a structure, a mechanical response amount, availability of production, and production cost.

FIG. 6 is a diagram showing CAD data of an example of the shape of a cushioning material that does not satisfy the design condition in the process of obtaining the optimum shape.

FIG. 7 is a diagram showing an example of an optimum shape of a cushioning material by CAD data.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Input device 2 ... Arithmetic processing device 2a ... Optimization control part 2b ... CAD part 2c ... CAD / CAE conversion part 2d ... CAE structure analysis part 2e ... Manufacturability determination part 2f ... Cost calculation part 3 ... Display device M, M _{1 to} M ₈ , Mopt ... CAD data N, N ₁ ... CAE data

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshito Fukasawa             Asahi Kasei Co., Ltd. 1-1 Hiranaka-cho, Suzuka City, Mie Prefecture             Inside the company F-term (reference) 5B046 AA00 DA01 JA08

Claims (8)

[Claims] 1. The CAD data of the structure created based on the design data of the structure is converted into CAE data, and the structure shape converted into the CAE data is CA.
E The mechanical response is detected by the structural analysis, and the feasibility of the structure shape defined as the CAD data is determined, and the CAD data of the structure, the mechanical response amount, and the feasibility of the production are determined. Correlation is detected, and based on the correlation, the mechanical response amount satisfies the design condition of the structure, and until the optimum shape of the structure is detected so that it can be manufactured, the structure The CAD data is changed, the CAD data of the structure, the mechanical response amount, and the production availability are updated based on the changed CAD data of the structure, and the updated correlation is obtained. Based on the above, the optimum shape design method is characterized by detecting the optimum shape of the structure such that the mechanical response amount satisfies the design condition of the structure and can be manufactured. 2. The CAD data of the structure created based on the design data of the structure is converted into CAE data, and the shape of the structure converted into the CAE data is CA.
E The mechanical response amount is detected by the structural analysis, whether or not the structure shape defined as the CAD data can be manufactured is determined, and the manufacturing cost is detected for the structure shape defined as the CAD data. The CAD data of the object, the mechanical response amount, the correlation between the manufacturing availability and the manufacturing cost is detected, and the mechanical response amount satisfies the design condition of the structure based on the correlation. And changing the CAD data of the structure until the optimum shape of the structure is detected so that the structure can be manufactured and has the minimum manufacturing cost, and the structure is changed based on the changed CAD data of the structure. Of the CAD data, the mechanical response amount, the production availability and the production cost are updated, and the dynamics are calculated based on the updated correlation. Satisfied quantity response design conditions of the structure, and can be fabricated, the design method of optimum shape, characterized in that and detecting the optimum shape of the structure so as to minimize production costs. 3. The structure is an article manufactured by using a molding die, and when the article and the molding die are separated from each other, the structure is divided by a plurality of planes perpendicular to a drawing direction. 3. The optimum shape designing method according to claim 1, wherein the manufacturing is determined by the fact that the outer circumference of the cross-sectional shape of each cross-section is projected from the drawing direction and does not intersect. 4. The structure is a cushioning material used for cushioning packaging, and the maximum deceleration occurring in the cushioned object is detected as the mechanical response amount. The method for designing the optimum shape according to item 1. 5. Input means for inputting design data of a structure, CAD means for defining a shape of a structure on the basis of design data for the structure inputted by said input means, and structure defined by said CAD means. CAD / CAE conversion means for converting CAD data of an object into CAE data, CAE structure analysis means for detecting a mechanical response amount for a structure shape converted into the CAE data, and a structure defined by the CAD means The manufacturability determination means for judging the feasibility of the shape, the CAD data of the structure defined by the CAD means, the mechanical response amount detected by the CAE structure analysis means, and the manufacturability determination means. The correlation with the manufacturing availability information is detected, and based on the correlation, the mechanical response amount satisfies the design condition of the structure. And change the CAD data of the structure until the optimum shape of the structure is detected to allow fabrication, CA of said structure on the basis of the CAD data of the structure was the change
The correlation between the D data, the mechanical response amount, and the production availability is updated, and the mechanical response amount satisfies the design condition of the structure based on the updated correlation, and the production is possible. An optimization control unit that detects the optimum shape of the structure so that the display unit outputs and displays the optimum shape of the structure that is detected by the optimization control unit. Optimal shape design system. 6. Input means for inputting design data of a structure, CAD means for defining a structure shape based on design data of the structure input by said input means, and structure defined by said CAD means. CAD / CAE conversion means for converting CAD data of an object into CAE data, CAE structure analysis means for detecting a mechanical response amount for a structure shape converted into the CAE data, and a structure defined by the CAD means Manufacturing availability determination means for determining whether the shape can be manufactured, cost calculation means for detecting the manufacturing cost for the structure shape defined by the CAD means, CAD data of the structure defined by the CAD means, and the CAE. The mechanical response amount detected by the structure analysis means, and the manufacturability information judged by the manufacturability judgment means. Detecting the correlation with the manufacturing cost information detected by the cost calculating means, and based on the correlation, the mechanical response amount satisfies the design condition of the structure, can be manufactured, and is the minimum manufacturing The CAD data of the structure is changed until the optimum shape of the structure is detected so that the cost is obtained, and the CAD data of the structure and the mechanical response are based on the changed CAD data of the structure. Quantity, the possibility of manufacturing, and the manufacturing cost are updated, and based on the updated correlation, the amount of mechanical response satisfies the design condition of the structure, is manufacturable, and is minimum. Optimization control means for detecting the optimum shape of the structure so that the manufacturing cost is obtained; and display means for outputting and displaying the optimum shape of the structure detected by the optimization control means. Design system optimum shape characterized by Rukoto. 7. The structure is an article manufactured by using a molding die, and the manufacturing possibility determination means is a plurality of units perpendicular to a drawing direction when the article and the molding die are released from each other. 7. The optimal shape design system according to claim 5 or 6, wherein the outer shape of the cross-sectional shape of each cross-section divided by the plane is determined so as to be producible from the drawing direction and not intersect with each other. . 8. The structure is a cushioning material used for cushioning packaging, and the CAE structure analysis means detects the maximum deceleration occurring in the cushioned object as the mechanical response amount. The optimal shape design system according to any one of 5 to 7.