JP2002324088A - Support apparatus for design of structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically allow acquiring an initial shape and calculation conditions for optimizing calculations to optimize a shape of a structure from desired performance. SOLUTION: In a support apparatus for design of structure, 3-D CAD models and performance information of structures designed in the past are stored into a model storage part 150. When the desired performance is inputted from an input means 110, a model search means 120 searches the part 150 to extract high-end and low-end models of the inputted desired performance and performance information of the models, a calculation condition decision means 130 acquires the initial shape and calculation conditions of the models for optimizing calculations from the extracted information, so that an optimizing calculation apparatus 140 executes the optimizing calculations by using the shape and conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for supporting a shape design of a structure, and more particularly, to a method for creating a new shape based on the shape of an existing structure and optimizing the shape as an initial shape. To determine a shape that satisfies the input condition.

[0002]

2. Description of the Related Art In recent years, in order to automate repetition of complicated analysis work, some optimization support programs (software) using optimization calculations have been partially used for designing structures (for example, CDAJ News 2000). AUTUMN vol.22 pp18
-23). In addition, this optimization support program and CAD
(Computer Aided Design) has been proposed a structure optimization device (Nonaka et al., "Construction of an optimized CAE system using CAD", 620.99-5 The 12th JSME Computational Mechanics Lecture Proceedings of the Society, pp.467-468 and JP-A-3-222063). Here, the optimization is to select the one that optimizes (maximum or minimum) the reference set by itself or the one that is close to it. For example, there are many problems aimed at optimizing certain criteria, such as maximizing pump efficiency and minimizing weight to reduce equipment prices (Hiroshi Yamakawa, "Optimization Design" pp.4 -5 Baifukan. See 1993).

[0003]

However, in the design using the above prior art, the initial shape is determined before performing the optimization calculation, the CAD model is created, and the design variables and the upper and lower limits thereof are calculated. It is necessary to manually perform preprocessing for performing optimization calculation, such as determination, through a designer or an operator, and further automation of work by these operators has been required.

An object of the present invention is to automatically create an initial shape for optimization calculation from a three-dimensional CAD model of a structure designed in the past, and to easily calculate and determine design variables and their upper and lower limits. It is an object of the present invention to provide a structure design support apparatus as described above.

[0005]

In order to achieve the above object, the present invention relates to a structure design support apparatus for obtaining an optimum shape of a structure that satisfies input required performance. Required performance input means for receiving the required performance, a model storage unit for storing a three-dimensional CAD model of the structure designed in the past and performance information of the structure, and an upper and lower required performance input from the required performance input means. A model search means for searching the model storage unit for a three-dimensional CAD model and performance information of the structure corresponding to the lower performance, and a three-dimensional CAD model and performance information used for optimization calculation based on the three-dimensional CAD model and performance information searched by the means. Determine and calculate the initial shape of the CAD model, a design variable T for changing the shape during the execution of the optimization calculation, and upper and lower limits that are variable ranges of the design variable. A calculation condition determining means for, the 3
An optimization calculation device that performs a calculation using the initial shape of the dimensional CAD model, the design variables and the upper and lower limits thereof, and the input required performance as calculation conditions, and derives a shape that satisfies the required performance; The present invention provides a structure design support device comprising:

Further, the present invention is a structure design support apparatus for obtaining an optimum shape of a structure that satisfies input performance requirements, and is provided for each user and receives an input for receiving the performance requirements of the user. Means, a user terminal installed for each input means for controlling data exchange with the input means, and a three-dimensional CAD model of a previously designed structure and performance information of the structure are stored. A model storage unit, input / output control means for communicating with each of the user terminals via a network, and receiving required performance input from one of the input means via the network and the input / output control means; Model search means for searching the three-dimensional CAD model and performance information of the structure corresponding to the higher and lower performances of the required performance from the model storage unit; From the three-dimensional CAD model and the performance information, the initial shape of the three-dimensional CAD model used for the optimization calculation, a design variable T for changing the shape during the execution of the optimization calculation, and an upper limit value that is a variable range of the design variable Calculation condition determining means for determining and calculating the lower limit value and the lower limit value;
An optimization calculation device that performs a calculation using the initial shape of the dimensional CAD model, the design variables and the upper and lower limits thereof, and the input required performance as calculation conditions, and derives a shape that satisfies the required performance; The present invention provides a structure design support device comprising:

Further, the present invention is characterized in that in the above structure design support apparatus, there is provided a result output means for registering the shape derived by the optimization calculation apparatus and its performance information in the model storage unit. Provided is a design support device for a structure.

[0008]

Embodiments of the present invention will be described below. The structure design support device of the present invention is a design support device for inputting required performance and finding an optimal shape of a structure. The design support device creates a new shape based on a three-dimensional CAD model of an existing structure, Calculate the upper and lower limits
The purpose of this is to determine a shape, perform an optimization calculation, and obtain a shape that satisfies the required performance, and particularly to assist design of a structural shape.

Hereinafter, description will be made with reference to the drawings. FIG.
FIG. 2 is a block diagram illustrating a configuration example of a structure design support apparatus according to the present invention, which includes a shape calculation unit 100 and a result output unit 160. The shape calculation unit 100 includes the required performance input unit 1
10, model search means 120, calculation condition determination means 13
0, an optimization calculation device 140, and a model storage unit 150.

FIG. 2 is a block diagram showing a modified example of the configuration example of FIG. 1. The shape calculating section 200 is provided with an input / output control means 220 in place of the required performance input means 110 of FIG. Other configurations are the same as those of the shape calculation unit 100 in FIG. Further, the input / output control means 220 is connected to the user terminals 201, 202... Via a network 230 such as the Internet or an intranet, and each user terminal is provided with required performance input means 211, 212. I have. The result output means 160 is the same as in FIG. The user terminals 201, 202... Are, specifically, terminal devices provided with input devices such as a keyboard and a mouse, and a CRT display. In the configuration shown in FIG. 2, the input / output control means 220 takes in information input from the required performance input means 211, 212... Via the network 230, and controls the information output to the required performance input means 211, 212. I do.

In FIG. 1 and FIG.
0 stores a three-dimensional CAD model of structures designed in the past and performance information of those structures. The required performance input means 110 is a means for displaying an input screen and receiving an input of required performance. In the case of FIG. 2, the required performance input means 2
11, 212..., User terminals 201, 202,.
And the input / output control means 220 has this function. The model retrieving means 120 is a means for retrieving and reading from the model storage unit 150 a three-dimensional CAD model and performance information of a structure corresponding to the higher performance and lower performance of the input required performance. The calculation condition determining unit 130 is configured to use the three-dimensional CAD model and the performance information retrieved from the model storage unit 150 to obtain a three-dimensional CAD model as an initial shape of the optimization calculation, and to change the shape during the execution of the optimization calculation. This is a means for determining and calculating design variables and their upper and lower limits. The optimization calculation device 140 is a device that includes a shape change program, three-dimensional CAD, CAE that performs numerical calculations, and an optimization engine, and that performs optimization calculations. The calculation result output unit 160 is a unit that registers a shape satisfying the required performance and its performance information in the model storage unit 150.

Next, the operation of the structure design support apparatus of the present invention will be described with reference to the flowchart of FIG. 3 using the configuration of FIG. 2 as an example. The user who uses the apparatus is a user terminal 20.
1 is operated. First, when the user operates the required performance input unit 211 to select a specific product, a screen for inputting the required performance is displayed, and the user inputs or selects a desired required performance using this screen. The input required performance is transmitted from the user terminal 201 to the network 230.
Is transferred to the input / output control means 220 of the shape calculation unit 200 through the step (step 301). In the case of the configuration of FIG. 1, the above is performed by the required performance input means 110. Input / output control means 22
0, when the required performance is received, the model search means 1
The required performance is sent to the model storage unit 20 and the model search unit 120 stores the three-dimensional CAD model and the performance information of the structure corresponding to the higher and lower performances of the received required performance in the model storage unit 1.
Search from 50. At this time, the searched three-dimensional CAD model and the performance information are transmitted to the user terminal 201, and displayed on the CRT screen by the required performance input means 211 to urge the user to confirm the model. When the confirmation input is performed from the required performance input unit 211, the model search unit 120 outputs the confirmed three-dimensional CAD model and performance information to the calculation condition determination unit 113 (Step 302).

The calculation condition determining means 130 receives the input 3
A three-dimensional CAD model that is an initial shape for optimization calculation is created from the three-dimensional CAD model and the performance information. At this time,
The created three-dimensional CAD model is transmitted to the user terminal 201 and displayed on the CRT screen by the required performance input means 211 to urge the user to confirm the initial shape. The calculation condition determining means 130 proceeds to the next step upon receiving an input for confirmation from the required performance input means 211 (step 303). That is, the confirmed three-dimensional CAD
From the model and the performance information, design variables for changing the shape in the process of executing the optimization calculation and their upper and lower limits are determined and calculated. Further, the calculation condition determining means 13
0 reads out the objective function and the constraint condition of the optimization calculation from the required performance (step 304). Further, the calculation condition determining means 130 transmits the three-dimensional CAD model, design variables and their upper and lower limits, the objective function, and the constraint, which are the initial shape created, calculated and determined by the previous step, to the optimization calculation device 140. Then, an instruction is issued to execute the optimization calculation (step 305).

When an instruction to execute the optimization calculation is input, the optimization calculation device 140 executes the optimization calculation and derives a shape that satisfies the required performance (step 306). This optimization calculation device itself is a conventional technology, for example, Japanese Patent Laid-Open No. Hei 3-2240.
No. 63 "Optimal design system" may be used. In this system, data of a 3D-CAD model is directly converted into CAE data (data for numerical calculation) by a data conversion device called a translator. Next, a mesh for numerical analysis is created and analysis conditions are defined by a preprocessor. At this time, by reading data prepared in advance, automatic mesh creation and analysis condition definition can be performed. Then, the analysis is performed by the solver. The analysis solver can be selected according to the purpose such as vibration, structure, fluid, and heat. After the analysis, the post-processor converts the analysis result into data that can be quantitatively evaluated. The optimization engine evaluates the analysis result (data) and objective functions and constraints set in advance, and changes design variables. Here, the 3D-CAD model is changed to correspond to the newly set design variables, and the same procedure is repeated until the required condition is satisfied. The above is the function of the optimization system.
D-CAD data can be obtained directly, and optimization calculation can be performed automatically.

The result obtained by the shape calculation unit 200 as described above is output to the user terminal 201 via the input / output control means 220 and the network 230 as a three-dimensional CAD model satisfying the required performance and its performance information. (Step 307). This is the performance request input means 211
Is displayed, the three-dimensional C
The user is prompted to confirm whether to register the model in order to use the AD model and its performance information for the next and subsequent model creations, and when an input to confirm the registration is made, a three-dimensional CAD that satisfies the required performance
Register the model and its performance information in the model storage unit 150,
A series of operations ends (step 308).

An operation example in the case of designing a pump blade shape using the structure design support apparatus described above will be described below. Here, it is assumed that the user performs a design operation from the required performance input unit 211 in FIG. It is also assumed that the three-dimensional CAD model of the pump designed in the past and its performance information are stored in the model storage unit 150, respectively. Here, the performance information includes a pump efficiency, a specific speed, a rotation speed, a product name, an output, a performance curve represented by a discharge amount and a head, main dimensions of each part, and the like. The pump shape includes a curved surface shape determined by some function, such as a blade shape or a curved surface shape of each part represented by a casing. For this reason, when changing the shape, it is necessary to change the variable value of the function that determines the curved surface shape, and therefore, the variable value for defining the curved surface of each product is also stored in the performance information.

First, when the user performs an operation for starting the design,
A list screen classified according to the purpose and use of the pump is displayed on the CRT screen of the user terminal 201, and the user selects a desired product model series on this screen. Then,
A screen as shown in FIG. 4 showing the performance of the product corresponding to the selected product model series is displayed, and an input column for the required performance is also displayed. Here, the performance table of the performance display section 411 is called a pump selection diagram in which the horizontal axis indicates the discharge amount (flow rate) and the vertical axis indicates the total head (head).
2, 413 and the like (actually, many curves are displayed, but FIG. 7 is simplified and only a part is shown) is the performance curve of the product. At this time, as a method of inputting the required performance, a desired performance point is selected in the performance display section 411 of the existing product by clicking the area 410 of the “click input screen”, or
Alternatively, the user can directly input each numerical value by clicking the “numeric value input screen” area 420. Here, by inputting numerical values, the discharge amount 421 and the head (head) 422
Is specified as a numerical value, the pump efficiency (fluid efficiency) is used as the objective function of the optimization calculation from the objective function input unit 424, and the upper limit value and the lower limit value of the head (head) are set as the constraint conditions of the optimization calculation from the constraint condition input unit 425. It is assumed that the blade shape has been input and further the blade shape has been selected from the shape change location selection unit 426. The input discharge amount and the head are the performance points indicated by the hollow arrow 414 in the performance display section 411 in FIG. 4, and it is assumed that the pump having the intermediate performance between the performance curves 412 and 413 is designed. I do. The above is the processing of step 301 in FIG.

The required performance information input from the required performance input means 211 is output to the model searching means 120, and the model searching means 120 outputs the performance as a higher performance model from the model storage unit 150 in accordance with the input request. A product with a curve 412 and a performance curve 4 as a lower model
13 with 3D CAD of each product
Assume that the model and performance information have been read. Here, the model searching means 120 checks the read three-dimensional CAD for confirmation.
The model and performance information are output to the user terminal 201, and a screen as shown in FIG. 5 is displayed on the required performance input means 211 to urge the user to confirm. In FIG. 5, the upper model 51
0, a lower model 520, and a confirmation area 530 are displayed. In each model, a three-dimensional CAD model 511,
521 and performance information 512 and 522, respectively. On this screen, when the user determines that this model can be confirmed as a preferable mode, the user selects the “YES” area 541 using the cursor 543, and when the user determines that the model is not preferable, the “NO” area 542 is displayed. Cursor 5
43 is selected. If "NO", the input screen of FIG. 4 is displayed again, and the process is repeated from model selection. When "YES" is selected, the two CAD models 511 and 521, their performance information 512 and 522, and the required performance input by the user are sent to the calculation condition determining means 130. In the following, the three-dimensional CAD model 511 may be abbreviated as model A, and the three-dimensional CAD model 521 may be abbreviated as model B.

The calculation condition determining means 130 firstly changes the shape based on the input required performance (shape changing portion).
, And a variable value defining the blade shape is read from the performance information 512 and 522 of the models A and B. Here, the function that represents the blade shape currently being handled is

(Equation 1) And Here, β is the angle of the blade, x is the distance along the blade, and a, b, c, and d are parameters (variable values) that determine the function. Then, the variable values representing the shape are a, b,
The four models c and d are given for the two models A and B, respectively (however, these functions and variable values are not displayed in the display example of FIG. 5). Therefore, the calculation condition determining means 130 determines a variable value for representing the initial shape from each variable value of the models A and B. As a method of this determination, for each of the variable values a to d of the two models A and B, the heads of the models A and B for the discharge amount of the required performance are defined as hA and hB, and the heads of the required performance are determined. Assuming that h0, | h0−hA | / | h0−
A method such as weighted averaging of each variable value at the ratio of hB | is used. Then, the variable values a to d obtained in this way are substituted into the function of (Equation 1) to calculate the blade shape of the initial shape model.

Next, the calculation condition determining means 130 selects, for example, a model A, which is a higher model, as a model for changing the shape, and changes the shape of the blade to the calculated shape based on the shape model of the model A. To create a three-dimensional CAD model, and use this as an initial shape. Here, the calculation condition determination means 130 outputs the initial shape model to the user terminal 201 for confirmation, and receives the required performance input means 211
6, an initial shape model 630 is displayed together with upper and lower model (A and B) models 610 and 620, as shown in FIG. If the user sees the result and clicks on the “NO” area 642, the screen returns to the required performance input screen of FIG. 4. If the user clicks on the “YES” area, the creation of the initial shape ends. The above is the processing of step 303 in FIG.

Next, the calculation condition determining means 130 defines design variables necessary for executing the optimization calculation. The design variable is a variable x of a function defining a blade shape as a shape changing unit, and a model A, which is a higher model of the required performance using the upper limit value of the design variable for creating a new shape model.
, And the lower limit value of the design variable is defined as the variable value of the model B which is a lower model of the required performance. The upper and lower limits may be input and determined by the user. Further, the objective function and the constraint condition are read from the required performance. Through the above operation, information necessary for the optimization calculation is prepared. The calculation condition determining means 130 includes, as calculation conditions for the optimization calculation, a three-dimensional CAD model as an initial shape, a design variable for performing shape change during the execution of the optimization calculation, and upper limit values thereof.
The lower limit value, the objective function (maximum pump efficiency), and the constraint conditions (the upper limit value and the lower limit value of the head) are output to the optimization calculation device 140. The above is the processing steps 304 and 305 in FIG.

The optimization calculation device 140 includes a shape change program for changing the shape in the process of executing the optimization calculation, a three-dimensional CAD representing the pump shape, a fluid analysis (CAE) for calculating the pump performance of the shape, and an analysis result. From the pump function, which is the objective function, and the head value, which is the constraint,
The shape that satisfies the required performance is calculated and derived by the optimization engine that changes the value of the design variable so that the required performance is satisfied. This device 140 is of the prior art.
The calculation result is sent to the user terminal 201 and is displayed on the screen of the required performance input means 211 as shown in FIG. 7 as a three-dimensional CAD model of the pump satisfying the required performance and its performance information. This is a CAD model 710 of the whole pump and a part model (only the model of this part is processed in FIGS. 5 and 6) 72
0, in the display example of the performance information 730, the user inputs the confirmation or accepts the registration of the calculation result in the model storage unit 150. "YE" which means confirmation from the user
When the “S” area 741 is selected by the cursor 743, the result output unit 160 satisfies the required performance.
The dimension CAD model and its performance information are stored in the model storage unit 150.
And a series of operations is completed. When the “NO” area is selected, a series of operations is ended here. The above is the processing steps 306 to 308 in FIG.

Using the embodiment of FIG. 1 or FIG. 2, the user can automate the creation of the initial shape, which has been manually performed until now, only by inputting and confirming the required performance.
By performing the optimization calculation using the initial shape as an initial value, the optimal solution of the design can be derived in a short time. Further, by registering the optimum calculation result in the model storage unit, it can be utilized for design support in the next and subsequent times.

In the above description, the existing upper model and lower model are used one by one for the creation of the three-dimensional CAD model, which is the initial shape of the optimization calculation, and the calculation and determination of the upper and lower limits of the design variables. Although it is assumed that a plurality is used, a plurality of them may be used. When it is not necessary to store a new design result in the model storage unit, the result output unit 160 in FIGS. 1 and 2 may be removed and step 308 in FIG. 3 may be omitted.

[0025]

According to the present invention, an initial shape and calculation conditions can be automatically created from an existing product model, and optimization calculation can be performed. Thus, the design period can be shortened and labor can be reduced by further automating the design process. Reduction can be achieved. Further, the result of the optimization calculation can be easily registered in the storage unit of the product model, and the calculation result can be reused. As the number of registered models increases, a better initial shape can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration example of a structure design support apparatus according to the present invention.

FIG. 2 is a block diagram showing a modification of the design support apparatus of FIG.

FIG. 3 is a flowchart showing a process performed by the apparatus shown in FIG. 1 or 2;

FIG. 4 is a display example of a required performance input screen.

FIG. 5 is a display example of a three-dimensional CAD model of a higher-order / lower-order model of required performance retrieved from a model storage means and its performance information.

FIG. 6 is a display example of a three-dimensional CAD model of a higher-order / lower-order model having required performance and a three-dimensional CAD model of an obtained initial shape.

FIG. 7 is a display example of a determined three-dimensional CAD model having an optimum shape and its performance information.

[Explanation of symbols]

 100, 200 Shape calculation unit 110, 211, 212 Required performance input means 120 Model search means 130 Calculation condition determination means 140 Optimization calculation device 150 Model storage unit 160 Result output means 220 Input / output control means

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Norihiko Nonaka 502 Kandachi-cho, Tsuchiura-city, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (72) Inventor Yuji Tanaka 7-1-1, Higashi-Narashino, Narashino-shi, Chiba F term in Hitachi Drive Systems (reference) 5B046 CA06 FA16 GA01 HA05 KA06

Claims (3)

[Claims] 1. A structure design support device for obtaining an optimum shape of a structure that satisfies input required performance, a required performance input means for receiving required performance, and a three-dimensional structure of a previously designed structure A model storage unit for storing a CAD model and performance information of the structure; and a three-dimensional CAD model and performance information of the structure corresponding to the upper and lower performances of the required performance input from the required performance input means. A model search means for searching from the model storage unit; and an initial shape of the three-dimensional CAD model used for the optimization calculation and a shape change during the execution of the optimization calculation from the three-dimensional CAD model and the performance information searched by the means. Calculation condition determination means for determining and calculating a design variable T to be performed, an upper limit value and a lower limit value which are variable ranges of the design variable, And an optimization calculator for performing a calculation using the initial shape, the design variables and the upper and lower limit values thereof, and the input required performance as calculation conditions, and deriving a shape that satisfies the required performance. A structure design support device characterized by the following. 2. A structure design support apparatus for obtaining an optimum shape of a structure that satisfies an input required performance, comprising: input means provided for each user for receiving the required performance of the user; A user terminal installed for each input means for controlling data exchange with the input means; a model storage section for storing a three-dimensional CAD model of a previously designed structure and performance information of the structure; An input / output control unit that communicates with each of the user terminals via a network; a request performance input from one of the input units via the network and the input / output control unit; A model search means for searching the model storage unit for a three-dimensional CAD model and performance information of a structure corresponding to higher-order and lower-order performances; From the D model and the performance information, the initial shape of the three-dimensional CAD model used for the optimization calculation, a design variable T for changing the shape in the process of executing the optimization calculation, an upper limit and a lower limit which are variable ranges of the design variable Calculation condition determining means for determining and calculating a value; calculating the initial shape of the three-dimensional CAD model, the design variables and their upper and lower limits, and the input required performance as calculation conditions; An optimization calculation device that derives a shape that satisfies the required performance. 3. The structure design support apparatus according to claim 1, further comprising a result output unit for registering the shape derived by the optimization calculation device and its performance information in the model storage unit. A structure design support device characterized by the following.