JPH06162149A - Fatigue life evaluation system - Google Patents

Abstract

PURPOSE:To evaluate the fatigue life of a structure in detail. CONSTITUTION:Data required to evaluate the fatigue of the structure are stored in a 1st device 1 and a curve for fatigue evaluation in a shape used for the fatigue evaluation is generated by a 2nd device 2 from retrieved data. The generated curve for fatigue evaluation or a curve for fatigue evaluation generated by another method is recorded in a 3rd device 3 and the stress value of the stress analytic result of the structure used for the fatigue evaluation is stored in a 4th device 4; and various fatigue evaluating methods and various data required for fatigue evaluation such as stress concentration coefficients are stored, the fatigue evaluation is carried out by a 5th device 5 according to the given information, and various data used for the fatigue evaluation and evaluation result are stored in a 6th device 6 to create a document. Further, the 1st-6th devices are controlled by a 7th device 7 to perform a series of operations for the fatigue evaluation of the structure in conversational form through the CRT of an electronic computer according to the intention of a designer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, in order to clarify the soundness and the remaining life of a structure at the time of designing the structure or during the period of use of the structure, has a high cycle fatigue evaluation and a low cycle The present invention relates to a systematic device that allows a general designer to perform fatigue evaluation and crack growth evaluation using a computer. Hereinafter, the high cycle fatigue evaluation, the low cycle fatigue evaluation, and the crack growth evaluation are collectively referred to as fatigue evaluation.

[0002]

BACKGROUND OF THE INVENTION Extensive research has been conducted on fatigue phenomena during the use of structures, and test data on material fatigue, fatigue theory and fatigue evaluation technology have been accumulated. However, in reality, the troubles caused by the fatigue phenomenon of the structure cannot be traced. In order to evaluate the fatigue of a structure using the current fatigue evaluation technology, search for the data to be used for the fatigue evaluation of the structure from the enormous data on the fatigue of the structure material, A series of work is performed in which the stress occurring in the material is obtained, the fatigue evaluation method to be applied is selected from the load state of the structure, and the evaluation is performed according to that. Fatigue expertise is required to perform this sequence of work, so it requires the assistance of a designer who is familiar with fatigue design, or a metal fatigue expert, and is required to perform a detailed fatigue assessment of a structure. Requires a lot of work. This situation prevents existing fatigue evaluation technology from being fully utilized in machine design, and allows troubles due to fatigue of structures.

As described above, since a large amount of research results and fatigue test data relating to fatigue of metallic materials have been accumulated, appropriate fatigue life is evaluated in the fatigue design of structures and reflected in the design. That is becoming difficult for general designers. In addition, it is necessary to carry out a considerable amount of calculation work in order to perform the evaluation in accordance with the fatigue evaluation procedure devised based on the fatigue research results of metal materials using various fatigue data accumulated up to now. It is difficult to carry out a detailed fatigue life evaluation in the design work and to reflect it in the fatigue design.

For this reason, excellent research results and fatigue test data relating to fatigue of metallic materials cannot be fully utilized in the fatigue design of structures, and problems in fatigue strength of structures can be avoided if sufficient fatigue life is examined. Invited.

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present invention have recently made progress in the use of electronic computers, such as the development of electronic computers and database technology, and the technology of interfacing humans with computers, including Al (artificial intelligence) technology. , It was thought that by using these technologies, it is possible to create a device using a computer that allows a general designer to perform more complicated fatigue evaluation work.

Therefore, the present invention makes it possible for general designers to easily use the research results and fatigue test data on the fatigue of metal materials accumulated in large quantities by using the computer and its utilization technology that have been remarkably developed in recent years. It is an object of the present invention to provide a system and an apparatus capable of performing detailed fatigue life evaluation of a structure based on this.

[0007]

The fatigue life evaluation system according to the invention of claim 1 which achieves the above object, is a general mechanical design using existing fatigue evaluation technology at the time of designing or during use of a structure. Person performs any or all of high cycle fatigue life evaluation, low cycle fatigue life evaluation, and crack growth evaluation required for fatigue design or residual life evaluation of a structure, and the evaluation result and the process of evaluation are documented. It is a comprehensive system configured on a computer that executes.

A second aspect of the present invention is a concrete fatigue life evaluation system, wherein any one or all of high cycle fatigue life evaluation, low cycle fatigue life evaluation and crack growth evaluation can be used for fatigue evaluation of a structure. From the data of the material test result and the first device that stores the data of the material test result necessary for the evaluation, the device that stores the data necessary for the work procedure A second device for retrieving data necessary for fatigue evaluation of a structure and creating a fatigue evaluation curve used for fatigue evaluation from the retrieved data, and a fatigue evaluation curve thus created, or another method The third device that stores the fatigue evaluation curve created in 1., the fourth device that stores the stress value of the stress analysis result of the structure used for fatigue evaluation, and various fatigue tests for fatigue evaluation. Evaluation Method and incorporates various data required in performing the stress concentration factor, such as fatigue evaluation, a fifth unit to perform a fatigue evaluation according to the given information,
Various devices used for fatigue evaluation and evaluation results are stored to prepare a document and all devices or a part of the sixth device are provided as independent constituent devices, and these devices are controlled, A seventh apparatus is configured as a system that interactively executes a series of work for evaluating fatigue of a structure through a CRT of a computer according to the designer's intention.

[0009]

[Function] To guarantee the soundness of the structure during its use,
Structure (1) High cycle fatigue evaluation (2) Low cycle fatigue evaluation (3) Crack growth evaluation A series of evaluation work is performed by operating the first to sixth devices interactively and the evaluation results are Can be obtained. That is, when the second device is operated by the seventh device and necessary instructions are given in an interactive manner, the material test data of the material of the structure to be evaluated is retrieved from the first device,
A curve for fatigue evaluation is created by the second device and stored in the third device. Next, the fifth device is operated by the seventh device to give necessary instructions interactively, and the fatigue evaluation curve used for the fatigue evaluation of the structure is retrieved from the third device, and the stress analysis result of the structure is also included. Then, the stress value at the fatigue evaluation point is retrieved from the fourth device, and the fatigue evaluation is performed using the evaluation method incorporated in the fifth device and various data necessary for the fatigue evaluation. Finally, the 7th device to the 6th device are operated to give necessary instructions in a conversational manner, and the fatigue evaluation result concerned, and the fatigue evaluation curve, stress value, fatigue evaluation method and various evaluations which are the basis for reaching the result. The data etc. are sent to the 6th apparatus and the document which recorded these is created. In this way, general designers can perform fatigue evaluation work, which was conventionally performed by experts for a long time.
This makes it possible to perform the evaluation work using the seventh device in a minimum time while using the functions and data of the first device to the sixth device.

[0010]

Embodiments of the present invention will be described with reference to FIGS. In order to avoid duplication of explanation, the examples deal with high cycle fatigue evaluation, but the operation function is the same for both low cycle fatigue evaluation and crack growth evaluation. As shown in FIG. 1, the system of this embodiment is composed of first to seventh individual devices 1 to 7 described below.

1. The first device that contains the data of the material test results necessary for the evaluation: Device 1 The device that contains the data of the test results related to the fatigue of the metal material in a fixed format together with the material name, load conditions, etc. It has a function to add additional data each time the material test result data is acquired.

2. The second device for searching the data necessary for fatigue evaluation from the data of the material test results and creating a curve for fatigue evaluation of the form used for the fatigue evaluation from the searched data: Device 2 Device which stores the data of the material test results A device for accessing the data, searching only data that can be used as fatigue and evaluation data of the structure, and performing statistical processing on the searched data in consideration of reliability and the like to create a fatigue evaluation curve.

3. Fatigue evaluation curve created from retrieved data or fatigue evaluation curve created by other method is recorded. Third device: Device 3 Created by performing necessary operations and processing from data of material test results. In addition to recording the fatigue evaluation curve, it has the function of additionally recording the standard design curve defined by various machine design standards and the fatigue evaluation curve newly obtained as a result of research on fatigue evaluation. A device that delivers the required fatigue evaluation curve in response to a request from the customer.

4. Fourth device that incorporates the stress value of the stress analysis result of the structure used for fatigue evaluation: Device 4 When performing the fatigue evaluation of the structure, know the stress generated in the structure under various load conditions. There is a need. A device that stores the stress values resulting from the analysis of the stress generated inside the material of a structure using a general-purpose structural analysis program according to a prescribed format, and can deliver the stress value at any point of the structure upon request. It is a device that can. This device can record stress values obtained by analysis with some typical general-purpose structural analysis programs.

5. Various fatigue evaluation methods for fatigue evaluation and various data necessary for fatigue evaluation such as stress concentration factors are recorded, and fatigue evaluation is executed according to the given information. Fifth apparatus: apparatus 5 current metal According to the fatigue research results, it is recommended to carry out the fatigue evaluation of a structure by using a specific fatigue evaluation method according to the type of material, use conditions, and load conditions. This device stores these fatigue evaluation methods and various engineering data required when using these fatigue evaluation methods, and when the information on the execution of the fatigue evaluation of the structure is given, the fatigue evaluation is performed. It is a device to be executed, and has a function to add a new fatigue evaluation method and new recording every time new engineering data required for fatigue evaluation is acquired.

6. A sixth device that creates a document that records various data used for fatigue evaluation and evaluation results: Device 6 The process of fatigue evaluation of a structure is stored, and what kind of evaluation process is performed and what kind of evaluation is performed. A device that creates a document that records what kind of fatigue evaluation result was obtained based on the information and data.

7. The seventh device for operating the above device interactively through the CRT of a computer to perform the fatigue life evaluation of a structure: Device 7: The individual work of the series of works required to perform the fatigue evaluation of a structure is described above. It can be implemented on the device. These devices are devices that perform the work required to evaluate the fatigue of the structure in accordance with the designer's intention.The computer should be designed so that general designers can perform fatigue evaluation work using these devices. A device on which a CRT connected to the machine displays the information necessary to promote the execution of the work, and the designer can give operating instructions of the device interactively according to the information.

As described above, the system according to the present embodiment uses a computer to perform the individual work required for evaluating the fatigue life of a structure with respect to high cycle fatigue, low cycle fatigue, and crack growth. The first to sixth devices and a general designer who is not an expert on fatigue phenomena operate the first to sixth devices interactively through a CRT of a computer to perform a fatigue life evaluation of a structure. It is a comprehensive device configured on an electronic computer that consists of devices.

Next, the operation of the system will be described with reference to FIGS.

FIG. 1 shows each device 1 interactively by the seventh device 7.
6 to 6 show the flow of instructions and the flow of data. Figure 2
10 shows a display example on the CRT screen.

First, the CRT screen of the seventh device 7 is used to instruct which of high cycle fatigue evaluation, low cycle fatigue evaluation and crack growth evaluation is to be performed (FIG. 2). In response to this instruction, an instruction from the seventh device 7 thereafter activates the first device 6 to the sixth device 6 which performs the instructed evaluation.

By instructing the material retrieval from the seventh equipment 7 to the second equipment 2 (FIG. 3), the test data of the designated material is retrieved, and the fatigue evaluation curve is created according to the instructed method ( (Fig. 4). This fatigue evaluation curve is stored in the third device 3 as an evaluation curve used for later evaluation work.

The seventh device 7 instructs the fifth device 5 which evaluation method is to be used (FIG. 5). After that, the seventh device 7 prompts only the instructions necessary for executing the evaluation method selected here. The structure of the fatigue evaluation target has been stress analyzed in advance, and the calculated stress value is the fourth device 4
If stored in, the seventh device 7 gives an instruction to retrieve the stress at the evaluation point (FIG. 6). At the same time, information required for the evaluation, such as the evaluation stress load type, is urged and instructions can be given to this. A separately known stress value and load condition can be directly input, or a complicated stress load condition can be directly input from the seventh device 7 (FIG. 7).

In order to carry out the evaluation according to the selected evaluation method, various data unique to the evaluation method such as the fatigue curve used are required. The seventh device 7 gives an instruction to call the data stored in the fifth device 5 (FIG. 8).

The designer can directly input data based on his own knowledge (FIG. 9).

Here, the instruction given from the seventh device 7, the input value, and various data called for use in evaluation are saved in a file for later reproduction or recording as a document.

When all the necessary inputs for fatigue evaluation are completed,
An instruction to carry out the evaluation work is sent via the seventh device 7,
The device 5 carries out the evaluation work. 7th device 7 after the work is completed
The evaluation result is displayed to the designer through (FIG. 10).

Finally, when it is desired to save the evaluation result as a document, the seventh device 7 sends an instruction to print out the evaluation result as a document. When this instruction is sent, it is called according to the instruction given from the seventh device 7 for the evaluation work, the input value and the instruction, and various data values used for the evaluation are documented and printed out together with the evaluation result. .

[0029]

According to the present invention, the evaluation of high cycle fatigue, low cycle fatigue and crack propagation of a structure is carried out by a general designer while being incorporated in various devices while being guided to carry out a correct work procedure. Accurate fatigue evaluation can be performed by using the evaluation method based on accumulated research results and various data for evaluation without fail. It is also possible to leave a document of the evaluation work process and evaluation results necessary for the subsequent examination. This can improve the soundness and reliability of the structure.

[Brief description of drawings]

FIG. 1 is a diagram showing a flow of instructions and a flow of data for operating each device according to an embodiment of the present invention.

FIG. 2 is a diagram of a CRT screen showing an example of instructing which function of the apparatus of the present invention, high cycle fatigue, low cycle fatigue, and crack growth evaluation is to be used.

FIG. 3 is a view of a CRT screen showing an example of instructing a material search to be sent from the seventh device to the second device.

FIG. 4 is a diagram of a CRT screen showing an example of a fatigue evaluation curve created by a second device.

FIG. 5 is a diagram of a CRT screen showing an example of an evaluation method selection instruction sent from a seventh device to a fifth device.

FIG. 6 is a view of a CRT screen showing an example of a stress value search instruction sent from the fourth device to the fifth device to evaluate a stress value.

FIG. 7 is a diagram of a CRT screen showing an example in which the stress value at the evaluation point is directly sent to the sixth device.

FIG. 8 is a diagram of a CRT screen showing an example of an instruction sent to a fifth device to call various data necessary for evaluation.

FIG. 9 is a diagram of a CRT screen showing an example in which various data required for evaluation are directly input data to a fifth device.

FIG. 10 is a diagram of a CRT screen showing an example in which an evaluation result is displayed to the designer after the work is completed.

[Explanation of symbols]

 1 1st apparatus 2 2nd apparatus 3 3rd apparatus 4 4th apparatus 5 5th apparatus 6 6th apparatus 7 7th apparatus

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Ryosuke Murai 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima-shi, Hiroshima Mitsubishi Heavy Industries Ltd. Hiroshima Research Institute (72) Inventor Katsuaki Inoue 5-chome, Fukahori-cho, Nagasaki-shi, Nagasaki No. 1 Sanryo Heavy Industries Co., Ltd. Nagasaki Research Institute (72) Inventor Michio Tanaka 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries Ltd. Kobe Shipyard (72) Inventor Kimihiko Aoyama Tokyo Port 5-33-8, Shiba-ku, Mitsubishi Motors Co., Ltd. (72) Inventor, Koji Iwasa 5-33-8, Shiba, Minato-ku, Tokyo Mitsubishi Motors Co., Ltd.

Claims (2)

[Claims] 1. A high cycle fatigue life evaluation and a low cycle evaluation which are required by general mechanical designers for fatigue design or residual life evaluation of a structure by using existing fatigue evaluation technology at the time of designing or during use of the structure. A comprehensive fatigue life evaluation system configured on a computer that performs either or all of cycle fatigue life evaluation and crack growth evaluation and documents the evaluation result and the evaluation process. 2. A high-cycle fatigue life evaluation, a low-cycle fatigue life evaluation, and a crack growth evaluation, or for all evaluations, a series of work execution procedures and works required for fatigue evaluation of a structure. A device that stores the necessary data, that is, the first device that stores the data of the material test results required for evaluation, and the data of the material test results, and retrieve the data necessary for the fatigue evaluation of the structure. A second device for creating a fatigue evaluation curve to be used for fatigue evaluation from the obtained data, and a fatigue evaluation curve created in this way or a fatigue evaluation curve created by another method are recorded. 3 device, a 4th device that incorporates the stress value of the stress analysis result of the structure used for fatigue evaluation, various fatigue evaluation methods for fatigue evaluation and necessary for performing fatigue evaluation such as stress concentration factor A fifth device which incorporates various data, which executes fatigue evaluation according to given information,
Various devices used for fatigue evaluation and evaluation results are stored to prepare a document and all devices or a part of the sixth device are provided as independent constituent devices, and these devices are controlled, A fatigue life evaluation system comprising a seventh device as a system for executing a series of work for fatigue evaluation of a structure interactively according to a designer's intention through a CRT of a computer.