JPS6345531A - Method for diagnosing life - Google Patents
Method for diagnosing lifeInfo
- Publication number
- JPS6345531A JPS6345531A JP18847486A JP18847486A JPS6345531A JP S6345531 A JPS6345531 A JP S6345531A JP 18847486 A JP18847486 A JP 18847486A JP 18847486 A JP18847486 A JP 18847486A JP S6345531 A JPS6345531 A JP S6345531A
- Authority
- JP
- Japan
- Prior art keywords
- crack
- life
- evaluation
- progression
- ductile
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 5
- 239000000463 material Substances 0.000 claims abstract description 15
- 238000002405 diagnostic procedure Methods 0.000 claims description 2
- 238000011156 evaluation Methods 0.000 abstract description 19
- 238000005260 corrosion Methods 0.000 abstract description 4
- 230000007797 corrosion Effects 0.000 abstract description 4
- 239000007769 metal material Substances 0.000 abstract description 2
- 238000003908 quality control method Methods 0.000 abstract description 2
- 238000005516 engineering process Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000003672 processing method Methods 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
Landscapes
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
機器に発生したき裂の進展量を評価し、機器の健全性と
余寿命を明らかとするための診断法に関する技術である
。[Detailed Description of the Invention] [Industrial Application Field] This technology relates to a diagnostic method for evaluating the amount of growth of cracks generated in equipment and clarifying the soundness and remaining life of the equipment.
重電機器のき裂進展評価は、線形破壊力学に基づく応力
拡大係数でその進展量及び限界き裂寸法を評価して来た
。しかし、高温環境下で使用される場合や延性材を用い
た機器では、塑性変形により、延性き裂′の発生及びき
裂の鈍化により機器に悪影響を及ぼす場合がある。この
現象は、弾塑性破壊力学に基づいた評価が必要である。In the evaluation of crack growth in heavy electrical equipment, the amount of growth and critical crack size have been evaluated using stress intensity factors based on linear fracture mechanics. However, when used in high-temperature environments or in devices using ductile materials, plastic deformation may generate ductile cracks and slow down the cracks, which may adversely affect the device. This phenomenon requires evaluation based on elastoplastic fracture mechanics.
本発明に関連する公知例として、特開昭５６−６３２２
０号公報がある。As a publicly known example related to the present invention, JP-A-56-6322
There is a publication No. 0.
従来技術の項でも述べたようにこれまでの機器の寿命評
価は、線形破壊力学（弾性輪）に基づく応力拡大係数を
パラメータとしたき裂の進展世評高温状態で使用される
機器や延性材機器に発生する塑性変形に伴う現象を評価
することはできない。As mentioned in the section on conventional technology, the lifespan evaluation of equipment up to now has been based on linear fracture mechanics (elastic rings) based on stress intensity factors as parameters for crack propagation. It is not possible to evaluate the phenomena associated with plastic deformation that occurs.
すなわち、き裂が塑性変形により鈍化し、大きな開口変
形を生じる点、さらに、不安定破壊に至る前に安定き裂
の進展がある点など延性破壊特有の現象がある。本発明
の目的は、これらの延性破壊有象をも考慮した寿命評価
を実施することにある。That is, there are phenomena peculiar to ductile fracture, such as the fact that the crack is slowed down by plastic deformation, resulting in large opening deformation, and furthermore, the stable crack propagates before reaching unstable fracture. An object of the present invention is to carry out a life evaluation that also takes into account these ductile fracture phenomena.
機器の寿命評価は、き裂が微小な場合は、高温環境や延
性材であってもその進展挙動は、応力拡大係数にとパラ
メータとして評価法に従うことが知られている。従って
、前記の問題点を解決するために、き裂の疲労又は腐食
、クリープによる進展（き裂が小さい状態での進展を支
配する因子）は、応力拡大係数Ｋにより評価し、同時に
、あるき裂進展量毎に、延性破壊挙動を評価するため、
弾塑性破壊力学パラメータＪ積分による安定き裂進展評
価を実施する。これ両者を同時に評価することによりき
裂を有する機器の総合的な寿命評価法が確立する。When evaluating the lifespan of equipment, it is known that when a crack is small, its propagation behavior is determined by the stress intensity factor as a parameter, even in high-temperature environments or in ductile materials. Therefore, in order to solve the above problems, the propagation of cracks due to fatigue, corrosion, and creep (factors that govern the propagation of cracks when they are small) is evaluated using the stress intensity factor K, and at the same time, In order to evaluate the ductile fracture behavior for each amount of progress,
Stable crack growth evaluation is performed using elastic-plastic fracture mechanics parameter J integral. By evaluating both at the same time, a comprehensive life evaluation method for equipment with cracks can be established.
き裂の進展挙動は大別する以下の現象に大別できる。 Crack growth behavior can be broadly classified into the following phenomena.
（１）疲労、腐食又はクリープによる進展（２）安定き
裂の進展
（３）不安定進展
これらの中で、線形破壊力学パラメータである応力拡大
係数には、（１）と（３）を規定するパラメータである
。脆性材の場合は、（１）の現象の後、材料の破壊靭性
Ｋｚｃを越えると（３）の現象となる。一方、延性材の
場合は、き裂が比較的微小の場合は、（１）の現象のみ
であり、これに対しては、Ｋによる評価が有効である。(1) Growth due to fatigue, corrosion, or creep (2) Stable crack growth (3) Unstable growth Among these, (1) and (3) are specified for the stress intensity factor, which is a linear fracture mechanics parameter. This is a parameter to In the case of brittle materials, after the phenomenon (1), when the fracture toughness Kzc of the material is exceeded, the phenomenon (3) occurs. On the other hand, in the case of a ductile material, if the crack is relatively small, only the phenomenon (1) occurs, and evaluation using K is effective for this.
しかし、き裂がある程度大きくなると（２）の現象が生
じ、これには、弾塑性破壊力学パラメータ、■を用いて
、靭性値、Ｌｒｃとの比較による評価を実施する。（３
）の現象は延性材の場合Ｋｔａでは、無く、Ｊを用いた
評価によって実施するとかできる。However, when the crack becomes large to a certain extent, the phenomenon (2) occurs, and for this purpose, evaluation is carried out by comparing the toughness value, Lrc, using the elastic-plastic fracture mechanics parameter, ■. (3
) phenomenon does not exist with Kta in the case of ductile materials, and can be carried out by evaluation using J.
以上、ＫとＪを組合せた評価法により、（１）〜（３）
の現象が評価できる。Above, using the evaluation method that combines K and J, (1) to (3)
This phenomenon can be evaluated.
本発明を用いた寿命及び健全性評価例を第１図に示す０
機器の設計段階で、材料、加工法１品質管理、供用中負
荷などから評価対象部位、初期き裂、材料特性データを
決定し進展評価を実施する。An example of lifespan and soundness evaluation using the present invention is shown in FIG.
At the equipment design stage, the evaluation target area, initial crack, and material property data are determined based on materials, processing method 1 quality control, and in-service load, etc., and progress evaluation is performed.
第１にブロックｈ）は、疲労又は腐食、クリープによる
進展量を評価し、脆性的破壊靭性ＫＩＯとの比較を行う
０次にブロックｊ）に進み、運転中に生じる実働負荷又
は極大負荷を設定し、延性き裂の進展評価を実施する。First, block h) evaluates the amount of progress due to fatigue, corrosion, and creep, and compares it with the brittle fracture toughness KIO. Next, block j) sets the actual load or maximum load that occurs during operation. and evaluate the growth of ductile cracks.
これらの評価は、次の２式により評価される。These evaluations are performed using the following two equations.
Ｋｒ≧ＫｆＣ・・・脆性的破壊 （１）Ｊ！≧Ｊｒｃ
・・・延性き裂の進展（２）ここで、
ＫＩＣ，Ｊｒｃは材料物性値。Kr≧KfC...brittle fracture (1) J! ≧Jrc
...Ductile crack growth (2) Here,
KIC and Jrc are material property values.
さらに寿命については、式（１）及び（２）において、
Ｋｒ＜Ｋｒｃ
Ｊｘ＜Ｊｘｃ
である場合、それぞれ、Ｋｒｃｅ Ｊｒａに達するまで
の１時間をブロックｈ）において計算し余寿命とする。Furthermore, regarding the lifespan, in equations (1) and (2), when Kr<Krc Jx<Jxc, one hour until reaching Krce Jra is calculated in block h) and used as the remaining life.
設計段階で本発明の評価により設計耐用年数以下で機器
の寿命が無くなる場合は、元に戻りブロックａ）の材料
、加工法の選定から再度検討し直すことになる。If the evaluation of the present invention at the design stage shows that the life of the equipment is less than the designed service life, the process should be returned to the original stage and the selection of the material and processing method for block a) should be reconsidered.
本発明によれば、機器を構成する材料が脆性。 According to the present invention, the material constituting the device is brittle.
延性のいずれであっても、又、高温、低温のいずれのＱ
Ｉｎにあってもその寿命、健全性を評価することができ
る。すなわち、金属材料の破壊モードである脆性破壊、
延性破壊の両者に対して、機器の寿命が評価でき、その
信頼性の大幅向上が期待できる効果がある。Regardless of whether it is ductile or whether it is high temperature or low temperature, Q
Even if it is In, its lifespan and soundness can be evaluated. In other words, brittle fracture, which is the fracture mode of metallic materials;
The life of the equipment can be evaluated against both ductile fractures and its reliability can be expected to be significantly improved.
Claims (1)
つて、計測又は推定されたき裂に対して応力拡大係数Ｋ
によるき裂の進展量評価とき裂サイズにより必要に応じ
て延性き裂の進展の有無を判定し、脆性材又は延性材に
よつて作られている機器の寿命を予測することを特徴と
する寿命診断法。1. A method for predicting the life of equipment under actual working conditions, in which the stress intensity factor K is calculated for measured or estimated cracks.
A life expectancy characterized by predicting the life of equipment made of brittle or ductile materials by evaluating the amount of crack growth and determining the presence or absence of ductile crack growth as necessary based on the crack size. Diagnostic method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18847486A JPS6345531A (en) | 1986-08-13 | 1986-08-13 | Method for diagnosing life |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18847486A JPS6345531A (en) | 1986-08-13 | 1986-08-13 | Method for diagnosing life |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6345531A true JPS6345531A (en) | 1988-02-26 |
Family
ID=16224356
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18847486A Pending JPS6345531A (en) | 1986-08-13 | 1986-08-13 | Method for diagnosing life |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6345531A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010002261A (en) * | 2008-06-19 | 2010-01-07 | Toshiba Corp | Instrument life evaluation method and instrument life evaluation system |
-
1986
- 1986-08-13 JP JP18847486A patent/JPS6345531A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010002261A (en) * | 2008-06-19 | 2010-01-07 | Toshiba Corp | Instrument life evaluation method and instrument life evaluation system |
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